|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Evolution of strontium isotopic composition of sea-water from Late Permian to Early Triassic based on study of marine carbonates,Zhongliang Mountain,Chongqing,China显示文摘Collected from a Late Permian to Early Triassic sedimentary section in the Zhongliang Mountain of Chongqing, Southwest China, sixty marine carbonate samples were measured for the 87Sr/86Sr ratios, and corresponding evolution curve was constructed. The concentrations of SiO2, CaO, MgO, Mn and Sr are used to evaluate reservation of strontium isotopic composition for original seawater and the credi-bility of the dissolution method for sample preparation. The results show that most of the samples (except seven samples with the Mn/Sr ratios higher than 2) contain the original geochemistry signa-tures of ancient seawater. Compared to the published 87Sr/86Sr ratios from the Late Permian to Early Triassic, our database reported here is the largest and the curve constructed is the most complete. The strontium isotopic curve from Late Permian to Early Triassic is consistent globally and exhibits a gen-eral trend of steady increase during this period. The minimum of 87Sr/86Sr ratios (0.707011) occurs in the Late Permian (30 m in thickness below the Permian-Triassic boundary), and the maximum (0.708281), near the Early-Middle Triassic boundary. The lack of land plants and the rapid continental weathering result in the increase of 87Sr/86Sr ratios during the interval. The Permian-Triassic boundary in Zhongli-ang Mountain Section has been accepted internationally. The 87Sr/86Sr ratios of six samples near the boundary vary from 0.70714 to 0.70715 with an average of 0.70714, which is consistent with the value of 0.70715 (samples are from articulate brachiopod shells) from Korte et al. published in 2006 (within the error range in experiment). Accordingly, the strontium isotope composition in the Permian-Triassic boundary in this paper is of global significance. It can be confirmed that the 87Sr/86Sr ratios of the sea-water in the Permian-Triassic transition are in the range of 0.70714―0.70715. | HUANG SiJing Qing HaiRuo HUANG PeiPei HU ZuoWei WANG QingDong ZOU MingLiang LIU HaoNian | 2008 | Science China Earth Sciences2008，51，4： | 24 |
| 2 | Carbon isotopic composition of Early Triassic marine carbonates, Eastern Sichuan Basin, China显示文摘As the interval following the biggest Phanerozoic mass extinction at the end of Permian, the Early Triassic is characterized by an immature, poorly functioned ecosystem.The effects of these extreme environmental conditions can be mirrored by the changes in the δ13C record of marine carbonates.However, the details about the carbon isotopic composition and evolution of the Early Triassic seawater remain poorly understood.A dataset of new δ13C and δ18O values as well as selected major and trace element data (including concentrations of CaO, MgO, Mn, and Sr) was obtained from 113 marine carbonate samples collected in Eastern Sichuan Basin.The isotopic and elemental data are used to evaluate effects of thermochemical sulfate reduction on δ13C.The δ13C values of a few samples affected by thermochemical sulfate reduction were corrected.By combining carbonate δ13C results in our investigated sections, we constructed a composite curve of the Lower Triassic.The results reveal a δ13C anomaly of carbonate rocks throughout the Early Triassic, accompanied by some rapid jumps and falls, such as those from approximately -2‰ to the extremely high value of 8‰ within a period of about 5 Ma.The Early Triassic δ13C profile derived from Eastern Sichuan Basin shows a close correspondence with Guandao section in Guizhou Province, whereas it yields an excursion pattern differing from Chaohu section in Anhui Province of the Lower Yangtze region (with the δ13C value from the minimum around -6‰ to the maximum near 4‰).The higher δ13C values and the positive carbon isotope excursions in the Lower Triassic from Eastern Sichuan Basin were most likely a consequence of the principal environmental change that may include: (1) the barren land surface due to the absence of vegetation, (2) the loss of diverse marine invertebrate groups and marine carbonates, (3) the thriving of bacteria, algae and methanogenus in ocean ecosystems, and (4) the local effect of the repositories of isotopically light carbon occurred in the form of methane hydrates.This process ended at the Early-Middle Triassic boundary, which indicates that the biotic recovery started at the end of the Lower Triassic.The terrestrial vegetation and marine invertebrates, as the regulators for carbon cycle, are irreplaceable and demand strong protections. | HUANG SiJing HUANG KeKe LÜ Jie LAN YeFang | 2012 | Science China Earth Sciences2012，55，12： | 18 |
| 3 | Diagenetic fluid evolution and water-rock interaction model of carbonate cements in sandstone: An example from the reservoir sandstone of the Fourth Member of the Xujiahe Formation of the Xiaoquan-Fenggu area, Sichuan Province, China显示文摘Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrology, mineralogy, carbon and oxygen isotope ratios and enclosure homogenization temperatures to study the precipitation mechanism, pore fluid evolution, and distribution of different types of carbonate cement in reservoir sand in the study area. Crystalline calcite has relatively heavy carbon and oxygen isotope ratios(δ13C = 2.14‰, δ18O = -5.77‰), and was precipitated early. It was precipitated directly from supersaturated alkaline fluid under normal temperature and pressure conditions. At the time of precipitation, the fluid oxygen isotope ratio was very light, mainly showing the characteristics of a mixed meteoric water-seawater fluid(δ18O = -3‰), which shows that the fluid during precipitation was influenced by both meteoric water and seawater. The calcite cement that fills in the secondary pores has relatively lighter carbon and oxygen isotope ratios(δ13C = -2.36‰, δ18O = -15.68‰). This cement was precipitated late, mainly during the Middle and Late Jurassic. An important material source for this carbonate cement was the feldspar corrosion process that involved organic matter. The Ca2+, Fe3+ and Mg2+ ions released by the clay mineral transformation process were also important source materials. Because of water-rock interactions during the burial process, the oxygen isotope ratio of the fluid significantly increased during precipitation, by about 3‰. The dolomite cements in calcarenaceous sandstone that was precipitated during the Middle Jurassic have heavier carbon and oxygen isotope ratios, which are similar to those of carbonate debris in the sandstone(δ13C = 1.93‰, δ18O = -6.11‰), demonstrating that the two are from the same source that had a heavier oxygen isotope ratio(δ18O of about 2.2‰). The differences in fluid oxygen isotope ratios during cement precipitation reflect the influences of different water-rock interaction systems or different water-rock interaction strengths. This is the main reason why the sandstone containing many rigid particles(lithic quartz sandstone) has a relatively negative carbon isotope ratio and why the precipitation fluid in calcarenaceous sandstone has a relatively heavier oxygen isotope ratio. | LIU SiBing HUANG SiJing SHEN ZhongMin Lü ZhengXiang SONG RongCai | 2014 | Science China Earth Sciences2014，57，5： | 13 |
| 4 | Carbon and Strontium Isotopes of Late Palaeozoic Marine Carbonates in the Upper Yangtze Platform,Southwest China显示文摘238 marine carbonate samples were collected from seven sedimentary sections ofthe entire late Palaeozoic (Permian, Carboniferous and Devonian) in the Upper Yangtze Plat-form, southwest China. Based on the absence of cathodoluminescence and very low Mn (gener-ally<50 ppm) contents of the samples, it is thought that they contain information on the orig-inal sea water geochemistry. The results of isotopic analyses of these samples are presented interms of δ13C and 87Sr/86Sr ratios versus geological time. The strontium data, consistent withother similar data based on samples from North America, Europe, Africa and other areas inAsia, support the notion of a global consistency in strontium isotope composition of marinecarbonates. The strontium data exhibit three intervals of relatively low 87Sr/86Sr ratios in thelate Middle Devonian to early Late Devonian, Early Carboniferous and Early Permian, corre-sponding to global eustatic high sea level stands. The lowest 87Sr/86Sr ratio recorded in theLate Permian was probably caused by substantial basalt eruptions in the Upper Yangtze Plat-form at the time. Three corresponding periods of relatively high δ13C values at roughly the samethe intervals were caused by a relatively high rate of accumulation of organic carbon duringsea level rises at these times. The deposition of coal was probably responsible for the increaseof sea water δ13C at other times. The δ13C values drop dramatically near theDevonian/Carboniferous, Carboniferous/Permian and Permian/Triassic boundaries, con-sistent with other similar data, which further support the notion that geological time boundariesare associated with mass extinction and subsequent rejuvenation. | Huang Sijing and Zhou Shaohua State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology, Chengdu, 610059, Sichuan, China Geological Institute, University of Copenhagen, Oster Voldgade 10,DK-1350 Copenhagen K,Denmark | 1997 | Acta Geologica Sinica(English Edition)1997，71，3： | 11 |
| 5 | Location characteristics and differentiation mechanism of logistics nodes and logistics enterprises based on points of interest (POI): A case study of Beijing显示文摘后勤节点和后勤企业是核心搬运人和后勤空间的组织上的题目,并且他们的地点特征和区别策略具有到优化城市的后勤的关键重要性空间模式和保证合理资源分配。从 2014 年 12 月基于 Tencent 联机地图站台,兴趣(夏威夷人用芋头做成的食品) 的 4396 个后勤点在中国北京被收集。由工业集中评估和核密度分析的方法,在北京的后勤的空间分发模式被探索,在类型差别,供应要求方面因素和地点选择行为之中的相互作用机制被澄清,并且在交通的联合影响下面的空间区别的内部机制,陆地租金和财产被揭示。下列结论在纸被得出。(1 ) 后勤企业和后勤节点在地点展出合作凝块和空间分离的特征,并且后勤活动显示“闹市区区域,郊区和城市远郊的区域的边缘的区域”的空间模式,它与后勤雇用空格有弱联合度。(2 ) 也就是,后勤停的公共后勤空间和后勤集中,在政府的指导下面被生产,并且由后勤分发组成的终端后勤空间集中服务因为特定的工业和终端用户被企业统治。在后勤空间的二个模式之间的位置上的区别是重要的。( 3 )在后勤的形成空间地点,政府能由重新计划改变交通条件运输线路和运费驻扎地点,并且由增加或减少控制陆地租金和不同区域的可获得性后勤的陆地使用,影响企业行为并且形成后勤空格和函数区别的不同类型。在比较,后勤企业通过财产分配的区别遇见服务目标的多样的要求支持分割的专门化并且形成后勤空间的目标区别。 | LI Guoqi JIN Fengjun CHEN Yu JIAO Jinjuan LIU Sijing | 2017 | Journal of Geographical Sciences2017，27，7： | 11 |
| 6 | Global correlation for strontium isotope curve in the Late Cretaceous of Tibet and dating marine sediments显示文摘87Sr/86Sr ratios of marine carbonate samples collected from a sedimentary section of the Late Cretaceous in the south of Tibet were measured. Based on the absence of cathodoluminescence and a very low Mn/Sr ratio (average 0.06) of the samples, it is thought that they contain information on the original seawater strontium isotope composition. The strontium isotope evolution curve of the Late Cretaceous in Tibet we established here, is consistent with other coeval curves from Europe, North America and Antarctica, supports the notion that the strontium isotope composition of seawater is governed by global events, which provides a new approach for the inter-continental and inter-basinal correlations of Late Cretaceous in the area and is a complementarity for biostratigraphy. In addition, we attempt to determine the age of the boundaries for Campanian/Santonian and Maastrichtian/Campanian by 87Sr/86Sr ratios for Gamba section in southern Tibet. The two boundaries are located in the thickness of 217 m (83.5 Ma) and 291 m (71.3 Ma), respectively. | HUANG Sijing SHI He SHEN Licheng ZHANG Meng WU Wenhui | 2005 | Science China Earth Sciences2005，48，2： | 11 |
| 7 | Rainfall-induced landslide stability analysis in response to transient pore pressure——A case study of natural terrain landslide in Hong Kong显示文摘Transient pore pressure in response to short intense rainfall process plays an important role in shallow landslide occurrence. Using GIS technology, we carry out the rainfall-induced landslide stability analysis in response to transient pore pressure by means of transient and unsaturated rainfall infiltration modeling. A case study is performed on the shallow landslide stability analysis in Hong Kong. Detailed analysis and discussion reached some useful conclusions on the tempo-spatial behavior and characteristics of slope stability response and pore pressure response to typical rainfall process. Comparison analysis is performed on some important issues including landslide stability response in different types of slopes with different hydraulic properties, antecedent rainfall and landslide stability, and the nature of pore pressure response time. These studies might give us an important insight into landslide tringgering mechanism and the hydrological process in response to rainfall, and provide systematic information and evidences for effective risk assessment and warning system establishment. | LAN Hengxing, ZHOU Chenghu C. F. LeeWANG Sijing & WU Faquan State Key Laboratory of Natural Resources and Environmental System, Institute of Geographical Sci-ences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Department of Civil Engineering, Hong Kong University, Hong Kong, China 3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China | 2003 | Science China(Technological Sciences)2003，46，z1： | 10 |
| 8 | The relationship between dolomite textures and their formation temperature: a case study from the Permian-Triassic of the Sichuan Basin and the Lower Paleozoic of the Tarim Basin显示文摘Study of dolomite texture can contribute to understanding the process of dolomitization. This research reports textures and homogenization temperatures of dolomites from the Permian–Triassic strata in the Sichuan Basin and the Lower Paleozoic strata in the Tarim Basin, which provided insights into relationships between dolomite textures and their formation temperatures. Our results are summarized as follows: 1) dolomites with well-preserved texture indicate low dolomitization temperature. However, in certain diagenetic environments, the hydrothermal dolomitization may completely or partially preserve the original texture of dolomites. 2) The formation temperatures of non-planar dolomites are always higher than those of planar dolomites. 3) The formation temperatures of dolomite cements are generally higher than those of replacive dolomites. 4) Although the formation temperatures of saddle dolomite cements have a wide range, they show higher values than those of the planar subhedral to euhedral dolomite cements. Thus, saddle dolomites could generally be an indicator of high precipitation temperature. 5) The fluid Mg/Ca ratio is another element controlling dolomite morphology. Micritic dolomites, which precipitate from hypersaline fluids with a high Mg/Ca ratio in a subaerial environment could also have features of non-planar anhedral crystal shape because of rapid nucleation and crystallization during dolomitization. | Huang Sijing Huang Keke Lü Jie Lan Yefang | 2014 | Petroleum Science2014，11，1： | 9 |
| 9 | Multiscale hierarchical analysis of rock mass and prediction of its mechanical and hydraulic properties显示文摘Engineering geological and hydro-geological characteristics of foundation rock and surrounding rock mass are the main factors that affect the stability of underground engineering. This paper presents the concept of multiscale hierarchical digital rock mass models to describe the rock mass, including its structures in different scales and corresponding scale dependence. Four scales including regional scale,engineering scale, laboratory scale and microscale are determined, and the corresponding scaledependent geological structures and their characterization methods are provided. Image analysis and processing method, geostatistics and Monte Carlo simulation technique are used to establish the multiscale hierarchical digital rock mass models, in which the main micro-and macro-structures of rock mass in different geological units and scales are reflected and connected. A computer code is developed for numerically analyzing the strength, fracture behavior and hydraulic conductivity of rock mass using the multiscale hierarchical digital models. Using the models and methods provided in this paper, the geological information of rock mass in different geological units and scales can be considered sufficiently,and the influence of downscale characteristics(such as meso-scale) on the upscale characteristics(such as engineering scale) can be calculated by considering the discrete geological structures in the downscale model as equivalent continuous media in the upscale model. Thus the mechanical and hydraulic properties of rock mass may be evaluated rationally and precisely. The multiscale hierarchical digital rock mass models and the corresponding methods proposed in this paper provide a unified and simple solution for determining the mechanical and hydraulic properties of rock mass in different scales. | Xiaoli Liu Guofeng Han Enzhi Wang Sijing Wang Kumar Nawnit | 2018 | Journal of Rock Mechanics and Geotechnical Engineering2018，10，4： | 8 |
| 10 | Experimental study on cracking behaviour of moulded gypsum containing two non-parallel overlapping flaws under uniaxial compression显示文摘Failure of rock mass that is subjected to compressive loads occurs from initiation, propagation, and linkage of new cracks from preexisting fissures. Our research investigates the cracking behaviour and coalescence process in a brittle material with two non-parallel overlapping flaws using a high-speed camera. The coalescence tensile crack and tensile wing cracks were the first cracks to occur from the preexisting flaws. The initiation stresses of the primary cracks at the two tips of each flaw were simultaneous and decreased with reduced flaw inclination angle. The following types of coalescence cracks were identified between the flaws: primary tensile coalescence crack, tensile crack linkage, shear crack linkage, mixed tensile-shear crack, and indirect crack coalescence. Coalescence through tensile linkage occurred mostly at pre-peak stress. In contrast, coalescence through shear or mixed tensile-shear cracks occurred at higher stress.Overall, this study indicates that the geometry of preexisting flaws affect crack initiation and coalescence behaviour. | Lekan Olatayo Afolagboye Jianming He Sijing Wang | 2017 | Acta Mechanica Sinica2017，33，2： | 7 |
| 11 | Origin of CO_2 in natural gas from the Triassic Feixianguan Formation of Northeast Sichuan Basin显示文摘The natural gas from the Triassic Feixianguan Formation of Northeast Sichuan Basin contains high H2S whereas relatively low CO2 concentrations and the CO2 display high δ13C values (ranging from -5.81‰ to 3.3‰ (PDB)). This seems to contradict the conventional wisdom that TSR should be a primary source of CO2 in natural gas from the Feixianguan Formation. In contrast, many authigenic calcite samples from these sites display very low δ13C values (ranging from -18.4‰ to -10.3‰ (PDB)). This suggests that the carbon from TSR source dominated the formation of calcite whereas the carbon from inorganic source came into CO2 in natural gas. In order to assess the origin of CO2 from these H2S-rich sites, we have calculated the relative contributions of organic and inorganic carbon sources to the CO2 and authigenic calcite. The organic carbon source possibly originated from TSR, whereas the inorganic one might be generated from marine carbonates dissolution. This calculation is based on the carbon isotopic compositions of CO2 and authigenic calcite as well as an isotopic mass balance. The results show that the contribution of organic carbon source to the CO2 is only 2%, whereas that to authigenic calcite is as high as 43% on average. Such results combined with thermodynamic evidence indicate that the isotopically light CO2 produced by TSR process may contribute to authigenic calcite precipitation during burial diagenesis. Distinguishable from Ordovician reservoir of Tarim Basin, Feixianguan reservoir of Northeast Sichuan Basin experienced rapid tectonic uplift due to Yanshanian movement after TSR occurred. Such tectonic event could induce temperature decrease and further promote carbonates dissolution. During these processes, secondary porosity has developed in Feixianguan carbonate reservoirs. Therefore, much attention should be paid to the structural highs in search of high quality carbonate reservoirs. | HUANG SiJing, HUANG KeKe, TONG HongPeng, LIU LiHong, SUN Wei & ZHONG QianQian State Key Lab of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China | 2010 | Science China Earth Sciences2010，53，5： | 7 |
| 12 | Geochemical characteristics of the Permian Changxing Formation reef dolomites,northeastern Sichuan Basin,China显示文摘The recent discovery of deep and ultra-deep gas reservoirs in the Permian Changxing Formation reefs, northeastern Sichuan Basin is a significant development in marine carbonate oil & gas exploration in China. Reef dolomites and their origins have been major research topics for sedimentologists and oil & gas geologists. The petrography, trace element and isotope geochemistry of the reef dolomites indicated that the dolomites are characterized by low Sr and Mn contents, relatively low Fe contents, very similar δ 13 C and δ 18 O values and very different 87 Sr/ 86 Sr ratios. Although the calculated results of the fluid mixing suggested that a mixture with 85%-95% meteoric water and 5%-15% seawater seemed to be the dolomitizing fluids of the reef dolomites, the low Mn contents, relatively low Fe contents, high δ 13 C values and high homogenization temperatures of the dolomites did not support that there were large proportions of meteoric water in the dolomitization process, and the 87 Sr/ 86 Sr ratios which were close to coeval seawater also did not support the possibility of the mixture of deep-burial circulated fluids from clastic rocks. High temperature deep-burial circulated seawater with low Mn and Fe contents, high Sr content and high δ 13 C values from the dissolution of widely distributed Triassic evaporites during the burial diagenetic processes (including dehydration of water-bearing evaporites) could have been the dolomitizing fluids of the reef dolomites. | Hu Zuowei Huang Sijing Li Zhiming Zhang Yingying Xu Ershe Qi Shichao | 2013 | Petroleum Science2013，10，1： | 6 |
| 13 | Evolution and global correlation for strontium isotopic composition of marine Triassic from Huaying Mountains,eastern Sichuan,China显示文摘Strontium isotope stratigraphy (SIS) has progressively become an efficient chemostratigraphic tool in the research and correlation of global geological events, such as global sea level fluctuations, orogeny, and paleoclimatic and paleoenvironmental changes. In this paper, 87Sr/86Sr ratios of the Triassic marine carbonate rock samples from Huaying Mountains, eastern Sichuan are measured, and the corre-sponding Sr-isotopic curve is constructed, based on the fundamental principle of strontium isotope stratigraphy, analysis of rock fabric, luminescent intensity, chemical composition and representative evaluation for the coeval seawater information. The 87Sr/86Sr ratios show a rapid rise from 0.70721 near the Permian-Triassic transition to 0.70830 at the end of Early Triassic, and then they decline rapidly to 0.70787 in the early Middle Triassic. These data are generally coincident with 87Sr/86Sr ratios of coeval seawater from previous papers, and the curve is also similar to other previous curves. This indicates that the global geological events are the most important controlling factors to the strontium isotope evolution of the global seawater in the Early and Middle Triassic. | ZuoWei Hu SiJing Huang HaiRuo Qing QingDong Wang ChunMei Wang XiaoYong Gao | 2008 | Science China Earth Sciences2008，51，4： | 5 |
| 14 | Origin of strong solid solution strengthening in the CrCoNi-W medium entropy alloy显示文摘Solid solution strengthening is one of the most conventional strategies for optimizing alloys strength,while the corresponding mechanisms can be more complicated than we traditionally thought specifically as heterogeneity of microstructure is involved.In this work,by comparing the change of chemical distribution,dislocation behaviors and mechanical properties after doping equivalent amount of tungsten(W)atoms in CrCoNi alloy and pure Ni,respectively,it is found that the alloying element W in CrCoNi alloy resulted in much stronger strengthening effect due to the significant increase of heterogeneity in chemical distribution after doping trace amount of W.The large atomic scale concentration fluctuation of all elements in CrCoNi-3W causes dislocation motion via strong nanoscale segment detrapping and severe dislocation pile up which is not the case in Ni-3W.The results revealed the high sensitivity of elements distribution in multi-principle element alloys to composition and the significant consequent influence in tuning the mechanical properties,giving insight for complex alloy design. | Yujie Chen Yan Fang Xiaoqian Fu Yiping Lu Sijing Chen Hongbin Bei Qian Yu | 2021 | Journal of Materials Science & Technology2021，，14： | 5 |
| 15 | Karst Collapse Mechanism and Criterion for Its Stability显示文摘Karst collapse, caused by natural or artificial abstraction of groundwater, has been a focus of environmental geological problems for its ever-increasing hazardousness. The potential erosion theory and vacuum suction erosion theory,which reveal the origin of karst collapse macroscopically, are popularly accepted. However, a mathematic prediction criterion for karst collapse cannot be established only by these two theories. From a new perspective, this paper attempts to explain the microcosmic mechanism of karst collapse on the basis of these two theories. When the shear stress surpasses the shear strength of soil, a certain point or a certain plane in the unconsolidated soil covering karst caves will fail under the mechanical effects of water and air as well as its load-pressure, and with the increase of damaged points, a breaking plane appears and the soil on karst caves is completely damaged; as a result, the karst ground collapses. On the basis of the MohrCoulomb failure theory and previous studies, the paper presents a prediction criterion of karst collapse. Finally, by taking,for example, nine typical cases of collapse caused by pumping tests in Guizhou, the paper gives the calculation process of the model and proves its reliability. | HE Keqiang LIU Changli WANG Sijing | 2001 | Acta Geologica Sinica(English Edition)2001，75，3： | 5 |
| 16 | Superconducting nanowire single-photon detection system and demonstration in quantum key distribution显示文摘We developed a superconducting nanowire single-photon detection(SNSPD) system based on Gifford-McMahon cryocooler for quantum communication applications.Environmental factors which may influence the system performance are intensively studied.Those factors include temperature fluctuations,the ambient magnetic field and the background radiation.By optimizing the bias circuit,the stability of SNSPD system to electrical noise and disturbance was effectively enhanced,thus making it more suitable for field application.A 4-channel SNSPD system with quantum efficiency higher than 4% at the dark count rate of 10 Hz for λ=1550 nm is integrated and applied into a quantum key distribution(QKD) experiment.QKD was successfully carried out over 100 km optical fiber with the final secure key rate of 1.6 kbps and the quantum bit error rate of less than 2%. | CHEN SiJing LIU DengKuan YOU LiXing WANG YongLiang QIU LongQing XIE XiaoMing JIANG MianHeng CHEN TengYun LIU Yang MIKI Shigehito WANG Zhen | 2013 | Chinese Science Bulletin2013，58，10： | 4 |
| 17 | Carbon isotope composition and comparison of Lower Triassic marine carbonate rocks from Southern Longmenxia section in Guang'an, Sichuan Basin显示文摘The Early Triassic was a period of ecological restoration for the earth's system after the end-Permian mass extinction.Geochemical records linked to the variations in marine ecosystems during this period have attracted the interest of geologists for many years.Based on petrographic analysis of samples and evaluations of their reliability as proxies for original seawater,this study investigated the carbon and oxygen isotopic compositions of 350 carbonate rock samples from the Lower Triassic(and adjacent strata)in the southern Longmenxia section of Guang'an,eastern Sichuan Basin.The results indicate that the Triassic carbonate rocks from the southern Longmenxia section favorably preserved the original seawater'sδ^(13)C signal.Furthermore,carbon and oxygen isotopic compositions are found to be poorly correlated,with a determination coefficient as low as 0.0205 and only 44 rock samples show results of Mn/Sr>2 and/orδ^(18)0<-6.5‰.The complete carbon isotopic curve for the Lower Triassic is established using the data from the remaining 306 samples with Mn/Sr<2 and/orδ^(18)O>-6.5‰.This curve presents favorable comparability on a global scale,specifically in theδ^(13)C minima near the Permian-Triassic boundary,at the top of the Jia1 and within the the Jia3,as well as in theδ^(13)C maxima at the tops of the Ye1 and Ye4,at the base of the Jia2 and at the top of the Ye3.The peaks and troughs corresponding to these maxima and minima all reflect global signals.By comparing these results to previous research on coeval carbon isotopic curves established within the chronostratigraphic framework,the ages of these critical evolution points are determined.The results show that the Ye1 roughly corresponds to the Griesbachian substage;the Ye2 through Ye4 correspond to the Dienerian substage;Jial corresponds to the Smithian substage;from the Jia2 to the lower part of the Jia4 correspond to the Spathian substage;and the middle and upper parts of the Jia4 belongs to the Aegean Substage of the Middle Triassic.Around the boundary between the Jial and Jia2(which represents the Smithian-Spathian boundary(SSB)),the value ofδ^(13)C increases rapidly from-0.911‰to 3.679‰.The span during which the seawater's carbon isotope experiences this drastic change may be less than36 kyr.The oxygen isotope,which is more sensitive to sedimentary environmental changes,exhibits changes prior to the carbon isotope near the SSB,indicating a significant increase in the salinity of the seawater before a sharp rise in the carbon isotope;this event leads to the formation of evaporites and dolomites. | HUANG SiJing HUANG KeKe ZHONG YiJiang LI XiaoNing MAO XiaoDong HU ZuoWei LIU SiBing ZHANG Meng WU WenHui | 2017 | Science China Earth Sciences2017，60，1： | 4 |
| 18 | Temperatures of dolomitizing fluids in the Feixianguan Formation from the Northeastern Sichuan Basin显示文摘The discovery of natural gas reservoirs from the Triassic Feixianguan Formation in the Northeastern Sichuan Basin is an important breakthrough in the field of marine carbonate rocks for Chinese oil and gas exploration in recent years.Because of the dolomite-hosted reservoirs in the Feixianguan Formation,these dolomites and their formation mechanisms have been a research focus for sedimentary geologists and petroleum geologists.Based on the homogenization temperatures of fluid inclusions,oxygen isotopic composition and their calculated temperatures,and the burial and thermal history of the typical well,it is considered that the majority of dolomites are formed by low-temperature dolomitizing fluids in the Triassic Feixianguan Formation,Northeastern Sichuan Basin.Only a minority of dolomites are formed by high-temperature dolomitizing fluids.The ending depth interval of low-temperature dolomitizing fluids was about 1000-2500 m,of which the correspondingly ending timing interval was approximately from early-middle Middle Triassic to early-middle Late Triassic.The main depth interval of high-temperature dolomitizing fluids was about 3200-4500 m,of which the correspondingly main timing interval was approximately early-middle Middle Jurassic.The low-temperature and high-temperature dolomitizing fluids have different meanings to the formation and evolution of the pore volumes of dolomite reservoirs in the Feixianguan Formation,Northeastern Sichuan Basin. | HU ZuoWei HUANG SiJing LI ZhiMing QING HaiRuo FAN Ming LAN YeFang | 2012 | Science China Earth Sciences2012，55，10： | 4 |
| 19 | Reliability of paste fill system of the Jinchuan No.2 mine显示文摘Because of poor ground conditions, stoping methods of underhand headings with cemented fill were used in the Jinchuan No. 2 mine, a paste fill system was set up. In order to evaluate the reliability of the new system, investigations and trial running have been done. More than 20 items of modification or improvements related to paste preparation subsystem, pump and pipe subsystem, auto-controlling and monitoring subsystem were finished. The reliability of the paste fill system was analyzed by using the theory of large complex system, and it is useful in reliability study on paste fill system. | Sijing Cai and Changjie ChenCivil and Environmental Engineering School, University of Science and Technology Beijing, Beijing 100083, China (Received 2001-10-24) | 2002 | Journal of University of Science and Technology Beijing2002，9，3： | 3 |
| 20 | Exploring detailed urban-rural development under intersecting population growth and food production scenarios: Trajectories for China’s most populous agricultural province to 2030显示文摘Henan,China,is likely the most populous agricultural province worldwide.It is China’s major grain-producing area,with a continuously increasing population(96 million),which is greater than 93%of countries worldwide.However,this province has been experiencing unprecedented urbanization recently due to national policies and measures,such as a plan to build the capital city of Henan into a national center,resulting in severe conflicts in land use that endanger food security regionally and globally.To facilitate decision-making on this problem,we explored the detailed urban-rural development of Henan by modeling these land-use conflicts.Conventional modeling of a region’s urban-rural development is to navigate trade-offs(a)solely between different land-use types(b)by assuming that each type provides a single service(e.g.,croplands produce all the food),and(c)under a polynomial regression-based projection of population.In contrast,we considered both land-use type and intensity,resulting in a detailed land system for Henan.By introducing the concept of land system services(e.g.,food production),we established a many-to-many relationship between land system classes and services.These allowed us to carry out the most comprehensive modeling of Henan’s urban-rural development under eighteen combined scenarios of population growth and land-use policies on food production.The modeling results of these scenarios provide a solid basis for making decisions regarding Henan’s urban-rural development.We also revealed the influence mechanism of population growth,land-use policies,and their combinations,highlighting the benefits of securing food production by agricultural intensification rather than merely expanding the area of cropland. | GAO Peichao XIE Yiru SONG Changqing CHENG Changxiu YE Sijing | 2023 | Journal of Geographical Sciences2023，33，2： | 2 |
您所在的机构暂未开通此部分的功能，请联系管理员