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    题名 作者 年代 出处 被引量
1Study on the prevalence of benlgn prostatic hyperplasia and prostatic cancer in China显示文摘StudyontheprevalenceofbenlgnprostatichyperplasiaandprostaticcancerinChinaGuFang-liu(顾方六)InstituteofUrology,BeijingMedicalUniv...$$$$ Gu Fang-liu(顾方六)Institute of Urology,Beijing Medical University,Beijing 100083,China 1994生殖医学杂志1994,3,S1:116
2Advanced characterization of pores and fractures in coals by nuclear magnetic resonance and X-ray computed tomography显示文摘This paper demonstrates capabilities of low-field nuclear magnetic resonance (NMR) and microfocus X-ray computed tomography (μCT) in advanced, nondestructive, and quantitative characterization of pore types, producible porosity, pore structure, and spatial disposition of pore-fractures in coals. Results show that the NMR transverse relaxation time (T2) at 0.5–2.5, 20–50, and >100 ms correspond to pores of <0.1 μm, >0.1 μm, and fractures, respectively. A much higher T2 spectrum peak reflects a much better development of pores (or fractures) corresponding to the T2, and vice versa. Three basic components in coals, i.e., the pores (or fractures), coal matrix, and minerals have their distinctive range of CT numbers. Among these, the CT number of pores is commonly less than 600 HU. The producible porosity, which is a determination of permeability, can be calculated by T2 cutoff value (T2C) of coal NMR. The coal pore structure can be efficiently estimated by the newly proposed 'T2C based model'. Finally, μCT scan was proven capable of modeling and spatial visualization of pores and fractures.YAO YanBin, LIU DaMeng, CAI YiDong & LI JunQian School of Energy Resources, China University of Geosciences, Beijing 100083, China 2010Science China Earth Sciences2010,53,6:61
3Mianlüe tectonic zone and Mianlüe suture zone on southern margin of Qinling-Dabie orogenic belt显示文摘The Mianle tectonic zone (Mianle zone), an ancient suture zone in addition to the Shangdan suture in the Qinling-Dabie orogenic belt, marks an important tectonic division geo-logically separating north from south and connecting east with west in China continent. To de-termine present structural geometry and kinematics in the Mianle tectonic zone and to recon-struct the formation and evolution history involving plate subduction and collision in the Qinling-Dabie orogenic belt, through a multidisciplinary study, are significant for exploring the mountain-building orogenesis of the central orogenic system and the entire process of the major Chinese continental amalgamation during the Indosinian.ZHANG Guowei1, DONG Yunpeng1, LAI Shaocong1, GUO Anlin1, MENG Qingren2, LIU Shaofeng3, CHENG Shunyou1, YAO Anping1, ZHANG Zongqing4, PEI Xianzhi5 & LI Sanzhong6 1. Department of Geology, Northwest University, Xian 710069, China 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100101, China 3. Earth Science and Resource Faculty, China University of Geosciences, Beijing 100083, China 4. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 5. Changan University, Xian 710054, China 6. Qingdao University of Oceanography, Qingdao 266003, China 2004Science China Earth Sciences2004,47,4:57
4INTERFACE REACTION IN MAGNETIC MULTILAYERS显示文摘Ta/NiO/NiFe/Ta multilayers were prepared by rf reactive and dc magnetron sputtering. The exchange coupling field (Hex) between NiO and NiFe reached 120Oe. The composition and chemical states at the interface region of NiO/NiFe were studied using the x-ray photoelectron spectroscopy (XPS) and peak decomposition technique. The results show that there are two thermodynamically favorable reactions at NiO/NiFe interface: NiO+Fe=Ni+FeO and 3NiO+2Fe = 3Ni+Fe2O3. The thickness of the chemical reaction as estimated by angle-resolved XPS was about 1-1.5nm. These interface reaction products are magnetic defects, and we believe that the Hex and the coercivity (Hc) of NiO/NiFe are affected by these defects. Moreover, the results also show that there is an 'intermixing layer' at the Ta/NiO (and NiO/Ta) interface due to a thermodynamically favorable reaction: 2Ta+5NiO=5Ni+ Ta2O5. This interface reaction has an effect on the exchange coupling as well. The thickness of the 'intermixing layer' as estimated by XPS depth-profiles was about 8-10nm.G.H. Yu, M.H Li, F. W Zhu, X.F. Cui and J.L. Jin ( Department of Materials Physics, University of Science and Technology Beijing, Beijing 100083, China) ( State key laboratory for Advanced Metals and Materials, University of Science and Technology Beijing 2001Acta Metallurgica Sinica(English Letters)2001,14,6:47
5Hepatoprotective role of ganoderma lucidum polysaccharide against BCG-induced immune liver injury in mice显示文摘AIM: To examine the effect of ganoderma lucidumpolysaccharide (GLP) on the immune liver injuryinduced by BCG infection, and investigate therelationship between degrees of hepatic damage andNO production in mice.METHODS: Immune hepatic injury was markedlyinduced by BCG-pretreatment (125 mg.kg-1, 2-week, iv)or by BCG-pretreatment plus lipopolysaccharide (LPS,125 μg.kg-1, 12-hour, iv) in mice in vivo.Hepatocellulardamage induced by BCG-pretreated plus inflammatorycytokines mixture (CM), which was included TNF-α, IL1β, IFN-γ and LPS in culture medium in vitro.Administration of GLP was performed by oral orincubating with culture medium at immune stimulisimultaneity. Liver damage was determined by activityof alanine aminotransferase (ALT) in serum and inhepatocytes cultured supernatant, by liver weightchanges and histopathological examination. NOproduction in the cultured supematant was determinedby the Griess reaction. Moreover, inducible nitric oxidesynthase (iNOS) protein expression was alsoexaminated by immunohistochemi1cal method.RESULTS: Immune hepatic injury was markedly inducedby BCG or BCG plus inflammatory cytokines in BALB/cmice in vivoand in vitro. Under BCG-stimulated condition,augment of the liver weight and increase of the serum/supernatant ALT level were observed, as well asgranuloma forming and inflammatory cells soakage wereobserved by microscopic analysis within liver tissues.Moreover, NO production was also increased by BCG or/and CH stimuli in the culture supernatant, and a lot ofiNOS positive staining was observed in BCG-prestimulated hepatic sections. Application of GLPsignificantly mitigated hepatic tumefaction, decreasedALT enzyme release and NO production in serum/supernatant, improved the pathological changes ofchronic and acute inflammation induced by BCG-stimuliin mice. Moreover, the immunohistochemical resultshowed that GLP inhibited iNOS protein expression inBCG-immune hepatic damage model.CONCLUSION: The present study indicates that NOparticipates in immune liver injury induced byMycobacterium bovis BCG infection. The mechanismsof protective roles by GLP for BCG-induced immune liverinjury may be due to influence NO production in mice.Guo-Liang Zhang Ye-Hong Wang Wei Ni Hui-Ling Teng Zhi-Bin Lin Department of Pharmacology,School of Basic Medical Sciences,Beijing University,Beijing 100083,China 2002World Journal of Gastroenterology2002,8,4:47
6华北燕山带:构造、埃达克质岩浆活动与地壳演化(英文)显示文摘埃达克质火成岩在中国东部,包括燕山带是很常见的,一般认为它们是下地壳不均匀的镁铁质岩石及/或富集的上地幔岩石在高压(≥1.5 GPa)下部分熔融的结果。在燕山带内埃达克岩浆的形成有一个很长的时间(约190~80 Ma),然而岩浆活动的峰期却与约170~130 Ma间有基底岩石卷入的陆壳收缩期相一致。尽管埃达克质岩浆活动的历史很长,但那种把岩浆活动与岩石圈的拆沉效应相联系的模式似乎是不适当的。在该带内,埃达克质与非埃达克质岩浆活动有一部分是同时的,而且在地理分布上也是相间的,这说明了在下地壳和上地幔岩石的部分熔融中成分是相当不均匀的。侏罗纪及白垩纪熔融作用的热源应当是与古太平洋板块俯冲相关的中生代板底垫托的玄武岩浆。除了局部例外,在燕山带,埃达克质岩浆活动的终结和碱性岩浆活动的开始约在130~120 Ma,在此时期收缩作用使东亚大达200万km^2以上的地区发生了NW—SE向的区域性伸展作用。强烈的地壳伸展仅局限于华北克拉通北缘分布的少数几个变质核杂岩中。陆壳的伸展减薄合理地解释了130~120 Ma间发生高压埃达克质熔融条件的终结,尽管还有局部年轻的埃达克火山活动(约120~80Ma)可以在伸展规模有限而厚的地壳依然存在的地区继续出现。燕山区早白垩世的碱性侵入体中的锆石不存在前寒武纪?Gregory A. DAVIS Department of Earth Sciences, University6 of Southern California, Los Angeles,California 90089-0740 USA Department of Geology , China University of Geosciences , Beijing 100083, China 2003地学前缘2003,10,4:46
7Characterization for commutators of n-dimensional fractional Hardy operators显示文摘In this paper, it was proved that the commutator Hβ,b generated by an n-dimensional fractional Hardy operator and a locally integrable function b is bounded from Lp1(Rn) to Lp2 (Rn) if and only if b is a C(M)O(Rn) function, where 1/p1 - 1/p2 = β/n, 1 < p1 <∞, 0 ≤β< n. Furthemore,the characterization of Hβ,b on the homogenous Herz space (K)qα,p(Rn) was obtained.Zun-wei FU~(1,2) Zong-guang LIU~3 Shan-zhen LU~(1+) Hong-bin WANG~3 ~1 School of Mathematical Sciences,Beijing Normal University,Beijing 100875,China ~2 Department of Mathematics,Linyi Normal University,Linyi 276005,China ~3 Department of Mathematics,China University of Mining and Technology (Beijing),Beijing 100083,China 2007Science China Mathematics2007,50,10:39
8Petrogenesis and dating of the Kangding complex,Sichuan Province显示文摘An analysis of major and trace element geochemistry and SHRIMP U-Pb zircon dating of mafic, intermediate, and felsic rocks from the Mianning metamorphic complex of Si- chuan Province was conducted. One of our conclusions is that a majority of the zircons crystal- lized between 721 and 773 Ma in a magmatic regime. The complexes contain early to late Pa- leo-proterozoic relict zircons from ancient continental crust. The oldest age, 2468 Ma, may rep- resent the basement of the Yangtze block. Overgrowth zircon rims and palingenetic zircons have been observed and dated, and are believed to have formed after crystallization, during Paleozoic and Mesozoic metamorphic-anatexis. We also conclude that depletion of Nb, Ta, HREE, in a spider-diagram normalized to primitive mantle and calc-alkaline association, implies that they formed in island-arc or under-plating settings.CHEN Yuelong 1 , LUO Zhaohua 1 , ZHAO Junxiang, LI Zhihong, ZHANG Hongfei & SONG Biao 3 1. Faculty of Earth Sciences and Natural Resources, China University of Geosciences, Beijing 100083, China 2. Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China 3. Beijing SHRIMP Center, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 2005Science China Earth Sciences2005,48,5:40
9The crustal structure under Sanjiang and its dynamic implications:Revealed by seismic reflection/refraction profile between Zhefang and Binchuan,Yunnan显示文摘The fault belts in Sanjiang mainly include Jinshajiang-Honghe fault, Lancangjiang fault and Nujiang fault (called Sanjiang faults) in western Yunnan Province, China. By interpreting the wide-angle seismic reflection/refraction profile between Zhefang and Binchuan, which crosses Tengchong and Baoshan blocks in Dianxi (western Yunnan) tectonic zone, we recon- struct the crustal structure with seismic traveltime tomography for crustal P-wave velocity and the seismic scattering image for crustal seismic reflection structure. In this paper, we firstly present the crustal structure images of P-wave velocity and seismic reflection under the wide-angle seismic profile. These results demonstrate that, the crustal velocity structure and seismic reflec- tion structure along the profile can be divided into 3 segments, and there is an obvious difference of crustal structure among the eastern, the western and the middle segment. Generally, crustal P-wave velocities in the Baoshan segment are 0.1―0.2 km/s slower and seismic reflection am- plitudes from Moho discontinuity are stronger than the other 2 segments. In the studied area, crustal thickness is about 40 km, and shows the thickening tendency from west to east along the profile. Additionally, it can be seen that there is one strong-amplitude seismic reflection event as bright points at the depths of 8―10 km, along the segment of 80―115 km of the profile (south- ward of Tengchong); and seismic reflection wave-field from Moho discontinuity varies obviously along the lateral direction. Finally, we make some discussions on the crustal thickening pattern in the Sanjiang fault belt, structural environment of earthquake development and the contact rela- tionship between the Tengchong block, Banshan block and Luxi trough.ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2, TENG Jiwen1, Lü Qingtian3, LI Jiliang1, LIU Yifeng1 & LIU Zhenkuan4 1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. Institute of Geophysics, China Seismological Bureau, Beijing 100085, China 3. Institute of Deposition Resource, Chinese Academy of Geosciences, Beijing 100037, China 4. School of Exploration and Information, China University of Geosciences, Beijing 100083, China 2005Science China Earth Sciences2005,48,9:39
10The Sequence of Magmatic-Tectonic Events and Orogenic Processes of the Yanshan Belt, North China显示文摘This paper emphasizes that the interactive constraints of geology and isotopic dating is the best approach to construct the geological event sequence, and has compiled 106 data of reasonable isotopic ages for the igneous rocks of the Yanshan belt. We propose a sequence of mgmatic-tectonic events in the Jurassic-Cretaceous Yanshan orogen of North China. Five orogenic episodes are divided, (1) pre-and initial orogenic episode (Early Jurassic); (2) early orogenic episode (Middle Jurassic); (3) peak orogenic episode (Late Jurassic); (4) late orogenic episode (early Early Cretaceous),and (5) post-orogenic episode. Each episode is a short cycle, all of the orogenic processes construct a longer cycle, and they, in general, followed a counter-clockwise (ccw) PTt path. Finally, it is suggested that the Yanshanian movement was so intensive that the magmatism and tectonic deformation had involved all the lithosphere thickness and the lateAchaean-formed cratonic lithosphere had been significantly reworked.DENG Jinfu, SU Shangguo, MO Xuanxue, ZHAO Guochun, XIAO Qinghiu, JI Guangyi,QIU Ruizhao, ZHAO Hailing, LUO Zhaohua, WANG Yang and LIU Cui China University of Geosciences, Beijing 100083 and Key Laboratory of Lithospheric Tectonics and Lithoprobe Techniques, Ministry of Education of China 2004Acta Geologica Sinica(English Edition)2004,78,1:35
11Sr-Nd isotopic compositions of the Changjiang sediments: Implications for tracing sediment sources显示文摘The suspended particulate and fine-grained floodplain sediments were collected from the main stream and tributaries of the Changjiang River for Sr-Nd isotopic measurements. The εNd(0) values gradually decrease downstream from -10.8 on average in the upper reaches to -12.3 in the lower reaches, whereas the 87Sr/86Sr ratios increase correspondingly, averaging 0.721899 and 0.725826 respectively in the upper and middle-lower reaches. The compositional variations primarily reflect the complex con- trols of provenance rocks, chemical weathering, and sediment characters between different catchments, among which the abnormal Sr-Nd isotopic compositions of the Yalong, Fujiang, Tuojiang and Yuanjiang rivers indicate the sediment provenance contributions from the Emeishan Basalt in the upper reaches and the old metamorphic and siliceous rocks in the middle-lower reaches. The Sr-Nd isotopic ratios of the Changjiang sediments can better reflect the average composition of weathered continental crust compared to other major rivers in the world because of the unique source rock types in the Changjiang drainage basin. The recognition of the Sr-Nd isotopic systematics of the Changjiang sediments will contribute to our understanding of the Changjiang evolution history and continental weathering processes during the Cenozoic, and also to reconstructing the paleoenvironmental changes in East China and the marginal seas.YANG ShouYe1?, JIANG ShaoYong2, LING HongFei2, XIA XiaoPing3, SUN Min3 & WANG DeJie4 1 State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China 2 State Key Laboratory for Mineral Deposit Research, Nanjing University, Nanjing 210093, China 3 Departmen of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China 4 Development Research Center, China Geological Survey, Beijing 100083, China 2007Science China Earth Sciences2007,50,10:32
12The control of syndepositional faulting on the Eogene sedimentary basin fills of the Dongying and Zhanhua sags, Bohai Bay Basin显示文摘The Dongying and Zhanhua sags are the major hydrocarbon exploration and produc- tion subbasins in the Bohai Bay Basin. Integrated analysis of the sedimentary basin fills has shown that the syndepositional faults and their arrangement styles exerted an important influ- ence on the development and distribution of the Eogene depositional systems. The sedimentary filling evolution of the subbasins reflects the general control of the episodic rifting process. The major long-term active normal faults formed a series of paleogeomorphic accident or slopebreak zones that commonly delineated the subsidiary palaeostructural units and the depositional facies tracts and constrained the general distribution of sedimentary facies zones. The central sag boundary fault slopebreak zones usually determined the distribution of the depocenters of ter- restrial clastic depositional systems, particularly the lowstand fans or deltaic depositional sys- tems, and have proven to be the economically important targets for the exploration of subtle sandstone reservoirs. A variety of syndepositional fault arrangement patterns, including the par- allel, en echelon, combo-like, broom-like fault systems and the fault overlap or transfer zones, have been recognized in the subbasins. They generated distinctive geomorphic features and exerted a direct influence on sediment dispersal and sandbody distribution during the Eogene synrift stage. It is the key for the prediction of depositional systems tracts and reservoir sand- stones to investigate the activity and distribution of the fault slopebreak zones and reconstruct the structural paleogeomorphy in different basin filling stages of the basin evolution.LIN Changsong1, ZHENG Herong2, REN Jianye1, LIU Jingyan1 & Qiu Yigang1 1. Department of Energy Geology, China University of Geosciences, Beijing 100083, China 2. Petroleum Exploration and Production Institute, Sino-Petroleum and Chemistry Cooperation, Beijing 100083, China 2004Science China Earth Sciences2004,47,9:33
13SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau显示文摘Metabasites consisting of metamorphic ultra-mafic rocks, cumulate gabbro, gabbro (diabase), basalt, and plagiogranite are exposed at the Taoxinghu area in central Qiangtang, northern Tibetan Plateau. Zircon SHRIMP U-Pb dating for the cumulate gabbro yields a weighted mean age of 467±4 Ma, which is the oldest and most reliable magmatic age in this area. Zircon 176Hf/177Hf ratios range from 0.282615 to 0.282657, with εHf(t) values of 5.02±0.28, indicating that the cumulate gabbro was mainly derived from the depleted mantle. In addition, geochemical data of metabasites suggest that they have similar characteristics to those in the mid-ocean ridge basalts (MORB). The Taoxinghu metabasites may represent the fragment of Early Paleozoic ophiolite in the 'Central Uplift' of the Qiangtang, northern Tibetan Plateau.ZHAI QingGuo1 WANG Jun1, LI Cai2 & SU Li3 1 Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 2 College of Earth Sciences, Jilin University, Changchun 130061, China 3 The Geological Laboratory Center and State Key Laboratory of Geological Processes and Mineral Resources, China University of Geo- sciences, Beijing 100083, China 2010Science China Earth Sciences2010,53,5:31
14Numerical simulation of mechanisms of deformation,failure and energy dissipation in porous rock media subjected to wave stresses显示文摘The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed.The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform.The failure processes of the porous rock media loaded by the split Hopkinson pressure bar(SHPB) were simulated by satisfying the elastic wave propagation theory.The dynamic responses,stress transition,deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed.It is shown that an explicit and quantitative analysis of the stress,strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models.With applied wave stresses of certain amplitude and velocity,no evident pore deformation was observed for the rock media with a porosity less than 15%.The deformation is dominantly the combination of microplasticity(shear strain),cracking(tensile strain) of matrix and coalescence of the cracked regions around pores.Shear stresses lead to microplasticity,while tensile stresses result in cracking of the matrix.Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values.The simulation results of stress wave propagation,deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests.The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response,stress transit mode,deformation and failure mechanisms and the disaster mechanisms of rock media.JU Yang1,2,WANG HuiJie1,YANG YongMing1,HU QinAng3 & PENG RuiDong1 1 State Key Laboratory of Coal Resources and Safe Mining,Beijing Key Laboratory of Fracture and Damage Mechanics of Rock and Concrete,China University of Mining and Technology,Beijing 100083,China 2 Department of Mechanical and Manufacturing Engineering,University of Calgary,Calgary,Alberta,T2N 1N4,Canada 3 School of Environment and Civil Engineering,College of Engineering,Oklahoma State University,Stillwater,OK 74078,USA 2010Science China(Technological Sciences)2010,53,4:32
15Energy analysis for damage and catastrophic failure of rocks显示文摘The development history and current state of studies on the characteristics and mechanisms of deformation and failure of rock materials were briefly reviewed from the viewpoint of energy.The main scope and the achievable objectives of the energy-based research system were expatiated.It was validated by experiments that the damage process of rocks can be well described by the rock damage evolution equation established based on energy dissipation.It was found from the uniaxial compression and biaxial compression tests that only a small proportion of the total input energy in hard rocks is dissipated before peak load and a large proportion in soft rocks is dissipated before peak load.For both hard and soft rocks,the energy dissipated after peak load accounts for a greater proportion.More energy would be required for rock failure under equal biaxial compression than under unequal biaxial compression.The total absorbed energy is different for rock failure under high-rate loading and low-rate loading.More fragmented failure pattern usually corresponds to higher energy absorption.The mesoscopic analysis on the damage and failure of bedded salt rocks showed that the energy dissipation is prominent and the total absorbed energy for rock failure is low when cracks propagate in the weak mud interlayer while it is contrary when cracks propagate in the salt rock.The energy accumulation,transfer,dissipation and release during the failure process of tunnel with impending failure under disturbance were analyzed theoretically based on the elastoplastic mechanics theory.Furthermore,the spatial distribution of energy dissipation and energy release of fractured rocks under unloading was simulated numerically.It was demonstrated that energy is likely to be released from the weakest surface under compression,which triggers the global failure of rocks.XIE HePing 1,2,LI LiYun 2,1,JU Yang 2,PENG RuiDong 2 & YANG YongMing 2 1 Sichuan University,Chengdu 610065,China 2 State Key Laboratory of Coal Resources and Safe Mining,Beijing Key Laboratory of Fracture and Damage Mechanics of Rock and Concrete,China University of Mining and Technology,Beijing 100083,China 2011Science China(Technological Sciences)2011,54,S1:29
16The intracellular mechanism of alpha-fetoprotein promoting the proliferation of NIH 3T3 cells显示文摘AIM The existence and properties of alpha-fetoprotein (AFP) receptor on the surface of NIH 3T3 cells and the effects of AFP on cellular signal transduction pathway were investigated. METHODS The effect of AFP on the proliferation of NIH 3T3 cells was measured by incorporation of 3H-TdR. Receptor-binding assay of 125I-AFP was performed to detect the properties of AFP receptor in NIH 3T3 cells. The influences of AFP on the [cAMP]i and the activities of protein kinase A (PKA) were determined. Western blot was used to detect the change of K-ras P21 protein expression. RESULTS The proliferation of NIH 3T3 cells treated with 0-80 mg/L of AFP was significantly enhanced. The Scatchard analysis indicated that there were two classes of binding sites with KD of 2.722×10-9M (Bmax=12810 sites per cell) and 8.931× 10-SM (Bmax=l19700 sites per cell) respectively. In the presence of AFP (20 mg/L), the content of cAMP and activities of PKA were significantly elevated . The level of K-ras P21 protein was upregulated by AFP at the concentration of 20 mg/L. The monoclonal antibody against AFP could reverse the effects of AFP on the cAMP content, PKA activity and the expression of K-ras p21 gene. CONCLUSION The effect of AFP on the cell proliferation was achieved by binding its receptor to trigger the signal transduction pathway of cAMP-PKA and alter the expression of K- ras p21 gene.MENG SEN LI, PING FENG LI, FBI YI YANG, SHI PENG HE, Guo GUANG DU, GANG LI1 Department of Biochemistry and Molecular Biology, 2 Department of Biophysics, Health Science Center, Peking University, Beijing 100083, China 2002Cell Research2002,12,2:27
17Next-generation sequencing technology:A technology review and future perspective显示文摘As one of the most powerful tools in biomedical research,DNA sequencing not only has been improving its productivity at an exponential growth rate but has also been evolving into a new layout of technological territories toward engineering and physical disciplines over the past three decades.In this technical review,we look into technical characteristics of the next-generation sequencers and provide insights into their future development and applications.We envisage that some of the emerging platforms are capable of supporting the USD1000 genome and USD100 genome goals if given a few years for technical maturation.We also suggest that scientists from China should play an active role in this campaign that will have a profound impact on both scientific research and societal healthcare systems.ZHOU XiaoGuang1,REN LuFeng1,LI YunTao2,ZHANG Meng1,YU YuDe2 & YU Jun1 1 Key Laboratory of Genome Sciences and Information,Beijing Institute of Genomics,Chinese Academy of Sciences,Beijing 100029,China 2 Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China 2010Science China(Life Sciences)2010,53,1:27
18Edge Effect Correction in the S-A Method for Geochemical Anomaly Separation显示文摘Anomaly separation using geochemical data often involves operations in the frequency domain, such as filtering and reducing noise/signal ratios. Unfortunately, the abrupt edge truncation of an image along edges and holes (with missing data) often causes frequency distribution distortion in the frequency domain. For example, bright strips are commonly seen in frequency distribution when using a Fourier transform. Such edge effect distortion may affect information extraction results; sometimes severely, depending on the edge abruptness of the image. Traditionally, edge effects are reduced by smoothing the image boundary prior to applying a Fourier transform. Zero-padding is one of the most commonly used smoothing methods. This simple method can reduce the edge effect to some degree but still distorts the image in some cases. Moreover, due to the complexity of geoscience images, which can include irregular shapes and holes with missing data, zero-padding does not always give satisfactory results. This paper proposes the use of decay functions to handle edge effects when extracting information from geoscience images. As an application, this method has been used in a newly developed multifractal method (S-A) for separating geochemical anomalies from background patterns. A geochemical dataset chosen from a mineral district in Nova Scotia, Canada was used to validate the method.Ge Yong Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences & Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Cheng Qiuming Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada Earth Systems and Mineral Resource Engineering Lab, China University of Geosciences, Wuhan 430074, China Zhang Shenyuan Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada Department of Resource and Earth Science, China University of Mining & Technology, Beijing 100083, China 2004Journal of China University of Geosciences2004,15,4:28
19Geochemistry and mineralogy of the Late Permian coals from the Songzao Coalfield, Chongqing, southwestern China显示文摘Mineralogy and geochemistry of the four main workable coal seams (No.6, No.7, No.8, and No.11) of Late Permian age from the Songzao Coalfield, Chongqing, Southwest China, were examined using in- ductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence spectrometry (XRF), cold-vapor absorption spectrometry (CV-AAS), ion-selective electrode (ISE), scanning electron mi- croscopy equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and X-ray diffraction analysis (XRD). The results showed that the main workable No.8 Coal that accounts for about 60% of the total coal reserves in the Songzao Coalfield was not enriched in hazardous trace elements. The No.11 Coal has high concentrations of alkaline elements, Be (9.14 μg/g), Sc (12.9 μg/g), Ti (9508 μg/g), Mn (397 μg/g), Co (23.7 μg/g), Cu (108 μg/g), Zn (123 μg/g), Ga (32 μg/g), Zr (1304 μg/g), Nb (169 μg/g), Hf (32.7 μg/g), Ta (11.4 μg/g), W (24.8 μg/g), Hg (0.28 μg/g), Pb (28.1 μg/g), Th (24.1 μg/g), and rare earth elements (509.62 μg/g). The concentration of Nb and Ta in the No. 11 Coal is higher than the industrial grade, and their potential utilization should be further studied. Besides pyrite, quartz, calcite, and clay minerals, trace minerals including chalcopyrite, marcasite, siderite, albite, mixed-layer clay minerals of illite and smectite, monazite, apatite, anatase, chlorite, and gypsum were found in the No.11 Coal. It should be noted that alabandite of hydrothermal origin and anatase occurring as cement were identi- fied in coal. In addition, the clayey microbands derived from alkaline volcanic ashes were identified in the coal. The dominant compositions of these clayey microbands were mixed-layer clay minerals of illite and smectite, which were interlayered with organic bands. The modes of occurrence of alkaline volcanic ash bands indicate that the volcanic activities were characterized by the multiple eruptions, short time interval and small scale for each eruption during peat accumulation. The alkaline volcanic ashes were the dominant factors for the enrichment of alkaline elements, Nb, Ta, Zr, Hf, and rare earth elements, and the sulfide minerals are the main carriers of Ga, Cu, and Hg in the No. 11 Coal.DAI ShiFeng1,2, ZHOU YiPing3, REN DeYi1, WANG XiBo1, 2, LI Dan1, 2 & ZHAO Lei1, 2 1 State Key Laboratory of Coal Resources and Safe Mining (China University of Mining and Technology), Beijing 100083, China 2 Department of Resources and Earth Science, China University of Mining and Technology, Beijing 100083, China 3 Kunming Research Institute of Coal Science, Kunming 650041, China 2007Science China Earth Sciences2007,50,5:27
20NUMERICAL SIMULATION OF ROUND TO OVAL ROLLING PROCESS显示文摘Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analysis was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to be elasto-plastic and it obey the Von Mises yield criterion and Prandtl- Reuss rule. Deformation of the workpiece is simulated in a step-by-step manner,updating the coordinates of material points and the property after each step, so that both nonsteady-state and stendy-state deformation can be simulated. The heat transfter between the workpiece, the rolls, and enviroment and the heat generation due to plastic work and friction force, are considered in the analys- is.Predicted the deformation shape of the workpiece, distributions of strains, stresses, strain rates and temperatures, roll-separating force and roll torque are presented.Y. W. Wang, Y. L. King, D. H. Yuan, S. G. Liu and Z. Y. Yu 1 ) University of Science and Technology Beijing, Beijing 100083, China 2) Daye Special Steel Co., Huangshi 435001, China 2000Acta Metallurgica Sinica(English Letters)2000,13,2:27
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