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| 1 | Sequencing of Cultivated Peanut, Arachis hypogaea, Yields Insights into Genome Evolution and Oil Improvement显示文摘Cultivated peanut (Arachis hypogaea) is an allotetraploid crop planted in Asia, Africa, and America for edible oil and protein. To explore the origins and consequences of tetraploidy, we sequenced the allotetraploid A. hypogaea genome and compared it with the related diploid Arachis duranensis and Arachis ipaensis genomes. We annotated 39 888 A-subgenome genes and 41 526 B-subgenome genes in allotetraploid peanut. The A. hypogaea subgenomes have evolved asymmetrically, with the B subgenome resembling the ancestral state and the A subgenome undergoing more gene disruption, loss, conversion, and transposable element proliferation, and having reduced gene expression during seed development despite lacking genome-wide expression dominance. Genomic and transcriptomic analyses identified more than 2 500 oil metabolism-related genes and revealed that most of them show altered expression early in seed development while their expression ceases during desiccation, presenting a comprehensive map of peanut lipid biosynthesis. The availability of these genomic resources will facilitate a better understanding of the complex genome architecture, agronomically and economically important genes, and genetic improvement of peanut. | Xiaoping Chen Qing Lu Hao Liu Jianan Zhang Yanbin Hong Haofa Lan Haifen Li Jinpeng Wang Haiyan Liu Shaoxiong Li Manish K.Pandey Zhikang Zhang Guiyuan Zhou Jigao Yu Guoqiang Zhang Jiaqing Yuan Xingyu Li Shijie Wen Fanbo Meng Shanlin Yu Xiyin Wang Kadambot H.M.Siddique Zhong-Jian Liu Andrew H.Paterson Rajeev K.Varshney Xuanqiang Liang | 2019 | Molecular Plant2019,12,7: | 23 |
| 2 | Climate and litter C/N ratio constrain soil organic carbon accumulation显示文摘Soil organic carbon(SOC) plays critical roles in stabilizing atmospheric CO2 concentration, but the mechanistic controls on the amount and distribution of SOC on global scales are not well understood. In turn, this has hampered the ability to model global C budgets and to find measures to mitigate climate change. Here, based on the data from a large field survey campaign with 2600 plots across China’s forest ecosystems and a global collection of published data from forested land, we find that a low litter carbon-to-nitrogen ratio(C/N) and high wetness index(P/PET, precipitation-to-potentialevapotranspiration ratio) are the two factors that promote SOC accumulation, with only minor contributions of litter quantity and soil texture. The field survey data demonstrated that high plant diversity decreased litter C/N and thus indirectly promoted SOC accumulation by increasing the litter quality. We conclude that any changes in plant-community composition, plant-species richness and environmental factors that can reduce the litter C/N ratio, or climatic changes that increase wetness index, may promote SOC accumulation. The study provides a guideline for modeling the carbon cycle of various ecosystem scales and formulates the principle for land-based actions for mitigating the rising atmospheric CO2 concentration. | Guoyi Zhou Shan Xu Philippe Ciais Stefano Manzoni Jingyun Fang Guirui Yu Xuli Tang Ping Zhou Wantong Wang Junhua Yan Gengxu Wang Keping Ma Shenggong Li Sheng Du Shijie Han Youxin Ma Deqiang Zhang Juxiu Liu Shizhong Liu Guowei Chu Qianmei Zhang Yuelin Li Wenjuan Huang Hai Ren Xiankai Lu Xiuzhi Chen | 2019 | National Science Review2019,6,4: | 21 |
| 3 | Enhanced mechanical properties and degradation rate of Mg-Ni-Y alloy by introducing LPSO phase for degradable fracturing ball applications显示文摘In this work,as-cast Mg-Ni-Y alloys were proposed to develop a feasible material for fracturing balls,and their mechanical performance and corrosion behavior were systematically investigated.Long period stacking order(LPSO)phase was firstly introduced to improve both the mechanical properties and degradation rate of magnesium alloys.With the increase of LPSO phase,the compressive strength was improved significantly,while the elongation of the alloys decreased owing to the relatively brittle nature of LPSO phase.Due to the higher corrosion potential of LPSO phase,the LPSO phase can accelerate the corrosion process by providing more micro-couples.However,the LPSO phase would serve as the corrosion barrier between the corrosion medium and the matrix when the contents of LPSO phase are too high in Mg92.5Ni3Y4.5 and Mg87.5Ni5Y7.5 alloys.As-cast Mg97.5Ni1Y1.5 alloy with satisfactory mechanical properties and rapid degradation rate was successfully developed,exhibiting a high degradation rate of 6675 mm/a(93℃)in 3 wt.%KCl solution and a favorable ultimate compressive strength of 410 MPa.The degradation rate of Mg97.5Ni1Y1.5 alloy is 2-5 times of the current commercial magnesium alloy fracturing materials. | Jingfeng Wang Shiqing Gao Xiuying Liu Xing Peng Kui Wang Shijie Liu Weiyan Jiang Shengfeng Guo Fusheng Pan | 2020 | Journal of Magnesium and Alloys2020,8,1: | 13 |
| 4 | Insight-HXMT observations of the first binary neutron star merger GW170817显示文摘Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics. On Aug. 17, 2017,Advanced LIGO and Fermi/GBM independently triggered the first BNS merger, GW170817, and its high energy EM counterpart,GRB 170817 A, respectively, resulting in a global observation campaign covering gamma-ray, X-ray, UV, optical, IR, radio as well as neutrinos. The High Energy X-ray telescope(HE) onboard Insight-HXMT(Hard X-ray Modulation Telescope) is the unique high-energy gamma-ray telescope that monitored the entire GW localization area and especially the optical counterpart(SSS17 a/AT2017 gfo) with very large collection area(~1000 cm^2) and microsecond time resolution in 0.2-5 MeV. In addition,Insight-HXMT quickly implemented a Target of Opportunity(ToO) observation to scan the GW localization area for potential X-ray emission from the GW source. Although Insight-HXMT did not detect any significant high energy(0.2-5 MeV) radiation from GW170817, its observation helped to confirm the unexpected weak and soft nature of GRB 170817 A. Meanwhile,Insight-HXMT/HE provides one of the most stringent constraints(~10^(-7) to 10^(-6) erg/cm^2/s) for both GRB170817 A and any other possible precursor or extended emissions in 0.2-5 MeV, which help us to better understand the properties of EM radiation from this BNS merger. Therefore the observation of Insight-HXMT constitutes an important chapter in the full context of multi-wavelength and multi-messenger observation of this historical GW event. | TiPei Li ShaoLin Xiong ShuangNan Zhang FangJun Lu LiMing Song XueLei Cao Zhi Chang Gang Chen Li Chen TianXiang Chen Yong Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng YongWei Dong YuanYuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo ShuMei Jia LuHua Jiang WeiChun Jiang Jing Jin YongJie Jin Bing Li ChengKui Li Gang Li MaoShun Li Wei Li Xian Li XiaoBo Li XuFang Li YanGuo Li ZiJian Li ZhengWei Li XiaoHua Liang JinYuan Liao CongZhan Liu GuoQing Liu HongWei Liu ShaoZhen Liu XiaoJing Liu Yuan Liu YiNong Liu Bo Lu XueFeng Lu Tao Luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge OU JinLu Qu Na Sai Liang Sun Yin Tan Lian Tao WenHui Tao YouLi Tuo GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BoBing WU Mei Wu GuangCheng Xiao He Xu YuPeng Xu LinLi Yan JiaWei Yang Sheng Yang YanJi Yang AiMei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang HongMei Zhang Juan Zhang Qiang Zhang Shu Zhang Tong Zhang Wei Zhang WanChang Zhang WenZhao Zhang Yi Zhang Yue Zhang YiFei Zhang YongJie Zhang Zhao Zhang ZiLiang Zhang HaiSheng Zhao JianLing Zhao XiaoFan Zhao ShiJie Zheng Yue Zhu YuXuan Zhu ChangLin Zou | 2018 | Science China(Physics,Mechanics & Astronomy)2018,61,3: | 12 |
| 5 | The enhanced X-ray Timing and Polarimetry mission—eXTP显示文摘In this paper we present the enhanced X-ray Timing and Polarimetry mission—eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to detect the electro-magnetic counterparts of gravitational wave sources.The paper provides a detailed description of:(1) the technological and technical aspects, and the expected performance of the instruments of the scientific payload;(2) the elements and functions of the mission, from the spacecraft to the ground segment. | ShuangNan Zhang Andrea Santangelo Marco Feroci YuPeng Xu FangJun Lu Yong Chen Hua Feng Shu Zhang Sφren Brandt Margarita Hernanz Luca Baldini Enrico Bozzo Riccardo Campana Alessandra De Rosa YongWei Dong Yuri Evangelista Vladimir Karas Norbert Meidinger Aline Meuris Kirpal Nandra Teng Pan Giovanni Pareschi Piotr Orleanski QiuShi Huang Stephane Schanne Giorgia Sironi Daniele Spiga Jiri Svoboda Gianpiero Tagliaferri Christoph Tenzer Andrea Vacchi Silvia Zane Dave Walton ZhanShan Wang Berend Winter Xin Wu Jean J.M.in't Zand Mahdi Ahangarianabhari Giovanni Ambrosi Filippo Ambrosino Marco Barbera Stefano Basso Jörg Bayer Ronaldo Bellazzini Pierluigi Bellutti Bruna Bertucci Giuseppe Bertuccio Giacomo Borghi XueLei Cao Franck Cadoux Francesco Ceraudo TianXiang Chen Yu Peng Chen Jerome Chevenez Marta Civitani Wei Cui WeiWei Cui Thomas Dauser Ettore Del Monte Sergio Di Cosimo Sebastian Diebold Victor Doroshenko Michal Dovciak YuanYuan Du Lorenzo Ducci QingMei Fan Yannick Favre Fabio Fuschino JoséLuis Ga'lvez Min Gao MingYu Ge Olivier Gevin Marco Grassi QuanYing Gu YuDong Gu DaWei Han Bin Hong Wei Hu Long Ji ShuMei Jia WeiChun Jiang Thomas Kennedy Ingo Kreykenbohm Irfan Kuvvetli Claudio Labanti Luca Latronico Gang Li MaoShun Li Xian Li Wei Li ZhengWei Li Olivier Limousin HongWei Liu XiaoJing Liu Bo Lu Tao Luo Daniele Macera Piero Malcovati Adrian Martindale Malgorzata Michalska Bin Meng Massimo Minuti Alfredo Morbidini Fabio Muleri Stephane Paltani Emanuele Perinati Antonino Picciotto Claudio Piemonte JinLu Qu Alexandre Rachevski Irina Rashevskaya Jerome Rodriguez Thomas Schanz ZhengXiang Shen LiZhi Sheng JiangBo Song LiMing Song Carmelo Sgro Liang Sun Ying Tan Phil Uttley Bo Wang DianLong Wang GuoFeng Wang Juan Wang LangPing Wang YuSa Wang Anna L.Watts XiangYang Wen Jörn Wilms ShaoLin Xiong JiaWei Yang Sheng Yang YanJi Yang Nian Yu WenDa Zhang Gianluigi Zampa Nicola Zampa Andrzej A.Zdziarski AiMei Zhang ChengMo Zhang Fan Zhang Long Zhang Tong Zhang Yi Zhang XiaoLi Zhang ZiLiang Zhang BaoSheng Zhao ShiJie Zheng Yu Peng Zhou Nicola Zorzi J.Frans Zwart | 2019 | Science China(Physics,Mechanics & Astronomy)2019,62,2: | 11 |
| 6 | Combined treatment of non-small cell lung cancer using radiotherapy and immunotherapy: challenges and updates显示文摘The efficacy of immunotherapy for advanced non-small cell lung cancer(NSCLC)remains unsatisfactory,as the majority of patients either do not experience an objective response or acquire secondary resistance.As a result,several methods to enhance the systemic efficacy of immunotherapy have been investigated,including a large area of active research by combining immunotherapy with radiation therapy(RT).Given the rapidly burgeoning concept of combining immunotherapy and RT for increasing therapeutic benefit,we review the progress in this field thus far and explore further avenues for enhancing this combination.This review commences with a discussion of the only two existing randomized trials(and a pooled analysis)showing that the addition of RT to immunotherapy improves the abscopal response rate,progression-free survival,and overall survival in metastatic NSCLC patients.We then discussed factors and biomarkers that may be associated with a proportionally greater benefit to additional RT,such as low programmed cell death protein ligand 1(PD-L1)status,tumor mutational burden(TMB),and patient’s immune function.Next,the implementation of RT to overcome immunotherapy resistance is discussed,including a mechanistic discussion and methods with which these mechanisms could be exploited.Lastly,the emerging role of low-dose RT is discussed,which may help to overcome inhibitory signals in the tumor stroma that limit T-cell infiltration.Taken together,given the current state of this rapidly expanding realm,these futuristic strategies may be reflected upon to further enhance the efficacy of immunotherapy for a wider group of patients. | Shijie Shang Jie Liu Vivek Verma Meng Wu James Welsh Jinming Yu Dawei Chen | 2021 | Cancer Communications2021,41,11: | 10 |
| 7 | Optically pumped terahertz sources显示文摘High-power terahertz(THz) generation in the frequency range of 0.1-10 THz has been a fast-developing research area ever since the beginning of the THz boom two decades ago, enabling new technological breakthroughs in spectroscopy, communication, imaging,etc. By using optical(laser) pumping methods with near-or mid-infrared(IR) lasers, flexible and practical THz sources covering the whole THz range can be realized to overcome the shortage of electronic THz sources and now they are playing important roles in THz science and technology. This paper overviews various optically pumped THz sources, including femtosecond laser based ultrafast broadband THz generation, monochromatic widely tunable THz generation, single-mode on-chip THz source from photomixing, and the traditional powerful THz gas lasers. Full descriptions from basic principles to the latest progress are presented and their advantages and disadvantages are discussed as well. It is expected that this review gives a comprehensive reference to researchers in this area and additionally helps newcomers to quickly gain understanding of optically pumped THz sources. | ZHONG Kai SHI Wei XU DeGang LIU PengXiang WANG YuYe MEI JiaLin YAN Chao FU ShiJie YAO JianQuan | 2017 | Science China(Technological Sciences)2017,60,12: | 9 |
| 8 | Investigation of the combustion deterioration of an automotive diesel engine under transient operation显示文摘With increasingly stringent emission regulations and demand for fuel economy by the public,the combustion and emission problems of automotive diesel engines during transient operation have become vital and urgent issues.In this study,combustion deterioration has been experimentally analyzed using a heavy-duty turbocharged diesel engine running under transient conditions(constant speed and increasing torque).Optimization of the transient combustion process was performed by adjusting the fuel injection parameters.The results indicated that the notable combustion deterioration relative to steady state operation while transient was a function of the delay in the air-supply to the turbocharged engine,and took the form of combustion phasing delay,resulting in rapidly increasing smoke emission and fuel consumption.However,the delay in combustion phasing can be controlled by advancing the fuel injection timing,effectively increasing thermal efficiency.Unfortunately,smoke and NO x emissions increased at the same time.The deterioration in combustion phasing can also be improved by increasing injection pressure,resulting in decreased smoke emission while NO x emission increased.It is worth noting that the effective thermal efficiency first increased and then decreased as fuel injection pressure increased during transient operation. | ZHANG LongPing LIU ZhongChang TIAN Jing SUN ShiJie | 2014 | Science China(Technological Sciences)2014,57,3: | 9 |
| 9 | Combined effects of cadmium and fluoranthene on germination, growth and photosynthesis of soybean seedlings显示文摘The single and combinational effects of cadmium (Cd) and fluoranthene (FLT) on germination, growth and photosynthesis of soybean seedlings were investigated. Exposure to 5, 10, or 15 mg Cd/L or 1, 5, or 10 mg FLT/L individually or in combination significantly decreased germination vigor (3 days) and final germination rate of soybean seeds, except at 1 and 5 mg FLT/L. The results of two-way ANOVA analysis and the Bliss independence model showed that at lower concentrations of FLT (1 mg/L), the interaction between Cd and FLT on germination was antagonistic, whereas the interaction was synergistic when the concentration of FLT was 5 or 10 mg/L and the concentration of Cd was 15 mg/L. Growth, expressed as dry weight, length of shoot and root, leaf area, and photosynthesis, expressed as net photosynthetic rate, intercellular CO2 concentration, chlorophyll contents and fluorescence of soybean seedlings were also reduced by exposure to 5 or 10 mg Cd/L or 1 or 5 mg FLT/L, singly or jointly. Significant antagonistic effects of exposure to 5 or 10 mg Cd/L or 1 or 5 mg FLT/L on shoot growth and photosynthesis were observed, whereas synergy and antagonism of Cd and FLT were both observed for root growth. | Qiushuang Li Yonglong Lu Yajuan Shi Tieyu Wang Kun Ni Li Xu Shijie Liu Lin Wang Qinli Xiong John.P Giesy | 2013 | Journal of Environmental Sciences2013,25,9: | 8 |
| 10 | Enrichment of heavy metal elements and their adsorption on iron oxides during carbonate rock weathering process显示文摘Analysis of trace elements in the Lower Palaeozoic carbonate rock strata of the Beijing area shows that the Cr, Zn, Cd and Pb contents increase from primary carbonate rocks to weathered carbonate rocks and from primary carbonate rocks to the soil coexisting with carbonate rock. Distributions of Cr, Zn, Cd and Pb have the same trends as that of Fe2O3. Iron oxides play different roles at different stages of weathering of carbonate rock. The adsorption of Cr, Zn, Cd and Pb on Fe2O3 is greater than on FeO in soil. However, FeO, as a main component of clay mineral, is a better adsorbent of Cr, Zn, Cd and Pb than Fe2O3 in weathered and primary carbonate rocks. According to R-type clustering analysis, the main components of carbonate rock are divided into marine and continental sediments. Correlation analysis shows that heavy metal elements mainly exist in continental substances. | Shanqin Ni Yiwen Ju Quanlin Hou Shijie Wang Qing Liu Yudong Wu Lingling Xiao | 2009 | Progress in Natural Science:Materials International2009,19,9: | 8 |
| 11 | Analytical Solutions of Cracks Emanating from an Elliptic Hole in an Infinite Plate under Tension显示文摘It is a common phenomenon that the cracks originating from a hole can cause structural damage in engineering.However,the fracture mechanics studies of hole edge crack problems are not sufficient.The problem of an elliptical hole with two collinear edge cracks of unequal length in an infinite plate under uniform tension at infinity is investigated.Based on the complex variable method,the analytical solutions of stress functions and stress intensity factors are provided.The stress distribution along the axes and the edge of the elliptical hole is given graphically.The numerical results show that there is obvious stress concentration near the hole and cracks,and the stresses tend to applied loads at distances far from the defect,which conform to Saint-Venant’s principle.Hence,the stress functions are proved to be right.Under special conditions,the present configuration becomes the Griffith crack,two symmetrical cracks emanating from an elliptical hole,two cracks of unequal length emanating from a circular hole,a crack at the edge of a circular hole,or a crack emanating from an elliptical hole.Compared with available results,stress intensity factors for these special shapes of ellipses and cracks show good coincidence.The stress intensity factor for two cracks of unequal length at the edge of an elliptical hole increases with the crack length and the major-to-minor axis ratio of the elliptical hole.The stress distribution in an infinite plate containing an elliptic hole with unsymmetrical cracks is given for the first time. | LIU Shuhong DUAN Shijie | 2014 | Chinese Journal of Mechanical Engineering2014,27,5: | 8 |
| 12 | A Review of Hydrophobic Nanocellulose and Its Applications显示文摘Nanocellulose is of great interest in various areas nowadays as a natural nanostructured biomaterial.However,in many applications,the high hydrophilicity due to a large number of hydroxyl groups is not desired.The hydrophobic modification of nanocellulose can thus increase its application.This work reviewed recent developments of methods for nanocellulose hydrophobic modification,through physical adsorption and chemical grafting.The applications of hydrophobic nanocellulose were also reviewed. | Jinglei Xie Shijie Liu | 2021 | Paper And Biomaterials2021,6,2: | 7 |
| 13 | Oxygen isotopic (^(17)O-^(18)O) heterogeneity in Archaean continental nucleus, North China Craton显示文摘The oxygen isotopic data for amphibolites from Archaean continental nucleus, North China Craton indicate that ( i ) the evolving lines structured by the data are parallel to the geoselenic evolving line, which means that the parent materials of these continental nucleus o-riginated from solar matter; ( ii ) different intercepts for these evolving lines manifest that oxy- | LIU Jianzhong, ZHANG Fuqin, LI Chunlai and WANG Shijie Institute of Geochemistry , Chinese Academy of Sciences , Guiyang 550002 , China Institute of Geophysics , Chinese Academy of Sciences , Beijing 100101 , China | 1999 | Chinese Science Bulletin1999,44,24: | 6 |
| 14 | Electro-elastic Fields of Piezoelectric Materials with An Elliptic Hole under Uniform Internal Shearing Forces显示文摘The existing investigations on piezoelectric materials containing an elliptic hole mainly focus on remote uniform tensile loads. In order to have a better understanding of the fracture behavior of piezoelectric materials under different loading conditions, theoretical and numerical solutions are presented for an elliptic hole in transversely isotropic piezoelectric materials subjected to uniform internal shearing forces based on the complex potential approach. By solving ten variable linear equations, the analytical solutions inside and outside the hole satisfying the permeable electric boundary conditions are obtained. Taking PZT-4 ceramic into consideration, numerical results of electro-elastic fields along the edge of the hole and axes, and the electric displacements in the hole are presented. Comparison with stresses in transverse isotropic elastic materials shows that the hoop stress at the ends of major axis in two kinds of material equals zero for the various ratios of major to minor axis lengths; If the ratio is greater than 1, the hoop stress in piezoelectric materials is smaller than that in elastic materials, and if the ratio is smaller than 1, the hoop stress in piezoelectric materials is greater than that in elastic materials; When it is a circle hole, the shearing stress in two materials along axes is the same. The distribution of electric displacement components shows that the vertical electric displacement in the hole and along axes in the material is always zero though under the permeable electric boundary condition; The horizontal and vertical electric displacement components along the edge of the hole are symmetrical and antisymmetrical about horizontal axis, respectively. The stress and electric displacement distribution tends to zero at distances far from the elliptical hole, which conforms to the conclusion usually made on the basis of Saint-Venant's principle. Unlike the existing work, uniform shearing forces acting on the edge of the hole, and the distribution of electro-elastic fields inside and outside the elliptic hole are considered. | DU Yanliang LIU Shuhong DUAN Shijie LI Yanqiang | 2013 | Chinese Journal of Mechanical Engineering2013,26,3: | 6 |
| 15 | Coupling Effect of Heat Transfer and Flow Resistance in the Rifled Tube Water Wall of a Ultra-Supercritical CFB Boiler显示文摘The coupling factor is used in this study to characterise the combined effect of the heat transfer and resistance characteristics of a rifled tube. Boundary layer theory is utilised to investigate the relationship between the comprehensive coefficient and Reynolds number in two regions, namely, higher and lower than pseudo-critical enthalpy. Results indicate that mass flux exerts a decisive negative influence on the coupling effect, and the impacts of pressure and heat flux are weak. The overall effect decreases rapidly as the mass flux increases, but it increases in the area behind the quasi-critical enthalpy. The coupling effect is also affected by specific heat ratio, thermal acceleration and buoyancy. The correlations of heat transfer and friction resistance are deduced with high precision according to experimental data. | LI Yaode YANG Dong OUYANG Shijie LIU Dan WANG Wenyu | 2019 | Journal of Thermal Science2019,28,5: | 5 |
| 16 | Urban and rural transport of semivolatile organic compounds at regional scale: A multimedia model approach显示文摘Urban areas are generally regarded as major sources of some semivolatile organic compounds and other persistent organic pollutants(POPs) to the surrounding regions. Huge differences in contaminant emissions between urban and rural areas directly affect their fate in environmental media. Little is known about POPs behavior between urban and rural areas at a regional scale. A spatially resolved Berkeley-Trent-Urban-Rural Fate Model(BETR-UR) was designed by coupling land cover information to simulate the transport of POPs between urban and rural areas, and the Bohai Rim was used as a case study to estimate Polycyclic Aromatic Hydrocarbon(PAH) fate. The processes of contaminant fate including emission, inter-compartmental transfer, advection and degradation in urban and rural areas were simulated in the model. Simulated PAH concentrations in environmental media of urban and rural areas were very close to measured values. The model accuracy was highly improved, with the average absolute relative error for PAH concentrations reduced from 37% to 3% compared with unimproved model results. PAH concentrations in urban soil and air were considerably higher than those in rural areas. Sensitivity analysis showed temperature was the most influential parameter for Phen rather than for Bap, whose fate was more influenced by emission rate, compartment dimension, transport velocity and chemical persistence. Uncertainty analysis indicated modeled results in urban media had higher uncertainty than those in rural areas due to larger variations of emissions in urban areas. The differences in urban and rural areas provided us with valuable guidance on policy setting for urban–rural POP control. | Shuai Song Chao Su Yonglong Lu Tieyu Wang Yueqing Zhang Shijie Liu | 2016 | Journal of Environmental Sciences2016,28,1: | 5 |
| 17 | Evidence of Nd isotope for unhomogeneity and origin of upper mantle of North China platform显示文摘Based on isptopic age of Sm-Nd and its initial composition and its evolution obtained during the recent years of archean metamorphic magnesio-ferro the vocanics of upper mantle of the North China platform, it is concluded that the isotopic composition of Archean upper mantle of the North China platform is not homogeneous, and values of /Nd don not change regularly through the whole Archean; in contrast, they present obvious differences in different regions. All this demands that the unhomogeneity of Archean upper mantle of the North China platform inherits initial unhomogeneity of origin, and the origin of the North China platform should contribute to uneven accumulation of planetesimals. | Jianzhong Liu Ziyuan Ouyang Fuqin Zhang Shijie Wang | 1999 | Chinese Science Bulletin1999,44,6: | 5 |
| 18 | Analytical solutions of cracks emanating from an elliptical hole under shear显示文摘Based on the complex variable method, the analytical solutions of stress functions and stress intensity factors(SIFs) are provided for the plane problem of two collinear edge cracks emanating from an elliptical hole in an infinite plate under shear. The stress distribution along the horizontal axis is given in graphical forms, which conforms to Saint-Venant's principle. The influences of crack length and ellipse shape on the stress intensity factors are evaluated. Comparing the analytical solutions with finite element method(FEM) results shows good coincidence. These numerical examples show that the present solutions are accurate. | Liu Shuhong Duan Shijie | 2014 | Chinese Journal of Aeronautics2014,27,4: | 5 |
| 19 | A Backstepping Simple Adaptive Control Application to Flexible Space Structures显示文摘Although the simple adaptive control (SAC) is widely studied both in theory and application in flexible space structure control and other control problems, it is restricted by the almost strictly positive real (ASPR) conditions. In most practical control problems, the ASPR conditions are not satisfied. Therefore, based on the SAC theory, this paper proposes a backstepping simple adaptive control algorithm which suits the system with arbitrary relative degree with no need of parallel feedforward compensator. The proposed control algorithm consists of decomposition of the arbitrary relative degree system into a known subsystem and an unknown ASPR subsystem which are connected in cascade, design of constant output feedback controller for the known subsystem, and implementation of backstepping method and SAC of the unknown ASPR subsystem. Inheriting the characteristics of the SAC, this method can be adaptive online for the parameter uncertainties. Then, the application of the proposed controller to large flexible space structure with collocated sensors and actuators is studied, and the simulation results validate the proposed controller. It is a new strategy to apply the classical SAC to high relative degree plants. | LIU Min XU Shijie HAN Chao | 2012 | Chinese Journal of Aeronautics2012,25,3: | 4 |
| 20 | Tectonic Evolution of Southeast Central Asian Orogenic Belt: Evidence from Geochronological Data and Paleontology of the Early Paleozoic Deposits in Inner Mongolia显示文摘In this study, we present detrital zircon U-Pb dating and paleontological data for the newly identified Ayadeng Formation in the northern margin of the North China Block(NCB) and Xibiehe Formation(molasse) in the Bainaimiao arc belt(BAB), which could provide strong evidence indicating the affinity of the BAB and the evolution of the southeast Central Asian orogenic belt(CAOB). Zircon U-Pb data of siltstone samples and paleontological data indicate the Ayadeng Formation dates back to the Early Ordovician. Although its location is near the NCB, its zircon age spectra and paleontology share a closer affinity with those of Tarim and NE Gondwana, as the U-Pb data suggest an age range of 490–2 192 Ma(peak age=629, 788, 965 and 1 935 Ma), and similar gastropod fossils are found in Tarim and NE Gondwana. The U-Pb ages of meta-sandstone samples in the Xuniwusu Formation indicate a shared inheritance with the Ayadeng Formation(before 440 Ma), and the U-Pb ages of sandstone samples in the Xibiehe Formation are concentrated, with age peaks centered at ca. 420 Ma. Fossil corals occur in these two formations, and their age components also indicate a collisional setting. Therefore, it is speculated that the BAB drifted away from Tarim or NE Gondwana during the Ordovician and became attached to northern NCB between 440–420 Ma as an exotic terrane. During the Early Paleozoic, there may have occurred a collision between an arc and a continental block. | Shijie Wang Shichao Li Wenjie Li Zhongyuan Xu Jinfeng Zhang Changhai Li Qiang Shi Yang Liu Wenlong Wang Qingbin Guan | 2020 | Journal of Earth Science2020,31,4: | 4 |