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The crystal structure of (Fe_(4)Cr_(4)Ni)_(9)C_(4)

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Science china Earth Sciences 2005年第3期48卷 338-345页

作者： shi {1.1. {3. zhesheng1. XIONG Ming1. DAI Mingquan1. BAI Wenji2, FANG Qingsong2, YAN Binggang2 & YANG Jingsui2 1. X-ray Diffraction Laboratory, china University of geosciences, beijing 1.0083. china 2. Institute of Geology, Chinese Academy of Geological Sciences, beijing 1.003., china 1. X-ray Diffraction Laboratory China University of Geosciences 100083 Beijing China 2. Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China

(Fe4Cr4Ni)9C4 is a metal carbide mineral formed by combination of Fe, Cr and Ni with C. It occurs in a chromite deposit in the Luobusha ophiolite, Tibet. Based on the determina- tion of its crystal structure, the empirical formula is (Fe4.1.Cr3.84Ni0.96)8.92C3.70 and the simplified formula is (Fe4Cr4Ni)4C9. The mineral is hexagonal with a = 1.3.3.2(2) nm, c = 0.44690(9) nm, space group P63.m c, Z=6 and the calculated specific gravity Dx = 7.089 g/cm3. Fe, Cr and Ni occupy different crystallographic sites and their coordination numbers are approximately 1., forming an alternate stacking sequence of flat and puckered layers along the c axis. Some me- tallic atoms have a defect structure. The interatomic distances of Fe, Cr and Ni are 0.2525— 0.2666 nm, and the distances between Fe, Cr, Ni and C are 0.1.93.0.21.9 nm. The coordina- tion number of carbon is 6. It occurs in interstices of the metallic atoms Fe, Cr and Ni to form trigonal-prismatically coordinated polyhedra. These coordination polyhedra are linked with each other via shared corners or shared edges into a new type of metal carbide structure.

关键词： Luobusha of Tibet, metal carbide, crystal structure.

SHRIMP zircon U-Pb age and Nd isotopic study on the Nyainqêntanglha Group in Tibet

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Science china Earth Sciences 2005年第9期48卷 1377-1386页

作者： HU Daogong1. WU Zhenhan1. JIANG Wan1. {3. Yuruo2, ye Peisheng{1. LIU Qisheng1.1. Institute of Geomechanics, Chinese Academy of Geological Sciences, beijing 1.0081. china 2. Institute of Geology, Chinese Academy of Geological Sciences, beijing SHRIMP Centre, beijing 1.003., china 1. Institute of Geomechanics Chinese Academy of Geological Sciences 100081 Beijing China 2. Institute of Geology Chinese Academy of Geological Sciences Beijing SHRIMP Centre 100037 Beijing China

The Nyainqêntanglha Group is traditionally viewed as the oldest metamorphic basement in the Lhasa block, but its formation age and tectonic setting remain debate. Zircons extracted from the metamorphic sequence of volcanics and intrusions of the Nyainqêntanglha Group, 10 km west of Nam Co in northern Lhasa block, have been investigated by cathodolu- minescence (CL), backscattered (BSE) and dated by ion microprobe (SHRIMP). We conclude that the U-Pb age of 787±9 ma of zircons from the trondhjemite imposes a constraint on maxi- mum protolith age, and minimum formation age of the Nyainqêntanglha Group is constrained by U-Pb age of 748±8 ma of zircons from the granite. The formation age of the Nyainqêntanglha Group is consistent with sedimentary age of Greater Himalayan rocks, showing that they devel- oped coevally in an arc-basin tectonic setting of Neoproterozoic active continental margin along the northern margin of the India shield. The inherited zircons from the tholetiite and granite give older 207Pb/206Pb ages from 947 to 1766 ma. The positive εNd( t ) value indicates that the mafic rocks were derived from the depleted mantle, but contaminated by the older continental crustal material. Integrated Nd model age and U-Pb age data provide excellent evidence for the exis- tence of Mesoproterozoic basement in the Lhasa block during Neoproterozoic time.

关键词： Nyainqêntanglha Group, SHRIMP dating, Nd isotope, Neoproterozoic, Tibet.

Response of phytoplankton functional group to spring drought in a large subtropical reservoir

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Journal of Oceanology and Limnology 2024年第5期42卷 1586-1596页

作者： Yue WU Qi ye Siwen CHEN Kaining CHEN Shuzhan ma Yiheng CHANG Xiaoli {1. State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China State Environmental Protection Key Laboratory of Aquatic Ecosystem Health in the Middle and Lower Reaches of Yangtze River Jiangsu Provincial Academy of Environmental ScienceNanjing 210036China

Global warming has caused an increase in the frequency and duration of droughts *** could trigger large changes in physico-chemical conditions and phytoplankton community in waterbodies,resulting in a shift in the phytoplankton *** diatom blooms in reservoirs have been increasingly observed in the past decade in the Taihu Lake *** aim of the present study is to elucidate the impacts of droughts on aquatic environment and to determine the driving factors for the succession of the phytoplankton functional groups based on the analysis of data collected during spring from 2009 to 2020 in the Daxi *** unimodal relationship between 1.month aggregated precipitation index and phytoplankton species richness indicated the competitive exclusion occurred in extremely drought *** structural equation modeling indicated that drought-related low water level conditions intensified sediment resuspension,and increased the phosphorus-enriched nonalgal turbidity in the Daxi ***,a steady shift in the Reynolds phytoplankton functional groups from L 0,TD,J,X 2,and A(phytoplankton taxa preferring low turbidity and nutrient conditions)to TB(pennate diatoms being adapt to turbid and nutrient-rich conditions)was *** increased TP and non-algal turbidity in addition to the lowered disturbance contribute to the prevalence of Group *** the difficulties in nutrient control,timely water replenishment is often a feasible method of controlling the dominance of harmful algae for reservoir ***,alternative water sources are in high demand for ensuring ecological safety and water availability when dealing with drought.

关键词： drought reservoir sediments resuspension phytoplankton functional group diatom

Crystal Structure of Natural Non-metamict Ti- and Fe2+-rich Chevkinite-（Ce）

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Acta Geologica Sinica(English Edition) 2005年第3期 325-331页

作者： LI Guowu1.YANG Guangming2,ma Zhengsheng1.{1. nicheng1.XIONG Ming1.FAN Haifu3.and SHENG Ganfu4 1.3. University of geosciences(beijing),beijing 1.0083.2 china University of geosciences(Wuhan),Wuhan,Hubei 43.074 3.Institute of Physics,Chinese Academy of Sciences,beijing 1.0080 4 Chengdu Institute of Geology and Mineral Resources,Chengdu,Sichuan 61.082

The crystal structure of non-metamict Ti- and Fe2+-rich chevkinite-(Ce) has been redetermined with the single -crystal sample collected from Bayan Obo, Inner Mongolia, china. The chemical formula of the sample is Ce4Fe2Ti3.i4O22. The crystals are monoclinic with the unit cell parameters a = 1..4656(1.) ?, b = 5.73.6(6) ?, c = 1..0977(1.) ?, β= 1.0.63.(2)o, V = 842.3. (1.) ?3.and Z = 2. The structures of Ti- and Fe2+-rich chevkinite-(Ce) were refined with space groups P21.a and C2/m. Least-squares refinement results show that both structural models of Ti- and Fe2+-rich chevkinite-(Ce) are very good, R[F2>2σ(F2)] =0.027 with P21.a and R[F2>2σ(F2)] =0.021.with C2/m. In order to illustrate the relation{1.p between the two space groups P21.a and C2/m, the distribution of diffraction intensities was inspected. Pseudo extinction was found, i.e., reflections with h+k=2n are systematically strong, while those with h+k=2n+1.are weak. By neglecting the systematically weak (h+k=2n+1. reflections the space group becomes C2/m. There is a mirror plane in the C2/m perpendicular to the b axis. However, oxygen atoms in the P21.a model are of a symmetrical relation{1.p with the corresponding pseudo mirror plane. It is concluded that the crystal structure of non-metamict Ti- and Fe2+-rich chevkinite-(Ce) is a superstructure with the space group of P21.a, which is of pseudo symmetry corresponding to the space group C2/m.

关键词： non-metamict Ti- and Fe2+-rich chevkinite-(Ce) crystal structure space group superstructure

Silicon-rutile - an ultra-high pressure (UHP) mineral from an ophiolite

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Progress in Natural Science:materials International 2003年第7期 50-53页

作者： YANG Jingsui , BAI Wenji, FANG Qingsong, YAN Binggang, shi {1., ma {3., DAI Mingquan and XIONG Ming (1. Institute of Geology, Chinese Academy of Geological Sciences, beijing 1.003., china 2. Geological University of china, beijing 1.0083. china) Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Geological University of china Beijing 100083 China

Silicon(Si)-rutile separated from the Luobusa podiform chromitite in the Yarlung Zangbo ophiolite of southern Tibet is typically about 50 μm × 50 μm × 200 μm in size and consists mainly of SiO2 and TiO2- The average mineral formula is (Ti0. 82Si0.1.)O2. Powder X-ray diffraction data show that it is tetragonal in form, and the unit cell dimensions and other parameters are: α= 4. 591.2) A , c = 2.946(2)A, v=62.09(5)A3. c/α=0.641., with a molar volume about 5 % smaller than rutile (JCPDS, 21.1.76). The Si4 + ions in silicon rutile are six-coordinated, and are substituted for Ti + in the rutile structural sites. The Si-rutile, along with other associated ultra-high minerals discovered in the chromitite, such as octahedral silicate, silicon-magnesium spinel (Si4+ ions are six-coordinated), diamond, and intergrown of SiO2 and FeO phases, probably originated from the transition zone or the lower mantle, and were brought to shallow levels beneath an oceanic spreading ridge by an upwelling superplurne.

关键词： Si-rutile UHP minerals ophiolite lower mantle chromitite.

Oxygen‑Coordinated Single Mn Sites for Efficient Electrocatalytic Nitrate Reduction to Ammonia

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Nano-Micro Letters 2024年第1期16卷 147-159页

作者： Shengbo Zhang Yuankang Zha Yixing ye Ke Li Yue Lin Lirong Zheng Guozhong Wang Yunxia Zhang Huajie Yin Tongfei shi Haimin Zhang Laboratory of materials Physics Centre for Environmental and Energy NanomaterialsAnhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031People’s Republic of China University of Science and Technology of china Hefei 230026People’s Republic of China Key Laboratory of Agricultural Sensors Ministry of AgricultureSchool of Information and ComputerAnhui Agricultural UniversityHefei 230026People’s Republic of China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026People’s Republic of China beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadBeijing 100049People’s Republic of China

Electrocatalytic nitrate reduction reaction has attracted increasing attention due to its goal of low carbon emission and environmental ***,we report an efficient NitRR catalyst composed of single Mn sites with atomically dispersed oxygen(O)coordination on bacterial cellulose-converted graphitic carbon(Mn-O-C).Evidence of the atomically dispersed Mn-(O-C_(2))_(4)moieties embedding in the exposed basal plane of carbon surface is confirmed by X-ray absorption *** a result,the as-synthesized Mn-O-C catalyst exhibits superior NitRR activity with an NH_(3.yield rate(RNH_(3.)of 1.76.9±62.6μg h^(−1.cm^(−2)at−0.7 V(*** hydrogen electrode,RHE)and a faradaic efficiency(FE)of 89.0±3.8%at−0.5 V(***)under ambient ***,when evaluated with a practical flow cell,Mn-O-C shows a high RNH_(3.of 3.06.7±552.0μg h^(−1.cm^(−2)at a current density of 1.0 ma cm−2,2.5 times of that in the H *** in situ FT-IR and Raman spectroscopic studies combined with theoretical calculations indicate that the Mn-(O-C_(2))_(4)sites not only effectively inhibit the competitive hydrogen evolution reaction,but also greatly promote the adsorption and activation of nitrate(NO_(3.^(−)),thus boosting both the FE and selectivity of NH_(3.over Mn-(O-C_(2))_(4)sites.

关键词： Atomically dispersed Oxygen coordination Nitrate reduction reaction In situ spectroscopic studies Hydrogen evolution reaction

Effects of resistance training on bone loss in 8 weeks hindlimb unloading rats

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Effects of resistance training on bone loss in 8 weeks hindl...

Genetic relationship between parasitized and non-parasitized Haloxylon ammodendron in the Alxa Desert

中国生理学会第23.全国会员代表大会暨生理学学术大会

作者： Zhi-Li LI~(1.2),Cheng TAN~1.Hui-Juan WANG~1.Wen-Juan CHEN~1.ye DING~3.Yu ZHU~1.Hong-Lei ma~1.De-Sheng WANG~1.{1.-Zhong JIANG~1.Jun WANG~2,Hong-Hui YANG~1.1.State Key Laboratory of Space Medicine Fundamentals and Application,{13. Astronaut Research and Training Center,beijing 1.0094,{13. 2 Fourth Military Medical University,Xi ''an 71.03.,Shaanxi,{13. 3.College of Veterinary Medicine,{13. Agricultural University,beijing 1.01.3.{13.

＜正＞Objective:The purpose of this research was to determine the effectiveness of resistance training in attenuating bone loss in hindlimb unloading rats undergoing a resistance training program for a period of 8 weeks. Methods:Forty male Wistar rats were divided randomly into four groups:an age-matched control group（C,n=1.）, a hindlimb unloading group（HU,n=1.）,a hindlimb unloading + stand group（HU+S,n=1.）,and a hindlimb unloading + resistance-training group（HU+RT,n=1.）.In HU+RT,1. rats were resistance trained for 8 *** resistance-training protocol was performed with 4 sets of 1. repetitions 5 days/week using 65%to 75%of one repetition maximum（maximum lifted weight） measured every 2 *** the end of 8 week resistance training, bone mineral density（BMD） and biomechanical properties of the femur were measured by Micro CT and three point bending test ***:Before the resistance training period,all the groups had similar repetition maximums However,at the end of the resistance training period,the repetition maximum in C and HU+RT was approximately 3.fold the body weight more than that in HU and HU+*** significant differences were observed for any of the bone parameters when comparing HU and HU+S rats.C and HU+RT rats had higher trabecular BMD than HU and HU+S *** Thickness（***） was greater in HU+RT than that in HU+***,no significant differences in BMD of cortical bone area were detected among all the groups in the femur *** maximal load and stiffness of the femur midshaft of rats in HU+RT were significantly higher than that in HU,while lower than that in ***:These results demonstrate that the resistance training can counter bone loss completely and mitigate the bone strength reduction caused by simulated weightlessness by hindlimb unloading.

关键词： resistance training hindlimb unloading bone mineral density

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Journal of Systematics and Evolution 2009年第3期47卷 255-262页

作者： 1.2,3.u-Mei WANG 1.ong-ye YANG 4Yong-Zhen TIAN 5Peng-Fei TU 2Qi-{3. SUN 1.iao-Bo LI 1.School of Phar{1.cy, Shanghai Jiao Tong University, Shanghai 200240, china) 2(College of Traditional Chinese {1.teria Medica, Shenyang Phar{1.ceutical University, Shenyang 1.001., china) 3.School of Medicine, Xi’an Jiaotong University, Xi’an 71.061. china) 4(Forest and Desert Control Research Institute of Alxa League, Alxa League 7503.6, china) 5(Modern Research Center of Traditional Chinese Medicine, School of Phar{1.ceutical Sciences, Peking University, beijing 1.0083. china) (Modern Research Center of Traditional Chinese Medicine School of Pharmaceutical Sciences Peking University Beijing 100083 China)

Haloxylon ammodendron (C. A. Mey.) Bunge is a host for the holoparasitic plant Cistanche deserticola Y. C. ma, the original source of medicinal material known as Herba Cistanchis. The inter-simple sequence repeat marker was used to assess the genetic variations and relation{3.ps among six accessions of H. ammodendron with a total of 1.0 individuals collected from three localities in the Alxa Desert, Inner Mongolia, china. At each locality, individuals both parasitized (PP) by C. deserticola and non-parasitized (NP) were sampled. The results showed that Nei’s gene diversity and Shannon’s index of PP accessions were higher, but were not significantly different, from those of NP accessions. An unweighted pair-group method arithmetic average dendrogram showed two clusters, one that included all PP accessions, and the other the NP accessions. Genetic differentiation therefore existed between PP and NP accessions, which might be attributed to low gene flow between the NP and PP groups (Nm1.. However, the relation{3.p between genetic distance and geographic distance within each group, although not statistically significant in this study, might be associated with high gene flow in both the NP and PP groups.

关键词： genetic relationship Haloxylon ammodendron ISSR marker parasitism.

The Design of GECAM Scientific Ground Segment

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Research in Astronomy and Astrophysics 2024年第10期24卷 1-10页

作者： shijie Zheng Liming Song Xiang {1. Ping Wang Rui Qiao Yue Huang Xiaoyun Zhao Hongmei Zhang Xiaobo Li Mingyu Ge Gang Chen Gongxing Sun Wenxi Peng Ce Cai Wei Chen Yanqi Du Dongya Guo Bing Li Chaoyang Li Jianhui Li Qingxin Li Jing Liang Jiacong Liu Ge Ou Dongli shi Jingyan shi Xinying Song Jin Wang Wenshuai Wang Hong Wu Shuo Xiao Wangchen Xue Min Yao Jianying ye Kai Zhang Peng Zhang Xiaolu Zhang Yanqiu Zhang Guoying Zhao shiyi Zhao Chao Zheng Shaolin Xiong Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Southwest Jiaotong University Chengdu 611756China Xiangtan University Changsha 411105China Qufu Normal University Qufu 273165China

The Gravitational wave burst high-energy Electromagnetic Counterpart All-sky Monitor(GECAM)is a dedicated mission for monitoring high-energy *** we report the design of the GECAM Scientific Ground Segment(GSGS)in terms of the scientific requirements,including the architecture,the external interfaces,the main function,and *** from the analysis and verification results during the commissioning phase,the GSGS functions well and is able to monitor the status of the payloads,adjust the parameters,develop the scientific observation plans,generate the scientific data products,analyze the data,***,the on-orbit operation and scientific researches of GECAM are guaranteed.

关键词： gravitational waves gamma-rays:general telescopes