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A New Three-Dimensional Superstructure in Bafertisite

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Acta Geologica Sinica(English Edition) 2011年第5期85卷 1028-1035页

作者： LI Guowu~*,XIONG Ming,shi nicheng and ma zhesheng Crystal structure laboratory,National Laboratory of Mineral materials,china university of geosciences (beijing),beijing 100083,china Crystal structure laboratory National Laboratory of Mineral Materials China University of Geosciences (Beijing) Beijing 100083 China *Correspondence: Guowu LI *Correspondence: Corresponding author. E-mail: liguowu@***

A new superstructure was found in bafertisite[(Ba;Na;);(Fe;Mn;Mg;);TiO [(Si;Ti;Al;Cr;);O;](OH;F;Cl;);]from Donghai County,Jiangsu Province,*** occurrence of the superstructure reflections were observed by single crystal diffraction using a SmaR APEX *** a;,b;and c;axis directions revealed extra weak reflection spots of the *** apparent 2a,2b and 2c superstructure is monoclinic with unit cell a=10.6502.1.） A,b= 13.7233（19）A,c=21.6897（3）A,α=90°,β=94.698（3）°,γ=90°,space group Cm,Z=*** c;extra weak reflections are ignored,the secondary supercell gave a cell a=10.6548（15）A,b=13.7284（19）A,c = 11.6900（17）A,α=90°,β=112.322（28）°,γ=90°,space group Cm,Z=*** basic subcell was obtained by ignoring all extra weak reflection spots and gave:a=5.3249（17）A,b=6.8669（22）A,c=10.8709（36） A,α=90°,β=94.740（62）°,γ=90°,space P2;/m,Z=*** superstructure has been refined to R = 0.063 for 7805[R;= 0.0266]unique reflections I>2δ（I）.The structure consists of an octahedra（O） sheet sandwiched between two heteropolyhedral（H） *** sheets consist of Ti-octahedra and twin tetrahedral disilicate groups[Si;O;].The O sheet comprises（Fe,Mg）O;*** large Ba cation is located in the interlayer *** refined structure shows Fe,Mg are partly *** shifting of the TiO;octahedron and SiO;tetrahedron sites in the sheet may be a consequence of the superstructure.

关键词： bafertisite superstructure crystal structure layered titanium silicate

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 shi 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

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 nicheng1, ma {2.1, XIONG Ming1, DAI Mingquan1, BAI Wenji2, FANG Qingsong2, YAN Binggang2 & YANG Jingsui2.1. X-ray Diffraction Laboratory, china university of geosciences, beijing 100083, china 2. Institute of Geology, Chinese Academy of Geological Sciences, beijing 100037, 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 (Fe4.12Cr3.84Ni0.96)8.92C3.70 and the simplified formula is (Fe4Cr4Ni)4C9. The mineral is hexagonal with a = 1.38392(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 12, 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 0.1893—0.2169 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.

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,shi nicheng1,XIONG Ming1,FAN Haifu3 and SHENG Ganfu4 1 china university of geosciences(beijing),beijing 100083 2.1. university of geosciences(Wuhan),Wuhan,Hubei 430074 3 Institute of Physics,Chinese Academy of Sciences,beijing 100080 4 Chengdu Institute of Geology and Mineral Resources,Chengdu,Sichuan 610082

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 Ce4Fe2Ti3Si4O22. The crystals are monoclinic with the unit cell parameters a = 13.4656(15) ?, b = 5.7356(6) ?, c = 11.0977(12) ?, β= 100.636(2)o, V = 842.39 (16) ?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 relationship 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 relationship 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

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 1476.9±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 3706.7±552.0μg h^(−1)cm^(−2)at a current density of 100 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

Efficacy and safety of transvaginal mesh repair in a cohort with a minimum of 10-year follow-up

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Science china(Life Sciences) 2024年第5期67卷 1061-1068页

作者： Zhibo Zhang Jianbin Guo Weijie Tian ye Zhang Yuelun Zhang Tianshu Sun Jiali Duan Xinmiao Bao Yuan Wang Yang ye Qianqian Gao Honghui shi Abraham Nick Morse Juan Chen Lan Zhu Departmentof Obstetrics and Gynecology Peking Union MedicalCollege HospitalChinese Academyof Medical Sciences&Peking Union MedicalCollegeNational Clinical Research Center for Obstetricand Gynecologic DiseasesBeijing 100730China Department of Gynecology Guizhou Provincial People’s HospitalMedical College of Guizhou UniversityGuiyang 550002China Department of Obstetrics and Gynecology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000China Medical Research Center Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Medical Doctor Program Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Department of Pathology Peking Union Medical College HospitalBeijing 100730China Tufts university School of Medicine Boston MA 02111USA

Although transvaginal mesh(TVM)repair is no longer used in some countries,long-term outcomes after TVM surgery are of great importance ***,reports with follow-up>10 years are ***,this study aimed to report outcomes in a prospective cohort with at least 10 years of *** with stageⅢ–Ⅳsymptomatic prolapse were approached consecutively from 2008 to 2.1. at one tertiary *** main outcome measure was symptomatic *** outcomes included anatomic failure,recurrence,patient satisfaction,complications,and *** Kaplan-Meier curve was used to estimate the cumulative failure *** the 121 patients enrolled in the study,103(85.1%)completed a median follow-up of 11 *** estimated probability rates of symptomatic and anatomic failure were 17.6%and 8.8%in 11 years,*** estimated incidence of symptomatic failure increased by 8.2%between 5 and 11 years;however,the corresponding rate for anatomic failure was 3.7%.The most common complication was vaginal mesh exposure,and its estimated probability increased from 19.3%to 28.4%from 5 to 11 years,*** trimming resolved 80.0%of vaginal *** patients did not report decreased overall *** with vaginal mesh exposure requiring>3 office procedures or mesh removal in the operating room(5.8%by 11 years)had lower satisfaction rates(P1)and were defined as having severe mesh *** rates of postoperative pain,reoperation,and Patient Global Impression of Improvement≥2 were 2.5%,3.3%,and 94.2%,*** results of this study implied that TVM treatment gradually increased the symptomatic failure rate but provided durable anatomical support of the vaginal *** mesh exposure was common in women who were largely not sexually active;however,80%of the cases could be managed in the outpatient clinic,which did not affect patient satisfaction.

关键词： complication efficacy long-term follow-up pelvic organ prolapse safety transvaginal mesh

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 nicheng, ma zhesheng, DAI Mingquan and XIONG Ming (1. Institute of Geology, Chinese Academy of Geological Sciences, beijing 100037, china 2. Geological university of china, beijing 100083, 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. 82Si0.18)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=0.6415, with a molar volume about 5 % smaller than rutile (JCPDS, 21-1276). 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.

THE SYNTHESIS AND CRYSTAL STRUCTURE OF NdBr₃（i-C₃H₇OH）₂（THF）₂

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Chinese Chemical Letters 1994年第3期5卷 255-258页

作者： Hong ye SUN Chun Hui HUANG and Guang Xian XU(Research Center of Rare Earth Chemistry,Peking university, beijing 100871)Zhe Sheng ma and Ni Cheng shi(china university of Geoscience, beijing 100083)

The title complex was synthesized under N2 and the crystal structure was determined by Xray diffraction method. This compound crystallized in the monoclinic system (12/a) with unit cell dimensions a=13. 313(2) A, b=10. 105(2) k, c=16. 652 (4) A,β=91. 43 (2)°, V= 2239. 5(4) A3, Z=8. The final R value is 0. 087. The three bromide ions and four oxygen atoms from THF and isopropanol are coordinated to the central Nd(Ⅲ) ion to give a pentagonal bipyramid polyhedron with coordination number 7.

关键词： i-C3H7OH THF THE SYNTHESIS AND CRYSTAL STRUCTURE OF NdBr3

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

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

作者： 1,2,3Xu-Mei WANG 1Dong-ye YANG 4Yong-Zhen TIAN 5Peng-Fei TU 2Qi-shi SUN 1Xiao-Bo LI 1(School of Pharmacy, Shanghai Jiao Tong university, Shanghai 200240, china) 2(College of Traditional Chinese materia Medica, Shenyang Pharmaceutical university, Shenyang 110016, china) 3(School of Medicine, Xi’an Jiaotong university, Xi’an 710061, china) 4(Forest and Desert Control Research Institute of Alxa League, Alxa League 750306, china) 5(Modern Research Center of Traditional Chinese Medicine, School of Pharmaceutical Sciences, Peking university, beijing 100083, 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 relationships among six accessions of H. ammodendron with a total of 120 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 relationship 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.