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Geochronology and Petrogenesis of Late Carboniferous to Early Permian Basalts in the Central Lhasa Subterrane, Southern Tibet: Implications for the Evolution of the Sumdo Paleo-Tethys Ocean

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 955-968页

作者： MA Wang liU Yingchao YANG Zhusen Jan-Marten HUIZENGA li zhenqing YUE Longlong ZHAO Sibo School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China Institute of Geology Sinoprobe LaboratoryChinese Academy of Geological SciencesBeijing 100037China MLR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesNO-1432ÅsNorway Economic Geology Research Centre(EGRU) College of Science and EngineeringJames Cook UniversityTownsvilleQueensland 4811Australia Department of Geology University of JohannesburgAuckland Park 2006South Africa

Basalts from the Late Carboniferous to Early Permian are extensively developed in the central Lhasa subterrane, southern Tibet. Studying the petrogenesis of these rocks may have implications for the late Paleozoic arc magmatism along the central Lhasa subterrane uncovering more of the evolution of the Sumdo Paleo-Tethys Ocean and its dynamic mechanism. Basalt samples from the Luobadui Formation in the Leqingla area, NW of linzhou City in the central Lhasa subterrane, southern Tibet exhibit arc-like geochemical signatures in a subduction-zone tectonic setting characterized by high Al_(2)O_(3) and low TiO_(2) contents, fractionated REE patterns with low Nb/La ratios and high LREE concentrations, and negative HFSE anomalies. Based on their higher Th/Ce, Nb/Zr, and lower Ba/Th, Pb/Nd ratios, slightly negative to positive ε_(Nd)(t) values, and the relatively high Sr-Pb isotopic compositions, these samples were probably derived from partial melting of a depleted mantle source of garnet + spinel lherzolite, metasomatized by subducted sediments around 297 Ma. Modeling of the trace elements indicates that these basalts experienced fractional crystallization of olivine, clinopyroxene and minor plagioclase during magma ascent and eruption. It is proposed that these Late Carboniferous–Early Permian basalts are associated with the northward subduction of the Sumdo Paleo-Tethys Ocean seafloor along the southern margin of the central Lhasa subterrane.

关键词： geochemistry northward subduction Sumdo Paleo-Tethys Ocean Lhasa terrane Tibet

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POX1 regulates the formation of viable but non-culturable brewer’s yeast induced by iso-alpha acid from hops

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Food Science and Human Wellness 2024年

作者： Zengyan Wang Yang Xiao Xuchen li zhenqing li Yan Wang Wei He Jiayang Wang li liu Ting Ding Pengdong Sun Jingyuan li Yang Deng Shandong Technology Innovation Center of Special Food 4. Qingdao Special Food Research Institute Key Laboratory of Special Food Processing (Co-construction by Ministry and Province)， Ministry of Agriculture Rural Affairs， Qingdao Agricultural University School of Food Engineering， Qingdao Institute of Technology College of Food Science and Engineering， Qingdao Agricultural University Shandong Huifa Foodstuff Co.， Ltd.

In this study， we utilized gene knockout and overexpression techniques to generate brewer’s yeast strains with either a deletion or overexpression of the POX1 gene. The strains studied included the parental strain， the POX1 deletion strain， and the POX1 overexpression strain. These strains were exposed to iso-alpha acid from hops at a concentration of 300 mg/L， leading to the induction of a viable but non-culturable (VBNC) state. Our results indicated that the silencing of the POX1 gene rendered brewer’s yeast cells unable to withstand the high concentration of iso-alpha acid stress， ultimately leading to cell death. Conversely， the overexpression of POX1 accelerated the transition of yeast cells into the VBNC state compared to the parental strain. Furthermore， we evaluated the levels of reactive oxygen species (ROS)， catalase (CAT) activity， superoxide dismutase (SOD) activity， glutathione reductase (GR) activity， and the mRNA expression of genes that regulate these enzymes (SYM1， CTA1， SOD1， and GLR1) in brewer’s yeast cells at three distinct stages: normal， short-term stress， and VBNC states. Based on these findings， it can be inferred that the formation of the VBNC state in brewer’s yeast is associated with the response to oxidative stress.

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Aqueous-phase hydrogenation of levulinic acid over carbon layer protected silica-supported cobalt-ruthenium catalysts

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Chinese Journal of Chemical Engineering 2021年第10期34卷 114-122页

作者： lihua Qian Guojun Lan Xiaoyan liu zhenqing li Ying li Institute of Industrial Catalysis Zhejiang University of TechnologyHangzhou 310014China

The hydrogenation of levulinic acid(LA)to c-valerolactone(GVL)by using water as solvent is a crucial process in the production of fine chemicals from *** ultrathin carbon layer coating CoRu bimetallic catalyst supported on silica(CoRu@C/SiO2)is prepared by using tannis-ligated cobalt-ruthenium complex on silica as precursors,and applied for catalyzed synthesis of GVL from *** of the synergistic effect between cobalt and ruthenium,the addition of small amounts of Ru to Co catalysts can increase the catalytic activity in the aqueous hydrogenation of *** ultrathin carbon layer covered on the CoRu bimetallic catalyst can greatly reduce the leaching of active *** CoRu@C/SiO2 catalyst achieves high stability and is reused up to 5 runs without significant loss of performance in aqueous hydrogenation of levulinic acid.

关键词： Levulinic acid Hydrogenation Cobalt-ruthenium Synergistic effect Carbon coating

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Immobilization of insulin-like growth factor-1 onto thermosensitive hydrogels to enhance cardiac progenitor cell survival and differentiation under ischemic conditions

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Science China Chemistry 2014年第4期57卷 568-578页

作者： li zhenqing XU YanYi li HaiChang GUAN JianJun Department of Materials Science and Engineering The Ohio State University Davis Heart and Lung Research Institute The Ohio State University

Stem cell therapy is a promising approach to treat myocardial infarction. However, direct delivery of stem cells into hearts experiences poor cell engraftment and differentiation, due to ischemic conditions （low nutrient and oxygen） in the infarct hearts. Development of suitable cell carriers capable of supporting cell survival and differentiation under these harsh conditions is critical for improving the efficacy of current stem cell therapy. In this work, we created a family of novel cell carriers based on thermosensitive hydrogels and insulin-like growth factor 1 （IGF-1）, and investigated if these cell carriers can improve cell sur- vival and differentiation under ischemic conditions. The thermosensitive hydrogels were synthesized from N-isopropylacryla- mide, acrylic acid, acrylic acid N-bydroxysuccinicimide ester, and 2-hydroxyethyl methacrylate-oligo（hydroxybutyrate）. The hydrogel solutions can be readily injected through 26G needles, and can quickly solidify at 37 ~C to form highly flexible hy- drogels. IGF-I was immobilized into the hydrogels in order to support long-term cell survival and differentiation. Different amount of IGF- 1 was immobilized by using hydrogels with different content of N-hydroxysuccinicimide ester groups. Cardio- sphere derived cells were encapsulated in the hydrogels and cultured under ischemic conditions. The results demonstrated that a significant improvement of cell survival and differentiation was achieved after IGF-1 immobilization. These IGF-1 immobi- lized hydrogels have the potential to improve cell survival and differentiation in infarct hearts.

关键词： thermosensitive hydrogels cardiosphere derived cells myocardial infarction cardiac differentiation stem cells

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Mineralogy and Chemistry of Sulfides from the Longqi and Duanqiao Hydrothermal Fields in the Southwest Indian Ridge

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Acta Geologica Sinica(English Edition) 2018年第5期92卷 1798-1822页

作者： ZHANG Baisong li zhenqing HOU Zengqian ZHANG Weiyan XU Bo China University of Geosciences Beijing 100083 Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 Second Institute of Oceanography State Oceanic Administration Hangzhou 310012

Recent investigations found that hydrothermal activity and sulfide mineralization occurs along the Southwest Indian Ridge（SWIR）. The Longqi and Duanqiao hydrothermal fields between 49° E and 53° E of the SWIR are two prospective mineralization areas discovered by Chinese scientists. With the aim to determine the mineralogical and chemical characteristics of sulfide minerals, we have conducted detailed studies for samples from the two areas using an optical microscope, X-ray diffractometer, scanning electron microscope, and electron microprobe. The mineralization processes in the Longqi area are divided into three main stages：（1） the low-medium-temperature stage： colloform pyrite（Py I）＋ marcasite → euhedral pyrite（Py II）,（2） the high-temperature stage： isocubanite（±exsolved chalcopyrite）＋ pyrrhotite → coarse-grained chalcopyrite（Ccp I）, and（3） the medium–low-temperature stage： sphalerite ＋ fine-grained chalcopyrite inclusions（Ccp II） → aggregates of anhedral pyrite（Py III） ± marcasite → Fe-oxide（-hydroxide）＋ amorphous silica. The mineralization processes in the Duanqiao area are divided into two main stages：（1） the medium–high-temperature stage： subhedral and euhedral pyrite（Py I′） → coarse-grained chalcopyrite（Ccp I′） and（2） the medium–low-temperature stage： sphalerite → fine-grained chalcopyrite（Ccp II′）＋ chalcopyrite inclusions（Ccp II′） → silica-cemented pyrite（Py II′）＋ marcasite → Fe-oxide ＋ amorphous silica. We suggest that the fine-grained chalcopyrite inclusions in sphalerite from Longqi and Duanqiao were formed by co-precipitation and replacement mechanisms, respectively. Primary sphalerites from both fields are enriched in Fe（avg. 5.84 wt% for the Longqi field vs. avg. 3.69 wt% for the Duanqiao field）, Co（avg. 185.56 ppm for the Longqi field vs. 160.53 ppm for the Duanqiao field）, and Cd（avg. 1950 ppm for the Longqi field vs. avg. 525.26 ppm for the Duanqiao field）. Cu contents in pyrite from the Duanqiao field（Py I′： avg. 849.23 ppm and Py II′： avg. 11

关键词： mineralogy mineralogical chemistry Longqi Duanqiao Southwest Indian Ridge(SWIR)

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The Zhaxikang Vein-type Pb-Zn-Ag-Sb Deposit in Himalayan Orogen, Tibet： Product by Overprinting and Remobilization Processes during Post-collisional Period

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Acta Geologica Sinica(English Edition) 2018年第2期92卷 682-705页

作者： liANG Wei HOU Zengqian ZHENG Yuanchuan YANG Zhusen li zhenqing Chengdu Center China Geological Survey Chengdu 610082 China Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China China university of geosciences Beijing 100037 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 10003 7 China

The Zhaxikang Pb-Zn-Ag-Sb deposit, the largest polymetallic deposit known in the Himalayan Orogen of southern Tibet, is characterized by vein-type mineralization that hosts multiple mineral assemblages and complicated metal associations. The deposit consists of at least six steeply dipping vein- type orebodies that are hosted by Early Jurassic black carbonaceous slates and are controlled by a Cenozoic N-S-striking normal fault system. This deposit records multiple stages of mineralization that include an early period （A） of massive coarse-grained galena-sphalerite deposition and a later period （B） of Sb-bearing vein-type mineralization. Period A is only associated with galena-sphalerite mineralization, whereas period B can be subdivided into ferrous rhodochrosite-sphalerite-pyrite, quartz -sulfosalt-sphalerite, calcite-pyrite, quartz-stibnite, and quartz-only stages of mineralization. The formation of brecciated galena and sphalerite ores during period A implies reworking of pre-existing Pb -Zn sulfides by Cenozoic tectonic deformation, whereas period B mineralization records extensive open- space filling during ore formation. Fluid inclusion microthermometric data indicate that both periods A and B were associated with low-medium temperature （187-267℃） and low salinity （4.00-10.18% wt. NaCl equivalent） ore-forming fluids, although variations in the physical-chemical nature of the period B fluids suggest that this phase of mineralization was characterized by variable water/rock ratios. Microprobe analyses indicate that Fe concentrations in sphalerite decrease from period A to period B, and can be divided into three groups with FeS concentrations of 8.999-9.577, 7.125-9.109, 5.438-1.460 mol.%. The concentrations of Zn, Sb, Pb, and Ag within orebodies in the study area are normally distributed in both lateral and vertical directions, and Pb, Sb, and/or Ag concentrations are positive correlation within the central part of these orebodies, but negatively correlate in th

关键词： polymetallic multiple period and stage mineralization overprinting and remobilization,orogenic belt Zhaxikang Tibet

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油气场所电动机接地常见问题与标准化做法研究

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石油工程建设 2024年第1期50卷 84-88页

作者：孔令超李振清刘军李江张铁君李影中国石油华北油田公司质量安全环保监督中心河北任丘062552 石油天然气华北工程质量监督站河北任丘062552 中国石油华北油田分公司河北任丘062552

电动机保护接地的可靠性是关系到人身安全和生产运行稳定的重要保证,但施工过程质量检查及生产过程的安全检查中发现较多接地做法不规范而失去防护功能的情况。通过阐述油气田站场内电动机安装或运行中常见质量安全问题,分析其功能及保... 详细信息

电动机保护接地的可靠性是关系到人身安全和生产运行稳定的重要保证,但施工过程质量检查及生产过程的安全检查中发现较多接地做法不规范而失去防护功能的情况。通过阐述油气田站场内电动机安装或运行中常见质量安全问题,分析其功能及保护工作原理,对标规范要求并结合实践经验,探讨电动机的标准化、样板化做法,以提高设备运行的可靠性和观感质量,并从根源避免因电动机接地问题而引起触电事故发生。

关键词：油气田电动机接地质量安全

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THE DYNAMICAL MODELS OF ACTIVATED SLUDGE SYSTEM： STOCHASTIC CELLULAR AUTOMATON AND DIFFERENTIAL EQUATIONS

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International Journal of Biomathematics 2012年第5期5卷 261-275页

作者： JINBAO liAO HUI LU zhenqing li XINZHU MENG GORAN ENGLUND State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 P. R. China Graduate University of Chinese of Academy Sciences Beijing 100049 P. R. China College of Information Science and EngineeringShandong University of Science and Technology Qingdao 266510 P. R. China Department of Ecology and Environmental Science Ume5 Marine Sciences Centre Umed University SE-901 87 UmeS Swede

A stochastic celhflar automaton （CA） model for activated sludge system （ASS） is for- mulated by a series of transition functions upon realistic treatment processes, and it is tested by comparing with ordinary differential equations （ODEs） of ASS. CA system performed by empirical parameters can reflect the characteristics of fluctuation, com- plexity and strong non-linearity of ASS. The results show that the predictions of CA are approximately similar to the dynamical behaviors of ODEs. Based on the extreme experimental system with complete cell recycle in model validation, the dynamics of biomass and substrate are predicted accurately by CA, but the large errors exist in ODEs except for integrating more spatially complicated factors. This is due to that the strong mechanical stress from spatial crowding effect is ignored in ODEs, while CA system as a spatially explicit model takes account of local interactions. Despite its extremely simple structure, CA still can capture the essence of ASS better than ODEs, thus it would be very useful in predicting long-term dynamics in other similar systems.

关键词： Cellular automaton activated sludge system ordinary differential equations dynamic models wastewater treatment.

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Effects of resource availability on the trade-off between seed and vegetative reproduction

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Journal of Plant Ecology 2010年第4期3卷 251-258页

作者： Lanke Fu Shichang Wang Zhenguo liu Ivan Nijs Keping Ma zhenqing li State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China Graduate University of Chinese of Academy Sciences Beijing 100049China School of life Sciences Shanghai UniversityShanghai 200444China Research Group of Plant and Vegetation Ecology Department of BiologyUniversity of AntwerpCampus Drie EikenUniversiteitsplein 1B-2610 WilrijkBelgium

Aims To explore whether the trade-off between seed and vegetative reproductive modes is flexible in environments with different amounts of available resources to maintain optimal *** A transition matrix model was established to determine the optimal trade-off between seed and vegetative reproduction in resources–variable *** Findings The model predicts that plants allocate more resources to seed reproduction when available resources are *** increasing resources,more vegetative propagules are ***,if resources keep increasing to a harmful level,plants would switch to seeds again.

关键词： sexual reproduction vegetative reproduction trade-off resource

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Robust transport of charge carriers in in-plane 1T′-2H MoTe_(2) homojunctions with ohmic contact

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Nano Research 2021年第5期14卷 1311-1318页

作者： Donglin Lu zhenqing li Congsheng Xu Siwei Luo Chaoyu He Jun li Gang Guo Guolin Hao Xiang Qi Jianxin Zhong Hunan Key Laboratory for Micro-Nano Energy Materials and Devices Laboratory for Quantum Engineering and Micro-Nano Energy Technologyand School of Physics and OptoelectronicsXiangtan UniversityHunan411105China

Metal-semiconductor ohmic contacts are required to reduce the energy dissipation for two-dimensional (2D) electronic devices, and phase engineering of 2D transition-metal dichalcogenides (TMDCs) is a promising approach for building ohmic contacts. Here, 2D in-plane 1T′-2H MoTe2 homojunctions were prepared by direct epitaxy via vapor deposition. The interface properties of in-plane 1T′-2H MoTe2 homojunction were investigated in detail by combining experiments, calculations and theories. The ohmic contact properties of 1T′-2H MoTe2 homojunction were proved according to Kelvin force probe microscopy and density functional theory calculations. The charge carriers robust transport in in-plane 1T′-2H MoTe2 homojunction without Fermi-level pinning can be well described by Poisson equation and band alignment. These results indicate that phase engineering of 2D TMDCs is promising to construct ohmic contacts for device applications.

关键词： 1T′-2H MoTe_(2)homojunction ohmic contact surface potential built-in potential

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