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Bioreduction of vanadium(V) in groundwater by autohydrogentrophic bacteria:Mechanisms and microorganisms

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Journal of Environmental Sciences 2015年第4期27卷 122-128页

作者： Xiaoyin Xu siqing Xia Lijie Zhou Zhiqiang Zhang Bruce E.Rittmann State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Swette Center for Environmental Biotechnology Biodesign Institute at Arizona State University Key Laboratory of Yangtze River Water Environment Ministry of Education College of Environmental Science and EngineeringTongji University

As one of the transition metals, vanadium（V）（V（V）） in trace amounts represents an essential element for normal cell growth, but becomes toxic when its concentration is above 1 mg/L. V（V） can alter cellular differentiation, gene expression, and other biochemical and metabolic phenomena. A feasible method to detoxify V（V） is to reduce it to V（IV）, which precipitates and can be readily removed from the water. The bioreduction of V（V） in a contaminated groundwater was investigated using autohydrogentrophic bacteria and hydrogen gas as the electron donor. Compared with the previous organic donors,H2 shows the advantages as an ideal electron donor, including nontoxicity and less production of excess biomass. V（V） was 95.5% removed by biochemical reduction when autohydrogentrophic bacteria and hydrogen were both present, and the reduced V（IV）precipitated, leading to total-V removal. Reduction kinetics could be described by a first-order model and were sensitive to p H and temperature, with the optimum ranges of p H 7.5–8.0 and 35–40°C, respectively. Phylogenetic analysis by clone library showed that the dominant species in the experiments with V（V） bioreduction belonged to theβ-Proteobacteria. Previously known V（V）-reducing species were absent, suggesting that V（V）reduction was carried out by novel species. Their selective enrichment during V（V）bioreduction suggests that Rhodocyclus, a denitrifying bacterium, and Clostridium, a fermenter known to carry out metal reduction, were responsible for V（V） bioreduction.

关键词： Vanadium Bioreduction Hydrogen Rhodocyclus Clostridium

Study on removing selenate from groundwater by autohydrogenotrophic microorganisms

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Frontiers of Environmental Science & Engineering 2013年第4期7卷 552-558页

作者： siqing XIA Shuang SheN Jun LIANG Xiaoyin XU State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China

Performance of autohydrogenotrophic bac- teria for bio-reduction of selenate （Se（VI）） under anaerobic conditions was investigated with batch experiments. Results showed Se（VI） was bio-reduced to selenite （Se（IV）） as an intermediate product, and then to elemental selenium （Se）. Reduction kinetics could be described by the pseudo-first-order model. In particular, the influences of pH value and temperature on Se（VI） reduction by autohydrogentrophic organisms were examined. The high degradation rate was achieved at pH 7.0 to 8.0; and the best reduction temperature was between 25℃ and 35℃. This study is of help for treating groundwater with selenium contamination by autohydrogenotrophic bacteria as well as its reactor development.

关键词： autohydrogenotrophic selenate hydrogen,groundwater

Improved GNSS Cooperation Positioning Algorithm for Indoor Localization

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Computers, Materials & Continua 2018年第8期56卷 225-245页

作者： Taoyun Zhou Baowang Lian siqing Yang Yi Zhang Yangyang Liu School of Electronics and Information Northwestern Polytechnical UniversityShaanxi710072China School of Information Hunan University of HumanitiesScience and TechnologyHunan417000China Radio Science Laboratory University of British ColumbiaVancouverCanada

For situations such as indoor and underground parking lots in which satellite signals are obstructed,GNSS cooperative positioning can be used to achieve highprecision positioning with the assistance of cooperative *** we study the cooperative positioning of two static nodes,node 1 is placed on the roof of the building and the satellite observation is ideal,node 2 is placed on the indoor windowsill where the occlusion situation is more serious,we mainly study how to locate node 2 with the assistance of node ***,the two cooperative nodes are located with pseudo-range single point positioning,and the positioning performance of cooperative node is analyzed,therefore the information of pseudo-range and position of node 1 is ***,the distance between cooperative nodes is obtained by using the baseline method with double-difference carrier ***,the cooperative location algorithms are *** Extended Kalman Filtering(EKF),Unscented Kalman Filtering(UKF)and Particle Filtering(PF)are used to fuse the pseudo-range,ranging information and location information *** to the mutual influences among the cooperative nodes in cooperative positioning,the EKF,UKF and PF algorithms are improved by resetting the error covariance matrix of the cooperative nodes at each update *** results show that after being improved,the influence between the cooperative nodes becomes smaller,and the positioning performance of the nodes is better than before.

关键词： Indoor localization GNSS cooperative positioning extended kalman filtering(EKF) unscented kalman filtering(UKF) particle filtering(PF)

Prediction of the smoothed monthly mean sunspot numbers for solar cycle 24

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Science China(Physics,Mechanics & Astronomy) 2008年第12期51卷 1938-1946页

作者： WANG JiaLong MIAO Juan LIU siqing GONG JianCun ZHU CuiLian National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Center for Space Science and Applied Research Chinese Academy of SciencesBeijing 100080China

The prediction for the smoothed monthly mean sunspot numbers (hereafter SMSNs) of solar cycle 23, which was given with a similar cycle method proposed by us at the beginning time of cycle 23, is analyzed and verified in this paper. Using our predicted maximum SMSN and the ascending length for solar cycle 24, and as- suming their relative errors to be respectively 20% and ± 7 months, solar cycles 2, 4, 8, 11, 17, 20 and 23 are selected to be the similar cycles to cycle 24. The selected solar cycles are divided into two groups. The first group consists of all the selected cycles; while the second group consists of only cycles 11, 17, 20 and 23. Two SMSN time profiles then may be obtained, respectively, for the two similar cycle groups. No significant difference is found between the two predicted time profiles. Consid- ering the latest observed sunspot number so far available for cycle 23 and the pre- dictions for the minimum SMSN of cycle 24, a date calibration is done for the ob- tained time profiles, and thus, SMSNs for 127 months of cycle 24, from October 2007 to April 2018, are predicted.

关键词： solar cycle sunspot numbers prediction of cycle 24

IL-33 drives the antitumor effects of dendritic cells via the induction of Tc9 cells

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Cellular & Molecular Immunology 2019年第7期16卷 644-651页

作者： Ning Liu Yuxue Jiang Jintong Chen he Nan Yinghua Zhao Xiao Chu Alison Wang Dongjiao Wang Tianxue Qin Sujun Gao Ying Yue siqing Wang Department of Gynecological Oncology The First Hospital of Jilin UniversityChangchun 130061China Department of Cancer Immunology The First Hospital of Jilin UniversityChangchun 130061China Department of Rheumatology and Immunology China-Japan Union Hospital of Jilin UniversityChangchun 130033China Department of hematology The First Hospital of Jilin UniversityChangchun 130061China and 5 Department of Cancer BiologyLerner Research InstituteCleveland ClinicClevelandOH 44195USA

Dendritic cell(DC)tumor vaccines exert their antitumor effects through the induction of effector T *** recently identified Tc9 cells as a new potent antitumor effector T cell ***,approaches to direct DCs to preferably prime antitumor Tc9 cells should be further ***,we demonstrate that the addition of interleukin(IL)-33 potently promotes the induction of Tc9 cells by DCs in vitro and in ***-33 treatment also drives the cytotoxic activities of DC-induced Tc9 ***,IL-33 treatment enhances cell survival and proliferation of DC-primed CD8+T *** importantly,the addition of IL-33 during in vitro priming of tumor-specific Tc9 cells by DCs increases the antitumor capability of Tc9 *** studies demonstrated that IL-33 treatment inhibits exhaustive CD8+T cell differentiation by inhibiting PD-1 and 2B4 expression and increasing IL-2 and CD127(IL-7 receptor-α,IL-7Rα)expression in CD8+T ***,the addition of IL-33 further promotes the therapeutic efficacy of DC-based tumor vaccines in the OT-I mouse *** study demonstrates the important role of IL-33 in DC-induced Tc9 cell differentiation and antitumor immunity and may have important clinical implications.

关键词： Interleukin-33 Dendritic cells Tc9 Cancer immunology

Partial inhibition of CDK4 gene expression leads to the extension of G1 phase of V79-8 cells

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Chinese Science Bulletin 1999年第2期44卷 149-153页

作者： Weiqun Xiao siqing Zhang Yongchao Wang Yue Wang Beijing Normal Univ Key Lab Cell Proliferat & Regulat Biol Beijing 100875 Peoples R China Natl Univ Singapore Inst Mol & Cell Biol Singapore 117609 Singapore

V79-8 is an abnormal cell line which does not have detectable G1 and G2 phases in its cell *** cell line is derived from V79 cell line which has G1 phase but lacks G2 phase. By using an anti-sense approach, CDK4 gene expression was partially inhibited to find whether CDK4 might contribute to the lack of G1 phase in V79-8 cells. Anti-CDK4 anti-sense plasmid was constructed and used to transfect V79-8 cells. Clones of transfected cells (V79-8-asCDK4) were examined, in comparison with V79-8 cells, to determine its growth curve, cell doubling-time (GT), the level of CDK4 gene expression and the levels of expression of some other growth related genes. V79-8-asCDK4 cells showed a slower growth rate with a doubling time 2.5-h longer than that of V79-8 cells. A flow cytometry (FCM) analysis demonstrated that the 2.5 h increase of the doubling time of V79-8-asCDK4 cells was mainly due to the appearance of G1 phase because its G2+M phase was not significantly different from that of V79-8 cells. The

关键词： CDK4 V79-8 cell line anti-sense and cell doubling time.

Biosorption of Direct Black 38 by dried anaerobic granular sludge

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Frontiers of Environmental Science & Engineering 2008年第2期2卷 198-202页

作者： Xuejiang WANG siqing XIA Jianfu ZHAO State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China

The biosorption of Direct Black 38 by dried anaerobic granular sludge in a batch system under specific temperatures and initial pH was *** adsorption reaction is pH dependent with higher removal at low *** adsorption equilibrium data fit very well with both Langmuir and Freundlich models in the concentration range of Direct Black 38 at all chosen *** adsorption parameters show that the adsorption of Direct Black 38 is an endothermic and more effective process at high *** kinetics of adsorption was found to be second order and adsorption rate constants increased with increasing *** energy was determined as 26.8 kJ/mol for the *** suggests that the adsorption of Direct Black 38 by dried anaerobic granular sludge is chemically controlled.

关键词： biosorption kinetics adsorption isotherms anaerobic granular sludge

Comparison of a new model with previous models for the low-latitude magnetopause size and shape

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Chinese Science Bulletin 2010年第2期55卷 179-187页

作者： LIN RuiLin ZHANG XiaoXin LIU siqing WANG YongLi GONG JianCun Centerfor Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100049 China National Center for Space Weather China Meteorological Administration Beijing 100081 China NASA/Goddard Space Flight Center Greenbelt Maryland 20771 USA

In this study, the advantages and the limitations of previous low-latitude magnetopause empirical models are discussed. In order to overcome their limitations and inherit their advantages, a new continuous function for the influence of the interplanetary magnetic field (IMF) Bz on the magnetopause, the Shue model function and the 613 low-latitude magnetopause crossings are used to construct a new low-latitude magnetopause model parameterized by the solar wind dynamic pressure (Dp) and IMF Bz. In comparison with the previous low-latitude magnetopause models, it is found that the new model improves the prediction capability and has a large range of validity for the low-latitude magnetopause. In addition, it is also demonstrated that the new model and the previous low-latitude magnetopause models are not appropriate for predicting the high-latitude magnetopause.

关键词：磁层顶低纬度国际货币基金组织型号形状行星际磁场经验模型连续函数

Selective laser melted AZ91D magnesium alloy with superior balance of strength and ductility

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Journal of Magnesium and Alloys 2023年第12期11卷 4644-4658页

作者： Xinzhi Li Xuewei Fang Shuaipeng Wang siqing Wang Min Zha Ke Huang State Key Laboratory for Manufacturing Systems Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiPR China School of Materials Science and Engineering Jilin UniversityChangchunPR China

In the context of global carbon neutrality, the application of lightweight magnesium alloys is becoming increasingly attractive. In this study, selective laser melting(SLM) was employed to achieve nearly full dense and crack-free AZ91D components with fine equiaxed grain structure. The formation mechanism of typical pore defects(gas pore, lack-of-fusion pore and keyhole pore) and melting modes(keyhole mode and conduction mode) were systematically studied by varying the laser power and scanning speed. The morphology and volume fraction of the pores under different processing conditions were characterized. A criterion based on the depth-to-width ratio of the melt pool was established to identify different melting modes. The strength and ductility(tensile strength up to 340 MPa and uniform elongation of 8.9%)of the as deposited AZ91D are far superior to those of the casting components and are comparable to those of its wrought *** superior balance of strength and ductility of SLMed AZ91D, as well as the negligible anisotropic properties are mainly ascribed to the extremely fine equiaxed grain structure(with average grain size of ~1.2 μm), as well as the discontinuous distribution of β-Al_(12)Mg_(17) phases. It thus provides an alternative way to fabricate high-strength magnesium alloys with complex geometry.

关键词： Magnesium alloy Selective laser melting Melting mode Defects Equiaxed grain structure Mechanical properties