检索结果-南通市图书馆

Reduction of dinitrogen to ammonia on doped three-atom clusters Nb_(2)M(M=Sc to Cu & Y to Ag)

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第8期43卷 3810-3818页

作者： Ran Cheng Chao-nan Cui zhi-Xun Luo Beijing National Laboratory for Molecular Science(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Science University of Chinese Academy of SciencesBeijing 100049China

Catalytic reduction of dinitrogen to ammonia under mild conditions remains an attractive topic for the purpose of lowering energy ***-atom metal clusters have been proved an ideal model to explore highly efficient catalysts taking advantage of unique geometric/electronic structures and cooperative active *** a study of N2 activation and reduction on seventeen bimetallic Nb_2M(M=Sc to Cu,and Y to Ag) clusters was *** key processes for ammonia fixation(namely nitrogen activation,hydrogenation,and ammonia desorption) are fully studied,and three preferred systems(Nb_2Ni,Nb_2Rh and Nb_2Pd) are highlighted with outstanding catalytic *** d-σ and d-π~* orbital hybridizations between these metal clusters and N_(2) were demonstrated and the internal association with the N≡N bond activation was *** examining the ammonia synthesis on four chosen Nb_(2)M clusters(M=Fe,Ni,Rh and Pd),it can be elucidated that the distal pathway is more favorable than the alternative pathway in these *** work not only clarifies the N_(2) reduction on the bimetallic Nb_(2)M clusters,but also guides efficient bimetallic catalyst design.

关键词： Three-atom cluster catalysis Three-criteria strategy Nitrogen fixation Ammonia synthesis Theoretical calculations

Modification of methyl oleate for silicon-based biological lubricating base oil

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第1期25卷 130-136页

作者： Shixing Cui zhi Yun xia Gui College of Chemistry and Chemical Engineering Nanjing University of Technology Nanjing 210009 China

A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl *** reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring *** order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.

关键词： Methyl oleate Trimethyl chlorosilane Acid binding agent N N-diisopropylethylamine Lubricity Silicon-based biological lubricating base oil

Continuous production of biodiesel from cottonseed oil and methanol using a column reactor packed with calcined sodium silicate base catalyst

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2016年第4期24卷 499-505页

作者： xia Gui Sichen Chen zhi Yun College of Chemistry and Chemical Engineering Nanjing Tech University

Sodium silicate and that calcined at 400℃ for 2 h were used to catalyze the transesterification of cottonseed oil with methanol. Calcined sodium silicate （CSS） catalyst exhibited much higher catalytic activity and stability. A maximum biodiesel yield of 98.9~ was achieved at methanol/oil mole ratio of 12：1, reaction temperature 65℃, reaction time 3.0 h, and CSS/oil mass ratio of 2 Wffo. After 7 consecutive reactions without any treatment, biodiesel yield reduced to 82.5%. Considering technological and economic feasibility, CSS base catalyst supported on 0 rings was prepared for continuous transesterification. The maximum yield was 99.1% under optimum conditions （reaction temperature 55 ~C, methanol velocity 1 ml. rain- 1, oil velocity 3 ml- rain- 1, and 5 tower sec- tions）. These results indicate that this new continuous biodiesel production process and apparatus present a great potential for industrial application in biodiesel.

关键词： TransesterificationCottonseed oilCalcined sodium silicateBiodieselSodium silicateContinuous production

A Train-Bridge Dynamic Interaction Analysis Method and Its Experimental Validation

在线全文

学校读者我要写书评

暂无评论

Engineering 2016年第4期2卷 528-536页

作者： nan Zhang Yuan Tian He xia School of Civil Engineering BeijingJiaotong University Beijing 100044 China

The train-bridge dynamic interaction problem began with the development of railway technology, and requires an evaluation method for bridge design in order to ensure the safety and stability of the bridge and the running train. This problem is studied using theoretical analysis, numerical simulation, and experimental study. In the train-bridge dynamic interaction system proposed in this paper, the train vehicle model is established by the rigid-body dynamics method, the bridge model is established by the finite element method, and the wheel/rail vertical and lateral interaction are simulated by the corresponding assumption and the Kalker linear creep theory, respectively. Track irregularity, structure deformation, wind load, collision load, structural damage, foundation scouring, and earthquake action are regarded as the excitation for the system. The train-bridge dynamic interaction system is solved by inter-history iteration. A case study of the dynamic response of a CRH380BL high-speed train running through a standard-design bridge in China is discussed. The dynamic responses of the vehicle and of the bridge subsystems are obtained for speeds ranging from 200 km-b-1 to 400 km.h-1, and the vibration mechanism are analyzed.

关键词： Train-bridge dynamic interaction Wheel/rail relationship Inter-history iteration Field measurement Experimental validation

Sulfur dioxide gas sensing at room temperature based on tin selenium/tin dioxide hybrid prepared via hydrothermal and surface oxidation treatment

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2021年第6期40卷 1588-1596页

作者： Qian-nan Pan zhi-Min Yang Wei-Wei Wang Dong-zhi Zhang College of Control Science and Engineering China University of Petroleum(East China)Qingdao 266580China

In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation *** as-prepared sample was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM).A series of morphological and structural characteristics confirm that the SnSe/SnO_(2) NPs composite shows a core-shell structure with a SnO_(2) shell with thickness of 6 *** prepared SnO_(2) NPs and SnSe/SnO_(2) NPs composite were applied as gas-sensing materials,and their gas-sensing properties were investigated at room temperature *** results show that the response value of the SnSe/SnO_(2) composite sensor toward 100×10^(-6) SO_(2) is 15.15%,which is 1.32 times higher than that of pristine SnSe(11.43%).And the SnSe/SnO_(2) composite sensor also has a detection limit as low as 74×10^(-9) and an ultra-fast response *** enhanced gas-sensing performance is attributed to the formation of p-n heterojunction between SnSe and SnO_(2) and the appropriate SnO_(2) shell thickness.

关键词： SO_(2)gas sensor Room temperature detection Core-shell structure SnSe/SnO_(2)composite Debye length

A Novel Statistical Manifold Algorithm for Position Estimation

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2019年第6期6卷 1513-1518页

作者： Bin xia Wenhao Yuan nan Xie Caihong Li the School of Computer Science and Technology Shandong University of Technology

In this paper, a novel statistical manifold algorithm is proposed for position estimation of sensor nodes in a wireless network, making full use of distance information available among unknown nodes and simultaneous localization of multiple unknown nodes. To begin, a ranging model including the distance information among unknown nodes is established. With the reparameterization of the natural parameter and natural statistic,the solution problem of the ranging model is transformed into a parameter estimation problem of the curved exponential ***, a natural gradient method is adopted to deal with the parameter estimation problem of the curved exponential *** ensure the convergence of the proposed algorithm, a particle swarm optimization method is utilized to obtain initial values of the unknown nodes. Experimental results indicate that the proposed algorithm can improve the positioning accuracy, compared with the traditional algorithm.

关键词： Natural gradient particle swarm optimization(PSO) ranging model statistical manifold(SM)

IFT52 plays an essential role in sensory cilia formation and neuronal sensory function in Drosophila

在线全文

学校读者我要写书评

暂无评论

Insect Science 2023年第4期30卷 1081-1091页

作者： Ya-nan Hou Ying-Ying Zhang Ya-Ru Wang zhi-Mao Wu Yun-xia Luan Qing Wei Center for Energy Metabolism and Reproduction Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina Shenzhen Key Laboratory of Metabolic Health ShenzhenGuangdong ProvinceChina Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Institute of BiotechnologyShanxi UniversityTaiyuanChina Guangzhou Key Laboratory of Insect Development Regulation and Application Research Institute of Insect Science and TechnologySchool of Life SciencesSouth China Normal UniversityGuangzhouGuangdongChina

Cilia are microtubule-based,hair-like organelles involved in sensory function or motility,playing critical roles in many physiological processes such as reproduction,or-gan development,and sensory *** insects,cilia are restricted to certain sensory neurons and sperms,being important for chemical and mechanical sensing,and *** great progress has been made regarding the mechanism of cilia assembly,the formation of insect cilia remains poorly understand,even in the insect model organism *** transport(IFT)is a cilia-specific complex that traffics protein cargos bidirectionally along the ciliary axoneme and is essential for most *** we investigated the role of IFT52,a core component of IFT-B,in cilia/flagellar formation in *** show that Drosophila IFT52 is distributed along the sensory neuronal cilia,and is essential for sensory cilia *** of Ift52 results in severe defects in cilia-related sensory *** should be noted that IFT52 is not detected in sper-matocyte cilia or sperm flagella of ***,ift52 mutants can produce sperms with normal motility,supporting a dispensable role of IFT in Drosophila sperm flagella ***,IFT52 is a conserved protein essential for sensory cilia formation and sensory neuronal function in insects.

关键词： Drosophila IFT52 sensory cilia sperm flagella

GIS-based Analysis of Main Air Pollutants of Changchun City in Summer

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2006年第4期22卷 447-450页

作者： JING nan xia Bin JING Ti-song Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 P. R. China Graduate School of Chinese Academy of Sciences Beijing 100039 P. R. China College of Environment and Resource Jilin University Changchun 130026 P. R. China

To gain a better understanding of the characteristics of air pollution of Changchun city, P. R. China, in summer, the analytical methods of geographical information system（GIS） and statistical analysis software SPSS were applied to the analysis of the monitored concentrations of SO2 , NO2, and O3 in July of 2002 to 2004 in Changchun city. The results obtained show that the average hourly O3 concentrations in July 2002 and 2004 were higher than the firstlevel hourly standard of China. At the same time, the dynamic distribution of the 03 concentration and the relationship between the concentration of 03 and that of NOx were studied. The air quality evaluation result of Changchun city indicates that the southwest of this city was heavily polluted during the monitored period.

关键词： Air pollutant Dynamic distribution Ozone Summer of Changchun city GIS

Synthesis and Evaluation of a Novel Small-molecule Compound as an Anticancer Inhibitor of CD147

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2019年第9期32卷 673-686页

作者： FU zhi Guang WANG Yan WANG Shuang SHAO Dan TIAN Li LI Yun xia JIANG Jian Li CHEN zhi nan WEN Ning Department of Stomatology Chinese PLA General HospitalBeijing 100850China Cell Engineering Research Center&Department of Cell Biology State Key Laboratory of Cancer BiologyNational Key Discipline of Cell BiologyFourth Military Medical UniversityXi'an 710032ShaanxiChina Department of Internal Neurology 309 Hospital of PLABeijing 100091China Department of Stomatology Huangdao District Central HospitalQingdao266000ShandongChina Department of Anesthesiology&Perioperative Medicine Xijing HospitalFourth Military Medical UniversityXi'an 710032ShaanxiChina Outpatient Department Special Police College of the Chinese Armed Police ForceBeijing 100621China

Objective Cancer is a serious threat to human health. Despite extensive research on cancer treatment,there is a growing demand for new therapies. CD147 is widely involved in tumor development, but it is unclear whether cancer cell malignancy is affected by CD147 expression level. The first compound(AC-73) targeting CD147 could only act on advanced tumors and inhibit metastasis. Therefore, new compounds with better anticancer activity should be *** Wst-1 assays were used to confirm the effect of novel compounds on *** tests were used to evaluate their proapoptotic capacity. A nude mouse model was used to demonstrate in vivo anticancer activity and safety of the compounds. Western blots were used to suggest a molecule *** There is a positive correlation between CD147 expression and tumor cell proliferation. A new compound, HA-08, was synthesized and proved to be more active than AC-73. HA-08 could inhibit cancer cell viability and promote cancer cell apoptosis both in vitro and in vivo. HA-08 induces cancer apoptosis, mainly by disrupting the CD147-CD44 interaction and then down-regulating the JAK/STAT3/Bcl-2 signaling *** Our results have clarified the tumor specificity of CD147 and its drug target *** biological profile of HA-08 suggests that this compound could be developed as a potential anticancer agent.

关键词： Antigens CD147 Antineoplastic agents Apoptosis