检索结果-南通市图书馆

Chinese Journal of Polymer Science 2020年第9期38卷 973-982,I0007页

作者： Dong Zhao shu-xi shan Meng Zhang xiao-A Zhang Sheng-Ling Jiang Ya-Fei Lyu Key Laboratory of Carbon Fiber and Functional Polymers of Ministry of Education College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Vinyl-containingtitanium-silphenylene-sioxane oligomers(O1,O2,O3,andO4)withdifferent molar ratios of titanium to silicon were successfully synthesized in high yields by nonhydrolytic sol-gel reaction,and the obtained four oligomers were further crosslinked with methylphenyl hydro-silicone oil(4)to form corresponding polymers(P1,P2,P3,and P4)by hydrosilylation *** structures were characterized with spectroscopic characterization techniques including FTIR,1H-NMR,and Raman *** effect of titanium element on crosslinking behavior,thermal resistance,refractive index,transparency,thermal aging stability,glass transition temperature,and surface properties of the polymers were *** with titanium-free polymer P1,the thermal resistance,refractive index,and thermal aging stability of titanium-silphenylene-siloxane polymers(P2,P3,and P4)were significantly *** titanium-silphenylene-siloxane polymers achieved a high refractive index(n=1.580-1.584)and thermostability(Tsd>500℃).In thermal aging,the polymers exhibited superior performances with high optical transparency(~90%at 450 nm)and exhibited high thermal stability(~84%at 450 nm after thermal aging at 150℃for 120 h).These data indicate that the polymers have potential application in optical materials such as LED encapsulants.

关键词： Titanium-silphenylene-siloxane hybrid polymers High refractive index and transmittance Thermal stability

A Novel Fuzzy Direct Torque Control System for Three-level Inverter-fed Induction Machine

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2010年第1期7卷 78-85页

作者： shu-xi Liu Ming-Yu Wang Yu-Guang Chert shan Li State Key Laboratory of Power Transmission Equipment % Systems Security and New Technology Chongqing University Chongqing 400044 PRC School of Electronic Information and Automation Chongqing University of Technology Chongqing 400050 PRC

Diode clamped multi-level inverter （DCMLI） has a wide application prospect in high-voltage and adjustable speed drive systems due to its low stress on switching devices, low harmonic output, and simple structure. However, the problem of complexity of selecting vectors and capacitor voltage unbalance needs to be solved when the algorithm of direct torque control （DTC） is implemented on DCMLI. In this paper, a fuzzy DTC system of an induction machine fed by a three-level neutral-point-clamped （NPC） inverter is proposed. After introducing fuzzy logic, optimal selecting switching state is realized by applying various strategies which can distinguish the grade of the errors of stator flux linkage, torque, the neutral-point potential, and the position of stator flux linkage. Consequently, the neutral-point potential unbalance, the dr/dr of output voltage and the switching loss are restrained effectively, and desirable dynamic and steady-state performances of induction machines can be obtained for the DTC scheme. A design method of the fuzzy controller is introduced in detail, and the relevant simulation and experimental results have verified the feasibility of the proposed control algorithm.

关键词： Multi-level inverter direct torque control (DTC) fuzzy controller space voltage vector induction machine

Influence of Isotope Effects on Product Polarizations of N(~2D)+D_2, N(~2D)+H_2 and N(~2D)+HD Reactive Systems

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2012年第5期28卷 897-902页

作者： NIE shan-shan CHU Tian-shu State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023P.R.China Institute for Computational Sciences and Engineering Laboratory of New Fiber Materials and Modern Textilethe Growing Base for State Key LaboratoryQingdao UniversityQingdao 266071P.R.China

To figure out the influence of isotope effect on product polarizations of the N（2D）＋D2 reactive system and its isotope variants, quasi-classical trajectory（QCT） calculation was performed on Ho＇s potential energy surface（PES） of 2A″ state. Product polarizations such as product distributions of P（θr）, P（φr） and P（θr,φr）, as well as the generalized polarization-dependent differential cross sections（PDDCSs） were discussed and compared in detail among the four product channels of the title reactions. Both the intermolecular and intramolecular isotope effects were proved to be influential on product polarizations.

关键词： Isotope effect Product polarization Quasi-classical trajectory calculation Potential energy surface

High shear stress-induced pulmonary hypertension alleviated by endothelial progenitor cells independent of autophagy

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2015年第2期11卷 171-176页

作者： Bi-Jun Xu Jian Chen xi Chen xi-Wang Liu shu Fang Qiang shu Lei Hu shan-shan Shi Li-Zhong Du Lin-Hua Tan Department of Cardiothoracic Surgery Children's HospitalZhejiang University School of Medicine3333 Binsheng RoadHangzhou 310051China Department of Cardiothoracic Surgery Sir Run Run Shaw HospitalZhejiang University School of MedicineHangzhou 310016China The First Affiliated Hospital of Zhejiang Chinese Medical University Hangzhou 310006China Central Laboratory Children's HospitalZhejiang University School of MedicineHangzhou 310051China Department of SICU Children's HospitalZhejiang University School of MedicineHangzhou 310051China

Background:Pulmonary hypertension(PH)is a progressive disease characterized by lung endothelial cell dysfunction and Vascular *** progenitor cells(EPCs)have been proved to be a potential therapeutic strategy to treat *** has been found to be protective to hypoxia-induced *** this study,we applied high shear stress(HSS)-induced PH,and examined whether EPCs confer resistance against HSS-induced PH through ***:Pulmonary microvascular endothelial cells(PMVECs)were cultured under HSS with pro-inflammatory factors in an artificial capillary system to mimic the PH *** of p62,a selective autophagy substrate,were quantified by western *** viability was determined by trypan blue exclusion ***:The p62 level in PMVECs was increased at 4 hours after HSS,peaked at 12 hours and declined at 24 *** cell viability gradually *** with PMVECs cultured by empty medium,in cells cultured by EPC-conditioned medium(EPC-CM),the cell viability was significantly higher;however,p62 levels were also significantly higher,suggesting inhibition of autophagy by *** choloquine to suppress autophagy decreased the cell viability of PMVECs under ***:EPC-CM could suppress the autophagic activity of PMVECs in HSS-induced ***,suppression of autophagy leads to ceil *** could fight against PH through cellular or molecular pathways independent of *** it is not proved if induction of autophagy could be a potential strategy to treat HSS-induced PH as hypoxia-induced PH.

关键词： autophagy endothelial progenitor cells pulmonary hypertension

New specimens of Stenocybus acidentatus(Therapsida: Dinocephalia) from the Middle Permian Dashankou Fauna of China

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

Acta Geologica Sinica(English Edition) 2014年第3期88卷 730-737页

作者： JIANG shan JI shu-an Institute of Geology Chinese Academy of Geological Sciences Key Laboratory of Stratigraphy and Paleontology Ministry of Land and Resources

The basal dinocephalian clade Stenocybusidae was known from two incomplete specimens representing one generus,Stenocybus,from Dashankou fanua in Yumen,Gansu Province of *** holotype of Stenocybus acidentatus is laterally compressed,making some characters *** we describe two new specimens of Stenocybus acidentatus from the same locality,an anterior portion of skull with articulated jaws,and a right dentary with nearly complete *** show some detailed features on the morphology of the premaxilla,maxilla,nasal,external nares and *** phylogenetic relationship between Stenocybus acidentatus and the relatively large Sinophoneus yumenensis is still difficult to determine,and needs more new complete material and further evidences.

关键词： Dinocephalia Stenocybusidae Dashankou Fauna Middle Permian

Visualization of cristae and mtDNA interactions via STED nanoscopy using a low saturation power probe

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第9期13卷 1741-1756页

作者： Wei Ren xichuan Ge Meiqi Li Jing Sun Shiyi Li shu Gao Chunyan shan Baoxiang Gao Peng xi Department of Biomedical Engineering National Biomedical Imaging CenterCollege of Future TechnologyPeking UniversityBeijing 100871China Key Laboratory of Analytical Science and Technology of Hebei Province College of Chemistry and Material ScienceHebei UniversityBaoding 071002China School of Life Sciences Peking UniversityBeijing 100871China National Center for Protein Sciences Peking UniversityBeijing 100871China

Mitochondria are crucial organelles closely associated with cellular metabolism and *** DNA(mtDNA)encodes a variety of transcripts and proteins essential for cellular ***,the interaction between the inner membrane(IM)and mtDNA remains elusive due to the limitations in spatiotemporal resolution offered by conventional microscopy and the absence of suitable in vivo probes specifically targeting the ***,we have developed a novel fluorescence probe called HBmito Crimson,characterized by exceptional photostability,fluorogenicity within lipid membranes,and low saturation *** successfully achieved over 500 frames of lowpower stimulated emission depletion microscopy(STED)imaging to visualize the IM dynamics,with a spatial resolution of 40 *** utilizing dual-color imaging of the IM and mtDNA,it has been uncovered that mtDNA tends to habitat at mitochondrial tips or branch points,exhibiting an overall spatially uniform ***,the dynamics of mitochondria are intricately associated with the positioning of mtDNA,and fusion consistently occurs in close proximity to mtDNA to minimize pressure during cristae *** healthy cells,>66%of the mitochondria are Class III(i.e.,mitochondria>5μm or with>12 cristae),while it dropped to<18%in *** dynamics,orchestrated by cristae remodeling,foster the even distribution of ***,in conditions of apoptosis and ferroptosis where the cristae structure is compromised,mtDNA distribution becomes *** findings,achieved with unprecedented spatiotemporal resolution,reveal the intricate interplay between cristae and mtDNA and provide insights into the driving forces behind mtDNA distribution.

关键词： metabolism saturation utilizing

The Nature of Bonding in PtC and PtN

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

Chinese Chemical Letters 2001年第6期12卷 541-544页

作者： xiao Guang xiE Xue Mei GAO Shi xi LUI Huai CAO shu shan DAI Department of Chemistry Yunnan University Kunming 650091 Modern Biological Center Yunnan University Kunming 650091

The nature of bonding in the title compounds has been studied by using CASSCF and FOCI techniques. The ground states of PtC and PtN are found to be (1)Sigma (+) and (2)Pi state arising primarily from:... 1 sigma (2)2 sigma (2)1 pi (4)1 delta (4)3 sigma (2) and...1 sigma (2)2 sigma (2)1 pi (4)1 delta (4)3 sigma (2)2 pi (1) configuration respectively and both of which form triple bond tone sigma, two pi bonds), but the bond of PtC is much stronger than that of PtN.

关键词： PtC and PtN nature of bonding molecular constants CASSCF FOCI

An Intrinsic Model for the Polarization Position Angle Swing Observed in QSO 1150+812

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2004年第1期4卷 37-50页

作者： shan-JieQian xi-ZhenZhang NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012

The rapid polarization position angle swing of ~ 180° observed in QSO 1150+812 at 2cm by Kochenov and Gabuzda is quite a regular event. One interesting property of the event is that, during the time of the swing the polarized flux density remained almost constant. We suggest that such an event can be explained in terms of a relativistic thin shock propagating through a uniform helical magnetic field, giving rise to relativistic aberration effects as the transverse field component rotates. The model may also be applicable to other similar events in which variations in polarization are not accompanied by variations in total flux density.

关键词： radio continuum: galaxies polarization quasars: individual: QSO 1150+812

The Nature of Bonding in WC and WN

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2001年第7期12卷 655-658页

作者： Xue Mei GAO Shi xi LIU xiao Guang xiE Huai CAO shu shan DAI Department of Chemistry Yunnan University Kunming 650091 Modern Biological Center Yunnan University Kunming 650091

The nature of bonding in the title compounds has been studied by using CASSCF and FOCI techniques. The ground states of WC and WN are found to be 3Δ and 4∑- state arising primarily from:...1(22(21(41(13(1 and ...1(22(21(41(23(1 configuration respectively. WC shows a strong character of covalent bond while WN have obvious character of ionic bond and the dissociation energy of WN is larger than that of WC (6.15 and 5.41 eV respective).

关键词： WC and WN nature of bonding molecular constants CASSCF FOCI

Theoretical Study of Haloacetonitrile Anions： CH2XCN^- （X=F, Cl）

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2008年第3期21卷 255-262页

作者： xin-wen Zhang Mei Li shan-xi Tian Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technologyof China Hefei 230025 China Department of Chemical Physics University of Science and Technology of China Hefei 230026China

Haloacetonitrile anions CH2XCN- （X=F, Cl） were studied by HF-SCF, Becke3-LYP, and MP2 methods together with the Dunning＇s basis set aug-cc-PVTZ. The vertical electron attachments to the neutral are endothermic. The geometrically optimized CH2FCN^- is mainly a valence-bounded anion and CH2FCN→CH2CN＋F^- is a nonadiabatic dissociation. This theoretical study in good agreement with the experimental results shows that the Becke3-LYP method is reasonable in describing the electronic structures of anions and dissociative attachment dynamics, while significant differences between MP2 and Becke3-LYP results are shown for the dissociation potential curves of CH2ClCN→CH2CN＋Cl^-.

关键词： Haloacetonitrile Electron attachment Dissociation dynamics Electron correlation effect