检索结果-南通市图书馆

Rare Metals 2002年第1期21卷 12-19页

作者： MO Zunli, CHEN hong and GAO Jinzhang Institute of Chemistry, Northwest normal {2., Lanzhou 730070, china Institute of Chemistry Northwest Normal University Lanzhou 730070

The bicyclic cryptand 1,4,7, 10,13,16,2., 2.-octaaza-bigcyclo [8, 8,8] hexacosan-3, 8, 12. 17, 2., 2.-hex-one (COBH) bearing diaminoethane groups along the eight-atom bridges was synthesized. The structure consists of discrete neutral macrobicyclic units; the two cycles share the two tertiary amine nitrogen atoms, which exhibit an endo-cndo conformation. Three identical branches formed by 1, 2.diaminoethane link the two tertiary amine groups. The protonation reactions of cryptand (COBH) and its complex formation with copper (II) were investigated by potentiometry in water and in a DMSO/water (80:2. in mass ratio) mixture as solvents. The cryptand acts as a his-base through its two N-bridgehead and exhibits a strong cooperativity that favors the first protonation and makes the second one difficult (△pK= 5.0). An inward rotation of the amide groups to form hydrogen bonds accounts for this cooperativity. The interaction of COBH with copper (II) leads to several binuclear complex proton contents.

关键词： COBH(cryptand 1,4,7, 10, 13, 16, 2., 2.-octaaza-bigcyclo hexacosan -3, 8, 12. 17,2.,2. - hex-one) macrobicyclic acid-base behavior complex formation proton contents

Electrochemical characteristics of CoSn_x alloy composite anode for lithium-ion rechargeable batteries

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2006年第Z1期25卷 369-373页

作者： GUO hong ZHAO Hailei JIA Xidi QIU Weihua School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Department of Chemistry and Biology Qujing Normal University Qujing 655000 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Nano/micro-scaled CoSnx alloy powders synthesized via carbothermal reduction at 800 ℃ with different compositions were characterized for anode materials in Li-ion battery. The synthesized spherical CoSnx particles show a loose nano/micro sized particle structural characteristic, which is apparently favorable for the improvement of cycling stability. The prepared CoSn3 alloy composite electrode exhibits a low initial irreversible capacity of ca.130 mAh·g-1 and a high specific capacity of ca.440 mAh·g-1 at constant current density of 100 mA·g-1. The relatively large particle size is considered to be the main reason for the lower irreversible capacity of CoSn3 electrode.

关键词： CoSnx composite anode materials carbothermal reduction Li-ion rechargeable batteries

Effect of P145^(INK4b/MTS2. on the proliferation of human hepatoma cells SMMC-772.

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2000年第15期45卷 1408-1412页

作者： ZHANG hong, LIU Huitu & SHI Fawu1. Key Laboratory of Cell Proliferation and Regulation Biology, beijing normal university, {2. 100875, china 2. Institute of Basic Medical Science, General Hospital of People’s Liberation Army LA, {2. 100039, china 3. Institute of Medical Information, Medical Academy of china, {2. 10002., china Correspondence should be addressed to Liu Huitu Key Laboratory of Cetl Proliferation and Regulation Biology Beijing Normal University Beijing China Institute of Medical Information Medical Academy of China Beijing China Institute of Basic Medical Science General Hospital of People’s Liberation Army LA Beijing China

The full length cDNA coding for P15 INK4b, which is a cyclin-dependent kinase inhibitor, was cloned to plasmid PXJ41-neo (Eco R I IXho 1 site) and the new constructed plasmid pXJp15 was obtained. pXJp15 was transferred into the human hepatoma SMMC-772. cells by lipofectine reagent. After G418 selection, a series of cell lines stably expressing high levels of P15 (named SHT) and the clone containing vector PXJ41-neo only (named SVXJ) were obtained by Northern and Western analysis. The results showed that the proliferation of SHT cells is inhibited compared with that of SVXJ cells. Cell cycle analysis indicated that overexpressing of P15 inhibited the growth of SHT cells by decreasing progrssion of cells from G1 to S and G2.to M phases. The levels of c-Myc and c-Fos were obviously decreased in SHT cells compared with control cells by Western blotting. The decreased expression of oncogene may be one of the molecular mechanisms of the effect of P15 on the proliferation of in SHT cells.

关键词： CKIP15 human hepatoma cell cycle oncogene.

FREE-SURFACE WAVES AND FAR WAKES GENERATED BY A FLOATING BODY IN A VISCOUS FLUID

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2003年第4期15卷 10-16页

作者： Lu Dong-qiang Department of Mechanical Engineering, The university of hong Kong, hong Kong, china Shanghai Institute of Applied mathematics and Mechanics, Shanghai university, Shanghai 2.0072. china Dept. of Mech. Eng. Univ. of Hong Kong Hong Kong Hong Kong Inst. of Appl. Math. and Mech. Shanghai Univ. Shanghai 200072 China

The free-surface waves and the flow field due to a body moving on the surfaceof an incompressible viscous fluid of infinite depth were studied analytically. The floating bodywas modeled as a normal point pressure on the free surface. Based on the Oseen approximation forgoverning equations and the linearity assumption for boundary conditions, the exact solutions inintegral form for the free-surface elevation, the velocities and the pressure were given. Byemploying Lighthill's two-stage scheme, the asymptotic representations in far field for largeReynolds numbers were derived explicitly. The effect of viscosity on the wave profiles was expressedby an exponential decay factor, which removes the singular behavior predicted by the potentialtheory.

关键词： free-surface waves velocity distribution floating body viscosity asymptotic representation light-hill's two-stage scheme

Optimizing near-carbon-free nuclear energy systems:advances in reactor operation digital twin through hybrid machine learning algorithms for parameter identification and state estimation

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第8期35卷 177-203页

作者： Li‑Zhan hong He‑Lin Gong hong‑Jun Ji Jia‑Liang Lu Han Li Qing Li Paris Elite Institute of Technology Shanghai Jiao Tong UniversityShanghai 200240China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610041China

Accurate and efficient online parameter identification and state estimation are crucial for leveraging digital twin simulations to optimize the operation of near-carbon-free nuclear energy *** previous studies,we developed a reactor operation digital twin(RODT).However,non-differentiabilities and discontinuities arise when employing machine learning-based surrogate forward models,challenging traditional gradient-based inverse methods and their *** study investigated deterministic and metaheuristic algorithms and developed hybrid algorithms to address these *** efficient modular RODT software framework that incorporates these methods into its post-evaluation module is presented for comprehensive *** methods were rigorously assessed based on convergence profiles,stability with respect to noise,and computational *** numerical results show that the hybrid KNNLHS algorithm excels in real-time online applications,balancing accuracy and efficiency with a prediction error rate of only 1%and processing times of less than 0.1 ***,algorithms such as FSA,DE,and ADE,although slightly slower(approximately 1 s),demonstrated higher accuracy with a 0.3%relative L_2.error,which advances RODT methodologies to harness machine learning and system modeling for improved reactor monitoring,systematic diagnosis of off-normal events,and lifetime management *** developed modular software and novel optimization methods presented offer pathways to realize the full potential of RODT for transforming energy engineering practices.

关键词： Parameter identification State estimation Reactor operation digital twin Reduced order model Inverse problem

Correlation between inhibition of calcium-dependent apoptosis by cyclosporin A and calcium transportation in HL-60 cells

在线全文

学校读者我要写书评

暂无评论

Cell Research 1996年第1期6卷 23-30页

作者： HUANG QI QING MING FANG hong QING ZHANG SHAO BAI XUE(Department of Biology, beijing normal university, {2. 100875, china.) Department of Biology Beijing Normal University Beijing China

Both calcium ionophore A2.187 and endoplasmic reticulum Ca2.- ATPase inhibitor thapsigargin (Tg) could increase intracellular free calcium concentration and induce apoptosis in some cell lines. In the present study, we found that HL-60 cells treated with A2.187 (1μg/ml) for 4 h or with Tg (0.5μg/ml) for 2.h showed typical characteristics of apoptosis. Pretreatment with nontoxic concentration of cyclosporin A (CsA) (1μg/ml) Could block these effects. Flow cytometric analysis of intracellular Ca2. after staining with fluo-3 AM showed that CsA did not prevent the increase of intracellular calcium induced by A2.187 or Tg, but it could maintain the high level of intracellular Ca2. for a long time. These results suggest that CsA may prevent calcium- induced apoptosis by blocking the transportation of Ca2. in HL-60cells.

关键词： Cyclosporin A calcium ionophore A2.187 thapsigargin apoptosis intracellular calcium

Features and distribution patterns of Chinese endemic seed plant species

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systematics and Evolution 2011年第2期49卷 81-94页

We compiled and identified a list of Chinese endemic seed plant species based on a large number of published references and expert reviews. The characters of these seed plant species and their distribution patterns were described at length. china is rich in endemic seed plants, with a total of 14 939 species (accounting for 52.1% of its total seed plant species) belonging to 1584 genera and 191 families. Temperate families and genera have a significantly higher proportion of endemism than cosmopolitan and tropical ones. The most primitive and derived groups have significantly higher endemism than the other groups. The endemism of tree, shrub, and liana or vine is higher than that of total species; in contrast, the endemism of herb is lower than that of total species. Geographically, these Chinese endemic plants are mainly distributed in Yunnan and Sichuan provinces, southwest china. Species richness and proportion of these endemic plants decrease with increased latitude and have a unimodal response to altitude. The peak value of proportion of endemism is at higher altitudes than that of total species and endemic species richness. The proportions of endemic shrub, liana or vine, and herb increase with altitude and have a clear unimodal curve. In contrast, the proportion of tree increases with altitude, with a sudden increase at ～4000 m and has a completely different model. To date, our study provides the most comprehensive list of Chinese endemic seed plant species and their basic composition and distribution features.

关键词： biodiversity conservation distribution pattern endemism flora of china seed plants.

Quantum chemical study on the thermal rearrangements of HNCRCR'CO

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1996年第2期14卷 105-108页

作者： LI,Yong-hong hong,San-GuoDepartment of Chemistry,Jiangxi {2. university,Nanchang,Jiangxi 330017,china Department of Chemistry Jiangxi Normal University Nanchang Jiangxi 330027 China

MINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'*** results obtained show that the activation energy of this rearrangement depends on the migrating group R and the group R'.

关键词： Thermal rearrangement MINDO/3 MO method transition state intrinsic reaction coordinate (IRC)

Local Dissipativity and Attractors for the Evolutionary Superconductivity Problem

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2001年第3期17卷 381-390页

作者： hong Jun GAO Department of mathematics,Nanjing {2. university,Nanjing 2.002.,P.R.china E-mail:gaohj@hotmail.comJi Shan FAN Department of Alathernatics,Suzhou university,Suzhou 2.5006.P.R.china Department of mathematics Nanjing Normal University Nanjing 210024 P. R. China

In this paper,under the Lorenz gauge,the global existence,local dissipativity and at- tractors of the evolutionary superconductivity problem which is a parabolic-hyperbolic system are obtained.

关键词： Superconductivity Attractor Ginzburg-Landau system

Extending Structures for Gel'fand-Dorfman Bialgebras

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第2期40卷 619-638页

作者： Jia Jia WEN Yan Yong hong School of mathematics Hangzhou Normal UniversityHangzhou 311121P.R.China

Gel'fand-Dorfman bialgebra,which is both a Lie algebra and a Novikov algebra with some compatibility condition,appeared in the study of Hamiltonian pairs in completely integrable *** also emerged in the description of a class special Lie conformal algebras called quadratic Lie conformal *** this paper,we investigate the extending structures problem for Gel'fand-Dorfman bialgebras,which is equivalent to some extending structures problem of quadratic Lie conformal ***,given a Gel'fand-Dorfman bialgebra(A,o,[.,.]),this problem is how to describe and classify all Gel'fand-Dorfman bialgebra structures on a vector space E(A⊂E)such that(A,o,[.,.])is a subalgebra of E up to an isomorphism whose restriction on A is the identity *** by the theories of extending structures for Lie algebras and Novikov algebras,we construct an object gH2.V,A)to answer the extending structures problem by introducing the notion of a unified product for Gel'fand-Dorfman bialgebras,where V is a complement of A in *** particular,we investigate the special case when dim(V)=1 in detail.

关键词： Gel'fand-Dorfman bialgebra Lie conformal algebra Extending structures problem Novikovalgebra