检索结果-南通市图书馆

Chinese Journal of Polymer Science 2007年第6期25卷 545-553页

作者： li-ming Tang ji Feng Yu Wang Advanced Materials Laboratory Department of Chemical Engineering Tsinghua University Beijing 100084 China

Five secondary amine terminated poly（ester-amine）s （defined as PEA） with controlled molecular structures were synthesized through reacting excessive piperazine with phthalicdiglycol diacrylate （PDDA） and 1,1,1-trimethylolpropane triacrylate （TMPTA） at a constant secondary amine/acrylate group ratio of 1.5/1 and at different PDDA/TMPTA molar ratios. Both IR and ^1H-NMR spectra indicated that all acrylate groups were consumed in the reaction, based on which the structural parameters were calculated from the ^1H-NMR spectra. With decreasing PDDA/TMPTA ratio, the content of secondary amine, degree of branching, molecular weight, Tg and Td increased accordingly. These polymers were further used as both crosslinkers and flexibilizers for a linear epoxy resin E51 to form cured films under ambient condition. The gel content, relative hardness and Tg of the resulting films increased as PEA molecules changed from linear to highly branching structures. Due to the flexibility of PEA molecules, all the films possessed excellent mechanical performance.

关键词： Poly(ester-amine) Molecular structure Epoxy resin Cured film.

The Monotone Method for Controllability of the Nonlinear Evolution Systems

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2011年第4期27卷 721-726页

作者： Yue LU Yong li ming-ji liU College of Mathematics Jilin University Changchun 130012 China

In this paper, we study the controllability of the nonlinear evolution systems. We establish the controllability results by using the monotone operator theory. No compactness assumptions are imposed in the main result... 详细信息

关键词： controllability monotone operator nonlinear control systems

Neurotoxicity of prenatal alcohol exposure on medullary pre-B?tzinger complex neurons in neonatal rats

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2015年第7期10卷 1095-1100页

作者： ming-li ji Yun-hong Wu Zhi-bin Qian Department of Physiology Xinxiang Medical University Department of Functional Laboratory Xinxiang Medical University

Prenatal alcohol exposure disrupts the development of normal fetal respiratory function, but whether it perturbs respiratory rhythmical discharge activity is unclear. Furthermore, it is unknown whether the 5-hydroxytryptamine 2A receptor（5-HT2AR） is involved in the effects of prenatal alcohol exposure. In the present study, pregnant female rats received drinking water containing alcohol at concentrations of 0%, 1%, 2%, 4%, 8% or 10%（v/v） throughout the gestation period. Slices of the medulla from 2-day-old neonatal rats were obtained to record respiratory rhythmical discharge activity. 5-HT2 AR protein and m RNA levels in the pre-B？tzinger complex of the respiratory center were measured by western blot analysis and quantitative RT-PCR, respectively. Compared with the 0% alcohol group, respiratory rhythmical discharge activity in medullary slices in the 4%, 8% and 10% alcohol groups was decreased, and the reduction was greatest in the 8% alcohol group. Respiratory rhythmical discharge activity in the 10% alcohol group was irregular. Thus, 8% was the most effective alcohol concentration at attenuating respiratory rhythmical discharge activity. These findings suggest that prenatal alcohol exposure attenuates respiratory rhythmical discharge activity in neonatal rats by downregulating 5-HT2 AR protein and m RNA levels.

关键词： nerve regeneration brain injury prenatal alcohol exposure pre-B?tzinger complex respiratory depression neonatal rats medullary slice medullary respiratory center respiratory rhythmical discharge activity respiratory neuron 5-hydroxytryptamine 2A receptor neural regeneration

Cooperative Dynamics in Lattice-Embedded Scale-Free Networks

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第9期52卷 411-415页

作者： SHANG li-Hui ZHANG ming-ji YANG Yan-Qing Department of Control Science and Engineering University of Shanghai for Science and Technology Shanghai 200093China

We investigate cooperative behaviors of lattice-embedded scale-free networking agents in the prisoner'sdilemma game model by employing two initial strategy distribution mechanisms,which are specific distribution to themost connected sites (hubs) and random *** study indicates that the game dynamics crucially dependson the underlying spatial network structure with different strategy distribution *** cooperators' specificdistribution contributes to an enhanced level of cooperation in the system compared with random one,and cooperationis robust to cooperators' specific distribution but fragile to defectors' specific ***,unlike the specificcase,increasing heterogeneity of network does not always favor the emergence of cooperation under random ***,we study the geographical effects and find that the graphically constrained network structure tends toimprove the evolution of cooperation in random case and in specific one for a large temptation to defect.

关键词： geographical networks prisoner's dilemma cooperation heterogeneity

Enhancement of Activity of SnO_(2)-doped In_(2)O_(3)/Al_(2)O_(3) Catalyst for NO Reduction with Propene in the Presence of H_(2)O and SO_(2)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2005年第11期16卷 1535-1538页

作者： Xiang Yu CUI Jun Hua li ji ming HAO li Xin FU Department of Environmental Science and Engineering Tsinghua University Beijing 100084

The novel bimetallic Sn-Im/Al2O3 catalysts prepared by three methods for NO reduction by propene were investigated. The results showed that the catalytic activity was enhanced significantly in the presence of H2O on sol-gel catalyst, and the maximum NO conversion increased from 46% to 92%, even in the presence of 100 ppm SO2, NO conversion was still 80%.

关键词： Selective catalytic reduction De-NOx lean burn In2O3/Al2O3 Sn-Ir/A12O3.

Estimating health damage cost from secondary sulfate particles—a case study of Hunan Province,China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2003年第5期15卷 611-617页

作者： HAO ji ming, li ji, YE Xue mei, ZHU Tian le (Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. ) Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

China's coal dominated energy pattern has resulted in large amount of SO 2 emissions. Estimate of the sulfur related health damage cost is necessary to help perform systematic cost benefit analysis and set national energy and emissions control priorities. Current researches were confined to gaseous SO 2 in urban areas; however, secondary sulfate (SO 2- 4) particles can exert serious impact in a wider region. Based on the concept of “intake fraction', CALPUFF long range dispersion model and 180 sample emission sources, multiple regression equation was obtained with good correlation( r =0 85), which illustrates that populations were key parameters to determine intake fraction but source characteristics were insignificant. Based on the formula and the population distribution data, county level intake fractions were mapped for Hunan Province(range: 1 1×10 -6 -3 2×10 -6 ) of China. A combination of county level SO 2 emissions with the intake fractions yields a total 1 98 tons of sulfate(SO 2- 4) inhalation, and resulting total health damage cost to be 0 76(willingness to pay approach, WTP) or 0 16(human capital approach, HC) billion USD in 1997, about 2.1% or 0 45% of GDP in Hunan in 1997. Average health damage cost per ton of SO 2 emission is 930(WTP) or 200 USD(HC). The results demonstrated that more stringent regulation should be forced.

关键词： intake fraction health impact Hunan Province sulfate regression analysis

Study of nitrogen doping behavior in diamond film

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2008年第6期4卷 433-436页

作者： li ming-ji YANG Bao-he SUN Da-zhi jiN Zeng-sun Tianjin Key Laboratory for Film Electronic and Communication Device Tianjin University of Technology Tianjin 300191 China State key Laboratory of Superhard Materials Jilin University Changehun 130012 China

Nitrogen-doped diamond films have been synthesized by EA-CVD （electron assisted chemical vapor deposition） technique. The quality and nitrogen impurity states of the diamond films are characterized by SEM, raman spectroscopy, XPS and EPR speclroscopy, respectively. The results show that the morphology changes from well-defined facets to cauliflower-like structures, the content of amorphous carbon increases and the quality drops with increasing the nitrogen flow rate. Furthermore, in the films, it can be observed that nitrogen impurity exists in the forms ofNs^0, [N-V]^0 and [N-V]^1. The contents of [N-V]^0 and [N-V]^-1 are lower when the nitrogen flow rate is relatively high, and the concentration of Ns^0 varies from 15 ppm to 483 ppm.

关键词：氮掺杂物金刚石薄膜物理研究

Manufacture the conducting polymer with light

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 8-9页

作者： Yang li Tianyu li Yan ji Baoguang liu College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology) Nanjing University of Posts & Telecommunications

Poly(3,4-ethylenedioxythiophene) (PEDOT), heralded as the “king” of conducting polymers, is esteemed in bioelectronics for its mixed electronic and ionic conductivity, mechanical properties compatible with biological tissues, tunable healing ability and stability in diverse environments [1]. Based on additive manufacturing of three-dimensional structures,PEDOT realizes the implementation in the efficient production of flexible bioelectronics, the construction of intricate electrode-neural implantations, and the development of smart brain-computer-interfaces [2].

关键词：

Endoscope-Assisted Cerebellopontine Angle Surgery

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 Otology 2009年第1期4卷 44-49页

作者： YANG Shi-ming,YU li-Mei,ZOU Yi-hui,YU li-ming,ji Fei,YANG Wei-yan,HAN Dong-yi Dept.Otolaryngology Head and Neck Surgery,Institute of Otolaryngology,Chinese PLA General Hospital,Beijing 100853 Dept. Otolaryngology Head and Neck Surgery Institute of Otolaryngology Chinese PLA General Hospital Beijing 100853

Objective To report experiences with use of otoendoscopy in cerebellopontine angle(CPA) *** Twenty five cases of CPA surgeries performed between November 2002 and December 2008 in which microscope enabled otoendoscopy was used were *** 25 cases included 19 cases of acoustic neuroma,3 cases of CPA facial nerve tumors,1 case of trigeminal neurinoma,a case of glossopharyngeal neuralgia and 1 case of hemifacial *** was used in all cases together with monitoring of brainstem auditory responses and facial *** hearing and facial nerve function were evaluated and compared to pre-operative *** Endoscopy provided improved visualization of local anatomy,revealed hidden lesions and reduced unnecessary anatomical *** resection was achieved in 18 of the 19 acoustic neuroma cases,Facial nerve anatomical integrity was preserved in all 19 *** week postoperative House-Brackmann grading was I in 3 cases,Ⅱ in 10 cases and Ⅲ in 6 *** nerve function continued to improve in some cases at 3 *** tumor resection was achieved in all 3 patients with facial *** facial nerve was sacrificed in 2 of the 3 cases with primary faciohypoglossal nerve *** nerve function was Grade Ⅱ and Grade III one year after surgery,*** the case with anatomically preserved facial nerve,postoperative facial nerve function was initially Grade Ⅲ and improved to Ⅱ at 3 *** tumor was completely resected in the trigeminal neurinoma patient with a Grade Ⅲ postoperative facial nerve function which improved Grade II three months *** of the 19 patients with acoustic neuroma retained hearing postoperatively,of these 12 maintained preoperative levels of *** hearing capacity was preserved in 2 of the 3 patients with facial nerve tumors,but lost in patients with other tumor *** neurotomy(n=1) and microvascular decompression(n=1) re

关键词： CPA endoscope retrosigmoid approach

全球化下公司治理趋势分析:模式趋同或功能趋同

在线全文

学校读者我要写书评

暂无评论

浙江学刊 2005年第6期 156-162页

作者：李纪明浙江大学城市学院商学院

WTO之后的国际竞争,在很大程度上将是公司治理的竞争。各国公司治理结构所具有的灵活性,以及各国政治、法律体系的差异,使得各国公司治理演进较预期在功能上更具有适应性,而在模式上则表现得较为稳定。本文试图就公司治理趋势的这二个... 详细信息

WTO之后的国际竞争,在很大程度上将是公司治理的竞争。各国公司治理结构所具有的灵活性,以及各国政治、法律体系的差异,使得各国公司治理演进较预期在功能上更具有适应性,而在模式上则表现得较为稳定。本文试图就公司治理趋势的这二个层面问题:模式和功能进行研究,检查制度维持或路径依赖和功能适应之间的交互关系,并试图分析在双失灵情况下契约趋同的作用,探讨全球化背景下公司治理演进趋势的方式和内在机理。

关键词：公司治理模式趋同功能趋同契约趋同路径依赖