检索结果-南通市图书馆

Experimental EOS determination of aluminum at Mbar pressure

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2004年第4期47卷 416-423页

作者： CHEN Jianping1.2, {1. Ruxin1. ZENG Zhinan1. WANG Xingtao1.& XU Zhizhan1.1. Shanghai Institute of Optics and Fine Mechanics, Shanghai 2.1.00, china 2. Beijing Aeronautical Technology Research Center, Beijing 1.0076, china 1. Shanghai Institute of Optics and Fine Mechanics 201800 Shanghai China 2. Beijing Aeronautical Technology Research Center 100076 Beijing China

A shock wave is driven by a laser pulse of 1.2 ps duration (FWHM), with the intensity of ～1.1. W/cm2.at 785 nm, irradiating a 500 nm thick aluminum foil. A chirped laser pulse sp{1.t from the main pulse is used to detect the shock breakout process at the rear surface of the target based on frequency domain interferometry. The mean shock velocity determination benefits from the precise synchronization (＜1.0fs resolution) of the shock pump and probe laser pulses, which is calculated from the time the shock takes to travel the 500 nm thick aluminum. The released particle velocity determination benefits from the chirped pulse frequency domain interferometry. The average shock velocity is 1..1. km/s and the shock release particle velocity is 1..2. km/s, and the corresponding pressure after shock is 3.1. Mbar under our experimental condition.

关键词： shock wave, equation of state, chirped laser pulse.

Regulation mechanism of EM parameters in natural ferrite and its application in microwave absorbing materials

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2006年第1期49卷 38-49页

作者： ZHENG Yongchun1.2, WANG Shijie2. FENG Junming2. {1. Chunlai1. OUyang Ziyuan1.2, {1.U Jianzhong1.& {1. Xiaobiao2.1. National Astronomical Observatories, Chinese Academy of Sciences, Beijing 1.001., china 2. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002. china 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China 2. State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Electromagnetic (EM) parameters (ε ′, ε ″, μ ′, μ″ ) of several M2.Fe2.4 and Fe2.3 type natural ferrites with different geological occurrences are measured in this pa-per. The measurement results show that EM parameters of a magmatic-occurring natural ferrite is very different from other types occurring from sedimentary-metamorphic iron deposit, hydrothermal vein iron deposit, outer contact of magmatic iron deposit. It has potential to be used as magnetic absorbent in microwave absorbing materials. After min-eral separation and concentration, this magmatic-occurring natural ferrite was processed into type A ferrite absorbent. Type A natural ferrite absorbent is a kind of magnetic material with low dielectric constants, high magnetic conductivity and high EM loss. Its EM pa-rameters are ε ′ = 58.60, ε ″ = 1..0, μ ′ = 1.2-1.5, μ ″ = 1.0-1.2, respectively. In order to illuminate the regulation mechanism of EM parameters, we studied the chemical and mineral composition of type A ferrite absorbent. There is high concentration of natural impurities, which regulate the EM parameters of type A ferrite greatly. For comparison, the other types of natural ferrite, single-phase magnetite and two-phase iron minerals (ilmen-ite and magnetite), have few impurity. Thus regulation mechanism of EM parameters was absent in these ferrites. As a result, the regulation of EM parameters is advantageous to develop type A natural ferrite as excellent absorbent, lowers the reflectivity coefficients and enhances the absorbing efficiency of MAM made from it. Furthermore, the impurities in type A natural ferrite and its effects on EM parameters are very difficult to simulate in the synthesize ferrite. The carbonyl-iron powder is another kind of absorbent that is used ex-tensively in MAM. To compare the absorbing properties of these two absorbent, type A natural ferrite and carbonyl-iron powder were mixed with rubber and processed into mi-crowave absorbing sheets with the same procedures and tec

关键词： natural impure ferrite, complex permittivity, complex permeability, microwave absorbing materials.

lipschitz spaces and Q_K type spaces

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第3期53卷 771-778页

作者： li Hao 1., WULAN Hasi 1. & ZHOU JiZhen {1. 1.Department of Mathematics, shantou University, shantou 51.063,{2. 2.School of Sciences, Anhui University of Science and Technology, Huainan 2.2.01.{2. 1. Department of Mathematics Shantou University Shantou 515063 China2. School of Sciences Anhui University of Science and Technology Huainan 232001 China

If f(z) =Σ∞ n=0 anzn and g(z) =Σ∞n=0bnzn for functions f, g are analytic in the unit disc, the Hadamard products of f and g is defined by f * g = ∞ n=0 a n b n z n . In this paper, the lipschitz spaces Λ(s, α) ... 详细信息

关键词： Q K type spaces lipschitz spaces Hadamard products

大跨度屋盖结构风振响应和等效静风荷载的快速算法和应用

在线全文

学校读者我要写书评

暂无评论

土木工程学报 2010年第7期43卷 29-36页

作者：李小康谢壮宁汕头大学汕头515063 华南理工大学广州510641

采用一种新的快速算法—谐波激励法(HEM)计算复杂大跨度空间结构的风致响应,该方法的精度等同于完全二次型组合(CQC)方法,对内存的消耗却要远小于CQC方法且计算速度要显著比CQC方法快。在得到结构风致响应的基础上,基于荷载响应相关(LRC... 详细信息

采用一种新的快速算法—谐波激励法(HEM)计算复杂大跨度空间结构的风致响应,该方法的精度等同于完全二次型组合(CQC)方法,对内存的消耗却要远小于CQC方法且计算速度要显著比CQC方法快。在得到结构风致响应的基础上,基于荷载响应相关(LRC)原理计算出包含共振响应和模态耦合的结构等效静风荷载(ESWL)。将本文方法应用于一复杂体育场屋盖的风振响应和ESWL的计算分析,通过对该结构风致响应的特征和ESWL分布的分析和讨论,证明了本文方法的有效性。文中还对响应的背景和共振分量的相关特征进行分析,结果显示:响应的背景和共振分量的相关系数最大可达-0.1.,忽略这种相关特征所产生的误差最大可达6%并高估了结构的风振响应。

关键词：大跨度屋盖风致响应谐波激励法等效静风荷载风洞试验

Stimulation of mucin secretion from human bronchial epithelial cells by mast cell chymase

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第6期25卷 125-130页

作者： Shao-heng HE1.2,3, Jian ZHENG1. 1.llergyand Inflammation Research Institute, {1. University MedicalCollege, {1. 51.031.{2. 2.mmunopharmacologyGroup, Southampton General Hospital, Southampton, UK Allergy and Inflammation Research Institute Shantou University Medical College Shantou 515031 Chin

AIM: To investigate the effect of chymase on the mucin secretion from human bronchialepithelial cells. METHODS: Primarily-cultured human bronchial epithelial (PCHBE) cells and normal human bronchial epithelial (NHBE) cells were cultured with chymase or other stimulus in a mixture of bronchial epithelial growth medium (BEGM) and Dulbecco’s modified Eagle’s medium (DMEM), and the quantities of stimulatory mucin release were recorded. MUC5AC mucin was measured with an EliSA and dolichos biflorus agglutinin (DBA) mucin was determined with an enzyme linked DBA assay. RESULTS: A dose-dependent secretion of DBA mucin from PCHBE cells was observed with chymase with a maximum secretion of 98 % above baseline being achieved following 3 h incubation. The action of chymase started from 1.h, peaked at 3 h and dramatically decreased at 2. h following incubation. Chymase was able to also stimulate approximately 38 % increase in MUC5AC mucin release from PCHBE cells, and about 1.1.% increase in DBA mucin release from NHBE cells. A chymase inhibitor soybean trypsin inhibitor (SBTI) was able to inhibit up to 85 % chymase induced mucin release, indicating that the enzymatic activity was essential for the actions of chymase on bronchial epithelial cells. CONCLUSION: Chymase is a potent stimulus of mucin secretion from human bronchial epithelial cells. It can contribute to mucus hypersecretion process in the patients with chronic obstructive pulmonary disease or asthma.

关键词： chymase mucins mast cells epithelial cells MUC5AC protein

On the siltation of the middle yangtze River

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2004年第5期47卷 463-480页

作者： YIN Hongfu1. CHEN Guojin2. li Chang抋n1.& WEI Yuan3 1. School of Earth Sciences,{1. University of Geosciences, Wuhan 430074,{1. 2. Hydrogeological Team, Hubei Bureau of Geology and Mineral Resources, Jingzhou 4341.0,{1. 3. Geological Survey of Jiangxi Province, Nanchang 3302.1.{1. china Univ Geosci Sch Earth Sci Wuhan 430074 Peoples R China Hubei Bur Geol & Mineral Resources Hydrogeol Team Jinzhou 434100 Peoples R China Geol Survey Jiangxi Province Nanchang 3300201 Peoples R China

About 5.2.1.8 t/a of silts from the upper reach of the yangtze River are transported through Yichang into the middle yangtze River. The middle yangtze itself and its tributaries yield ca. 0.8×1.8 t silts annually. Of this total 6×1.8 t/a input of silts, ca. 1.2×1.8 t/a are deposited within the river artery and lakes, while ca 4.83×1.8 t/a are at first transported into the lower reach through Datong, and then either deposited along the river and the yangtze Delta, or output into the sea. Along the middle yangtze River silting generally exceeds scouring, but the spatial and temporal distributions of scour-and-fill, as well as its distribution in the river valley transections, are uneven. Along the Yichang-Chenglingji and Jiujiang-Datong Segments of the middle yangtze, scouring exceeds or equals silting. Silting mainly occurs along the Luoshan-Wuhan-Huangshi Segments with Wuhan as the pivotal point, as well as in the Dongting and Poyang Lakes. Even in these silting-dominated areas, there are times and parts of segments that scouring prevails. As to the transections, generally the river channel of main stream is scouring-dominated, forming V-shaped sections to a depth of 2.30 m or more, whereas the floodplains and bar islands are silting-dominated, forming wide and relatively high flats, which are often artificially transformed into protected embankments. Because the Jingjiang Levee separates the Jianghan Plain from yangtze to the south, little has been deposited in that plain except a few sediments from the Han River—a tributary of the middle yangtze. This factor plus the tectonic sag of that plain has made the altitude of plain surface several meters lower than that of the levee in most of the areas. Sil-tation along the Luoshan-Wuhan-Huangshi Segments has resulted in the elevation of flood level in this and upstream segments. River channel scouring plus floodplain silting have caused the transections of the middle yangtze valley typically with deep channel and height

关键词： the middle yangtze, scour-and-fill, siltation, silt utilization.

在线全文

学校读者我要写书评

暂无评论

广州西塔风致响应和气动阻尼特性的试验研究

土木工程学报 2009年第7期42卷 58-64页

作者：嵇学培谢壮宁李小康汕头大学广东汕头515063 华南理工大学亚热带建筑科学国家重点实验室广东广州510641

在边界层风洞中对432.高的广州珠江新城西塔进行多自由度气动弹性模型试验,并和刚性模型的高频底座力天平(HFBB)结果作比较,采用随机减量技术(RDT)识别该超高层建筑的气动阻尼特性。结果显示:在采用相同的阻尼比情况下,气弹模型和HFBB... 详细信息

在边界层风洞中对432.高的广州珠江新城西塔进行多自由度气动弹性模型试验,并和刚性模型的高频底座力天平(HFBB)结果作比较,采用随机减量技术(RDT)识别该超高层建筑的气动阻尼特性。结果显示:在采用相同的阻尼比情况下,气弹模型和HFBB的结果具有较好的一致性;西塔的横风向气动阻尼基本上均为正数,在低风速段随风速的增加而增加,在梯度风风速为45.4m/s时达到最大值为1.75%,随后在临界风速附近急剧下降,在51./s时降到最小值,约为-0.06%。得出的一些结果可以作为西塔抗风设计参考的依据。

关键词：高层建筑气动阻尼风致响应风洞试验随机减量技术

Synthesis and Characterization of a Novel pH-sensitive Complex for Drug Release

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2010年第1期25卷 24-27页

作者：许东颖李光吉 Department of Polymer Science and Engineering South China University of Technology

A novel pH-sensitive complex was prepared by using oxidized konjac glucomannan and 4-aminosalicylic acid （4-ASA） through glutaraldehyde as a cross-linking agent. The product was characterized by FTIR and 1.C NMR spectra, and the thermogravimetric analysis was also studied. The drug release studies in vitro showed that the amount of 4-ASA released from the complex was about 4%, 56% and 1.% after 1. h at pH 1.2, 6.8 and 7.4, respectively. The data demonstrate that the rate of the drug release of the complex can be more effectively controlled by pH value. The results showed that the novel pH-sensitive complex could be potentially useful for colon-targeting drug delivery system.

关键词： konjac glucomannan pH-sensitivity drug release

A 6.2.9.5 GHz receiver for Wimedia MB-OFDM and china UWB standard

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第2期54卷 407-418页

作者： GAO Ting1. ZHOU Feng1. {2. Wei1. LAN Fei1. {2. Ning1.& REN JunYan1.2 1.tate Key Laboratory of ASIC & System, Fudan University, Shanghai 2.1.03, china 2.icro-/Nano-Electronics Science and Technology Innovation Platform, Shanghai 2.1.03, china 1. State Key Laboratory of ASIC & System Fudan University Shanghai 201203 China2. Micro-/Nano-Electronics Science and Technology Innovation Platform Shanghai 201203 China

An integrated 6.2.9.5 GHz UWB receiver for both WiMedia MB-OFDM and china UWB standard is proposed. The receiver can cover Group#3, Group#4 for WiMedia and Group#2.5 for china UWB standard respectively. The fully differential receiver consists of a wideband LNA and a down conversion mixer with high gain and low gain mode. A low-pass filter with controllable gain and cut-o? frequency along with a programmable gain amp{2.fier are also included. The chip was fabricated in TSMC 0.1.-μm RF CMOS process. Measurement results show that the receiver achieves voltage gain from 2.3}to 69 dB with 2.dB/step and an NF of 3.2.4.6 dB over 6.2.9.5 GHz and 1.dB compression point of ?2.3}dBm. The intermediate frequency of the receiver can be switched between 2.4 and 1.2 MHz, which enables the receiver app{2.cable for both WiMedia and china UWB standard. Power consumption is only 47 mA with 1.2–V supply voltage.

关键词： CMOS ultra-wideband (UWB) MB-OFDM china UWB standard radio frequency (RF) low noise amplifier (LNA) quadrature mixer low-pass filter (LPF) Gm-C noise figure