检索结果-南通市图书馆

Endopeptidase Isoenzyme Characteristics in Cucumis sativus Leaves During Dark-induced Senescence

Journal of Integrative Plant Biology 2007年第4期49卷 507-514页

作者： Peng zhang Fei Wang Lie-feng zhang qi Rui Lang-Lai Xu College of Life Sciences Nanjing Agricultural University Nanjing 210095 China

The changes and characteristics of endopeptidase （EP） isoenzymes in cucumber （Cucumis sativus L.） leaves during dark-induced senescence were investigated by activity staining after gradient-polyacrylamide gel electrophoresis （G-PAGE） containing co-polymerized gelatin as substrate. The results showed that both the chlorophyll and the protein contents of leaves were decreased, and the protein degradation was correlated with the increase of proteolytic activity during the course of leaf senescence. Meanwhile, nine cucumber endopeptidases isoenzymes （CEP） with 140, 120, 106, 94, 76, 55, 46, 39 and 35 kDa molecular weights were detected. Four of these, CEP2, 3, 4 and CEP9 appeared all the time, but the changes of the activity were different during incubation. Another four CEPs （CEP5, 6, 7 and CEP8） whose activities increased with dark-induced time were only detected in senescent leaves. Furthermore, the biochemical properties of these nine CEP were also characterized. All the CEPs had high activities from 35 ℃ to 45 ℃, and the optimum temperature was found to be 40 ℃. However, the activities of CEPs were not detected below 25 ℃ or over 60 ℃. The activity bands appeared at a wide range of pH from 5.0 to 9.0, but the optimum pH was found at 7.0. No CEPs were detected at pH 4 or pH 10. By inhibition analysis we concluded that CEP2, 3, 4 and CEP9 were serine endopeptidases and CEP6 was a kind of cysteine protease. It is suggested that serine endopeptidases might play a major role in cucumber leaf senescence, and for the first time, six senescencerelated endopeptidases （CEP1, 5, 6, 7, 8 and 9） were found in cucumber leaves.

关键词： Cucumis sativus cucumber endopeptidase leaf senescence.

来源：

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

Multiple Linear Regression Application on the Inter-Network Settlement of Internet

引用

The Journal of China Universities of Posts and Telecommunications 2006年第2期13卷 103-107页

作者： YANG qing-feng zhang qi-xiang Lǖ Ting-jie School of Management and Economics Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

This paper develops an analytical framework to explain the lnternet interconnection settlement issues. The paper shows that multiple linear regression can be used in assessing the network value of lnternet Backbone Providers （ IBPs）. By using the exchange rate of each network, we can define a rate of network value, which reflects the contribution of each network to interconnection and the interconnected network resource usage by each of the network.

关键词： multiple linear regression network value internet settlement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influences of supply voltage on single event upsets and multiple-cell upsets in nanometer SRAM across a wide linear energy transfer range

引用

Chinese Physics B 2021年第4期30卷 596-604页

作者： Yin-Yong Luo Wei Chen feng-qi zhang Tan Wang State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear TechnologyXi'an 710024China

The influences of reducing the supply voltage on single event upset(SEU) and multiple-cell upset(MCU) in two kinds of 65-nm static random access memories(SRAMs) are characterized across a wide linear energy transfer(LET) *** results show that the influence of the voltage variation on SEU cross section clearly depends on the LET value which is above heavy ion LET threshold no matter whether the SRAM is non-hardened 6 T SRAM or radiation-hardened double dual interlocked cells(DICE) *** the LET value is lower than the LET threshold of MCU,the SEU only manifests single cell upset,the SEU cross section increases with the decrease of *** lower the LET value,the higher the SEU sensitivity to the voltage variation *** the voltage has no evident influence on SEU cross section while the LET value is above the LET threshold of ***,the reduction of the voltage can result in a decrease in the highest-order MCU event cross section due to the decrease of charge collection efficiency of the outer sub-sensitive volume within a certain voltage *** further scaling the feature size of devices down,it is suggested that the dependence of SEU on voltage variation should be paid special attention to for heavy ions with very low LET or the other particles with very low energy for nanometer commercial off-the-shelf(COTS) SRAM.

关键词： supply voltage single event upsets multiple-cell upsets 65-nm SRAM double DICE SRAM

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synergistic effect of total ionizing dose on single event effect induced by pulsed laser microbeam on SiGe heterojunction bipolar transistor

引用

Chinese Physics B 2018年第10期27卷 612-621页

作者： Jin-Xin zhang Hong-Xia Guo Xiao-Yu Pan qi Guo feng-qi zhang Juan feng Xin Wang Yin Wei Xian-Xiang Wu Xidian University Xi'an 710126 China Xinjiang Technical Institute of Physics & Chemistry Chinese Academy of Sciences Urumqi 830011 China Northwest Institution of Nuclear Technology Xi'an 710024 China

The synergistic effect of total ionizing dose（TID） on single event effect（SEE） in SiGe heterojunction bipolar transistor（HBT） is investigated in a series of experiments. The SiGe HBTs after being exposed to 60 Co g irradiation are struck by pulsed laser to simulate SEE. The SEE transient currents and collected charges of the un-irradiated device are compared with those of the devices which are irradiated at high and low dose rate with various biases. The results show that the SEE damage to un-irradiated device is more serious than that to irradiated SiGe HBT at a low applied voltage of laser test. In addition, the g irradiations at forward and all-grounded bias have an obvious influence on SEE in the SiGe HBT, but the synergistic effect after cutting off the g irradiation is not significant. The influence of positive oxide-trap charges induced by TID on the distortion of electric field in SEE is the major factor of the synergistic effect. Moreover, the recombination of interface traps also plays a role in charge collection.

关键词： SiGe HBT synergistic effect single event effects total ionizing dose

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of proteinase A on cultivation and viability characteristics of industrial Saccharomyces cerevisiae WZ65

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第10期10卷 769-776页

作者： Hong-bo zhang Hai-feng zhang qi-he CHEN Hui RUAN Ming-liang FU Guo-qing HE Department of Food Science and Nutrition Zhejiang University Hangzhou 310029 China

Proteinase A （PrA）, encoded by PEP4 gene, is a key enzyme in the vacuoles of Saccharomyces cerevisiae. We characterized the effects of PrA on cell growth and glucose metabolism in the industrial S. cerevisiae WZ65. It was observed that the lag phase of cell growth of partial PEP4 gene deletion mutant （36 h） and PrA-negative mutant （48 h） was significantly extended, compared with the wild type strain （24 h）（P〈0.05）, but PrA had no effect on glucose metabolism either under shaking or steady state cultivations. The logistic model was chosen to evaluate the effect of PrA on S. cerevisiae cell growth, and PrA was found to promote cell growth against insufficient oxygen condition in steady state cultivation, but had no effect in shaking cultivation. The effects of glucose starvation on cell growth of partial PEP4 gene deletion strain and PrA-negative mutant were also evaluated. The results show that PrA partial deficiency increased the adaption ofS. cerevisiae to unfavorable nutrient environment, but had no effect on glucose metabolism under the stress of low glucose. During heat shock test, at 60 ℃ the reduced cell viability rate （RCVR） was 10% for the wild type S. cerevisiae and 90% for both mutant strains （P〈0.01）, suggesting that PrA was a negative factor for S. cerevisiae cells to survive under heat shock. As temperatures rose from 60 ℃ to 70℃, the wild type S. cerevisiae had significantly lower relative glucose consumption rate （RGCR）（61.0% and 80.0%） than the partial mutant （78.0% and 98.5%） and the complete mutant （80.0% and 98.0%）（P〈0.05）, suggesting that, in coping with heat shock, cells of the PrA mutants increased their glucose consumption to survive. The present study may provide meaningful information for brewing industry; however, the role of PrA in industrial S. cerevisiae physiology is complex and needs to be further investigated.

关键词： Proteinase A (PrA) PEP4 gene Saccharomyces cerevisiae WZ65 Cell metabolism Viability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Two New Sesquiterpenes from Atractylodes macrocehpala

引用

Chinese Chemical Letters 1998年第12期9卷 0-0,0-0页

作者： qi feng zhang Shi De LUO Hut Yin WANG(Laboratory of Phytochemistry, Kundring institute of Botang, Academia Sinica, Kunndng, 650204) Acad Sinica Kunming Inst Botang Lab Phytochem Kunming 650204 Peoples R China

Two new sesquiterpenes: beishulenolide A 1 and peroxiatractylenolide III 2 wereisolated from Atraclylodes macrocephala Koids (compositae).Their structures were elucidated onthe basis of spectral evidence, especially 2... 详细信息

关键词： Beishulenolide A peroxiatractylenolide Ⅲ atractylodes macrocephala, compositae

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dependence of single event upsets sensitivity of low energy proton on test factors in 65 nm SRAM

引用

Chinese Physics B 2018年第7期27卷 566-571页

作者： Yin-Yong Luo feng-qi zhang Xiao-Yu Pan Hong-Xia Guo Yuan-Ming Wang State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear TechnologyXi＇an 710024China

In order to accurately predict the single event upsets （SEU） rate of on-orbit proton, the influence of the proton energy distribution, incident angle, supply voltage, and test pattern on the height, width, and position of SEU peak of low energy protons （LEP） in 65 nm static random access memory （SRAM） are quantitatively evaluated and analyzed based on LEP testing data and Monte Carlo simulation. The results show that different initial proton energies used to degrade the beam energy will bring about the difference in the energy distribution of average proton energy at the surface and sensitive region of the device under test （DUT）, which further leads to significant differences including the height of SEU peak and the threshold energy of SEU. Using the lowest initial proton energy is extremely important for SEU testing with low energy protons. The proton energy corresponding to the SEU peak shifts to higher average proton energies with the increase of the tilt angle, and the SEU peaks also increase significantly. The reduction of supply voltage lowers the critical charge of SEU, leading to the increase of LEP SEU cross section. For standard 6-transitor SRAM with bit-interleaving technology, SEU peak does not show clear dependence on three test patterns of logical checkerboard 55H, all＂ 1＂, and all ＂0＂. It should be noted that all the SEUs in 65 nm SRAM are single cell upset in LEP testing due to proton＇s low linear energy transfer （LET） value.

关键词： low energy proton energy distribution tilt angle supply voltage test pattern

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

酸助剂对现场混装乳化炸药敏化速率的影响研究

引用

火工品 2025年第1期 55-61页

作者：黄乾悦冯章启樊保龙葛立芳方志梅倪林吴攀宇魏国南京理工大学化学与化工学院江苏南京210094 安徽江南化工股份有限公司安徽合肥230088 安徽江南化工股份有限公司宁国分公司安徽宁国242300

为探讨酸助剂对现场混装乳化炸药敏化速率的影响,本研究通过改变酸助剂的种类、浓度和添加量来优化炸药的性能和安全性,通过测量基质发泡高度来计算乳化炸药密度。结果表明:草酸作为酸助剂时能显著提升现场混装乳化炸药基质的敏化速率,... 详细信息

为探讨酸助剂对现场混装乳化炸药敏化速率的影响,本研究通过改变酸助剂的种类、浓度和添加量来优化炸药的性能和安全性,通过测量基质发泡高度来计算乳化炸药密度。结果表明:草酸作为酸助剂时能显著提升现场混装乳化炸药基质的敏化速率,最大可以达到0.03 g·cm-3·min^(-1),而硝酸助剂的敏化速率最低,最大仅为0.008 g·cm^(-3)·min^(-1)。研究发现:弱酸助剂的氢离子(H+)电离能力是影响敏化速率的关键因素,而强酸与亚硝酸钠的副反应和气泡逸出效应会降低强酸助剂的敏化速率;当选择草酸作为酸助剂时,增大草酸的浓度和添加量可以进一步提高敏化速率。本研究为现场混装乳化炸药的定制化提供了理论支撑。

关键词：乳化炸药酸助剂现场混装敏化速率

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Na_2SO_4- and NaCl- Induced Hot Corrosion Behaviors of a Nickel-Base Superalloy with Aluminide Diffusion Coating

引用

Journal of Wuhan University of Technology(Materials Science) 2001年第1期16卷 59-62页

作者：安涛峰 State Key Lab. Fatigue/Fracture Mat. Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

Hot-corrosion behaviors of nickel-base superalloy and aluminide diffusion coating have been investigated in conditions of contents of Na2SO4 and NaCI molten salts at 900℃ by means of XRD and SEM. Hot-corrosion scale of the superalloy and aluminide diffusion coating were analyzed and their surface morphologies were observed. The results demonstrate that both coated and uncoated specimens are not susceptible to various contents of NaCI. That may be resulted from the AI2O3 scale formation. Growth stress was characterized by the formation of convoluted scales.

关键词： nickel-base superalloy aluminlde diffusion coating hot-corrosion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Heavy Ion and Laser Microbeam Induced Current Transients in SiGe Heterojunction Bipolar Transistor

引用

Chinese Physics Letters 2017年第10期34卷 100-103页

作者： Pei Li Chao-Hui He Gang Guo Hong-Xia Guo feng-qi zhang Jin-Xin zhang Shu-Ting Shi School of Nuc/ear Science and Tochnology Xi＇an Jiaotong University Xi＇an 710049 China Institute of Atomic Energy Beijing 102413 Northwest Institution of Nuclear Technology Xi＇an 710024

Silicon-germanium （SiGe） hereto-junction bipolar transistor current transients induced by pulse laser and heavy iron are measured using a real-time digital oscilloscope. These transients induced by pulse laser and heavy iron exhibit the same waveform and charge collection time except for the amplitude of peak current. Different laser energies and voltage biases under heavy ion irradiation also have impact on current transient, whereas the waveform remains unchanged. The position-correlated current transients suggest that the nature of the current transient is controlled by the behavior of the C/S junction.

关键词： HBT Heavy Ion and Laser Microbeam Induced Current Transients in SiGe Heterojunction Bipolar Transistor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：