检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

汽车交通事故智能报警系统

北京汽车 2014年第4期 24-27页

作者：洪印涛王俊明张洋建梁植淇重庆交通大学机电学院重庆400074 太原理工大学机电学院山西太原030024

当汽车发生交通事故时,如果驾驶员发生昏迷,且车辆所在路段又没有车辆或行人经过,驾驶员将很难得到及时救治,如果能够尽早向外界发出求救信息,则可以挽救驾驶员的生命;而且,如果相关部门能够早一步到达事故现场,将会使调查、取证更为容... 详细信息

当汽车发生交通事故时,如果驾驶员发生昏迷,且车辆所在路段又没有车辆或行人经过,驾驶员将很难得到及时救治,如果能够尽早向外界发出求救信息,则可以挽救驾驶员的生命;而且,如果相关部门能够早一步到达事故现场,将会使调查、取证更为容易,减小证据灭失的可能性,有助于客观公正地处理事故,及时排除隐患。为此文中提出了一种车载交通事故智能报警系统。

关键词：汽车交通事故智能报警

CONCEPTUAL MODELING BASED ON LOGICAL EXPRESSION AND EVOLVEMENT

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2007年第1期20卷 64-68页

作者： YI Guodong zhang Shuyou TAN Jianrong JI yangjian State Key Laboratory of CAD ＆ CG Zhejiang University Hangzhou 310027 China

Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions of the product conceptual design information, a fimction/logic/strucmre mapping model is set up. First, the fimction semantics is transformed into logical expressions through fimction/logic mapping. Second, the methods of logical evolvement are utilized to describe the fimction analysis, fimction/strucmre mapping and structure combination. Last, the logical structure scheme is transformed into geometrical sketch through logic/structure mapping. The conceptual design information and modeling process are described uniformly with logical methods in the model, and an effective method for computer aided conceptual design based on the model is implemented.

关键词： Conceptual modeling Function/logic/structure mapping Logical evolvement

藏北高山嵩草草甸群落特征及生产力对模拟增温幅度的响应

在线全文

学校读者我要写书评

暂无评论

生态学报 2019年第2期39卷 474-485页

作者：李军祥张扬建朱军涛曾辉常文静丛楠刘瑶杰俎佳星黄珂朱艺旋王荔唐泽陈宁北京大学深圳研究生院深圳518055 拉萨高原生态试验站生态系统网络观测与模拟重点实验室中国科学院地理科学与资源研究所北京100101 中国科学院青藏高原地球科学卓越创新中心北京100101 中国科学院大学资源与环境学院北京100190 北京大学城市与环境学院北京100871 中国科学院大学北京100190

青藏高原气候严酷,陆地表层生态系统脆弱,其高寒植物群落特征及生态系统生产力对气候变化的响应极其敏感。利用开顶箱(OTCs,Open Top Chambers)式装置在藏北高山嵩草(Kobresia pygmaea)草甸设置不同增温梯度实验(W1、W2、W3、W4),探究... 详细信息

青藏高原气候严酷,陆地表层生态系统脆弱,其高寒植物群落特征及生态系统生产力对气候变化的响应极其敏感。利用开顶箱(OTCs,Open Top Chambers)式装置在藏北高山嵩草(Kobresia pygmaea)草甸设置不同增温梯度实验(W1、W2、W3、W4),探究增温对高寒草甸植物群落特征及地上生产力的影响。研究结果表明:1)与对照样地相比,增温减少了植物群落总盖度(2015年,W1、W2、W3、W4分别显著减少了28%、23%、59%、60%; 2016年,W4显著减少了83%)和高山嵩草盖度(2015年,W1、W2、W3、W4分别显著减少了26%、33%、681%、64%; 2016年,W4显著减少了85%),而低幅度增温(W1、W2)对委陵菜属植物盖度无显著影响,高幅度增温(W3、W4)显著减少了委陵菜属植物盖度(2015年,W3、W4分别显著减少了58%和60%;2016年,W4显著减少了71%); 2)对整个植物群落而言,增温幅度较低时,增温对群落的生长和生物量的积累有促进作用,当温度升高超过一定程度,这种促进作用会逐渐减弱甚至变成抑制作用(2015年,W4显著减少了地上生物量69%; 2016年,W4显著减少了地上生物量82%); 3)高山嵩草盖度和其他物种总盖度存在显著的年际差异,而委陵菜属植物盖度无明显的年际变化。研究结果预示着,一定程度的升温会促进高寒草甸植物群落的生长,但温度升高超过一定幅度时,会导致草地生产力下降,草地退化加剧,同时当地群落中委陵菜属植物在全球变化背景下相对稳定,这类物种在未来气候变暖的背景下可能具有更强的竞争力。

关键词：地上生产力群落特征多梯度增温高山嵩草草甸藏北高原

Recent progress in electrospun nanofibers and their applications in heavy metal wastewater treatment

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2023年第3期17卷 249-275页

作者： Xizi Xu He Lv Mingxin zhang Menglong Wang yangjian Zhou Yanan Liu Deng-Guang Yu School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Engineering Technology Research Center for High-Performance Medical Device Materials Shanghai 200093China

Novel adsorbents with a simple preparation process and large capacity for removing highly toxic and nondegradable heavy metals from water have drawn the attention of *** nanofiber membranes usually have the advantages of large specific surface areas and high porosity and allowing flexible control and easy *** membranes show remarkable application potential in the field of heavy metal wastewater *** this paper,the electrospinning technologies,process types,and the structures and types of nanofibers that can be prepared are reviewed,and the relationships among process,structure and properties are *** one hand,based on the different components of electrospun nanofibers,the use of organic,inorganic and organic−inorganic nanofiber membrane adsorbents in heavy metal wastewater treatment are introduced,and their advantages and future development are summarized and *** the other hand,based on the microstructure and overall structure of the nanofiber membrane,the recent progresses of electrospun functional membranes for heavy metal removal are reviewed,and the advantages of different structures for applications are ***,this study lays the foundation for future research aiming to provide more novel structured adsorbents.

关键词： electrospinning heavy metal adsorption nanostructure wastewater

Identification and characterization of the chromium(Ⅵ) responding protein from a newly isolated Ochrobactrum anthropi CTS-325

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第12期21卷 1673-1678页

作者： CHENG yangjian XIE Yongming ZHENG Jing WU Zhaoxian CHEN Zhi MA Xiaoyan LI Bin LIN zhang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou 350002 China Beijing Deputy Office Bruker Daltonics Inc. Beijing 100081 China Fujian Entry-exit Inspection and Quarantine Bureau Fuzhou 350001 China

A Gram-negative, chromium（Ⅵ） tolerant and reductive strain CTS-325, isolated from a Chinese chromate plant, was identified as Ochrobactrum anthropi based on its biochemical properties and 16S rDNA sequence analysis. It was able to tolerate up to 10 mmol/L Cr（Ⅵ） and completely reduce 1 mmol/L Cr（Ⅵ） to Cr（Ⅲ） within 48 h. When the strain CTS-325 was induced with Cr（Ⅵ）, a protein increased significantly in the whole cell proteins. Liquid chromatography tandem mass spectrometry （LC-MS/MS） analysis revealed that this protein was a superoxide dismutase （SOD） homology. The measured superoxide dismutase activity was 2694 U/mg after three steps of purification. The SOD catalyzes the dismutation of the superoxide anion （O2^←） into hydrogen peroxide and molecular oxygen. This protein is considered to be one of the most important anti-oxidative enzymes for O. anthropi as it allows the bacterium to survive high oxygen stress environments, such as the environment produced during the reduction process of Cr（Ⅵ）.

关键词： chromium LC-MS/MS superoxide dismutase Ochrobactrum anthropi

Helcionelloids from the Cambrian Fortunian of the Northern Yangtze Platform,China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2023年第6期97卷 1587-1603页

作者： zhang Mengshao PANG Yanchun YANG Ben HE yangjian LIANG Siyu HU Qiang LIN Li Institute of Sedimentary Geology Chengdu University of TechnologyChengdu 610059China Shanxi Geological Exploration Bureau 214 Geological Team Co. Ltd.YunchengShanxi 044000China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China College of Earth Sciences Chengdu University of TechnologyChengdu 610059China

A study of the morphological and microstructural characteristics of helcionelloids from the Nanjiang area(north Sichuan,China)at the northern Yangtze Platform was undertaken,in order to understand their phylogenetic *** fossils from the Kuanchuanpu Formation of the Changtanhe–Maolinzi section include 7 genera and 11 *** are distinct differences in the degree of shell bending,the apical morphology and apex position,the outline of the aperture and the height of the shell,all of which constitute important identification *** helcionelloid apices exhibit varying degrees of rotation towards the aperture,they do not show any signs of evident distortion.A pair of basally-symmetrical muscle scars are discovered on the shells of helcionelloids(such as Bemella simplex),showing a distinct difference when compared with those of the stem-group gastropod(e.g.,Pelagiella).The prismatic shell layer of helcionelloids has been observed,which are common components in Cambrian molluscs,but differ significantly from the dense layer microstructure found in contemporary *** microstructures,muscle scars and morphological characteristics demonstrate that helcionelloids represent a stem-group of molluscs.

关键词： helcionelloids mollusc muscle scar Cambrian Fortunian Yangtze Platform

Economical generation of high-quality optical vortices with gradual-width Fermat spiral slit mask

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2023年第4期66卷 75-83页

作者： Qi Huang Xingyuan Lu Hao zhang Zhuoyi Wang Yuanjie Yang Qiwen Zhan yangjian Cai ChengLiang Zhao School of Physical Science and Technology Soochow UniversitySuzhou 215006China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shandong Provincial Engineering and Technical Center of Light Manipulations&Shandong Provincial Key Laboratory of Optics and Photonic Device School of Physics and ElectronicsShandong Normal UniversityJinan 250358China

A general model for creating an optical vortex using a variable-width Fermat spiral slit(FSS)mask was *** generated optical vortex demonstrates much better quality than those produced by slits with a uniform *** depth of focus was nearly doubled,which can be explained by discretizing the gradual-width *** demonstrate the generation robustness,the slits were printed on a transparent slide,and an output vortex beam with greater than 98%intensity purity was *** the high quality and simplicity of this vortex generation method,its analysis and generation scheme are expected to be extended to generation of plasmonic vortices and short-wavelength light sources such as X-rays and electron *** of highquality optical vortex beams at an almost negligible cost will make investigation much more accessible.

关键词： optical vortex gradual-width Fermat spiral slit high quality economical generation

Theoretical analysis of periodically poled LiNbO_(3) nonlinear mirror and its application in a passively mode-locked Nd:YSAG laser

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2021年第9期19卷 63-67页

作者： Lina Zhao Fangxin Cai Luyang Tong Ye Yuan Wenyu zhang yangjian Cai College of Physics and Electronics Center of Light Manipulations and ApplicationsShandong Normal UniversityJinan 250014China Shandong Provincial Key Laboratory of Optics and Photonic Device Jinan 250014China

In this paper, we report a passively mode-locked Nd∶Y3Sc2Al3O12(Nd:YSAG) laser using a periodically poled Li Nb O3(PPLN)superlattice. Nonlinear mirror mode locking based on PPLN intracavity frequency doubling was theoretically analyzed. The modulation depth of nonlinear reflectivity of the nonlinear mirror is approximately 8.8%. Optical performances of the modelocked laser including output power, radio frequency spectrum, and optical spectrum were experimentally investigated. An average output power of 710 m W with a slope efficiency of 14.6% was obtained at the pump power of 6.5 W. The repetition rate is 101.7 MHz, and the signal-to-noise ratio of the mode-locked pulse is 45 d B. The mode-locked pulse width was approximately 9 ps.

关键词： Nd:YSAG periodically poled LiNbO3 superlattice passively mode-locked laser

补阳还五汤通过BDNF/TrkB介导PI3K/Akt信号通路抗脊髓神经元凋亡的机制研究

在线全文

学校读者我要写书评

暂无评论

齐齐哈尔医学院学报 2024年第15期45卷 1408-1412页

作者：张华龙欧阳建倪力力张江谢毅杰陆小龙沅陵县中医院湖南怀化419600 湖南中医药大学第二附属医院湖南长沙410000 湖南中医药大学第一附属医院湖南长沙410000

目的探讨补阳还五汤通过BDNF/TrkB介导PI3K/Akt信号通路抗脊髓神经元凋亡的机制。方法将48只SD大鼠分为标准模型组、补阳还五汤组、抑制剂组、假手术组四组,每组各12只。采用标准方法损伤大鼠脊髓,分别连续治疗7 d。改良神经功能评分(mN... 详细信息

目的探讨补阳还五汤通过BDNF/TrkB介导PI3K/Akt信号通路抗脊髓神经元凋亡的机制。方法将48只SD大鼠分为标准模型组、补阳还五汤组、抑制剂组、假手术组四组,每组各12只。采用标准方法损伤大鼠脊髓,分别连续治疗7 d。改良神经功能评分(mNSS)评价大鼠经7 d治疗后神经功能,进行组织切片,用尼氏染色(NS)法、免疫组织化学法(Immunohistochemistry)和蛋白质印记(WB)法分别检测各组脊髓神经元细胞形态及BDNF、TrkB、PI3K/Akt的表达情况。结果给药治疗后对各组大鼠第1、3、7天mNSS评分,补阳还五汤组、抑制剂组分别与标准模型组相比,得分均有明显降低(P<0.05);治疗7 d后,补阳还五汤组与抑制剂组相比,两组得分有明显差异(P<0.05);尼氏染色显示,标准模型组镜下脊髓神经元破坏明显,大量空洞样改变,神经元髓鞘脱落散乱,余各组镜下神经元损伤较轻;标准模型组较假手术组明显减少(P<0.05);补阳还五汤组与标准模型组比较,明显增多(P<0.05);抑制剂组较标准模型组明显增多(P<0.05),但与补阳还五汤组比,明显降低(P<0.05);在BDNF表达方面,标准模型组较假手术组降低(P<0.05),补阳还五汤组、抑制剂组较标准模型组有所升高(P<0.05);在TrkB表达方面,补阳还五汤组、抑制剂组较标准模型组降低(P<0.05),抑制剂组比补阳还五汤组降低(P<0.05);在PI3K/Akt表达方面,补阳还五汤组、抑制剂组较标准模型组升高(P<0.05)。结论补阳还五汤可通过BDNF/TrkB介导PI3K/Akt信号通路,促进神经元修复,对于脊髓神经元再生、修复以及运动功能的恢复都具有一定的促进作用。

关键词：补阳还五汤脊髓神经元 PI3K/Akt 信号通路