检索结果-南通市图书馆

Magnetic resonance cholangiopancreatography for the detection of pancreatic duct stones in patients with chronic pancreatitis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第20期15卷 2543-2546页

作者： Zhen-Hua Ma Qing-Yong Ma Huan-Chen Sha sheng-li Wu jun Wen Department of Hepatobiliary Surgery the First Affiliated Hospital Medical School of Xi'an Jiaotong University Xi'an 710061 Shaanxi Province China

AIM:To assess the role of magnetic resonance cholangiopancreatography(MRCP) in detection of pancreatic duct stones(PDS) in patients with chronic pancreatitis(CP).METHODS:Clinical data of 78 CP patients who were treated at the First Affi liated Hospital of Xi'an Jiaotong University(China) between January 2004 and July 2008 were retrospectively analyzed.A predictive model of pancreatic duct stones was established through logistic regression and its effectiveness was verifi *** these patients, MRCP was performed in 60 patients who served as a control group, while 44 patients with a higher predictive value than the entry threshold of the predictive model served as an experimental ***:The positive rate of PDS in the 78 patients with CP was 19.2%(15/78).The predictive entry threshold of the predictive model was 5%(P lity of existence of PDS could be predicted according to the following 4 indexes:gastrointestinal symptoms, intermittent abdominal pain, diabetes mellitus(DM)/impaired glucose tolerance(IGT) and positive B-mode ultrasound *** incidence of PDS in the experimental group was higher than that in the control group(P < 0.05).CONCLUSION:MRCP is strongly suggested for the detection of PDS in patients with gastrointestinal symptoms, intermittent abdominal pain, DM/IGT and positive B-mode ultrasound results.

关键词： Chronic pancreatitis Pancreatic duct stone Magnetic resonance cholangiopancreatography B-mode ultrasound Logistic regression

The fragmentation of ^(20)Ne at 400 A MeV

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

Chinese Physics C 2012年第1期36卷 37-42页

作者： CHENG Jin-Xia ZHANG Dong-Hai YAN Shi-Wei li jun-sheng WANG li-Chun li Yan-Jing N.Yasuda College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China Institute of Modern Physics Shanxi Normal UniversityLinfen 041004China Beijing Radiation Center Beijing 100875China Fundamental Technology Center National Institute of Radiological

The total charge-changing cross sections and partial cross sections for the production of projectile fragments are measured in the interactions of 400 A MeV 20 Ne with aluminum,carbon and polyethylene targets sandwiched with CR-39 plastic nuclear track *** measured total charge-changing cross sections are compared with the predictions using the Bradt-Peters semi-empirical formula,and the NUCFRAG2 and PHITS *** is shown that the measured experimental results are in good agreement with the theoretical model prediction and other experimental results,and it can be clearly seen that the partial cross sections for fragment production show obvious odd-even effects.

关键词： heavy ion fragmentation charge-changing cross sections CR-39

Theoretical study on tetranuclear boron clusters: B4X4 (X = H, F, Cl, Br, I)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1994年第4期12卷 305-313页

作者： liN, Chen-sheng li, jun liU, Chun-WanFujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, State Key Laboratory of Structural Chemistry, Fuzhou, Fujian 350002, China Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences State Key Laboratory of Structural Chemistry Fuxhou Fujian 350002 China

The molecular orbitals for B4H4, B4F4, B4Cl4, B4Br4 and B4I4 have been calculated by using all-electron or effective core potential ab initio method at the self-consistent field level using basis sets with diffuse and polarization functions. The boron-boron and boron-halide (-hydrogen) distances of these cage compounds are optimized with three kinds of basis sets constrained to a tetrahedral symmetry. According to the localization scheme of Boys, four three-centered two-electron (3c2e) B-B-B bonds localized on each of the faces of the B4 tetrahedron are derived for B4X4 clusters. The HOMO-LUMO energy gaps, atomization energies and Mulliken overlap populations of these compounds indicate that the stabilities of the clusters decrease in the sequence of B4F4 > B4Cl4, B4H4 > B4Br4 > B4I4.

关键词： Ab initio tetraboron balogenide multi-center bonds localized molecular orbitals.

THE SIMULATION OF THE SAR IMAGE OF INTERNAL SOliTARY WAVES IN ALBORAN SEA

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2001年第3期13卷 88-92页

作者： Meng jun min Ocean University of Qingdao, Qingdao 266003, China Zhang Zi li, Zhao jun sheng First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China Zhang Jie Key Laboratory of Marine Science and Numerical Modelling, Ocean Univ. of Qingdao Qingdao 266003 China

SAR imaging mechanism of internal wave is studied. The numerical modelling of internal waves is obtained by the two level scheme. The simulaed SAR images that have better expressed the features of internal waves are ... 详细信息

关键词： internal wave soliton SAR simulation

SUSTAINABLE AGRICULTURE DEVELOPMENT IN SAliNE-ALKAli SOIL AREA OF SONGNEN PLAIN,NORTHEAST CHINA

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2003年第2期13卷 171-174页

作者： WANG Zhi-chun, li Qu-sheng, li Xiu-jun, SONG Chang-chun, ZHANG Guang-xin (Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun 130012, P. R. China) Northeast Institute of Geography and Agricultural Ecology Chinese Academy of Sciences Changchun 130012 P. R. China

There is great potential for agriculture in saline-alkali soil area in Songnen Plain, Northeast China. But the sustainable crop production in this area has been restricted by a few of main factors, such as less precipitation, h igher evaporation and frequent drought, high salinity and alkalinity, high excha ngeable sodium content and poor infiltration of the soil, and insufficiency and low availability in nutrition. It is also considered that there are a few of fav orable conditions for agricultural development in this region, such as sufficien t light and heat resources, rich ground water resources, plenty of manure produc ed by livestock, and so on. At the same time, scientific management and measurem ents have been employed; rational irrigation and drainage system has been establ ished; reclamation, amendment and fertilization of soil, and suitable strategies of cropping practices have been made for the sustainable development of agricul ture. Great progress has been made during 1996-2000.

关键词： sustainable agriculture development saline-alkali soil songnen plain

在线全文

学校读者我要写书评

暂无评论

倒置芯片单面出光白光数码管的光色性能

光电子．激光 2018年第2期29卷 138-142页

作者：盛立军绍兴职业技术学院浙江绍兴312000

将掺杂TiO_2颗粒的高折射胶层旋涂于倒置芯片侧面,荧光粉胶层喷涂于芯片正表面,制备了白光数码管;并对样品进行了光色性能测试分析。结果表明,随着TiO_2颗粒浓度增加,白光数码管的光通量呈先上升后下降的趋势,在颗粒掺杂浓度为0.34%时... 详细信息

将掺杂TiO_2颗粒的高折射胶层旋涂于倒置芯片侧面,荧光粉胶层喷涂于芯片正表面,制备了白光数码管;并对样品进行了光色性能测试分析。结果表明,随着TiO_2颗粒浓度增加,白光数码管的光通量呈先上升后下降的趋势,在颗粒掺杂浓度为0.34%时达到最大值161.2lm,相较于掺杂浓度为0.00%时的155.0lm提高了3.85%,在掺杂浓度为0.40%时色温下降了33.4%。同时通过实验发现,五面出光结构白光数码管光的通量和色温分别比单面出光结构高7.80%和16.73%,通过比对芯片光强分布,单面出光芯片的可视角度为114.6°。结果表明,通过适当的掺杂颗粒浓度调制,可制备出可视角度小、相关色温可调和光通量适当的白光数码管。

关键词：光学器件白光数码管 Ti02颗粒可视角度

TiO_2掺杂浓度对倒装白光数码管光色性能的影响

在线全文

学校读者我要写书评

暂无评论

光电子．激光 2017年第11期28卷 1186-1190页

作者：盛立军绍兴职业技术学院浙江绍兴312000

采用热压法将TiO_2按一定计量比掺入AB混合胶制备折射胶层,在芯片和荧光粉胶层间利用甩胶旋涂工艺添加折射胶层,封装成白光数码管;对样品的光色性能进行了测试和机理分析。结果表明,折射层中掺杂TiO_2颗粒浓度为0.3%时,白光数码管单笔... 详细信息

采用热压法将TiO_2按一定计量比掺入AB混合胶制备折射胶层,在芯片和荧光粉胶层间利用甩胶旋涂工艺添加折射胶层,封装成白光数码管;对样品的光色性能进行了测试和机理分析。结果表明,折射层中掺杂TiO_2颗粒浓度为0.3%时,白光数码管单笔段光通量达到了最高值175lm,比TiO_2浓度为0%时提高了约为7.5%。在相同测试条件下,掺杂0.3%浓度TiO_2颗粒的倒装白光数码管比传统点胶白光数码管平均光通量提高了约为6.5%,平均色温下降约为9.6%,出光一致性更理想。TiO_2颗粒的掺入不仅提高了器件光通量,降低了色温,同时为白光数码管实现远程荧光粉涂覆工艺提供了一种有效的途径。

关键词：光学器件白光数码管 TiO2颗粒远程荧光粉

在线全文

学校读者我要写书评

暂无评论

呼吸音信号的包络特征提取方法

计算机工程与应用 2008年第32期44卷 151-154页

作者：李圣君曲阜师范大学计算机科学学院山东日照276826

针对时变宽带的呼吸音信号,在分析传统Hilbert变换方法提取包络的缺点基础上,提出基于复小波变换的呼吸音信号包络特征提取方法。选取Morlet复小波,以适当的尺度对预处理后的呼吸音数据进行变换得到包络,提取包络的统计量和能量作为特征... 详细信息

针对时变宽带的呼吸音信号,在分析传统Hilbert变换方法提取包络的缺点基础上,提出基于复小波变换的呼吸音信号包络特征提取方法。选取Morlet复小波,以适当的尺度对预处理后的呼吸音数据进行变换得到包络,提取包络的统计量和能量作为特征,构造BP分类神经网络的输入矢量,经训练识别取得较好分类效果。研究表明该文的特征提取方法是行之有效的。

关键词：呼吸音 Hilbert变换复小波变换包络提取

Fluorine-functionalized zirconium-organic cages for efficient photocatalytic oxidation of thioanisole

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2025年第1期36卷 632-636页

作者： Jia-Ru li Ning li li-ling He jun He School of Chemical Engineering and light Industry Guangdong University of TechnologyGuangzhou 510006China School of Chemistry South China Normal UniversityGuangzhou 510006China

Zirconium-based metal-organic cages(Zr-MOCs)typically exhibit high stability,but their structural and application reports are scarce due to stringent crystallization *** have successfully fluorinated the classical Zr-MOCs(ZrT-3)for the first time,obtaining the fluorinated MOCs(ZrT-3-F).Notably,ZrT-3-F not only inherits the high stability of its parent structure,but also acts as a catalyst for the effective oxidation of benzyl thioether for the first *** reaction can reach a conversion rate of 99%in 6 h,and the selectivity reaches 95%,which far exceeds the non-fluorinated *** work proves that the specific functionalization of the classical Zr-MOCs can further expand their application potential,such as catalysis.

关键词： Ultraviolet light Fluorine Zirconium-based metal-organic cages Sulfide oxidation Multiphase photocatalysis