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Risk Assessment and Zoning of Agricultural Drought Disaster in Heilongjiang Province

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Agricultural Science & Technology 2011年第4期12卷 588-591页

作者： ZHENG Kai CHEN Hong ZHANG Li-juan gao yu-hong Weather Modification Office of Heilongjiang Province Harbin 150030 College of Geographic Science Harbin Normal University Harbin150025

In this study,we first zoned the drought degree in the years from 1971 to 2000 in Heilongjiang Province by using precipitation anomaly equation as an indicator,and analyzed the temporal distribution characteristics and laws of arid disaster in different *** the method of human being habitat risk assessment,we further studied and zoned the drought disaster risk index(DDRI)of maize cultivated in 74 stations in Heilongjiang Province via GIS *** results showed that(1)the occurrence frequency of moderate and heavy drought in Heilongjiang Province was 1970s>1990s>1980s,and(2)the high risk area of drought disaster for maize production mainly assembled in Qiqihar and Daqing regions in west Heilongjiang Province,where agricultural drought should be highly concerned,while low risk and slight risk areas mainly distribute in middle areas and east plain areas in Heilongjiang *** study provided basis for the defense of agricultural drought disaster.

关键词： Drought disaster Risk index Zoning Helongjiang Province

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定子双绕组异步发电机漏电抗计算的研究

航空学报 2006年第1期27卷 109-114页

作者：刘陵顺胡育文黄文新南京航空航天大学航空电源科技重点实验室

漏电抗的准确计算是电机设计中十分关键的问题。基于静止励磁调节器的双绕组异步发电机定子绕组漏抗计算比传统的三相电机更复杂。首先给出了定子双绕组异步电机通用数学模型及等效电路,采用解析法对不同绕组结构的定子双绕组异步电机... 详细信息

漏电抗的准确计算是电机设计中十分关键的问题。基于静止励磁调节器的双绕组异步发电机定子绕组漏抗计算比传统的三相电机更复杂。首先给出了定子双绕组异步电机通用数学模型及等效电路,采用解析法对不同绕组结构的定子双绕组异步电机漏电抗计算进行了系统地分析,导出了相应的计算公式。最后,利用所得计算公式设计了一种静止励磁调节器控制的定子双绕组异步发电机,并对其定子漏电抗参数、性能指标及运行特性进行了计算。

关键词：定子双绕组异步电机漏电抗参数计算电机设计

双肢拼合冷弯薄壁型钢工字形截面梁受弯性能研究

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土木工程学报 2016年第8期49卷 16-27,52页

作者：周绪红管宇高婷婷石宇长安大学陕西西安710061 重庆大学重庆400045

对6个单肢冷弯薄壁型钢C形截面梁和18个双肢拼合冷弯薄壁型钢工字形截面梁进行了受弯性能试验研究，考察梁跨高比、翼缘宽厚比、截面高宽比、螺钉连接间距以及腹板开孔对双肢拼合工字形截面梁破坏模式和极限受弯承载力的影响，验证双肢... 详细信息

对6个单肢冷弯薄壁型钢C形截面梁和18个双肢拼合冷弯薄壁型钢工字形截面梁进行了受弯性能试验研究，考察梁跨高比、翼缘宽厚比、截面高宽比、螺钉连接间距以及腹板开孔对双肢拼合工字形截面梁破坏模式和极限受弯承载力的影响，验证双肢拼合截面梁受弯承载力具有“1×2≥2”的拼合效应，并采用ANSYS有限元软件进行数值模拟与影响因素分析。结果表明：试件的破坏模式为翼缘及腹板局部屈曲和畸变屈曲的相关屈曲形式。改变翼缘宽厚比和截面高宽比对双肢拼合冷弯薄壁型钢工字形截面梁的承载力影响最大，而改变螺钉连接间距（300～600mm范围内）和梁跨高比对工字形梁的承载力影响较小。在实际工程设计中，建议腹板开孔采用圆形孔洞形式，腹板开孔截面积比例取为35％～50％之间，同时腹板开孔间距应不小于400mm。在双肢拼合工字梁受弯承载力折减强度法的基础上，提出了适用于腹板开孔双肢拼合冷弯薄壁型钢工字形截面梁受弯承载力计算的强度折减修正法。

关键词：冷弯薄壁型钢双肢拼合工字形梁受弯承载力试验研究数值分析

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熔融沉积成型加工的结晶性聚合物结构与性能

高分子学报 2020年第11期51卷 1214-1226,I0002页

作者：高霞戚顺新苏允兰黎静王笃金中国科学院重庆绿色智能技术研究院重庆市3D打印应用工程技术研究中心重庆400714 中国科学院化学研究所中国科学院工程塑料重点实验室北京100190 中国科学院大学北京100049

熔融沉积成型(fused deposition modeling,FDM)作为一种新型的聚合物加工方式,可制备外形复杂、性能可靠、功能集成的聚合物制品,并随着新打印工艺和新材料体系的不断涌现,显示出巨大的应用和发展潜力.但层层堆积的加工方式为FDM成型件... 详细信息

熔融沉积成型(fused deposition modeling,FDM)作为一种新型的聚合物加工方式,可制备外形复杂、性能可靠、功能集成的聚合物制品,并随着新打印工艺和新材料体系的不断涌现,显示出巨大的应用和发展潜力.但层层堆积的加工方式为FDM成型件引入了薄弱层间结合界面和较大残余内应力,限制了可FDM加工的聚合物材料种类,并制约着FDM成型件的性能和功能.本文结合FDM加工原理分析了可FDM加工的聚合物材料特性,重点关注FDM成型件的微观结构包括多层次聚集态结构、层间结合界面,总结FDM成型件的宏观力学性能及其各向异性,以此构建FDM成型的聚合物结构-性能关系,并展望高性能FDM成型件的发展前景.

关键词：熔融沉积成型结晶性聚合物材料多层次结构各向异性

Use of preoperative ultrasound in designing the true pectoralis major myocutaneous island flap

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Chinese Medical Journal 2012年第4期125卷 667-670页

作者： Chen Xiao-hong Zhao Han-xue Fang Ju-gao yu Zhen-kun Huang Zhi-gang Capital Med Univ Key Lab Otolaryngol Head & Neck Surg Dept Otolaryngol Head & Neck SurgMinist Educ Beijing Tongren HospBeijing Inst Otolaryngol Beijing 100730 Peoples R China Capital Med Univ Beijing Tongren Hosp Dept Ultrasound Beijing 100730 Peoples R China

Background Traditional techniques used for harvesting the pectoralis major myocutaneous （PMMC） flap have accompanying disadvantages,such as the necessity for an upper chest skin incision,the bulkiness of myocutaneous tissue at the pedicle of the flap,and the risk of total or partial necrosis of flap *** aim of this study was to develop a safe and fast method for preparing PMMC island flaps using preoperative ultrasonography for vessel *** Forty-one PMMC island flaps were used for one-stage reconstruction of head and neck defects,including 21 cases in the treatment group and 20 cases in the control *** the treatment group,ultrasonography was used to mark out the course of the thoracic branches of the thoracoacromial artery and the lower end of this artery perforating from the fascia into the muscles,as well as the largest perforating branch of the fourth or fifth internal mammary artery entering the PMMC flap.A line,from the lower end of the thoracic branch to the largest perforating branch of the fourth or fifth internal mammary artery,was drawn to determine the axis of the PMMC *** the control group,PMMC island flaps were designed according to conventional methods without using *** According to the ultrasonic marks,the distance from lower end of thoracic branch to the midpoint of the margin of the inferior clavicular was （5.1±1.2） *** time from designing to transferring the island flap was significantly shorter in the treatment group （（51.0±10.5） minutes） compared with the control group （（78.0±13.9） minutes,P 〈0.01）.The rate of partial necrosis was 4.7% （1/21） in the treatment group and 35.0% （7/20） in the control *** was one case of flap failure in the control group due to vascular injury during vascular pedicle *** Preoperative vessel detection by ultrasonography facilitates easy and safe harvesting of the true PMMC island flap.

关键词： ultrasonic pectoralis major island flap reconstruction surgery

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反射剖面精确拟合的次表面散射计算方法

软件学报 2023年第8期34卷 3757-3773页

作者：梁仕宇高阳丛宇郝爱民虚拟现实技术与系统国家重点实验室(北京航空航天大学) 北京100191 西安电子科技大学计算机科学与技术学院陕西西安710071 中国医学科学院虚拟人体和虚拟手术技术创新单元北京100032 北京众绘虚拟现实技术研究院有限公司北京101300

近年来,随着电影、游戏、虚拟现实应用等对真实感要求的不断提高,针对人体组织、牛奶等半透明材质的实时渲染变得越发重要.针对当前大部分次表面散射计算方法难以正确估计散射范围的问题,提出了一种全新的次表面散射计算方法用以精确表... 详细信息

近年来,随着电影、游戏、虚拟现实应用等对真实感要求的不断提高,针对人体组织、牛奶等半透明材质的实时渲染变得越发重要.针对当前大部分次表面散射计算方法难以正确估计散射范围的问题,提出了一种全新的次表面散射计算方法用以精确表示最大散射距离.首先,针对暴力蒙特卡洛光子追踪结果进行模拟,以得到反射剖面结果.其次通过多项式模型进行反射剖面拟合,计算精确着色点处的最大散射范围.最后,提出了一种新的重要性采样方案以减少蒙特卡洛所需的采样数,进一步提高计算效率.此外,方法所需的参数仅由着色点上的反射率以及材质平均自由程提供,以便于灵活调整渲染效果.实验证明,所提模型避免了之前对于散射范围的错误估计,对材质反射率复杂的区域具有更好的渲染精度,且渲染速率满足实时要求.

关键词：次表面散射半透明材质真实感渲染函数拟合实时渲染

Spleen volume is associated with overt hepatic encephalopathy after transjugular intrahepatic portosystemic shunt in patients with portal hypertension

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World Journal of Gastrointestinal Surgery 2024年第7期16卷 2054-2064页

作者： Chun-Juan Zhao Chao Ren Zhen yuan Guo-Hui Bai Jin-yu Li Long gao Jin-Hui Li Ze-Qi Duan Dui-Ping Feng Hui Zhang College of Medical Imaging Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Radiology The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Occupational Health School of Public HealthShanxi Key Laboratory of Environmental Health Impairment and PreventionNHC Key Laboratory of PneumoconiosisMOE Key Laboratory of Coal Environmental Pathogenicity and PreventionShanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Oncological and Vascular Intervention The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Shanxi Provincial Clinical Research Center for Interventional Medicine The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina First Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Shanxi Key Laboratory of Intelligent Imaging and Nanomedicine The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Intelligent Imaging Big Data and Functional Nano-imaging Engineering Research Center of Shanxi Province The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina

BACKGROUND Portal shunt and immune status related to the spleen are related to the occurrence of hepatic encephalopathy(HE).It is unknown whether spleen volume before transjugular intrahepatic portosystemic shunt(TIPS)is related to postoperative *** To investigate the relationship between spleen volume and the occurrence of *** This study included 135 patients with liver cirrhosis who underwent TIPS,and liver and spleen volumes were elevated upon computed tomography *** Kaplan-Meier curve was used to compare the difference in the incidence rate of HE among patients with different spleen *** and multivariate Cox regression analyses were performed to identify the factors affecting overt HE(OHE).Restricted cubic spline was used to examine the shapes of the dose-response association between spleen volumes and OHE *** The results showed that 37(27.2%)of 135 patients experienced OHE during a 1-year follow-up *** with preoperative spleen volume(901.30±471.90 cm3),there was a significant decrease in spleen volume after TIPS(697.60±281.0 cm^(3))in OHE *** the severity of OHE increased,the spleen volume significantly decreased(P<0.05).Compared with patients with a spleen volume≥782.4 cm^(3),those with a spleen volume<782.4 cm^(3) had a higher incidence of HE(P<0.05).Cox regression analysis showed that spleen volume was an independent risk factor for post-TIPS OHE(hazard ratio=0.494,P<0.05).Restricted cubic spline model showed that with an increasing spleen volume,OHE risk showed an initial increase and then decrease(P<0.05).CONCLUSION Spleen volume is related to the occurrence of OHE after *** spleen volume is an independent risk factor for post-TIPS OHE.

关键词： Hepatic encephalopathy Transjugular intrahepatic portosystemic shunt Spleen volume Portal hypertension Cirrhosis

Reversible switching of Kondo resonance in a single-molecule junction

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Nano Research 2022年第2期15卷 1466-1471页

作者： yuqing Xing Hui Chen Bin Hu yuhan Ye Werner AHofer Hong-Jun gao Institute of Physics Chinese Academy of Sciences and University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

The control of the Kondo effect is of great interest in single-molecule junction due to its potential applications in spin based ***,we demonstrate that the Kondo effect is reversibly switched on and off in an iron phthalocyanine(FePc)single-molecule junction by using a superconducting Nb *** a scanning tunneling microscope-based Nb-insulator-FePc-Au junction,we achieve a reversible switching between the Kondo dip and inelastic electronic tunneling spectra by simply adjusting the tip-sample distance to tune the tunnel coupling at low *** approaching the tip leads to the picking up of the molecule to the tip apex,which transfers the geometry of the single-molecule junction into a Nb-FePc-insulator-Au *** the molecule forms an effective magnetic impurity embedded into the superconducting ground states of the Nb tip,the out-gap Kondo dip switched to an in-gap yu-Shiba-Rusinov *** results open up a new route for manipulating the Kondo effect within a single-molecule junction.

关键词： iron phthalocyanine(FePc) scanning tunneling microscope superconducting tip Kondo resonance inelastic electron tunneling yu-Shiba-Rusinov states

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细叶石仙桃乙酸乙酯部位化学成分研究

中药材 2014年第6期37卷 986-989页

作者：李斌高洁莹李娟陈钰妍李顺祥湖南中医药大学药学院中药现代化重点实验室湖南长沙410208

目的:研究细叶石仙桃乙酸乙酯部位的化学成分。方法:采用硅胶、Sephadex LH-20、MCI gel柱色谱及重结晶分离和纯化,根据理化性质和波谱数据鉴定化合物结构。结果:从细叶石仙桃乙酸乙酯部位中分离纯化了10个化合物,分别鉴定为:batatasin... 详细信息

目的:研究细叶石仙桃乙酸乙酯部位的化学成分。方法:采用硅胶、Sephadex LH-20、MCI gel柱色谱及重结晶分离和纯化,根据理化性质和波谱数据鉴定化合物结构。结果:从细叶石仙桃乙酸乙酯部位中分离纯化了10个化合物,分别鉴定为:batatasinⅢ(1)、orchinol(2)、ephmeranthoquinone(3)、densiflorol B(4)、3,5-二甲氧基-4-羟基-苯丙酮(5)、桂皮酸(6)、丁香脂素(7)、二十四亚甲基环阿尔廷醇(8)、麦角甾醇过氧化物(9)、β-谷甾醇(10)。结论:其中,化合物6、9为首次从石仙桃属植物中分离得到,化合物4、5、7为首次从该植物中分离得到。

关键词：细叶石仙桃石仙桃属化学成分