期刊文献+
共找到2,707篇文章
< 1 2 136 >
每页显示 20 50 100
中孕期胎儿系统超声检查切面及临床意义 被引量:100
1
作者 李胜利 文华轩 《中华医学超声杂志(电子版)》 2010年第3期9-13,共5页
目的研究中孕期胎儿系统超声检查中的各种切面,探讨这些切面的临床意义。方法总结和归纳我院2000年7月至2009年7月9年间的胎儿系统超声检查的经验,对比分析国外产科超声检查经验和规范,通过研究各种畸形在不同切面上的表现,对中孕期产... 目的研究中孕期胎儿系统超声检查中的各种切面,探讨这些切面的临床意义。方法总结和归纳我院2000年7月至2009年7月9年间的胎儿系统超声检查的经验,对比分析国外产科超声检查经验和规范,通过研究各种畸形在不同切面上的表现,对中孕期产科超声检查过程中需要检查的切面进行详细研究,规范胎儿系统超声检查的标准切面。结果笔者研究了中孕期胎儿系统超声检查的各个切面,发现32~39个胎儿切面在胎儿超声检查中非常重要,绝大部分胎儿结构畸形可通过这些切面筛查并诊断出来,从而提高胎儿畸形产前检出率。结论胎儿系统超声检查中32~39个切面是中孕期系统超声检查中的重要切面,这些切面的制定和规范,有利于提高胎儿畸形产前检出率,为产前超声诊断规范化培训和质量控制奠定基础。 展开更多
关键词 胎儿 中孕期 产前诊断 超声检查 切面
原文传递
周期反复荷载下L型截面柱的试验研究 被引量:8
2
作者 卫园 冯建平 《华南理工大学学报(自然科学版)》 EI CAS CSCD 1995年第3期44-51,共8页
本文通过对十二根试件的试验,研究了轴压比、箍筋的配筋率、纵筋的配筋率对L型截面柱子的破坏形态、滞回曲线和延性的影响。本文把单调加载的钢筋混凝土压弯构件承载力的计算结果与本文的试验结果作了比较。证明用单调加载的钢筋混凝... 本文通过对十二根试件的试验,研究了轴压比、箍筋的配筋率、纵筋的配筋率对L型截面柱子的破坏形态、滞回曲线和延性的影响。本文把单调加载的钢筋混凝土压弯构件承载力的计算结果与本文的试验结果作了比较。证明用单调加载的钢筋混凝土压弯构件承载力计算方法来计算反复荷载作用下的钢筋混凝土压弯构件的承载力是安全的。 展开更多
关键词 周期性 载荷 L型截面柱 钢筋混凝土 承载能力
下载PDF
超可解群的若干充分条件 被引量:13
3
作者 张勤海 赵俊英 《数学杂志》 CSCD 北大核心 2005年第4期399-404,共6页
本文研究了有限群的超可解性问题,利用子群的共轭可换性概念及极小反例法,获得了一个群为超可解的若干充分条件.举例说明了主要结果中的假设条件是不可少的.
关键词 共轭可换子群 超可解群 极小非超可解群 截断
下载PDF
高速公路路段通行能力仿真研究 被引量:13
4
作者 杜攀峰 金双泉 李嘉 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2009年第6期7-12,共6页
基于VISSIM交通仿真软件可重复性和可延续性的特点,以高速公路交通流运行特征作为分析对象,对通行能力仿真研究的关键参数进行标定与评价.并以标定的VIS-SIM作为平台建立典型的高速公路基本路段仿真模型,再现复杂交通条件下的车流运行... 基于VISSIM交通仿真软件可重复性和可延续性的特点,以高速公路交通流运行特征作为分析对象,对通行能力仿真研究的关键参数进行标定与评价.并以标定的VIS-SIM作为平台建立典型的高速公路基本路段仿真模型,再现复杂交通条件下的车流运行特性以及影响通行能力各参数的度量指标.对比现行高速公路服务水平分级标准,分析了产生差别的原因,并由此推算出分级服务水平下的通行能力和交通流临界密度. 展开更多
关键词 高速公路 交通仿真 路段 标定 通行能力 临界密度
下载PDF
Deep structures of the east Dabie ultrahigh-pressure metamorphic belt, East China 被引量:16
5
作者 杨文采 《Science China Earth Sciences》 SCIE EI CAS 2003年第6期612-624,共15页
The geophysical investigations with seismic and MT methods were carried out in the east Dabie Mountain area in 1997, producing detailed results about crustal structures with good compatibility between different geophy... The geophysical investigations with seismic and MT methods were carried out in the east Dabie Mountain area in 1997, producing detailed results about crustal structures with good compatibility between different geophysical methods. After integrated interpretation of both avail-able geophysical and geological data, the author compiles a crustal tectonic section across the east Dabie Mountain (Plate II), which provides much more structural details with improved reliabil-ity due to geophysical constraints applied to the deep structures. The east Dabie orogenic belt can be divided into 4 geologic units from north to south: the north Huaiyang, the north Dabie, the south Dabie and the Susong. The Mesozoic northward subduction of the Yangtze craton caused the Yangtze crust to insert into the middle and lower crust of the Susong high-pressure metamorphic zone, while the middle and lower crust below the north Huaiyang and the Hefei basin contains the basement of the Sino-Korean craton. The middle and lower crust of the south Dabie is rather dif-ferent from that of the north Dabie, showing that the north and the south Dabie had different evolu-tional trajectories and should not belong to a single tectonic unit. The current crustal pattern has resulted mainly from deformation caused by the post-collisional intracontinental subduction of both the Yangtze and Sino-Korean cratons before the late Jurassic, and deformation caused by later crustal extension including doming and unroofing around the north Dabie. It can be inferred that the suture zone of the Triassic collision between the Sino-Korea and the Yangtze was located along the Xiaotian-Mozitan fault zone, which contains a group of normal faults dipping north in the upper crust, but becomes steep thrusts of dipping south in the middle crust, accompanied by ex-tensive deformation between this fault zone and the Hefei basin. The middle crust below the north Huaiyang unit is connected to the basement of the Sino-Korean craton, showing the plate com-pressional convergence bet 展开更多
关键词 geophysical investigations CRUSTAL tectonic sections COLLISIONAL belt ULTRAHIGH-PRESSURE zone east DABIE Mountain.
原文传递
HER2 in gastric cancer: Comparative analysis of three different antibodies using whole-tissue sections and tissue microarrays 被引量:13
6
作者 Lucas Faria Abraho-Machado Alexandre Andrade dos Anjos Jácome +4 位作者 Durval Renato Wohnrath José Sebastio dos Santos Estela Cristina Carneseca José Humberto Tavares Guerreiro Fregnani Cristovam Scapulatempo-Neto 《World Journal of Gastroenterology》 SCIE CAS 2013年第38期6438-6446,共9页
AIM:To compare the performance of three commercially available anti-human epidermalgrowth factor receptor 2(HER2)antibodies in whole-tissue sections and tissue microarrays(TMAs)of a series of gastric tumors.METHODS:We... AIM:To compare the performance of three commercially available anti-human epidermalgrowth factor receptor 2(HER2)antibodies in whole-tissue sections and tissue microarrays(TMAs)of a series of gastric tumors.METHODS:We present a comparative analysis of three anti-HER2 antibodies(HercepTest,4B5 and SP3)using TMA and whole-tissue sections prepared from the same paraffin blocks of 199 gastric adenocarcinomas operated upon between January 2004 and December2008 at a Brazilian cancer hospital.The data on the patients’age,sex,the anatomical location of the tumor and the Lauren’s histological classification were collected from clinical and pathological records.The immunohistochemical(IHC)results were examined by two pathologists and the cases were classified as positive(3+),equivocal(2+)and negative(0 or 1+),according to the criteria of the IHC scoring system of gastric cancer.TMAs and whole-tissue sections were evaluated separately and independently.All cases yielding discordant IHC results and/or scored as 2+were subjected to dual-color in situ hybridization in order to determine the final HER2 status.Besides determining the sensitivity and predictive value for HER2-positive status,we measured the accuracy of each antibody by calculating the area under the receiver operating characteristic(ROC)curve.The agreement between the results obtained using the TMAs and those obtained using the whole-tissue sections was assessed by means of Kappa coefficient.RESULTS:Intratumoral heterogeneity of HER2 expression was observed with all antibodies.HER2-positive expression(3+)in the whole-tissue sections was observed in 23 cases(11.6%)using the 4B5 antibody,in 18 cases(9.1%)using the SP3 antibody and in 10 cases(5.1%)using the HercepTest antibody.In the TMAs,11 positive cases(5.6%)were identified using SP3 antibody,9(4.6%)using the 4B5 antibody and 6(3%)using the HercepTest antibody.The sensitivity using whole-tissue sections and TMA,respectively,was 95.2%and 42.9%with 4B5,90.5%and 66.7%with SP3 and 47.6%and42.9%with HercepTest.Th 展开更多
关键词 Gastric cancer Human epidermalgrowth factor receptor 2 IMMUNOHISTOCHEMISTRY Whole-tissue sections TISSUE MICROARRAY TRASTUZUMAB
下载PDF
Nonlinear dynamics analysis of a new autonomous chaotic system 被引量:14
7
作者 CHU Yan-dong LI Xian-feng +1 位作者 ZHANG Jian-gang CHANG Ying-xiang 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第9期1408-1413,共6页
In this paper,a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further,to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied eith... In this paper,a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further,to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied either analytically or nu-merically,such as Poincaré map,Lyapunov exponents and Lyapunov dimension. Based on this flow,a new almost-Hamilton chaotic system with very high Lyapunov dimensions is constructed and investigated. Two new nonlinear autonomous systems can be changed into one another by adding or omitting some constant coefficients. 展开更多
关键词 Lyapunov exponents BIFURCATION CHAOS Phase space Poincaré sections
下载PDF
UPLC法测定不同加工方式鹿茸中的生物胺成分 被引量:14
8
作者 王燕华 孙印石 +4 位作者 王玉方 陈宝 霍晓慧 刘畅 张磊 《分析测试学报》 CAS CSCD 北大核心 2018年第9期995-1001,共7页
首次应用超高效液相色谱法(UPLC)同时测定了鹿茸中10种生物胺组分的含量,比较了不同加工方式的鹿茸中生物胺的差异。鹿茸样品中的生物胺用0. 4 mol/L高氯酸浸提,10 g/L丹磺酰氯衍生化,UPLC法定量分析。色谱柱为ACQUITY UPLC@BEH C18(2. ... 首次应用超高效液相色谱法(UPLC)同时测定了鹿茸中10种生物胺组分的含量,比较了不同加工方式的鹿茸中生物胺的差异。鹿茸样品中的生物胺用0. 4 mol/L高氯酸浸提,10 g/L丹磺酰氯衍生化,UPLC法定量分析。色谱柱为ACQUITY UPLC@BEH C18(2. 1 mm×100 mm,1. 7μm),流动相为乙腈-水,柱温为35℃,流速为0. 4 m L/min,检测波长为217 nm。结果显示,10种生物胺在一定浓度范围内呈良好线性关系,其相关系数为0. 997 8~0. 999 9,检出限为10. 87~19. 63μg/L,回收率为71. 6%~101%。煮炸茸和冻干茸蜡片、粉片、纱片、骨片4个部位的生物胺总量依次为312. 33、176. 88、105. 31、55. 674 mg/kg和291. 77、152. 85、114. 49、74. 73 mg/kg;排血茸蜡片、粉片、纱片、骨片4个部位的生物胺总量分别为357. 07、226. 26、125. 18、77. 74 mg/kg,带血茸的分别为343. 42、216. 72、125. 15、76. 16 mg/kg。就生物胺总量而言,冻干茸高于煮炸茸,排血茸高于带血茸,且按蜡片、粉片、纱片、骨片部位依次减少,不同部位之间差异显著(P <0. 05)。 展开更多
关键词 鹿茸 生物胺 加工方式 部位 比较 超高效液相色谱法(UPLC)
下载PDF
中孕早期胎儿心脏超声检查在先天性心脏病筛查中的价值分析 被引量:9
9
作者 陈昌秀 赵颉 +2 位作者 张雪梅 冯露 王渝娜 《实用医院临床杂志》 2023年第1期36-40,共5页
目的 探讨中孕早期应用胎儿心脏超声检查在胎儿先天性心脏病筛查中的价值。方法 对有先心病高危因素及其他早期筛查胎儿心脏需求的82名孕妇,92例胎儿,在孕14~16周经孕妇腹壁对胎儿心脏进行超声检查;同时期具有同类先心病高危因素或筛查... 目的 探讨中孕早期应用胎儿心脏超声检查在胎儿先天性心脏病筛查中的价值。方法 对有先心病高危因素及其他早期筛查胎儿心脏需求的82名孕妇,92例胎儿,在孕14~16周经孕妇腹壁对胎儿心脏进行超声检查;同时期具有同类先心病高危因素或筛查需求的1846名孕妇、1856例胎儿中孕中期心脏超声筛查结果为对照组。记录两组切面获得情况和检查结果;以引产后及出生后结果为金标准,计算该时期超声检查的灵敏度、特异度、准确度、阳性预测值和阴性预测值。结果 研究组92例胎儿中孕早期检查全部完成,各切面平均获得率为99%;心脏结构阴性81例,中孕中期复查检出永存左上腔静脉1例;检出先天性心脏病11例,1例室间隔缺损在中孕中期复查时未见异常,中孕早期先心病超声筛查的灵敏度90.9%,特异度98.7%,准确度97.7%,阳性预测值90.9%,阴性预测值98.7%;另检出心内染色体异常软指标三尖瓣反流3例和心室灶状强回声17例,经羊水穿刺明确染色体异常1例。对照组检出胎儿先心病47例,灵敏度97.9%,特异度99.9%,准确度99.9%,阳性预测值97.9%,阴性预测值99.9%,两组比较差异无统计学意义(P>0.05)。结论 在中孕早期进行胎儿心脏超声检查能够检出严重复杂的心脏畸形和部分简单畸形,发现心内染色体异常的软指标,对出生缺陷早期防治具有重要价值。 展开更多
关键词 中孕早期 胎儿心脏 超声 切面 先天性心脏病
下载PDF
广东省跨市河流边界水质状况研究 被引量:12
10
作者 温丽容 刘乙敏 +1 位作者 刘国光 崔光琦 《生态环境》 CSCD 2004年第2期177-179,190,共4页
对1994~2001年间广东省25个边界水质控制断面的氨氮、生化需氧量和高锰酸钾指数等监测资料进行统计分析,结果显示,全省跨市河流边界水质状况总体上趋于好转,但部分断面有恶化趋势.2001年污染较为严重的边界断面主要有西湖村、企坪、上... 对1994~2001年间广东省25个边界水质控制断面的氨氮、生化需氧量和高锰酸钾指数等监测资料进行统计分析,结果显示,全省跨市河流边界水质状况总体上趋于好转,但部分断面有恶化趋势.2001年污染较为严重的边界断面主要有西湖村、企坪、上垟、石碧、青洋大桥及雁田等6个.氨氮污染最为严重. 展开更多
关键词 水质 跨市河流 控制断面 广东省
下载PDF
Research on multi-terminal traveling wave fault location method in complicated networks based on cloud computing platform 被引量:12
11
作者 Feng Deng Xiangjun Zeng Lanlan Pan 《Protection and Control of Modern Power Systems》 2017年第1期199-210,共12页
Cloud computing technology is used in traveling wave fault location,which establishes a new technology platform for multi-terminal traveling wave fault location in complicated power systems.In this paper,multi-termina... Cloud computing technology is used in traveling wave fault location,which establishes a new technology platform for multi-terminal traveling wave fault location in complicated power systems.In this paper,multi-terminal traveling wave fault location network is developed,and massive data storage,management,and algorithm realization are implemented in the cloud computing platform.Based on network topology structure,the section connecting points for any lines and corresponding detection placement in the loop are determined first.The loop is divided into different sections,in which the shortest transmission path for any of the fault points is directly and uniquely obtained.In order to minimize the number of traveling wave acquisition unit(TWU),multi-objective optimal configuration model for TWU is then set up based on network full observability.Finally,according to the TWU distribution,fault section can be located by using temporal correlation,and the final fault location point can be precisely calculated by fusing all the times recorded in TWU.PSCAD/EMTDC simulation results show that the proposed method can quickly,accurately,and reliably locate the fault point under limited TWU with optimal placement. 展开更多
关键词 Wide Area Network Fault location Traveling wave Junction Point between sections Cloud computing platform
原文传递
卡尔·刘易斯100m跑速度节奏特征的分析 被引量:10
12
作者 申伟华 付声波 《武汉体育学院学报》 CSSCI 北大核心 1999年第1期46-47,共2页
刘易斯不适宜采用高速起伏式速度节奏模式 ,它不利于发挥其“绝佳的后程提速能力”;刘易斯虽然具有很高的速度调节能力 ,但仍应加强起跑反应的训练。
关键词 百米跑 速度节奏 过度加速 全程分段
下载PDF
PE文件格式剖析 被引量:7
13
作者 嵇海明 杨宗源 《计算机应用研究》 CSCD 北大核心 2004年第3期165-166,193,共3页
主要分析了PE(PortableExecutable)文件格式,重点探讨了PE文件中的输入表、输出表以及资源段的格式,还探究了在微软全新的.Net平台上对PE文件的扩展,给出了一些分析PE文件格式的工具。
关键词 PE文件格式 PE扩展
下载PDF
Partial wave scattering cross sections for He-HBr collision 被引量:7
14
作者 余春日 凤尔银 +1 位作者 汪荣凯 杨向东 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第11期2571-2577,共7页
A new anisotropic potential is fitted to ab initio data. The close-coupling approach is utilized to calculate state-tostate rotational excitation partial wave cross sections for elastic and inelastic collisions of He ... A new anisotropic potential is fitted to ab initio data. The close-coupling approach is utilized to calculate state-tostate rotational excitation partial wave cross sections for elastic and inelastic collisions of He atom with HBr molecule based on the fitted potential. The calculation is performed separately at the incident energies: 75, 100 and 200 meV.The tendency of the elastic and inelastic rotational excitation partial wave cross sections varying with total angular quantum number J is obtained. 展开更多
关键词 close-coupling approach partial wave cross sections He-BrH complex
下载PDF
三峡库区澎溪河河段间水华程度差异及其机制 被引量:4
15
作者 罗晓佼 张钘 +3 位作者 黄伟 胡鹏飞 谭炳圆 张磊 《环境科学》 EI CAS CSCD 北大核心 2023年第1期282-292,共11页
三峡大坝蓄水以来,库区50%一级支流水华频发,且不同支流水华高发断面的地理位置不同,受干流影响程度存在差异.为探讨水华暴发的河段差异,及其与长江回水的关系,以库区一级支流澎溪河为例,在2019年春季水华季,进行了间隔期一周、总时长... 三峡大坝蓄水以来,库区50%一级支流水华频发,且不同支流水华高发断面的地理位置不同,受干流影响程度存在差异.为探讨水华暴发的河段差异,及其与长江回水的关系,以库区一级支流澎溪河为例,在2019年春季水华季,进行了间隔期一周、总时长一个月的采样,从河口至上游设置7个采样断面(PX1~PX7),根据各断面的垂向水温和电导率特征推断长江回水的影响范围和形式;并通过对水华高发的高阳平湖断面(PX5)和分别距其4 km的上游断面(PX6)和下游断面(PX4)的水文、水质和底泥营养盐等指标,探究断面间水华暴发程度的差异及其机制.结果表明,水华季澎溪河下游(PX1~PX4)的ρ(Chl-a)较低,为14.55~44.00μg·L^(-1),上游(PX5~PX7)则达到42.66~175.40μg·L^(-1),其中PX5的ρ(Chl-a)最高时达413.00μg·L^(-1),显著高于其余位点(P<0.05).温度和电导率结果显示,4~5月长江干流回水从中下层潜入澎溪河,下游(PX1~PX4)处于长江干流回水与澎溪河上游来水的交汇区域,水体不稳定,不利于水华暴发;而澎溪河中上游(PX5~PX7)未直接受到长江干流回水的影响,营养交换以垂向为主.PX4~PX6的水体各层的n(TN)/n(TP)和n(DTN)/n(DTP)均值多数远高于16,水体营养盐为磷限制状态.采样期内,PX5底泥全磷均值为相距仅4 km的上游PX6断面的91%,而其表层水体总磷为PX6的180%.产生该现象的原因为PX5水面宽度是PX6的3.6~4.7倍,PX5过风距离更长,在库区多河谷少风和低风速条件下,风浪对PX5的扰动强于PX6,导致PX5底泥释放的营养盐更易补给表层水体,故PX5处水华最严重.可见,导致库区支流水华的主要原因是水体分层稳定性和内源磷的供应.水体分层稳定性主要受干流回水影响;而中上游水体内源磷的供应受库区支流特殊水体分层现象(表密度层)的影响,其受天气扰动的时间和程度可用于预测预警水华暴发的时间和规模. 展开更多
关键词 三峡库区 澎溪河 断面 水华 长江回水 内源磷迁移
原文传递
Progress of quantum molecular dynamics model and its applications in heavy ion collisions 被引量:8
16
作者 Ying-Xun Zhang Ning Wang +6 位作者 Qing-Feng Li Li Ou Jun-Long Tian Min Liu Kai Zhao Xi-Zhen Wu Zhu-Xia Li 《Frontiers of physics》 SCIE CSCD 2020年第5期1-64,共64页
In this review article,we first briefty introduce the transport theory and quantum molecular dynamics model applied in the study of the heavy ion collisions from low to intermediate energies.The developments of improv... In this review article,we first briefty introduce the transport theory and quantum molecular dynamics model applied in the study of the heavy ion collisions from low to intermediate energies.The developments of improved quantum molecular dynamics model(ImQMD)and ultra-relativistic quantum molecular dynamics model(UrQMD),are reviewed.The reaction mechanism and phenomena related to the fusion,multinucleon transrer,fragmentation,collective flow and particle production are reviewed and discussed within the framework of the two models.The constraints on the isospin asymmetric muclear equation of state and in-medium nucleon nucleon cross sections by comparing the heavy ion collision data with transport models calculations in last decades are also discussed,and the uncertainties of these constraints are analyzed as well.Finally,we discuss the future direction of the development of the transport models for improving the understanding of the reaction mechanism,the descriptions of various observables,the constraint on the nuclear equation of state,as well as for the constraint on in-medium nucleon-nucleon cross sections. 展开更多
关键词 quantum molecular dynamics model low energy heavy ion collisions low-intermediate energy heavy ion collisions fusion multinucleon transfer reaction MULTIFRAGMENTATION collective flow isospin asymmetric equation of state in-medium nucleon-nucleon cross sections
原文传递
Cr-induced fusion reactions to synthesize superheavy elements
17
作者 S.Madhu H.C.Manjunatha +3 位作者 N.Sowmya B.M.Rajesh L.Seenappa R.S.Susheela 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期122-130,共9页
We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 range.The cross sections produced in this investigation using ^(54)Cr projectiles were compared wit... We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 range.The cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior experiments.The estimated cross sections from this analysis are consistent with the findings of prior studies.From the current study,the predicted cross section was found to be 42fb at 236 MeV for ^(53)Cr+^(243)Am,23.2 fb at 236 MeV for ^(54)Cr+^(247)Cm,95.6 fb at 240 MeV for ^(53)Cr+248Bk,and 1.33 fb at 242 MeV for ^(53)Cr+250Cf.Consequently,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations. 展开更多
关键词 Fusion cross sections Compound nucleus formation probability Survival probability Evaporation residue cross sections
下载PDF
The n-resolved single-electron capture in slow O^(6+)-Ne collisions
18
作者 崔述成 邢大地 +7 位作者 朱小龙 苏茂根 高永 郭大龙 赵冬梅 张少锋 符彦飙 马新文 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期16-20,共5页
A study of single-electron capture(SEC) in 18-240 keV O^(6+)-Ne collisions has been conducted employing a combination of experimental and theoretical methodologies.Utilizing a reaction microscope,state-selective SEC c... A study of single-electron capture(SEC) in 18-240 keV O^(6+)-Ne collisions has been conducted employing a combination of experimental and theoretical methodologies.Utilizing a reaction microscope,state-selective SEC cross sections and projectile scattering angle distributions were obtained.The translational energy spectra for SEC reveal the prevailing capture into n=3 states of the projectile ion,with a minor contribution from n=4 states.Notably,as the projectile's energy increases,the relative contribution of SEC n=4 states increases while that of SEC n=3 states diminishes.Furthermore,we computed state-selective relative cross sections and angular differential cross sections employing the classical molecular Coulomb over-the-barrier model(MCBM) and the multichannel Landau-Zener(MCLZ) model.A discernible discrepancy between the state-selective cross sections from the two theoretical models is apparent for the considered impact energies.However,regarding the angular differential cross sections,an overall agreement was attained between the current experimental results and the theoretical results from the MCLZ model. 展开更多
关键词 charge exchange state-selective cross sections angular differential cross sections COLTRIMS
下载PDF
A Bayesian-neural-network prediction for fragment production in proton induced spallation reaction 被引量:7
19
作者 Chun-Wang Ma Dan Peng +2 位作者 Hui-Ling Wei Yu-Ting Wang Jie Pu 《Chinese Physics C》 SCIE CAS CSCD 2020年第12期163-170,共8页
Fragment production in spallation reactions yields key infrastructure data for various applications.Based on the empirical SPACS parameterizations,a Bayesian-neural-network(BNN)approach is established to predict the f... Fragment production in spallation reactions yields key infrastructure data for various applications.Based on the empirical SPACS parameterizations,a Bayesian-neural-network(BNN)approach is established to predict the fragment cross sections in proton-induced spallation reactions.A systematic investigation has been performed for the measured proton-induced spallation reactions of systems ranging from intermediate to heavy nuclei systems and incident energies ranging from 168 MeV/u to 1500 MeV/u.By learning the residuals between the experimental measurements and SPACS predictions,it is found that the BNN-predicted results are in good agreement with the measured results.The established method is suggested to benefit the related research on nuclear astrophysics,nuclear radioactive beam sources,accelerator driven systems,proton therapy,etc. 展开更多
关键词 Bayesian neural network(BNN) spallation reaction cross sections
原文传递
Cause of over Water Quality Standard and Control Measures of State-controlled Sections in Northern Water-deficient Area of Jiangsu 被引量:5
20
作者 胡永定 韩宝平 +1 位作者 钱新 袁兴程 《Meteorological and Environmental Research》 CAS 2010年第2期91-94,99,共5页
Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan r... Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan river were mainly from the urban river segment,and the immediate cause of over standard was tributary pollutants in urban river segment with the runoff into rivers.So we should strengthen the maintenance of drainage control and gate-han,accelerate the construction of urban wastewater treatment facilities and supporting pipe network,promote rural decentralized sewage treatment,prevent and control livestock and poultry pollution,pesticides and fertilizers pollution,and intercept non-point source pollution by using eco-technology. 展开更多
关键词 State-controlled sections Cause analysis Control measures Water-deficient area China
下载PDF
上一页 1 2 136 下一页 到第
使用帮助 返回顶部