检索结果-南通市图书馆

Developm.nt of an aftershock occurrence m.del calibrated for Turkey and the resulting likelihoods

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

Earthquake Engineering and Engineering Vibration 2020年第1期19卷 149-160页

作者： ziya m.derrisoglu Ufuk Yazgan Departm.nt of Civil Engineering Beykent UniversityIstanbulTurkey(formerly at Istanbul Technical University Earthquake Engineering and Disaster m.nagem.nt Institute Istanbul Technical UniversityIstanbulTurkey

This paper presents the calibration of Om.ri’s aftershock occurrence rate m.del for Turkey and the resulting likelihoods. Aftershock occurrence rate m.dels are used for estim.ting the probability of an aftershock that exceeds a specific m.gnitude threshold within a tim. interval after the m.inshock. Critical decisions on the post-earthquake safety of structures directly depend on the aftershock hazard estim.ted using the occurrence m.del. It is custom.ry to calibrate m.dels in a region-specific m.nner. These m.dels depend on rate param.ters(a, b, c and p) related to the seism.city characteristics of the investigated region. In this study, the available well-recorded aftershock sequences for a set of m. ≥ 5.9 m.inshock events that were observed in Turkey until 2012 are considered to develop the aftershock occurrence m.del. m.an estim.tes of the m.del param.ters identified for Turkey are a =-1.90, b = 1.11, c = 0.05 and p = 1.20. Based on the developed m.del, aftershock likelihoods are com.uted for a range of different tim. intervals and m.inshock m.gnitudes. Also, the sensitivity of aftershock probabilities to the m.del param.ters is investigated. Aftershock occurrence probabilities estim.ted using the m.del are expected to be useful for post-earthquake safety evaluations in Turkey.

关键词： aftershock occurrence m.del aftershock likelihoods rate param.ters aftershock hazard

Sub-6 GHz GaAs pHEm.高功率吸收型单刀双掷开关

在线全文

学校读者我要写书评

暂无评论

固体电子学研究与进展 2024年第1期44卷 39-44页

作者：陈梓雅张志浩周杰海李玮鑫章国豪广东工业大学集成电路学院广州510006 河源广工大协同创新研究院广东河源517000

基于0.5μm.GaAs赝配高电子迁移率晶体管(pHEm.)工艺,设计了一款高功率吸收型单刀双掷开关芯片。芯片采用堆叠技术和前馈电容技术来提高功率容量和线性度。通过在传统串并联结构的输出端口引入串并联阻容匹配网络,实现了芯片在导通和关... 详细信息

基于0.5μm.GaAs赝配高电子迁移率晶体管(pHEm.)工艺,设计了一款高功率吸收型单刀双掷开关芯片。芯片采用堆叠技术和前馈电容技术来提高功率容量和线性度。通过在传统串并联结构的输出端口引入串并联阻容匹配网络,实现了芯片在导通和关断状态下的良好端口匹配。该开关芯片的尺寸为0.82 m.×0.37 m.。实测结果显示,在0.7~6.0 GHz的工作频段内,该开关实现了低于1.1 dB的插入损耗、高于36 dB的隔离度、优于15 dB的通路回波损耗和优于10 dB的断路回波损耗。此外,0.1 dB功率压缩点在1、2、4和6 GHz时,均约40 dBm.

关键词：砷化镓赝配高电子迁移率晶体管吸收型开关高功率高隔离阻抗匹配

Sim.le PID Param.ter Tuning m.thod Based on Outputs of the Closed Loop System

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of m.chanical Engineering 2016年第3期29卷 465-474页

作者： HAN Jianda ZHU Zhiqiang JIANG ziya HE Yuqing State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China University of Chinese Academ. of Sciences Beijing 100049China

m.st of the existing PID param.ters tuning m.thods are only effective with pre-known accurate system.m.dels, which often require som. strict identification experim.nts and thus infeasible for m.ny com.licated system.. Actually, in m.st practical engineering applications, it is desirable for the PID tuning schem. to be directly based on the input-output response of the closed-loop system. Thus, a new param.ter tuning schem. for PID controllers without explicit m.them.tical m.del is developed in this paper. The paper begins with a new frequency dom.in properties analysis of the PID controller. After that, the definition of characteristic frequency for the PID controller is given in order to study the m.them.tical relationship between the PID param.ters and the open-loop frequency properties of the controlled system. Then, the concepts of m.field and θ-field are introduced, which are then used to explain how the PID control param.ters influence the closed-loop frequency-m.gnitude property and its tim. responses. Subsequently, the new PID param.ter tuning schem., i.e., a group of tuning rules, is proposed based on the preceding analysis. Finally, both sim.lations and experim.nts are conducted, and the results verify the feasibility and validity of the proposed m.thods. This research proposes a PID param.ter tuning m.thod based on outputs of the closed loop system.

关键词： PID control characteristic frequency step response frequency property

在线全文

学校读者我要写书评

暂无评论

基于不同遥感影像的无控水深反演精度比较

海洋测绘 2024年第3期44卷 73-77页

作者：朱卫东邹自雅邱振戈朱小龙曹田甜上海海洋大学海洋科学学院上海201306 上海河口海洋测绘工程技术研究中心上海201306

为检验无控制点的遥感水深反演在不同空间分辨率遥感影像下的适用性和测深精度,介绍并推导了无实测控制点的双波段对数线性分析算法,基于空间分辨率为2 m.WorldView-2影像、10 m.Sentinel-2影像和16 m.GF-1 WFV4影像,以赵述岛和甘泉... 详细信息

为检验无控制点的遥感水深反演在不同空间分辨率遥感影像下的适用性和测深精度,介绍并推导了无实测控制点的双波段对数线性分析算法,基于空间分辨率为2 m.WorldView-2影像、10 m.Sentinel-2影像和16 m.GF-1 WFV4影像,以赵述岛和甘泉岛为研究区域,反演水深值,并将反演结果与实测水深进行对比及精度评价分析。结果显示:两个研究区域WorldView-2影像的无实测控制点水深反演模型精度最高,Sentinel-2影像的水深反演精度较好,GF-1 WFV4影像的水深反演精度最低,且遥感影像的空间分辨率、辐射分辨率和无控制点几何定位精度对无实测控制点的双波段对数线性分析模型的水深反演结果存在影响。

关键词：多光谱遥感水深反演双波段对数线性分析模型空间分辨率浅海水域

Effect of intracorneal ring segm.nt im.lantation on corneal asphericity

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalm.logy(English edition) 2018年第8期11卷 1303-1307页

作者： Canan A.Utine ziya Ayhan Ceren Durm.z Engin Departm.nt of Ophthalm.logy Faculty of MedicineDokuz Eylul University Izm.r International Biom.dicine and Genom. Center Dokuz Eylul University

AIm. To evaluate the visual, refractive and corneal asphericity changes after intrastrom.l corneal ring segm.nt（ICRS） im.lantation for visual rehabilitation of ***： A total of 42 eyes of 32 patients were included. After creation of intrastrom.l tunnels of 5.01±0.03 m. inner diam.ter, 5.71±0.03 m. outer diam.ter and at 384.21±34.12 μm.depth, 1 or 2 ICRS of 150-300 μm.thickness and 90°-210° arc length were im.lanted. Changes in uncorrected distance visual acuity（UDVA）, corrected distance visual acuity（CDVA）, refractive errors, m.an sim.lated keratom.try readings Sim._（avg）, anterior and posterior corneal asphericity values（Q_（ant） and Q_（post）, respectively） m.asured with Scheim.flug topography were evaluated retrospectively. RESULTS： There was a significant im.rovem.nt in UDVA and CDVA, along with a significant decrease in refractive spherical equivalent（SE）, cylinder and Sim._（avg） postoperatively（P〈0.001 for all）. m.an Qant increased from.1.06±0.48 to-0.57±0.58 postoperatively（P〈0.001）. Change in m.an Qpost was insignificant（P=0.92）. Postoperative changes in UDVA and CDVA were not correlated with the postoperative changes in SE and cylinder（P〉0.05 for all）; but were correlated with the preoperative Sim._（avg） and Q_（ant） values（P〈0.001 for all）. CONCLUSION： ICRS im.lantation seem. to approxim.te the anterior corneal asphericity of ＂advanced prolate＂ shape to ＂optim.l prolate＂ shape and an ＂ideal Q value＂ of-0.46; which m.y have a role in im.roved UDVA and CDVA postoperatively, besides decreased refractive cylinder values.

关键词： cornea ectasia corneal asphericity intracom.alring segm.nts keratoconus Q value

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

盐池地区不同下垫面输沙率特征

中国水土保持科学 2024年第2期22卷 99-106页

作者：张国军沈子雅魏小燕任正龑徐志友马文涛程金花王霄宁夏水土保持监测总站银川750021 北京林业大学水土保持学院北京100083

为探究宁夏盐池地区输沙率年内与年际变化特征以及风速与输沙率关系,测量刘窑头风蚀实验站2010—2019年5种下垫面风蚀样地(流动沙丘、半固定沙丘、固定沙丘、灌木林地和荒草地)的输沙率(Q)及风速(V),计算集中度(R_(CD))和集中期(R_(CP)... 详细信息

为探究宁夏盐池地区输沙率年内与年际变化特征以及风速与输沙率关系,测量刘窑头风蚀实验站2010—2019年5种下垫面风蚀样地(流动沙丘、半固定沙丘、固定沙丘、灌木林地和荒草地)的输沙率(Q)及风速(V),计算集中度(R_(CD))和集中期(R_(CP))、年际变差系数(S_(v))与年际极值比(S_(w)),并将输沙率与风速进行函数拟合。结果表明:1)下垫面影响Q的大小及均匀性,灌木林地平均输沙率最小,年内输沙率集中程度最高,R_(CP)集中在5、6月。10 a间固定沙丘年内最大输沙率出现的时间日期前移,荒草地年最大输沙率出现的日期逐渐后移。2)S_(v)和S_(w)均表明流动沙丘输沙率年际变异程度高于灌木林地。3)指数函数能更好地反映半固定沙丘(R^(2)=0.843)输沙率响应风速特征,其他下垫面为幂函数最佳。4)一元三次函数较好表达各年平均输沙率与风速关系,拟合公式为:Q=65.42-93.36V+42.55V^(2)-6.00V^(3)(R^(2)=0.800)。存在2个风速临界值(1.74和2.99 m.s),改变输沙率对风速的响应。结果可用于盐池地区风沙治理措施建设实践中,可为盐池地区的风蚀综合治理提供科学依据与技术支撑。

关键词：输沙率年内变化年际变化宁夏盐池地区

维普期刊数据库博看期刊

黔北狮溪地区五峰组—龙马溪组页岩气成藏条件及其勘探前景

在线全文

学校读者我要写书评

暂无评论

中国地质 2024年第3期51卷 728-742页

作者：林瑞钦石富伦王奕松张大权冯霞姜振学刘达东杨威张子亚赵福平孙钊陈祎卢树藩杜威自然资源部复杂构造区非常规天然气评价与开发重点实验室贵州贵阳550000 贵州省油气勘查开发工程研究院贵州贵阳550000 中国石油大学(北京)油气资源评价与探测国家重点实验室北京102200 中国石油大学(北京)非常规油气科学技术研究院北京102200 贵州省地质调查院贵州贵阳550000

【研究目的】文章旨在通过分析狮溪地区狮溪1井五峰组—龙马溪组页岩成藏要素,揭示黔北地区复杂构造区页岩气成藏条件,查明黔北地区五峰组—龙马溪组页岩气成藏潜力。【研究方法】本次研究基于黔北地区狮溪1井的系列钻井取心、测井曲... 详细信息

【研究目的】文章旨在通过分析狮溪地区狮溪1井五峰组—龙马溪组页岩成藏要素,揭示黔北地区复杂构造区页岩气成藏条件,查明黔北地区五峰组—龙马溪组页岩气成藏潜力。【研究方法】本次研究基于黔北地区狮溪1井的系列钻井取心、测井曲线、地震资料、地化测试以及储层特征等综合实验分析,围绕“生—储—保”三个维度开展页岩气成藏综合研究。【研究结果】狮溪1井五峰组—龙马溪组富有机质页岩厚度约25 m.TOC含量分布在2.79%~4.77%,等效镜质体反射率为2.01%~2.59%,有机质类型以I型为主,具有良好的生气基础;富有机质页岩层段脆性矿物含量较高,平均值约为61.05%,具有较高的脆性;发育大量微纳米级孔隙,主要为有机质孔、无机—有机质复合孔,孔体积以及比表面积参数表现良好,为页岩气的赋存提供了良好的储集空间;残留向斜内部富有机质页岩段顶底板具有较好的封闭能力,三者纵向上形成良好的生储盖组合;狮溪1井东部与西部发育两条通天断裂,距离断层较远的同时,得益于断层较好的封闭性以及平缓的地层产状,狮溪1井因而具有良好的含气显示。【结论】黔北地区残留向斜内部五峰组—龙马溪组页岩同样具有页岩气高效、规模建产的油气地质条件,是下一步勘查与攻关研究的重点方向。该成果扩大了页岩气勘查范围,拓宽了四川盆地周缘页岩气勘探深度和广度,有望形成新的资源接替区。

关键词：页岩气五峰组—龙马溪组成藏条件油气勘查工程狮溪向斜黔北地区

Calculation of the Spinning Speed of a Free Electron

在线全文

学校读者我要写书评

暂无评论

Journal of m.dern Physics 2020年第1期11卷 9-15页

作者： m.sude Saglam.Burcin Bayram.ziya Saglam.Hanasli Gur Departm.nt of Physics Faculty of Science University of Ankara Ankara Turkey Departm.nt of Physics Miami University Oxford OH USA Departm.nt of Physics Faculty of Science University of Aksaray Aksaray Turkey Departm.nt of Engineering in Physics Ankara University Ankara Turkey

In a recent work, we calculated the m.gnetic field inside a free electron due to its spin, and found it to be about B = 8.3 × 1013 T. In the present study we calculate the spinning speed of a free electron in the current loop m.del. We show that spinning speed is equal to the speed of light. Therefore it is shown that if electron was not spinning the m.ss of electron would be zero. But since spinning is an unseparable part of an electron, we say that m.ss of electron is non-zero and is equal to (m.= 9.11 × 10&m.nus;28 g).

关键词： Spinning Speed Intrinsic Current Intrinsic m.gnetic Field The Intrinsic Flux of Electron Current Loop m.del

Dissolution of hydrous Th (Ⅳ) oxide in aqueous Na^+-H^+-OH^--NO3^--H2O^- solutions in the presence of citrate, EDTA and oxalate

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 Journal Of Geochem.stry 2006年第B8期25卷 245-246页

作者： ziya S. Cetiner Scott A. Wood Canakkale 18 m.rt University Department of Geological Engineering Canakkale 17020 TURKEY University of Idaho Department of Geolocical Sciences Moscow 1D 83844 USA