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THE EFFECTS OF MARKET DEPTH ON THE ARRIVAL RATE OF ORDERS

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Journal of Systems Science & Complexity 2014年第6期27卷 1192-1203页

作者： ZHANG Qiang LIU Shancun QIU wanhua School of Economics and Management Beijing University of Chemical Technology School of Economics and Management Beihang University

This paper presents a model to describe the dynamic trading process in limit order *** studying the dynamic pattern of execution probabilities of limit orders with both time and the depth of limit order book,the authors conclude with the following properties:Arrival rates of market buy orders increase as the depth of buy queue in the book increases and decrease as the depth of sell queue increases,and vice versa;similar regularities for the arrival rate of market sell orders;both the arrival rate of market buy order and market sell orders increase as the depth of both sides in the book increases by the same ***,the authors describe more detailed temporary and permanent effects of the market depth on the arrival rates of orders.

关键词： Arrival rate limit order market market depth private value.

Heavy Atom Effect on the First Hyperpolarizabilities of Squaric Acid Homologues Studied by Ab Initio and DFT Methods

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Chinese Journal of Structural Chemistry 2004年第5期23卷 480-485页

作者： FUWei-Wei ZHOULi-Xin wanhua-Ping CollegeofChemistryandChemicalEngineering FuzhouUniversityFuzhou350002China DepartmentofChemistry JinanUniversityGuangzhou510632China

We have calculated the first hyperpolarizabilities of four squaric acid homologue molecules: 3,4-dithiohydroxy-3-cyclobutene-1,2-dione (OSSQ), 3,4-dithiohydroxy-3-cyclobutene-1, 2-dithione (SSSQ), 3,4-dithiohydroxy-3-cyclobutene-1,2-diselenone (SeSSQ) and 3,4-dithiohydroxy- 3-cyclobutene-1,2-ditellurone (TeSSQ). The correlation effect was investigated at the second-order Mller-Plesset (MP2) perturbation and density functional theory (DFT) levels. The frequency disper- sion and solvent effect were considered to compare the theoretical values with the experimental observations. Based on all of these studies, it is worthy to point out that the heavy atom effect dis- covered for furan homologues is an influence on the first hyperpolarizabilities of squaric acid homologues.

关键词： first hyperpolarizability correlation effect dispersion effect solvent effect

长三角地区联合河长制政策效果模拟与仿真研究

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生态经济 2024年第9期40卷 187-198页

作者：黄万华冯燕高红贵黄轲武汉工程大学管理学院湖北武汉430205 中南财经政法大学经济学院湖北武汉430073

基于DPSIR理论,运用系统动力学的方法,构建长三角地区联合河长制政策仿真模型,从水资源保护、水污染防治、水生态修复、水环境治理等维度,通过模拟与仿真,纵横对比联合河长制的政策效果,分析联合河长制政策2023—2035年的政策效果。研... 详细信息

基于DPSIR理论,运用系统动力学的方法,构建长三角地区联合河长制政策仿真模型,从水资源保护、水污染防治、水生态修复、水环境治理等维度,通过模拟与仿真,纵横对比联合河长制的政策效果,分析联合河长制政策2023—2035年的政策效果。研究结果表明:(1)长三角地区联合河长制政策整体效果比较显著,在水资源保护、水污染防治、水生态修复、水环境治理四个方面的政策效果明显;(2)自2023年起的未来十多年,联合河长制政策效果呈减弱趋势,并不具有较强的可持续性,要持续实现联合河长制较好的政策效果,需要进一步深化完善与联合河长制政策相配套的协作机制、动力机制、保障机制、监督机制等政策体系。论文为解决长三角地区流域治理中上下游,干支流、左右岸不协同,优化流域单元与行政单元间的“条”“块”协同机制,推进长三角地区协同大保护与高质量发展具有十分重要的理论意义和实践价值。

关键词：系统动力学联合河长制政策效果仿真模拟长三角地区

Analysis of switching conditions of chalcogenide alloys during crystallization

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Journal of University of Science and Technology Beijing 2006年第5期13卷 446-449页

作者： wanhua Yu C.D. Wright Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China School of Engineering and Computer Science University of Exeter Exeter EX4 4QF UK

To understand the principle and limitation of chalcogenide alloy Ge2Sb2Te5 （GST） in solid-state memory devices during crystallization, it was necessary to develop a physically realistic model that could reflect the electrical and thermal properties of these media. A novel comprehensive numerical model has been developed for simulating these memory devices, which describes the electrical and thermal behavior using the solution of the nonlinear, time-dependent electrical and heat conduction equation. The finite-difference-time-domain technique was adopted to compute the electrical field and heat distribution in the device. Several contributing factors that affect the crystallization switching process such as the geometry of the GST layer, temperature and electric field dependency of the electrical conductivity have been discussed. The results of the simulations were then used to provide critical guidelines for fabrication and optimization of the device performance.

关键词： chalcogenide alloy crystallization simulation modeling memory

Influence of Strut Cross-section of Stents on Local Hemodynamics in Stented Arteries

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Chinese Journal of Mechanical Engineering 2016年第3期29卷 624-632页

作者： JIANG Yongfei ZHANG Jun ZHAO wanhua State Key Laboratory for Manufacturing System Engineering Xi'an Jiaotong University

Stenting is a very effective treatment for stenotic vascular diseases, but vascular geometries altered by stent implantation may lead to flow disturbances which play an important role in the initiation and progression of restenosis, especially in the near wall in stented arterial regions. So stent designs have become one of the indispensable factors needed to be considered for reducing the flow disturbances. In this paper, the structural designs of strut cross-section are considered as an aspect of stent designs to be studied in details. Six virtual stents with different strut cross-section are designed for deployments in the same ideal arterial model. Computational fluid dynamics（CFD） methods are performed to study how the shape and the aspect ratio（AR） of strut cross-section modified the local hemodynamics in the stented segments. The results indicate that stents with different strut cross-sections have different influence on the hemodynamics. Stents with streamlined cross-sectional struts for circular arc or elliptical arc can significantly enhance wall shear stress（WSS） in the stented segments, and reduce the flow disturbances around stent struts. The performances of stents with streamlined cross-sectional struts are better than that of stents with non-streamlined cross-sectional struts for rectangle. The results also show that stents with a larger AR cross-section are more conductive to improve the blood flow. The present study provides an understanding of the flow physics in the vicinity of stent struts and indicates that the shape and AR of strut cross-section ought to be considered as important factors to minimize flow disturbance in stent designs.

关键词： stent restenosis wall shear stress hemodynamics computational fluid dynamics

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铁路运输调度领域数据分级及保护策略研究

铁道运输与经济 2024年第2期46卷 134-141页

作者：陈亚茹洪鑫张红斌毛万华中国铁道科学研究院集团有限公司电子计算技术研究所北京100081 中国铁道科学研究院集团有限公司北京经纬信息技术有限公司北京100081 中国铁路兰州局集团有限公司调度所甘肃兰州730000

数字经济时代,数据安全性日益凸显,国家先后出台了一系列法律法规加快构建数据分类分级治理体系。在梳理我国部分行业领域数据分级现状的基础上,针对铁路运输调度领域数据,从需求感知、计划编制、计划执行与调整、评价分析4个维度分析... 详细信息

数字经济时代,数据安全性日益凸显,国家先后出台了一系列法律法规加快构建数据分类分级治理体系。在梳理我国部分行业领域数据分级现状的基础上,针对铁路运输调度领域数据,从需求感知、计划编制、计划执行与调整、评价分析4个维度分析铁路运输调度指挥全流程各环节数据,并提出运输调度数据分级的必要性。选取《数据安全法》作为数据分级基本依据,制定数据分级流程,综合考量数据规模、重要性等要素以及数据遭到破坏后造成的影响程度,将运输调度数据分为一般、重要、核心3个级别。针对不同级别的数据,采用多种数据安全保护技术组合方式制定数据分级保护策略,进一步完善铁路运输调度数据安全治理体系的构建,驱动铁路数字化转型。

关键词：铁路运输调度数据数据分级保护策略安全治理

An Intelligent Non-Collocated Control Strategy for Ball-Screw Feed Drives with Dynamic Variations

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Engineering 2017年第5期3卷 641-647页

作者： Hui Liu Jun Zhang wanhua Zhao State Key Laboratory for Manufacturing Systems Engineering Xi'an fiaotung University. Xi'an 710054 China Collaborative Innovation Center of High-End Manufacturing Equipment Xi'an fiaotong University Xi'an 710054 China

The ball-screw feed drive has varying high-order dynamic characteristics due to flexibilities of the slender screw spindle and joints between components, and an obvious feature of non-collocated control when a direct position measurement using a linear＇scale is employed. The dynamic characteristics and non- collocated situation have long been the source of difficulties in motion and vibration control, and deterio- rate the achieved accuracy of the axis motion. In this study, a dynamic model using a frequency-based sub- structure approach is established, considering the flexibilities and their variation. The position-dependent variation of the dynamic characteristics is then fully investigated. A corresponding control strategy, which is composed of a modal characteristic modifier （MCM） and an intelligent adaptive tuning algorithm （ATA）, is then developed. The MCM utilizes a combination of peak filters and notch filters, thereby shaping the plant dynamics into a virtual collocated system and avoiding control spillover. An ATA using an artificial neural network （ANN） as a smooth parameter interpolator updates the parameters of the filters in real time in order to cope with the feed drive＇s dynamic variation. Numerical verification of the effectiveness and robustness of the orooosed strategy is shown for a real feed drive.

关键词： Ball-screw feed drives Varying high-order dynamics Non-collocated control Modal characteristic modifier Intelligent adaptive tuning algorithm

术前术中人性化护理对子宫动脉栓塞患者应激反应及并发症的影响

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实用妇科内分泌电子杂志 2024年第17期11卷 143-145页

作者：宋婷婷王万花南京市高淳人民医院肿瘤与血管介入科江苏高淳211300

目的研究术前术中人性化护理对子宫动脉栓塞患者应激反应及并发症的影响。方法选取40例子宫动脉栓塞患者,参考随机信封原则分为对照组与观察组,各20例。对照组给予传统模式护理,观察组在对照组基础上给予术前术中人性化护理,比较两组并... 详细信息

目的研究术前术中人性化护理对子宫动脉栓塞患者应激反应及并发症的影响。方法选取40例子宫动脉栓塞患者,参考随机信封原则分为对照组与观察组,各20例。对照组给予传统模式护理,观察组在对照组基础上给予术前术中人性化护理,比较两组并发症发生情况及应激反应指标。结果观察组并发症发生率略低于对照组,但对比差异无统计学意义(P>0.05)。两组患者术前心率(HR)、收缩压(SBP)水平比较,差异无统计学意义(P>0.05);观察组患者的术中HR、SBP水平均低于对照组,差异有统计学意义(P<0.05)。结论子宫动脉栓塞患者术前术中接受人性化护理服务,有助于减轻应激反应,保证患者生命体征稳定性,降低围术期并发症风险,临床推广应用价值较高。

关键词：术前术中人性化护理子宫动脉栓塞应激反应并发症

Production technique of vermicular graphite iron cylinder head of vehicle diesel engine

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China Foundry 2008年第3期5卷 153-161页

作者： Zhou Gen Liu wanhua Wuxi Diesel Engine Works China First Automobile Group Co. Ltd. Wuxi 214026 China Wuxi FAW Foundry Co. Ltd. China First Automobile Group Co. Ltd. Wuxi 214026 China

The 25 years＇ production and application have proved that vermicular graphite iron cylinder heads with vermicularity ≥50% satisfy the machinability and performance demand of diesel engine. The method, in which using cupola-induction furnace duplex melting and pour-over process with rare earth-ferrosilicon or rare earthsilicon compound as vermJcularizing alloy plus rare earth-magnesium-ferrosilicon as stirring alloy, is an optimal vermicularizing process for obtaining satisfied vermicularity. Using top kiss risers, enlarging kissing areas and expanding covering width and making ingates to freeze earlier are the effective measures to eliminate shrinkage, blowhole and oxide inclusions in the vermicular graphite iron cylinder heads.

关键词： vermicular cast iron cylinder head melting and treatina process: castina method