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Search Results: 1 - 10 of 387030 matches for " 王春伟 "
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B/S结构权限管理的研究与实现
Privilege Management Research and Practice under B/S Structure
 [PDF]

何信, ,
Computer Science and Application (CSA) , 2014, DOI: 10.12677/CSA.2014.412042
Abstract:
在B/S结构的应用系统中,权限管理功能有着广泛的应用。由于需求的不同权限管理功能有不同的设计和实现方式,RBAC (基于角色的访问控制)作为一种比较成熟的模型,为权限管理的设计和实现方式提供了参考。基于Web环境下资源标示的唯一性和权限控制算法,并参考RBAC和学习多种权限管理的实现,总结出一种简单实用的权限管理实现方式。
In this B/S structure of the application system, privilege management used broad. According to the different requirements, privilege management functions have different ways of design and im-plementation, and RBAC (Role Based Access Control) provides a common way to achieve guidance, RBAC based on the uniqueness of the next B/S URL environmental resources, the use of access control algorithm and role-core to achieve the user’s permission to perform operations managed by the role to perform operations.
克拉玛依石化工业园污水处理厂曝气生物滤池工艺除磷效果分析
Analysis on the Effect of Dephosphorization by Biological Aerated Filter Process in Sewage Treatment Plant of Karamay Petrochemical Industrial Park
 [PDF]

刘兵, , 李娟,
Water pollution and treatment (WPT) , 2015, DOI: 10.12677/WPT.2015.31001
Abstract:
克拉玛依石化工业园污水处理厂采用气浮、S3D加三级生物滤池工艺,处理后的出水要求达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A的标准,即处理后的总磷要求达到0.5 mg/L以下。结合污水处理厂的实际工艺,重点研究了系统的化学除磷和生化混合除磷,对以后类似的工艺运行具有参考意义。
The sewage treatment plant of Karamay petrochemical industrial park uses flotation, S3D and three-stage biological aerated filter process; the treated water has reached level A standard of the “Urban Sewage Treatment Plant Pollutant Discharge Standard” (GB18918-2002), meaning that the total phosphorus after treatment are less than 0.5 mg/L. Combined with actual process of the se-wage treatment plant, this paper focuses on chemical dephosphorization system and biochemical mixed dephosphorization, having reference significance to the later similar process.
基于认知无线电通信系统的最优中继集合选择方案
A Best Relay Set Selection Scheme for Cooperative Transmission in Cognitive Radio Network
 [PDF]

, 刘顺兰, 余杰,
Hans Journal of Wireless Communications (HJWC) , 2015, DOI: 10.12677/HJWC.2015.51004
Abstract:
针对认知无线电通信系统的协作通信问题,本文提出一种基于解码转发和接收信噪比最大化的最优中继集合选择方案,同时理论推导出基于该最优中继集合选择方案的认知无线电通信系统的中断概率,并对传统直接通信(direct)方案,随机选择中继方案和本文提出的方案进行了性能仿真,仿真表明本文提出的方案能有效降低认知无线电系统的中断概率。
In this paper, a best relay set selection scheme based on Decode and Forward and received SNR maximization is proposed for cooperative communication in Cognitive Radio system, and the closed-form expression of outage probability based on the proposed scheme is derived. Further-more, the proposed scheme is compared with traditional direct communication scheme and the random relay selection scheme in terms of outage probability through numerical experimentation. Numerical results illustrate that the proposed scheme can greatly decrease outage probability.
面向协同创新的产学研知识转移研究现状及展望
,
科技进步与对策 , 2014, DOI: 10.6049/kjjbydc.2014020483
Abstract: 查阅大量国内外相关研究文献,从产学研知识转移的含义、过程、渠道、模式、影响因素、绩效评价、产学研知识转移与协同创新的关系等方面展开综述,总结了协同创新环境下产学研知识转移的研究现状,分析该领域研究中存在的不足,并提出未来重点研究方向。协同创新产学研知识转移产学研知识转移
带干扰复合泊松模型下对调整系数的新研究
,
应用概率统计 , 2010,
Abstract: 本文研究了带干扰复合泊松模型中采用成数再保与超额损失再保险混合策略时作为自留额水平函数的调整系数.我们按照原始条款计算成数再保费,按照期望值保费原则计算超额损失再保费,这样得到了调整系数是超额损失自留额极限的单峰函数的结论.本文最后部分给出了有限时间破产概率的上界.
基于COMSOL连铸坯壳测厚横波EMAT优化
COMSOR based shear wave EMAT optimization for thickness measurement of continuous casting shell

,
- , 2018, DOI: 10.16300/j.cnki.1000-3630.2018.03.008
Abstract: 为了研究电磁超声传感器(Electromagnetic Acoustic Transducer,EMAT)横波测量连铸坯壳厚度的机理及横波在连铸坯中的传播情况,选取坯壳厚度为10~50 mm的Q235小方坯为研究对象,利用有限元软件COMSOL建立脉冲电磁铁和螺旋线圈的电磁超声模型,分析在不同EMAT结构参数下,连铸坯中电磁场、力场、声场的分布规律。研究结果表明:脉冲电磁铁和螺旋线圈组成的EMAT能够在连铸坯壳集肤层激发出超声波横波。脉冲电磁铁空心螺线管线圈匝数、内半径、线圈导线半径对换能效率的影响依次减小,且当脉冲电磁铁内半径尺寸大于螺旋线圈尺寸时,产生横波的效率最高。坯壳厚度越小,螺旋线圈最优激励频率越大,测量精度越高,信号衰减越快。因此,坯壳厚度为10~50 mm的Q235小方坯选择1.1 MHz为最佳激励频率。
In order to study the mechanism and propagation of the shear wave generated by EMAT (electromagnetic acoustic transducer) in continuous casting shell, the Q235 billet with shell thickness of 10~50 mm is taken as the re-search object. The electromagnetic ultrasonic model of pulsed electromagnet and spiral coil is established by using the finite element software COMSOL. The distributions of electromagnetic field, force field and sound field in continuous casting slab under different EMAT parameters are analyzed. The results show that the EMAT made by the combination of the pulse electromagnet and the spiral coil can excite the ultrasonic shear wave in continuous casting shell. The effects of the coil winding number, inner radius, and radius of coils on the transfer efficiency decrease in turn. When the radius of the pulse electromagnet is larger than the size of the spiral coil, the efficiency of generating transverse wave is the highest. The smaller the thickness of the shell causes the higher the optimal excitation frequency, the higher the precision and the faster the attenuation. The frequency of 1.1 MHz is chosen as the optimum excitation frequency for the Q235 billet with the shell thickness of 10~50 mm.
温度对“SH-A”工艺处理阿托伐他汀钙制药废水的影响研究
Study on the Influence of Temperature on the “SH-A” Process of Atorvastatin Calcium Pharmaceutical Wastewater
 [PDF]

孙锋, 潘大,, 树成
Advances in Microbiology (AMB) , 2013, DOI: 10.12677/AMB.2013.21008
Abstract:
本文采用SH-A工艺对处理阿托伐他汀钙制药废水的效果进行了研究,重点研究了温度对SH-A工艺处理阿托伐他汀钙制药废水的影响。实验结果显示:采用SH-A工艺处理阿托伐他汀钙制药废水,能够有效去除废水中的COD-N;温度对SH-A工艺处理阿托伐他汀钙制药废水具有较大的影响。在给定条件下,对于COD,随着系统温度的升高,COD的去除率明显提高,当温度达到35COD去除率达到最大值,继续升高温度,COD去除率有所降低;对于NH4+-N,随着系统温度的升高,其去除率亦明显提高,当温度达到29-N去除率达到100%,继续升高温度,去除率保持不变。根据实验结果,应选择35作为本工艺处理阿托伐他汀钙制药废水的最佳温度。
In this paper, the effect of using SH-A process to treat Atorvastatin Calcium pharmaceutical wastewater is studied. This study mainly focuses on the effect of temperature on the SH-A process. The experimental results show that: the SH-A process has an effective removal of COD and -N; temperature is key factor of the treatment effects. Under the given conditions, the COD removal efficiency improved significantly with the increasing system
1例晚期胃癌患者的循证治疗
Evidence-Based Treatment for 1 Case with Advanced Gastric Cancer Patients
 [PDF]

江平, 崇高, 胡昇庠, 张增岭,, 桂德
Asian Case Reports in Oncology (ACRPO) , 2015, DOI: 10.12677/ACRPO.2015.43004
Abstract:
目的:采用循证医学方法为1例晚期胃癌患者制定诊治方案。方法:根据临床问题检索MEDLINE、ACP Journal Club、中国知网,并利用搜索引擎——谷歌学术搜索在互联网所获取的文献进行归纳分析。结果:共获得有关晚期胃癌姑息手术和新辅助化疗时机的系统评价6篇,临床对照研究病例756例。以上证据表明:晚期胃癌行新辅助化疗的根治性手术率及生存率优于姑息手术组。结合客观证据及患者意愿,为患者实施了两个疗程的奥沙利铂+希罗达(Cape + OX)化疗方案,结合化疗前后病灶的影像学变化,成功实施了手术,无手术后并发症发生。结论:循征医学方法对疑难病例的治疗有一定的指导作用。
Objective: To make the diagnosis and treatment for advanced gastric cancer patients using evi-dence-based medicine method. Methods: Retrievalling MEDLINE, ACP Journal Club, Chinese How-Net according to the clinical question, and then searching and summarizing the literature in Internet using the search engines—Google academic search. Results: 6 systematic reviews about advanced gastric cancer palliative operation and neoadjuvant chemotherapy time and 756 cases of controlled clinical study were obtained. The above evidence approved that it was superior to palliative operation group in the radical surgery and survival rates. Combining the objective evidence and the patients’ willingness, patients were treated with two courses of chemotherapy options with oxaliplatin plus capecitabine (Cape + OX) regimen. The operation was performed successfully without complications combining with the change of focus images before and after chemotherapy. Conclusion: The evidence-based medicine method was useful for the treatment of difficult patients.

恒定电压下变压器油隙放电特性
Discharge Behaviors of Transformer Oil-Gap under Constant Voltage
 [PDF]

李伟, 任志刚, 石磊, 辛锋, 马光耀, 郑殿,
Advances in Condensed Matter Physics (CMP) , 2016, DOI: 10.12677/CMP.2016.54008
Abstract:
以变压器油作为研究对象,采用有限元方法(finite element method, FEM)对应用场致电离机理建立的用于表述液体电介质流注放电过程中载流子的产生及输运特性的偏微分方程(partial differential equations, PDE)进行求解分析,获得直流电压下变压器油隙放电过程空间电荷动力学特性。数值模拟结果表明,场致电离导致液体击穿的根本原因是油隙中自由载流子的产生、迁移形成了预击穿电流,由此产生的焦耳热使得油隙中形成低密度区,利于流注发展。根据这些现象得出的结论能够很容易理解液体电介质的击穿机理,有利于液体电介质在电力系统领域得到更合理的应用。
The transformer oil was taken as the object of study, and the finite element method (FEM) was employed to analyze and solved the partial differential equations (PDE) which was built by field ionization for describing the generation and transport properties of free charge carriers. The results showing that the dynamic characteristics of space charges in the liquid-gap discharge under DC were gained. According to the simulating results, the fundamental causes of the dielectric liquids breakdown by the electric field dependent molecular ionization are described as following; the pre-breakdown current is firstly formed by the generation and migration of the charge carriers in the oil gap, then the joule heat generated from it makes liquid-gap to form the low density region in the liquid, which facilitate initiated little streamer emergence as avalanche in gas discharge, meanwhile, the streamer is continuously evolving. Then these conclusions enable ones easily understand breakdown mechanism of the liquid dielectrics that are reasonably applied to power system fields.
1995年民事诉讼法学研究的回顾与展望
,肖建国,
法学家 , 1996,
Abstract:
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