规模化电动汽车充电对配电网电缆老化的影响

电动汽车规模化且带有随机特性的充电行为将给城市电网运行和维护带来新的挑战。提出了计及充电随机特性的电动汽车充电负荷模型,考虑了电动汽车接入水平、用户出行和充电习惯,在此基础上,研究了规模化电动汽车充电对配电网电缆老化的影响。所提出的电缆老化模型计及了不同季节、不同环境下每一负荷周期内电缆所承受电应力、热应力的随机特性,提高了电缆剩余寿命估算的准确性,解决了规模化电动汽车入网后如何确定电缆寿命所受影响这一技术难题。     

NUMERICAL SIMULATION OF TRANSIENT CUTTINGS TRANSPORT WITH FOAM FLUID IN HORIZONTAL WELLBORE

With considering the interlayer mass transfer and fluid influx from the reservoir, a one-dimensional two-layer hydraulic model was established to describe the mechanism of transient cuttings transport with foam fluid in horizontal well section. The model was numerically calculated based on the modified SIMPLE algorithm, and the height of cuttings bed was predicted by the trial-and-error method. Sensitivity analysis was conducted on the affecting factors on the cuttings transport performance. Results show that cuttings deposition moves along the horizontal wellbore from the drilling bit, and finally achieves a steady state with dynamic balance. Dimensionless cuttings bed height decreases with the increase of foam quality or foam flow rate, but increases with the increase of drillpipe eccentricity, cuttings size or drilling rate. The influx of water and gas from the reservoir is helpful to improve the cuttings transport efficiency with foam. The proposed model offers theoretical guidelines for hydraulic parameter design and hole cleaning control in foamed horizontal drilling.     

UF-RO系统处理污水厂二级出水用于电厂循环冷却水的研究

采用超滤-反渗透处理污水厂二级出水,其中将超滤作为预处理,结果发现,反渗透膜对无机离子的去除率较高。CODMn去除率达到了96%以上;TDS去除率保持在91%左右;碱度、Ca2+、Mg2+、NH4+-N平均去除率分别在90%、98%、98%、90%左右;PO43-的去除率基本达到了100%;SO42-、Cl-的平均去除率分别在97%、90%左右。出水各项指标均能达到循环冷却水用再生水的标准,可成功用于热电厂的循环冷却水。     

我国延迟焦化技术的专利保护现状与展望

为了全面准确了解我国延迟焦化技术的专利保护现状,对1985年以来我国公开的延迟焦化技术的相关专利进行了系统的分析,研究提出了未来先进延迟焦化技术的研究方向和保护重点。     

A modification of Smith–Watson–Topper damage parameter for fatigue life prediction under non‐proportional loading

In this paper, the shortcomings of the Smith–Watson–Topper (SWT) damage parameter are analysed on the basis of the critical plane concept. It is found that the SWT model usually overestimates the fatigue lives of materials since it only takes into account the fatigue damage caused by the tensile components. To solve this problem, Chen et al. (CXH) modified the SWT model through considering the shear components. However, there are at least two problems present in CXH model: (1) the mean stress is not considered and (2) the different influence of the normal and shear components on fatigue life is not included. Besides, experimental validations show that the modification by Chen et al. usually leads to conservative fatigue life predictions during non‐proportional loading. In order to overcome the shortcomings of SWT and CXH models, a damage parameter as the effective strain energy density (ESED) is proposed. Experimental validations by using eight kinds of materials show that the ESED model can give satisfactory fatigue life predictions under the non‐proportional loading.     

SiCsFuzzer:基于稀疏插桩的闭源软件模糊测试方法

传统的基于覆盖率反馈的模糊测试工具通过跟踪代码覆盖率来指导测试用例的变异,从而发现目标程序中潜在的漏洞。但在闭源软件的模糊测试过程中,跟踪覆盖率不仅带来额外的开销,而且在模糊测试开销中占据主导。本文通过对Windows平台闭源软件模糊测试开销的剖析,锁定其中两个主要来源,插桩开销和“预热”开销。基于上述分析,提出了一种基于稀疏插桩跟踪的模糊测试方法,在不影响覆盖率计算精度的前提下,采用基于稀疏插桩的跟踪策略,仅对目标程序中覆盖率不可推导的基本块或分支进行插桩跟踪,并根据跟踪结果推导其余基本块或分支的被覆盖情况;同时结合“预热”优化,避免因动态插桩平台反复启动以及对目标程序代码的重复翻译所引入的时间开销。基于上述方法实现的原型工具SiCsFuzzer,在Windows平台9个规模在286KB～19.3MB,类型涉及图片处理、视频处理、文件压缩、加密和文档处理等类型应用所组成的测试集上,跟踪覆盖率引入的额外开销为程序正常执行时间的1.1倍,比传统的基于覆盖率反馈的模糊测试工具快3倍,并发现PDFtk和XnView程序最新版本中的未知漏洞各1个。     

Influence of the preparation process on the performance of three hydrotalcite-based De-SOx catalysts

In this study, three hydrotalcite-based De-SO_x catalysts were prepared using different approaches: impregnation, coprecipitation, and precipitation using the separate nucleation and aging steps (SNAS) method. The physicochemical properties of these catalysts were studied and their SO_x removal behaviors were characterized with a custom-built apparatus simulating the conditions in a fluid catalytic cracking (FCC) regenerator. The results showed that the catalyst prepared using the SNAS method had the highest SO_x adsorption rate, the largest SO_x pick-up capacity (1.31 g/g cat.) and the lowest onset reduction temperature (805 K), which makes it an excellent De-SO_x catalyst with promising applications in industry.     

国内外煤层气利用现状及技术途径分析

介绍了国内外煤层气资源利用的现状,对煤层气利用的几种主要技术途径进行了分析和展望,认为目前国外煤层气化工利用发展较慢,煤层气除用于发电和作为燃料之外,其他应用未形成规模;国内煤层气开发利用处于起步阶段,在满足燃料市场需求的同时,应加大技术创新,重点研究煤层气制合成气、甲醇新型下游产品如烯烃、二甲醚以及煤层气制氢气、乙二醇等技术,实现煤层气资源合理有效利用;深入研究低浓度煤层气脱氧及浓缩技术,为煤层气综合利用创造条件;煤矿企业应与资金、技术雄厚的石油天然气公司联合,采取"先采气、后采煤"开发模式,实现煤层气开发利用的快速发展。     

交流电磁场检测技术的探头激励装置优化设计

利用交流电磁场检测试验台对交流电磁场检测设备的探头激励装置进行优化设计。选取U形磁芯结构的激励方式,对比分析磁芯材料、磁芯结构、激励线圈结构、激励电压等因素对检测效果的影响,完成激励装置的优化设计。使用设计的激励装置对4种尺寸的典型缺陷进行检测,验证了激励装置的检测效果,使裂纹检测的分辨率达到了3mm。     

兰州石化50万t/a催化轻汽油醚化装置运行与优化

采用中国石油自主研发开发的催化轻汽油醚化工艺(LNE)技术,兰州石化建成50万t/a轻汽油醚化装置并投产成功。装置数据表明,C5、C6叔碳烯烃转化率分别为72%~77%、50%~60%,催化轻汽油烯烃减少量为18.0个百分点以上,醚化产品油中总醚化物含量为46%~60%,醚化产品油辛烷值(RON)为98~100,目前该装置已不间断平稳运行1年以上。醚化装置运行效果良好,产生了显著的经济效益和社会效益。