摘要：为提升短舱外罩层流区域面积以降低阻力,基于PARSEC(parametric section)曲线的型线参数化方法,同时采用遗传算法,以推后短舱外罩转捩位置为优化目标,对短舱特征型线进行优化。同时,研究不同来流马赫数下短舱型面优化结果;对比分析优化前后型面的气动性能与阻力发散特性。结果表明:优化后短舱型面较优化前在设计点阻力降低2.25×10^(-3),但在高来流马赫数的非设计点工况,阻力恶化现象较为严重,导致优化后短舱在较低马赫数即产生阻力发散。

摘要：In order to design a complex laser resonator with multi-parameters, the method of particle swarm optimization(PSO) algorithm is employed. The parameters influencing the resonator stability and mode size distribution are taken into consideration, and the stability criteria index and the mode size distribution are used as target values. The absolute values of the differences between practical and the target values are set as the fitness function for the PSO. By minimizing the fitness function, a laser resonator with the optimized cavity parameters can be found. The analyses for the design example demonstrate the feasibility and validity of the PSO method in the computer aided design of multi-parameters laser resonator. Applying PSO algorithm in the intelligent design of solid state laser resonators can realize the transition from manual trial-and-error to computer intelligent design of the laser resonators.

摘要：Background People recently realized that it is important for artificial vascular biodegradable graft to bionically mimic the functions of the native vessel. In order to overcome the high risk of thrombosis and keep the patency in the clinical small-diameter vascular graft （SDVG） transplantation, a double-layer bionic scaffold, which can offer anticoagulation and mechanical strength simultaneously, was designed and fabricated via electrospinning technique. Methods Heparin-conjugated polycaprolactone （hPCL） and polyurethane （PU）-collagen type I composite was used as the inner and outer layers, respectively. The porosity and the burst pressure of SDVG were evaluated. Its biocompatibility was demonstrated by the 3-（4,5-dimethyl-2-thiazol）-2,5-diphenyl-2H tetrazolium bromide （MTT） test in vitro and subcutaneous implants in vivo respectively. The grafts of diameter 2.5 mm and length 4.0 cm were implanted to replace the femoral artery in Beagle dog model. Then, angiography was performed in the Beagle dogs to investigate the patency and aneurysm of grafts at 2, 4, and 8 weeks post-transplantation. After angiography, the patent grafts were explanted for histological analysis. Results The double-layer bionic SDVG meet the clinical mechanical demand. Its good biocompatibility was proven by cytotoxicity experiment （the cell＇s relative growth rates （RGR） of PU-collagen outer layer were 102.8%, 109.2% and 103.5%, while the RGR of hPCL inner layer were 99.0%, 100.0% and 98.0%, on days 1, 3, and 5, respectively） and the subdermal implants experiment in the Beagle dog. Arteriography showed that all the implanted SDVGs were patent without any aneurismal dilatation or obvious anastomotic stenosis at the 2nd, 4th, and 8th week after the operation, except one SDVG that failed at the 2nd week. Histological analysis and SEM showed that the inner layer was covered by new endothelial-like cells. Conclusion The double-layer bionic SDVG is a promising candidate as a replacement of native smal

摘要：文章以黄阁水厂二期扩建工程排泥水系统设计为研究对象,黄阁水厂排泥水采用分质处理方案,通过对原水浊度的分析确认了排泥水系统设计规模,探讨了回收水池、调节池、浓缩池和污泥脱水车间的工艺设计参数,并就系统运行提出了优化方向,有效减少了水厂外排水,改善了运行效果,可为其他水厂排泥水设计提供参考。

摘要：为了提高微柱阵列与透镜导管耦合系统的光斑整形效果,设计了一种横截面是椭圆、且椭圆离心率随位置变化的不规则导管设计方案。在导管的前端面,椭圆长轴在水平方向,以与激光二极管阵列的发光面形状相匹配;在导管后端面,椭圆长轴逐渐过渡到竖直方向。利用3维光线追迹方法进行仿真计算,可知该不规则导管可以得到圆对称性较好的光斑整形效果,微柱阵列和该导管的能量传输效率分别为90.84%和91.98%,对应于整个耦合系统的能量传输效率为83.55%。结果表明,该不规则导管在光斑整形效果和能量传输效率方面与普通导管相比具有一定优势。

摘要：科学处理工业园区生态环境保护与产业发展的关系,有助于社会经济持续高质量发展与生态文明建设的协调统一。以梅州市某工业园区为例,结合生态环境保护专项规划技术路线和指标,制定工业园区生态环境保护专项规划,提出相应保障措施。总体来说,应结合工业园区近远期发展趋势,根据污染物类别和产生情况,超前规划建设污染物集中治理设施,加强生态环境保护专项规划设计,最大限度减少工业集聚的生态环境影响。

摘要：针对5G中的高速移动场景,设计了面向快时变信道的导频结构,对快时变信道下系统ICI进行了分析,并提出了一种基于GFDM数据块的BEM 2维滑动维纳滤波信道估计方案以降低ICI所带来的性能损失.仿真结果能够有效地抑制高速移动带来的频域弥散,降低相邻子载波间的干扰,同时由于滑动维纳滤波的采用,降低了运算的复杂度.

摘要：根据拉伸法测量金属杨氏模量的原理,利用现有的杨氏模量仪,设计了一套应用游标卡尺测定金属杨氏模量的方法。

摘要：总结了巴黎公共自行车租赁点规划中采用的出行需求预测方法,规划在分区基础上,根据居住人口、就业岗位、商业和设施4种类型,测算各区日均出行次数,进而确定公共自行车租赁点数量及自行车规模。阐述了租赁点定位的影响因素、定位方法及布设原则。详细分析了租赁点的布设方式,明确路边租赁点、人行道上的租赁点和行道树附近租赁点的布设要点,对自行车、停车桩、服务终端等设施也提出了相关要求。最后,在巴黎经验基础上指出,我国部分城市提出的"解决公交出行最后一公里"的公共自行车系统单一功能定位,不利于租赁点的合理布局;租赁点主要布设在人行道的做法也会引发新的交通问题。

摘要：为寻找路内停车泊位在道路上巡游的车辆是造成交通拥堵的原因之一。首先指出路内停车低价与路外停车高价共同刺激驾驶人选择巡游而非使用路外停车场(库)。其次针对洛杉矶的巡游开展调查,得到车辆平均巡游时耗和距离,并得出每年由此产生的车辆行驶里程、时间浪费、燃油消耗及CO2排放。然后通过分析路内停车价格与车辆巡游的关系,提出城市全日泊位使用率大约为85%时,停车泊位处于供需平衡状态,停车价格较合理。接着以加利福尼亚格雷伍德城停车价格制定及停车收益使用为例,给出停车增量融资的收益回馈方式。最后指出,为了减少拥堵、降低温室气体排放、改善街区环境等,城市应制定合理的路内停车价格并将产生的收益用于改善公共服务。