摘要：某锅炉用楔形双闸板闸阀在实际使用过程中出现了闸板密封面磨损严重、阀体上导轨槽与闸板上导轨翻边现象,这会对阀门密封面及其整体结构造成很严重的破坏,影响使用寿命。结合尺寸链理论对导轨间隙尺寸进行分析,对导轨槽挤压应力进行校核,并基于热固耦合仿真分析方法对其进行模拟。结果表明:由于导轨间隙尺寸过大,闸板提起时不能及早使两密封体完全脱离产生磨损,导轨结构尺寸的不合理使其导轨上挤压应力不满足要求,在长期高压高温工况使用下,阀体导轨槽产生屈服被压溃,致使闸板倾斜挤压密封面,造成进一步的磨损破坏。根据研究结果对闸板上导轨结构尺寸进行优化改进,满足了所需应力要求,减小磨损程度。此研究可为该类阀门的设计及优化提供一定的参考依据。

摘要：由于我国市场化制度的不完善和文化创意产业自身的特征,社会资本成为影响文化创意产业创新的重要因素。基于2016年国家工商总局1对全国文化创意产业园区的调研数据,从实证角度研究了社会资本与文化创意产业创新之间的内在关系。研究发现:企业的政治社会资本对创新具有显著的正向作用,并受到地区市场化程度的负向调节作用影响。企业间的横向和纵向社会资本同样促进了企业的创新绩效,但地区的市场化程度对于企业间纵向社会资本和创新的关系并不具有显著的负向调节作用。

摘要：1 雕刻工具雕刻工具古称之为“剞劂”，如汉·严忌《楚辞·哀时命》曰：“握剞劂而不用兮，操规矩而无所施。”王逸注云：“剞劂，刻镂刀也。”其是将设计创意进行物化的有力武器，自身质量的优与劣直接关系到所雕刻器物的最终品相的好与坏及使用者工作效率的高与低，故古语有云：“工欲善其事，必先利其器”。伴随着冶铁及木工技术的发展，到了明代，以凿类和刀类（刻刀）等作为雕刻主要工具的配套组合状况已完全成熟并定型，并一直沿用至今。

摘要：AIM: To evaluate the biological functions of tissue-engineered human corneal epithelium (TE-HCEP) by corneal transplantation in limbal stem cell deficiency (LSCD) rabbit models. METHODS: TE-HCEPs were reconstructed with DiI-labeled untransfected HCEP cells and denuded amniotic membrane (dAM) in air-liquid interface culture, and their morphology and structure were characterized by hematoxylin-eosin (HE) staining of paraffin-sections, immunohistochemistry and electron microscopy. LSCD models were established by mechanical and alcohol treatment of the left eyes of New Zealand white rabbits, and their eyes were transplanted with TE-HCEPs with dAM surface outside by lamellar keratoplasty (LKP). Corneal transparency, neovascularization, thickness, and epithelial integrality of both traumatic and post transplantation eyes were checked once a week by slit-lamp corneal microscopy, a corneal pachymeter, and periodic acid-Schiff (PAS) staining. At day 120 post surgery, the rabbits in each group were sacrificed and their corneas were examined by DiI label observation, HE staining, immunohistochemistry and electron microscopy. RESULTS: After cultured for 5 days on dAM, HCEP cells, maintaining keratin 3 expression, reconstructed a 6-7 layer TE-HCEP with normal morphology and structure. The traumatic rabbit corneas, entirely opaque, conjunctivalized and with invaded blood vessels, were used as LSCD models for TE-HCEP transplantation. After transplantation, obvious edema was not found in TE-HCEP-transplanted corneas which became more and more transparent, the invaded blood vessels reduced gradually throughout the monitoring period. The corneas decreased to normal thickness on day 25, while those of dAM eyes were over 575 mu m in thickness during the monitoring period. A 45 layer of epithelium consisting of TE-HCEP originated cells attached tightly to the anterior surface of stroma was reconstructed 120 days after TE-HCEP transplantation, which was similar to the normal control eye

摘要：Rock pillar is the key supporting component in underground *** an earthquake,the key rock pillar must bear both the seismic load and the load transferred from other damaged *** paper attempts to reveal the influence of the mainshock on damage evolution and failure characteristic of the key rock pillar during aftershocks by cyclic loading test of *** levels of pre-damage stress(i.e.,10,30,50 and 70 MPa)in the first cycle were used to simulate the mainshock damage,and then cyclic stress with the same amplitude(namely 10 MPa)was conducted in the subsequent cycles to simulate the aftershock until rock *** results indicate that the presence of pre-damage has an obvious weakening effect on the bearing capacity and deformation resistance of rock materials during the aftershock ***,the increase of pre-damage significantly changes the final failure pattern of the key rock pillar,and leads to an increase in the proportion of small-scale rock *** study may contribute to understanding the seismic capacity of the unreinforced rock pillar during mainshock-aftershock seismic sequences and to optimizing the design of the key rock pillar in underground engineering.

摘要：在移动IP中,根据子网前缀以及均匀分布于区间[min,max]上的广告间隙,移动节点检测它自身是否移动.因此,区间的长度对于移动检测延时有直接的影响.然而,在移动IP 中,区间的静态配置既不方便也不灵活.根据链路带宽的利用率,提出了一种动态调整区间的新方法,并且进行了理论分析.结果显示,与静态区间相比,动态区间的方法显著地减少了不必要的移动检测延时.

摘要：为了研究荔枝振动分离特性,以此为基础优化振动器结构,利用往复振动采收装置在不同振动参数下对荔枝进行振动分离试验,并采用MatLab软件分析高速相机拍摄的荔枝运动视频,获得荔枝运动参数(轨迹、速度、加速度等)。为了确定振动机构的最优工作参数,利用Design-Expert软件处理试验数据并得到回归模型,再通过响应曲面分析振动频率、振幅和振动距离对荔枝分离特性(分离时间、碰撞次数和惯性力)的影响,对回归模型进行优化,结果表明:当振动频率为9.7 Hz、振幅为80 mm、振动距离为29.4 mm时,既能保证较短的分离时间又能减轻荔枝果实所受的机械损伤。为了基于最优工作参数对振动器进行结构优化,以采收效率高和损伤小为目标,以尺寸约束、角度约束和强度约束为约束条件,建立多目标优化模型。优化后的振动器为对心曲柄滑块机构,曲柄长度为56 mm,连杆为127 mm,角速度为62 rad/s。经验证,优化后的振动器可以提高采收效率,减少果实所受损伤,为荔枝振动采收器的设计提供依据。

摘要：以目前华南地区最大的国家湿地公园——西津国家湿地公园为案例,坚持生态资源保护下的适度开发与利用原则,以当地现有的自然生态环境为本,致力于打造经济、民生、风土等多维度可持续和谐发展样本.以"真湿地,深生态,大花园"为核心理念,结合现有自然水系,打造具有天然属性的真湿地景观体系.以对大自然的敬畏之心,尊重环境规律,在实地调研背景下寻找本地的气候、植物生长、风向等规律,营造和谐发展的生态运作链.并运用花海的形式增加景观特色,形成规模性的大花园,为游客及当地居民带来愉悦的视觉效果.

摘要：为适应未来航空电气化的发展需求,研究了30kW级航空电驱动涵道风扇设计方法。涵道风扇性能设计基于航空发动机压缩部件设计流程。以推进系统总体性能为设计目标,完成了转子、流道以及短舱的气动外形设计。对各组成部件建立性能分析模型,评估全工况范围特性。涵道风扇结构设计采用风扇-电机一体化设计思想,简化连接方式的同时减少零件数。采用航空发动机结构强度分析方法,对涵道风扇各部件的应力、振动等特性进行评估分析。完成了30kW涵道风扇试制并开展地面和飞行试验研究。按照航空发动机整机试验方法,在整机试验台架完成涵道风扇地面性能试验。通过对比分析,试验结果与设计值误差在5%以内,验证了设计方法的有效性与正确性。涵道风扇配装轻型通航飞机完成了飞行试验,全系统工作正常,进一步验证了实际使用环境下涵道风扇的工作可靠性。

摘要：人工湿地是宋公河综合整治工程的重要组成部分,对整体治理方案进行了介绍,重点针对原湿地设计方案存在的水质处理达标难度大、场地景观效果不佳、工程造价高等问题,提出了减小场地填方、优化工艺流程、对湿地单元进行艺术化改造和梯级布置、优化渡槽走向和铺设形式、优化拦水坝形式等措施,对工程进行整体艺术构思和景观设计,最终将湿地打造为工艺功能与景观功能并重的湿地公园,为山地条件下水处理型人工湿地的构建提供了案例借鉴。