卷边板件屈曲分析的半能量法     

周绪江  王世纪 《湖南农业大学学报(自然科学版)》1991,18(2)

A semi-energy method to analyse the buckling behaviour of edge-stiffened plates under combined compression and bending is presented in this paper, One unloaded edge of the plate is restrained elastically against rotation and the other is stiffened by a st  相似文献   

薄型高密度纤维板生产设备的要求分析     

何剑锋 《林业机械与木工设备》2011,39(8)

对薄型中高密度纤维板生产设备的要求作了简要分析。

Abstract：

A brief analysis is made of the requirements for thin medium high density fiberboard product manufacturing equipment.  相似文献   

早胜牛的采精及细管冻精制作技术要点     

梁永虎 《现代农业科技》2023,(22)

近年来，伴随我国畜牧业蓬勃发展的同时，为了更大限度的提高母畜的受胎率和充分利用优秀种畜的基因，人工授精技术得到了不断完善和发展，并在全国各地广泛推广和应用。本文结合实践经验总结出的一些技术措施，阐述了对早胜牛这一地方优良种质资源进行保种和开发利用的重要意义，同时指出人工授精技术和低温冷冻保存精液技术在早胜牛上的实践，对于进一步开发利用培育优质高产肉牛新品种，促进肉牛产业高质量发展具有非常重要的现实意义。通过早胜牛种公牛采精的全过程以及细管冻精制作要点的详细讲解，低温冷冻保存精液技术，可更经济、可靠地实现家畜品种资源的保护，让优良基因长时间保存使得后续研究需要得到保障。  相似文献   

水头可调薄壁堰式渠道流量智能测控系统优化试验研究     

甄晶博  吕宏兴  庞凯文  王露  王家琪 《节水灌溉》2015,(3):62-65

采用巴赞堰流公式计算流量的水头可调薄壁堰式渠道流量智能测控系统通过渠道流量量测与控制试验,验证了其精准的测流功能和智能控制技术的可行性。为进一步提高该测控系统运行的效率和稳定性,减少运行能耗,对矩形薄壁堰堰流公式进行水力试验研究,通过分析堰上水头和流量关系,拟合出矩形薄壁堰流量计算公式。通过向该拟合公式引入修正系数λ=0.848,将测控系统测得的堰上水头数据值代入该拟合公式求得的流量值与电磁流量计测得流量值的差值的平均值为-0.004L/s,标准差为0.119,线性相关系数R2=0.989 1。该拟合公式相对于巴赞堰流公式形式简单、参数较少、运算简便,同时也满足节水灌溉对精准测流的要求,更适用于水头可调薄壁堰式渠道流量智能测控系统,对于在灌区推广和使用该测控系统具有重要的意义。  相似文献   

Analysis on Micro-structure of TiN Thin Film and Polyimide with AFM     

BAI Hai-hui  YANG Xue-heng  PENG Guang-han 《保鲜与加工》2006,(8):138-140145

The study in molecular morphology is given with a highresolution Atomic Force Microscope AFM.IPC-208B.By taking TiN thim film prepared by magnerton sputtering method and polymide(PI) fibre for examples,the preferenthal growing plme of TiN thin film,the atomic arranges of TiN thin film on the preferential growing plme and the surficial micro-structure can be ascertained form the three-dimensional images obtamed by AFM.IPC-208B.These experiments not only identify small structures of the materials,but also affirm that AFM.IPC-208B holds the precision of atomic level and potential application in micro-structure field,at the same time it establishs the groundwork for the application in micro-process kingdom.  相似文献   

Preparation of V2O5 Semiconductor Thin Films From Induststrial V2O5     

YANG Shao li  XU Chu shao  CHEN Hou Sheng  HU Zai yong 《保鲜与加工》2002,(5):97-100

  相似文献   

AN APPRONTMATE CALCULATING METHOD FOR WALL PLATES OF MAN'' S DRY GAS HOLDERS     

You lihua Wu Huibi Sun Renbo Wang Daivu 《保鲜与加工》1992,(4):48-53

The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision.  相似文献   

多线圈薄板电磁加热的均匀性及可控性     

王宏民  刘燕鑫  许家忠 《东北林业大学学报》2020,(4):120-124

以矩阵式多线圈结构电磁加热方式为研究对象,采用数值模拟仿真和对比研究的方法对薄板温度均匀性和可控性进行了分析,设计并优化多线圈电磁加热模型。首先,对加热薄板进行有限元分析与数值模拟,并在涡流损耗与模型尺寸相同条件下,对矩阵式线圈结构与蜂窝式线圈结构进行仿真结果比较;其次,分析电流强度以及线圈间距离对薄板温度均匀性影响;获得气隙尺寸与频率对温度的影响关系。结果表明:等温度区间,矩阵式多线圈结构在薄板温度均匀性以及可控性方面优于蜂窝结构;在电流密度一定条件下,薄板加热的径向温度梯度与电流呈正相关;适当调整相邻线圈的间距,薄板表面温度的均匀性得到改善;薄板表面温度,与气隙长度呈负相关,与频率呈正相关。  相似文献   

心土培肥犁改良瘠薄土壤的效果   总被引：2，自引：2，他引：2  

王秋菊  刘峰  高中超  姚春雨  张劲松  常本超  高盼  张春峰  贾会彬  焦峰  姜辉 《农业工程学报》2016,32(6):27-33

研究根据心土培肥的改土技术要求研制出心土培肥犁,并分别在瘠薄黑土和碳酸盐草甸黑钙土上开展大面积机械改土试验,明确自主研发的心土培肥犁改土后对土壤理化性质影响及对作物产量的效果,为其广泛应用到低产土壤改良提供机械及技术支持。试验设深松、心土培肥和常规对照耕作,采用大田对比方法。研究结果表明:心土培肥和深松在不同类型土壤上对土壤理、化性质,对作物产量及产量性状影响后效不完全一致;心土培肥降低土壤抗剪强度后效明显,碳酸盐草甸黑钙土10~30 cm土层土壤抗剪强度比对照降低6.65~12.16 k Pa,黑土比对照降低8.20~11.31 k Pa,碳酸盐草甸黑钙土改土后效果明显,黑土改土后效长,心土培肥改土效果优于深松;土壤容质量和硬度趋势同上;心土培肥提高土壤透气系数为2.78~14.28倍,饱和导水率为2.38~11.62倍;深松和心土培肥可提高下层土水分消耗比例,30~60 cm土层耗水量为心土培肥区深松区对照区,心土培肥耗水量比照高10%;心土培肥处理可提高土壤磷含量和供磷强度,20~30 cm和30~40 cm土层土壤供磷强度比对照分别提高4.19~5.17倍和4.96~17倍,碳酸盐草甸黑钙土高于黑土;心土培肥可提高玉米产量,碳酸盐草甸黑钙土上心土培肥增产幅度为6.82%~18.01%,黑土增产幅度为6.45%~11.18%,平均增产效果碳酸盐草甸黑钙土薄层黑土,但黑土持续增产效果好。  相似文献   

氧化节杆菌生物降解苯并芘     

PENG Hui  YIN Hu  DENG Jun  YE Jin-Shao  CHEN Shuo-N  HE Bao-Yan  ZHANG Na 《土壤圈》2012,22(4):554-561

A pot experiment was conducted with multi-metal (Pb, Cd, Cu, and Zn) contaminated acidic soil to investigate changes in available metal burden resulting from the application of industrial wastes (fly ash and steel slag). The efficiency of amendments-induced metal stabilization was evaluated by diffusive gradients in thin films (DGT), sequential extraction, and plant uptake. The stability of remediation was assessed by an acidification test and by chemical equilibrium modeling. Addition of fly ash (20 g kg-1 ) and steel slag (3 g kg-1 ) resulted in similar increase in soil pH. Both amendments significantly decreased the concentrations of metals measured with DGT (C DGT) and the metal uptake by Oryza sativa L. Significant correlations were found between C DGT and the concentration of a combination of metal fractions (exchangeable, bound to carbonates, and bound to Fe/Mn oxides), unraveling the labile species that participate in the flux of metal resupply. The capability of metal resupply, as reflected by the R (ratio of C DGT to pore water metal concentration) values, significantly decreased in the amended soils. The C DGT correlated well with the plant uptake, suggesting that DGT is a good indicator for bioavailability. Acidification raised the extractable metal concentration in amended soil but the concentration did not return to the pre-amendment level. Equilibrium modeling indicated that the soil amendments induced the precipitation of several Fe, Al and Ca minerals, which may play a positive role in metal stabilization. Chemical stabilization with alkaline amendments could be an effective and stable soil remediation strategy for attenuating metal bioavailability and reducing plant metal uptake.  相似文献