共查询到20条相似文献，搜索用时 15 毫秒
1.
Considering the large negative bending moment at the end of frame beam and low tensile strength of concrete,a new composite steel-concrete frame beam(CSCFB),reinforced by a T shape steel beam at the negative bending regions,was brought forward.Through two full-scale of single-layer CSCFB frame models experiment,the load-displacement curves of CSCFB and strain distribution at cross section were obtained.Compared with the ordinary composite beam,the T shape reinforcing section can enhance the beam stiffness effectively,and make it distribute reasonably.The segment flexural rigidity method is presented and validated. 相似文献
2.
This article takes SOFC-PEM hybrid systems as the research object and considers the operating parameters to be uncertainty. Uncertainty analysis method based on Latin hypercube sampling involves quantifying the uncertainty in the input parameters in the form of appropriate distribution functions, propagating the uncertainty through a deterministic model to construct the output variability distributions, and analyzing the effects of operational parameter uncertainty on system output. Furthermore, non-traditional sensitivity analysis approach is used to evaluate the relative importance of various parameters considering this distribution structure. Results show that higher operating temperature of SOFC stack, lower fuel rate and lower fuel utilization of SOFC stack can reduce the influence of uncertainty on system output at the expense of system output. Uncertainty analysis can provides more credible basis for the optimization of design parameters under uncertainty. 相似文献
3.
实验以3株贵州市采集的松乳菇菌种和西南大学储存的一株松乳菇菌种为材料,利用PDA培养基培养活化的母种,马丁氏培养基筛选最优碳源、氮源以及pH,通过观察菌丝密度、菌丝颜色形态、菌丝过滤干燥称重等方法确定最优条件,对比各组别中松乳菇菌丝生长状况确定最优菌种。将菌丝置于不同栽培种配方中培养,确定最佳的栽培种配方。试验表明：Ld1为最优菌种,能够产生大量菌丝,PDA培养基能较好的培养、保存菌种。最优条件为葡萄糖作碳源,KNO3作氮源,pH 6,且以松木屑、麦麸、棉籽壳按照一定的配比做栽培种能使松乳菇菌丝生长发育得最好。 相似文献
4.
An original variable valve timing mechanism with two-mode intake timing was developed according to the structural characteristics of small medium displacement motorcycle engine. Based on cycle simulation, the effects of the VVT mechanism structural parameters, control parameters and operational parameters on the engine performance were analyzed by embedding the VVT mechanism operational mode and control strategies in the engine cycle simulation. Optimum design for the late intake valve closing, the valve lift, as well as the switching speed of the VVT system was carried out. It has been proved that power and torque of the JH125 motorcycle engine can be effectively improved by loading the new type VVT system. 相似文献
5.
Sonoprobe method has been applied in non-destructive inspection of anchorage project. Its fundament is to cause anchor bar's elastic vibration by dynamic transient excitation and the flaws of anchor bar can be estimated or deduced by determining the transient response. The numeric solution!of hyperbolic equation by FEA indicates that the deductions should comply with the acoustic parameters such as sound velocity, vibration range, wave shape etc., when inspecting the interior flaws in grouting of anchor bar. As a non-linear dynamic system,"the artificial neural networks dealing with quality inspection of gray system have been proved efficient. 相似文献
6.
为解决真空冷冻干燥后的干花容易断裂、破碎,且易吸潮不利于贮藏运输的问题,以经过真空冷冻干燥后的牡丹干花为材料,利用超声雾化技术对其进行软化护形处理,并利用质构仪测量其软化护形后牡丹干花的刺穿强度和拉伸强度。结果表明,经过软化护形液处理过后的干花其刺穿强度和拉伸强度明显大于未处理的干花,其力学特性也优于后者。 相似文献
7.
A new de noising method based on parameter optimized Morlet wavelet is put forward. The Morlet wavelet is chosen as the mother wavelet because its shape is similar to the mechanical shock signals. The mother Morlet wavelet is improved by adding two parameters which decide the shape of the mother wavelet in time domain. The added parameters and the appropriate scale parameter for the wavelet transformation are designed by the cross validation method. Finally, the useful components of the signal can be obtained by the improved Morlet wavelet de noising method. The gear fault diagnosis experimental result shows that the proposed method has a good de nosing performance and it is effective in fault feature extraction. 相似文献
8.
The large quantity of MSW (municipal solid waste) and ISW (industrial sold waste) piled up in Chongqing has been threatening ecological environment and water resource. Efficient management is the important guarantee of disposing solid waste. This paper describes the data system of Management Information System of the Solid Waste in Chongqing based on the GIS, construction of information database, overall structure, main functions, etc. Integrating related solid waste technology with computer and geographical system, it can provide the reliable, scientific and convenient management and decision-making support of solid waste in Chongqing. The information system, developed by means of Geographical Information System (GIS) on the basis of a great deal of data and graphs of solid waste of Chongqing, includes six sub-systems as follows:data input sub-system;data query sub-system;database management and maintenance sub-system;database of modal management sub-system;application and output sub-system;system management. This system provides friendly and easy operational interface, and plays a significant role in the disposal and management of solid waste in Chongqing. 相似文献
9.
用遗传算法进行RFD装置优化设计 总被引：1，自引：0，他引：1
免维修流体输送装置RFD由压缩空气做动力,通过气液换能驱动被输送液体间歇性出料。该装置不含运动部件,其优化设计是关系到装置高效稳定运行的关键理论。文中分析了传统枚举法和边际效用法在方案搜索中存在的问题,重点讨论了遗传算法在多目标高维优化问题中的应用,通过计算实例比较了3种方法的计算结果,得出遗传算法在本问题求解中的优势。最后,针对流量和扬程需求,采用遗传算法进行了装置的系列化设计,并分析了有关结构参数和运行参数的变化规律,进一步给出了不同密度和粘度下,RFD装置输送流量的换算关系,为RFD装置的工业设计打下坚实的基础。 相似文献
10.
In order to subdivide the market during the process of project planning and orient the group of client, then determine the sale price; on the condition that the traditional orientation procedure cant grasp the payment capability of the aim client, the anthors can adapt the powerful finance analysis ability of EXEL to design the procedure of determining the purchasing power and payments ability of the aim client, and shape a set of orientation system based on quantitative analysis method. The result is, the character of the aim client can be grasp accurately depend on this orientation system, and providing a scientific gist for the accurate orientation of price and lowing the risk of investment etc. 相似文献
11.
作物株型信息多媒体图像处理技术的研究 总被引：26，自引：3，他引：23
用计算机多媒体图像处理技术对作物植株株型信息进行了提取、描述和管理的研究。植株图像经摄像或照片输入计算机并数字化后,通过计算机可完成对植株图像的编辑和特征信息提取,输出近３０个描述株型信息的指标,包括一些基于多媒体图像技术的新指标,如用于描述植株与叶片占据空间大小的株幅值（Ｒｐ）,叶幅值（ＲＩ）、茎叶距（ＳＬＤ）;描述叶片空间分布状态的叶均角（ＬＡＡ）;描述株型优化程度的叶均角指数（ＬＡＡＩ）、茎 相似文献
12.
通过盆栽试验对收集保存的38个观叶秋海棠种类的15个观赏性和适应性指标进行观测统计,构建观叶秋海棠品质性状综合评价体系,为筛选和利用适宜产业化生产的种类提供依据。应用层次分析法对各评价因子的权重进行定量评价,其中株型、叶面斑纹颜色、生长势、叶面斑纹大小的权重值分别为0.2210,0.1368,0.1041,0.0880,所占比重较大。对38个观叶秋海棠种类进行K-Means聚类分析,将其划分为优、良、一般3个等级,筛选出17个株形丰满紧凑、叶色鲜艳、生长势强的优等级种类,综合性状符合选择目标。结果表明应用层次分析法和K-Means聚类法建立的评价体系,可以有效地对观叶秋海棠品种进行评价和分级,为进一步合理开发利用观叶秋海棠种质资源提供了一种相对科学严谨的方法。 相似文献
13.
Li Wenyuan Sun Hongbo Zhou Jiaqi 《保鲜与加工》1989,(3):92-98
The paper presents a Monte-carlo method for reliability evaluation of large scale composite generation transmission systems. The method, which possesses coputational rapidity and sufficient accuracy,is based on combining the dispersed sampling techique with the analysis approach and the optimization model of power not supplied. Because the amount of calculation increases only linearly with, the number of elements, it is specially sui-
table for large scale systems. The Monte-carlo sampling draws more near the
real situation than determinate state enumeration in simulating occurrence of power system outages. Also, the method can be easily generalized to involve multi-states of elements, multi-levels and stochastic distribution of loads. The results of IEEE-RTS, as example, are given and compared with ones obtained by using the other two methods. 相似文献
14.
食品专业课程体系建设初探 总被引：4，自引：1，他引：3
通过分析食品专业课程体系的现状和存在的问题,提出食品专业课程体系建设中理论教学、实验教学和实践教学的改革方案。引进学生自主因素,使食品专业的课程体系更加人性化、合理化。充分调动学生学习的积极性、主动性,培养学生的动手能力和创新能力,为国家经济建设培养出高素质的食品专业人才。 相似文献
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16.
In order to comprehensively and correctly analyze the real-time operational characteristics of a grid-connected wind turbine generator system, it is necessary to analyze the overall control strategies and operation performances of the wind turbine generator system. According to the type of a doubly fed wind turbine generator system, the mathematical models of wind turbine, drive train and doubly fed induction generator (DFIG) are presented. From the viewpoints of the maximum wind energy capture and safe operation of the wind turbine, a maximum power output control strategy is proposed by considering the DFIG loss minimization, and a variable pitch control strategy is also presented by considering generator rotational speed restriction and the output power restriction. Combined with a power decoupling strategy of DFIG, the overall operational performances of the doubly fed wind turbine generator system are simulated. By comparing the simulation, theoretical analysis and actual operational data, the results show that the presented model and overall control strategies of the doubly fed wind turbine generator system are valid. 相似文献
17.
The criterion for remeshing and the automatic generating method of new mesh system are studied. The parameter transmitting method for the information transferring between new and old meshes is put forward by using Sherpard shape function. A general remeshing method suitable for two dimensional rigid plastic analysis is derived. The numerical examples show that the method is of high presicion and efficiency. 相似文献
18.
Erosion Optimized Diagnosis of Brand Grounding Grid 总被引：1，自引：0，他引：1
To find the corrosion of the grid ,large area cutting has been adopting in practice for a very long time. But this method is blind, difficult and influences the system operating. The erosion diagnosis method in the past is effective for the smaller grid. To the brand ones, it can not take effect. The method of separating the grounding grid into several parts and diagnosing step by step is discussed by lots of simulation about middle or brand grounding grid erosion diagnosis. This method makes the brand grounding grid erosion diagnosis quick and truly without power cut and digging large area, satisfies the demand in practice. Putting this optimized diagnosis method into practice , the result is good. 相似文献
19.
基于GF-1卫星数据与面向对象分类的达里诺尔湿地自然保护区土地覆盖信息提取 总被引：1，自引：1，他引：0
以达里诺尔湿地自然保护区为研究区，基于国产GF-1遥感影像，采用面向对象和传统目视解译的分类方法对研究区土地覆盖遥感信息进行提取，并对其结果进行对比分析，采取混淆矩阵对面向对象分类结果进行精度验证。结果表明：（1）充分利用了GF-1遥感影像的光谱信息，面向对象分类采取试错法确定最优分割尺度为550，形状和紧致度因子分别为0.6和0.5，各波段权重均为1。（2）面向对象分类总体分类精度达98.22％，KAPPA系数为0.96；（3）面向对象分类方法可快速准确提取类型较为复杂的土地覆盖信息，为内陆湿地精准快速提取研究区土地覆盖分类信息提供参考，以期为湿地遥感业务化监测提供技术规范。 相似文献
20.
作物蒸散不同时空尺度模型及尺度转换方法研究进展 总被引：1，自引：1，他引：0
为了通过比较经济的成本灵活获取不同尺度的蒸散量,回顾了作物蒸散研究的历史发展,重点评述了作物蒸散不同时空尺度模型及尺度转换方法研究现状,在此基础上,预测了作物蒸散的发展趋势：以精确的点尺度作物蒸散模型为基础,结合遥感数据、数字高程模型和GIS技术建立新颖的空间插值方法,从而实现作物蒸散的空间尺度转换;通过建立精确的基于遥感数据的作物系数模型,利用基于作物系数的时间尺度转换方法,实现作物蒸散时间尺度扩展;基于上述时空尺度转换方法,建立综合性的,面向业务化运行的系统作物蒸散模型。 相似文献