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221.
A finite element model of an automobile seat structure is established using Hypermesh. The statics and dynamics of the seat structure are performed through simulation based on GB 15083—1994, which is a motor vehicles seat system strength regulation and te  相似文献   
222.
The absorption of uranium by ion exchange resin is studied based on the characters of pregnant solution for a new uranium in situ leaching mine. The resin types, the absorption parameters and the eluting parameters are chosen in the experiments. The results showd that the 201×7 strong alkaline anion exchange resin and TSF 2 anion exchange resin had good absorption and eluting effects. The fixed bed anion exchange absorption is a suitable technology and NH4NO3+HNO3 mixed solution is an appropriate eluting reagent for this technology.  相似文献   
223.
The microbiology was introduced in foundation treatment. Several Carbonate mineralization microorganisms and polysaccharides viscose microorganisms were screened and the microorganisms No.ATCC 6453,3,polysaccharides viscose microorganisms 5 and 6 were used in silt modification. The engineering properties of silt before and after modification were compared by unconfined compressive strength test and indoor seepage test. The microstructures of silt incorporating different microorganisms were analysed by mean of scanning electron microscope and energy dispersive X ray (EDX) analysis. And the modification mechanism of silt has been revealed. These studies indicate that certain engineering properties of silt can be improved by incorporating microorganisms.  相似文献   
224.
为了解保存在长期库、冰柜和干燥器中的种质,其田间出苗率、主要农艺性状和含油量如何变化,调查了三种贮藏方式下的53份油菜。结果表明储藏11~14年之间的种质田间出苗率平均值都高于储藏19~25年之间的种质,长期库和冰柜中保存的种子出苗率高于干燥器中保存的,表明干燥器不利于种子的长期保存。在长期库、冰柜和干燥器三种保存方式下,11个农艺性状的平均值一致表现为长期库优于冰柜,更优于干燥器;其中全株角果数、单株产量、单株重和分枝高度在三种保存方式下变异较大,变异系数在20%以上;角果宽度和含油量变异较小,变异系数在9%以下,说明不同保存方式不但影响种子活力和田间出苗率,还影响农艺性状。相关分析表明,因保存方式不同,出苗率表现不一致,与之相关的农艺性状也不同;在不同的储藏年限间,出苗率与株高、一次分枝数、全株角果数、主序角果数、单株产量均呈显著正相关。干燥器中保存的种质,因为活力丧失严重,整体出苗率较低,很难判断出苗率与农艺性状间的相关性。  相似文献   
225.
小麦叶绿素缺失突变体Mt135的叶绿体基因差异表达分析   总被引:1,自引:0,他引:1  
小麦叶绿素缺失突变体Mt135自交后代稳定表现绿株、条纹株和白化株3种类型, 其中条纹株白色组织和白化株的叶绿体数目和结构发生突变, 完全失去光合能力。为研究该突变体叶绿体基因表达与光合作用的关系, 采用实时荧光定量PCR技术, 分析了白化株和条纹株的叶绿体基因表达。在白化株中共检测到40个差异表达基因, 涉及4类功能(编码光反应相关蛋白、编码叶绿体内能量代谢相关酶、核糖体合成和tRNA合成), 包括18个上调表达和22个下调表达基因;在条纹株中共检测到13个上调表达基因, 其表达变化趋势与在白化株中一致。白化株的差异表达基因中, 编码光系统II、I结构蛋白的psb、psa及ycf等基因家族的基因表达量显著下调;多个编码核糖体蛋白大、小亚基的基因表达量改变, 尤其是核糖体蛋白小亚基编码基因rps14和23S rRNA的编码基因23S rDNA表达量显著下调。推测Mt135突变性状与参与光反应相关蛋白的编码基因、叶绿体内能量代谢相关酶的编码基因、核糖体合成相关基因以及tRNA合成相关基因表达量的改变密切相关。  相似文献   
226.
Insulated gate bipolar transistor (IGBT) power module operating performance and reliability and its design of heat dissipation system in inverter are directly related to its operation junction temperature. Investigation of temperature of power device junc  相似文献   
227.
The Kalman filter algorithm can be used to estimate the state of charge (SOC) of power batteries, however, it easily causes divergence due to uncertain of system noise and its estimation performance is affected by model. An adaptive Kalman filter algorithm is adopted to dynamically estimate SOC of lithium iron phosphate batteries for application in electric vehicles. At first, an equivalent circuit model, appropriate for SOC estimation is built after studying battery models. Then some charging and discharging experiments are carried out for parameter identification and the results are verified. At last, the adaptive Kalman filter algorithm is used on this model for on-line SOC estimation under unknown interfering noise. Simulation results show that adaptive Kalman filter method can correct SOC estimation error caused by tiny model error online, and the estimate accuracy is higher than Kalman filter method. Adaptive Kalman filter algorithm can also correct the initial error. Full-cycle test in electric vehicles proves that the algorithm is appropriate for SOC estimation of lithium iron phosphate battery.  相似文献   
228.
For the duct grouting of prestressed beams,due to the narrow passageways grouting,the paste in the flow condition is very complex. In order to understand the grouting body in flow,the article establishes a three dimension finite element model of the grouting body,and uses the fluid mechanics software Fluent to analyze the grouting process of the standard prestressed beams through the finite element numerical method for the first time. The results show in the speed of cloud,the paste which is in a straight space and passes top space flows slow,may cause grouting defects. In the cloud of duct static pressure,the static pressure in the centre of the duct is greater than those on both ends. When paste is in hydration process,secrete water is forced to flow to the two ends,which causes grouting defects. The analysis results provide theoretical and actual testing data processing support for grouting nondestructive testing technology.  相似文献   
229.
To obtain the influence of outer environmental condition on the indoor airflow distribution for the 25T air-conditioned train in Qinghai-Tibet, the Realizable k-ε model is adopted to numerically analyze the indoor temperature and velocity fields of the running train. The results indicate that solar radiation has great effect on the indoor temperature field and it is meaningful for improving the thermal comfort to adjust the air supply parameters with the outer environmental condition. Under different air supply conditions, it is the conjugating relation between the indoor temperature field and velocity field that leads to different thermal comfort in different regions of the running train. In addition, the operating modes exchange under different outdoor environmental conditions is also discussed and some additional functions of the using air-conditioning system are put forward too.  相似文献   
230.
In order to find out the effect of site structure and distribution of cut-fill area on the seismic responses rules of Xigeda formation three-dimensional subgrade in Xichang, finite element method software is used to simulate the acceleration distribution on the surface of three-dimensional calculation models under seismic load. This paper discusses differences of subgrade seismic response from three aspects, including platform structure of the site, elevation mutation, and excavation and filling area. And there are four conclusions can be drawn. Firstly, the higher the elevation sites platform is,the greater the acceleration amplification factors are,especially in the changes of vertical acceleration amplification factors. Secondly, a sudden increase of elevation causes a sudden increase of vertical acceleration magnification factors, and acceleration amplification factors is getting smaller while extending to the platform inside. Thirdly, the acceleration amplification factors of filled area are greater than those of the excavation area. Fourthly, because terrain amplification of the seismic response is directional, three-dimensional calculation models should be used to numerical analysis. The results provide an important basis for the Xigeda subgrade base plan selection in Xichang and seismic design.  相似文献   
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