首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
对机械力作用下魔芋葡甘聚糖的变化影响进行了研究总结,介绍了不同粉碎方式产生的机械力,以及机械力对魔芋葡甘聚糖的影响,并揭示机械力对魔芋葡甘聚糖影响的作用机理。对机械力作用其他多糖的研究提供理论指导,为KGM在机械力作用下的分子链保护提供理论指导,为魔芋葡甘聚糖乃至其他天然植物多糖的精深加工提供重要的依据。  相似文献   

2.
The epicyclic gear drive with internal tooth has been analysed,the formula has been also deduced for computing the inertial force and change of contact force,and the dynamic optimization of system parameters for the force of bearing has been carried,it has given a reliable proof to reduce the dynamic load and prolong the life of bearing of three ring type reducer.  相似文献   

3.
In order to realize optimization of production organization and put forward a reasonable calculation model for the turnover number of steel ladle, the turnover process and time of steel ladle are analyzed with steel ladle of Q steelmaking plant. Gantt charts of steel ladle turnover for single casting schedule and double casting schedule are drawn. Calculation model for turnover number of steel ladle is put forward by analyzing the relationship between casting schedule and the turnover time of steel ladle, and the accuracy of the model is verified by simulation method. Researches show that the turnover number of steel ladle can be reduced 1-2 by adjusting cast starting time, and have significance for the optimization of steel ladle production organization.  相似文献   

4.
In this paper,several calculation methods for hawser cables as the crane stability system in loading and unloading forces is put out by coordinating principle of deformed body.It is convenient for adjustment of crane in unloading state to benifit accurance of the equipment installation and safrty of device during hoisting.It is also a more accurate and practical method for choice of the cable.  相似文献   

5.
6.
In the construction of high-rise and long-span reinforced concrete structures, many safety accidents result from the defect of the analysis and erection of scaffold. To solve the problem, an accurate FEM model is adopted to analyze the scaffold and is compared with the common simplified models in practice. The comparison shows that the simplified models may do give unsafe results and so several suggestions for improvement are put forward.  相似文献   

7.
张俊 《中国农学通报》2011,27(3):293-297
摘要:为充分认识湖北省畜牧业发展现状,促进其更快更好发展。在展开理论研究的同时,运用层次聚类法对省内畜产品结构和畜种结构进行了分析,运用灰色系统对湖北省2009-2012年畜牧业总产值进行了预测。结果显示,湖北省畜牧业以发展生猪、家禽、肉牛和肉羊养殖为主,以畜养马、驴、骡等多元畜禽种类为目标,同时还产出少量羊毛、蚕茧和蜂蜜等产品,具有较大发展潜力,且畜牧业总产值呈逐年稳定增长趋势;建议应不断优化省内畜牧业内部生产结构,实行生产、加工、流通一体经营等,以加快畜牧业发展速度。  相似文献   

8.
This paper presents a method which can accurately calculate the fault voltages and currents of the transposed and untransposed transmission lines.It can be applied to the simulation of protection relay analysis and fault location and so on.The principle of method is clear,the computational precision is high and usage is simple.  相似文献   

9.
The illumination computational formula recommended by the International Commission on Illumination (CIE) does not adapt to the modern construction materials with mixed reflection characters. In order to find a new luminance computational method adapting to the modern construction materials and to save building energy and control urban nightscape luminance, 30 frequently-used construction materials with respect to various directions in photometric laboratory were measured. Then the luminance modified coefficient K(i,β) was figured out, and analysed the connection of reflection luminance and atmospheric attenuation in the process of divergence of light. The K(i,β) and viewing distance, light kinds, luminaire use, material cleanliness, maintenance condition of lighting system as modified coefficient was adopted to amend the computational formula of CIE, and then a new calculation model is derived. Through calculating and comparing, the luminance value of the new calculation model is one-third as much as that of the traditional one.  相似文献   

10.
Based on the data of dynamic tests of small single-storey steel frames,the suitability of simplified hi-linear restoring force model in earthquake response analysis is discussed, and the Maximum displacement response MD, the sum of squares of the displacements in the whole vibrating history SSD, and the total dissipated energy EI are considered respectively as equivalent object.  相似文献   

11.
In the smart bar-beam structure with piezoelectric strain actuator active control function to vibration, the thickness effect of paste layer is considered and strain is assumed linear distribution along the thickness direction of each layer. The piezoelectric actuator point force model of Crawley and Luis is refined, a more general point force model is established to the smart beam with strain actuator. Point force model calculation formula is educed to smart beam with two-side symmetry paste actuator or one-side paste actuator. The computer simulation is done and the result reveals modified point model is right. The modified model is more common, as is important to design piezoelectric smart structure.  相似文献   

12.
为更好的解释农村剩余劳动力转移的影响因素,在国内外农村剩余劳动力研究的基础上,笔者运用定性和定量相结合的分析方法进行分析。为避免多重共线性在模型中的影响,采用岭回归模型对相应影响变量进行分析。通过模型综合分析,验证了影响中国农村剩余劳动力转移的推动因素和制约因素。同时提出发展区域经济,提高农民收入;推进城镇化进程,拓宽农民就业渠道;促进二、三产业发展转型与加强农民专业培训齐头并进;深化以户籍制度为中心的制度变革等4项政策建议。  相似文献   

13.
For making the theoretic results close to the fact,two methods used to calculate the internal force of beams with finite length bearing several point loads and on soil foundation were compared.These two methods were based on the Winkler's assumption and the half-space elastic foundation theory respectively.Through theoretic analysis,the difference between the two methods was found.And with the aid of FLAC~(3D) analysis,it was clear that the results deduced by the method based on the Winkler's assumption were more close to the fact.  相似文献   

14.
玉米茎剪断力研究   总被引:6,自引:0,他引:6  
玉米秸秆是东北农牧交错地区冷季重要饲料来源。决定玉米秸秆饲料品质的结构部位是茎,茎的剪断力直接反映其物理特征。本文选择四密21、农大3138和登海1号3个玉米品种进行试验。将玉米植株叶片、叶鞘及果穗等去除,按50 cm高度分段,研究了玉米茎不同高度处剪断力随时间变化情况。研究结果表明,随着时间推进,茎的剪断力逐  相似文献   

15.
This thesis studies mathematical model for calculating electromagnetic fields in space around lightning path.The calculating method which can more exactly calculate the distribution of electrocmagnetic fields in space around lightning path is developed.The results are consistent with results of refereces and simulating test.It supplies references for interference protection desigh of electronics such as computers ect.  相似文献   

16.
For the distributed fiber optical sen sor based on the principle of mede-coupling of polarization-maintaining fiber and the theory of partial coherence of quasi-monochromatic light,it is of great importance to process the weak optical signal from the sensing fiber.The characteristics of the optical slgnal was analyzed and suggestions were given for medified Mach-Zehnder interfer-ometer,which in cludes an acoustooptical medulator and a polarized-beam splitter to realize the het-erodyne in terferen ce. The method not only eliminates the influences of light source fluctuation and background light,but decreases the loss of the signal ptocessing,and improves S/N ratio.The experi-ment results coincide well with the analysis.  相似文献   

17.
There are three working modes of electro rheological(ER) damper, flow mode of fixed electrode, shear mode of slide electrode, mixer mode of slide electrode. The damping force is analyzed for gas-filled ER damper of flow mode of fixed electrode. There are three sections of damping force, and they are background damping force of a fluid viscosity, electric damping force of applied electric field and pressure of gas. The characteristic of ER damper is adjustable by electric filed strength for electric damping force. At the same time, some structure factors of ER damper are discussed.  相似文献   

18.
Combining the resource-based view and corporate governance perspective and strategic management theory, the paper studies the effects of internal governance mechanism on technological innovation of the stated-owned enterprises. It is found that a significant and positive association among technological innovation, firm' s ROA, leadership structure and asset-debt ratio. Although the ownership concentration provides a negative effect, it is no evidence thats firm' s technological innovation is related to the firm' s shares holded by top management.  相似文献   

19.
The inverse problem of circular low frequence electric current field is calculated using simulated and actually measured data by modified iterative equipotential line algorithm.  相似文献   

20.
Earthquake induced dynamic axial force in reinforced concrete (RC) bridge bent columns will not only change the yield strength of the columns but also change their stiffness, which is seldom considered by the common lumped plasticity line model. Based on the fiber element model results that taking into account the influence of dynamic axial force on strength and stiffness simultaneously, the axial force stiffness interaction effect on the seismic responses of RC double column bridges was analyzed. The results show that, axial force stiffness interaction has a large effect on the seismic responses of the double column bridge in the elastic range, and it does not alter the ultimate capacity of the columns. Since the stiffness of the columns under compression and tension dynamic axial forces offset each other, the global displacement of bridge bent with equal columns is relatively unaffected by the axial force stiffness interaction, however, the differences of the column member forces are manifest. For the short column controls the global stiffness, the axial force stiffness interaction has significant influences on both the global displacement and member force responses. The influences become larger as the irregularity of the bridge bent increases, so the interaction between axial force and member stiffness should be sufficiently considered in seismic analyses.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号