Dynamic characteristics and static response analysis of interval parameters structure

Determining the interval parameters of structural dynamic characteristics and the extreme value of static response can solve some structural uncertainties. The dynamic characteristics and static response of structures are always closely linked with the parameters. Finding the intrinsic link between them can make the calculation of the dynamic characteristics and the extreme value of interval structure simple and effective. Through function derivation of elastic modulus E and mass density ρ, it can be found that they are related to structural dynamic characteristics and static response. And the dynamic characteristics of trusses are taken as an example to calculate the maximum displacements of loading direction and unloading direction, their parameters are compared and the relation between elastic modulus and the displacement of loading direction are verified.     

Sliding mode control of robot with dynamic friction and dead zone compensation using fuzzy logic and neural network

Aiming to solve the problem of nonlinear uncertainties LuGre dynamic friction and non-symmetric dead zone in the robot,this paper presents a sliding mode robust robot control algorithm,compensates for the uncertainties of robot manipulator respectively LuGre dynamic friction with fuzzy radial base function (RBF)neural network and asymmetrical dead zone with fuzzy logic,trains parameters of nonlinear dynamic friction and asymmetrical dead zone real-timely and adaptively,to achieve an accurate reproduction of the actual robot system,and proves the Lyapunov stability of the algorithm. The simulation of a two-degree-of-freedom robot manipulator proves that the algorithm improves the trajectory tracking accuracy,the control torque stability and friction torque stability of the robot. Meanwhile,it is found that control moment pulse compensation error,rhombus attractor in the kinetic properties of the friction model of robot manipulator,and lacking of dead zone compensation cause nonlinear kinetic phenomena,such as limit cycle oscillation of control system. And the estimation of ε in the dead zone inverse model plays a decisive role in the accuracy of the system.     

Research on a dynamic tracking model for reservoir water flooding of separated zone water injection

Waterflood is one of the main oil reservoir development ways. Premature flooding of production wells during water flooding process will reduce oil recovery. Therefore,it is particularly important to establish a dynamic tracking model for reservoir water flooding of separated zone water injection. Based on the basic principles of heat and mass transfer,according to well temperature curve to determine the water profile,Poisson process analysis and stochastic process methods are adopted to calculate water saturation,water breakthrough time and water cut of each layer in water flooded reservoir at any one time. When oil reservoir gradually become water flooded,the calculated water cut of model considering micro-pore distribution of the reservoir tends to the measured water cut,and the calculation error is less than 5%. Case study shows that the layer of the higher injection rate,with high flow channel such as micro fracture,where there is the faster increase in water saturation,the shorter water breakthrough time and faster increase in water cut,and vice versa. Research result provides time guarantee to take measures for inhibiting or delaying water breakthrough of production wells.     

有机磷类农药微生物修复研究进展

有机磷类农药是目前化学防治常用种类之一,过量施用导致环境污染、农产品质量安全等问题日趋严重,国内外各学科领域科研人员也在积极探索该类农药污染的修复治理方法。本文在总结有机磷类农药应用现状及微生物降解机制基础上,详细汇总了有机磷类农药降解微生物种类,总结了功能微生物对有机磷类农药的降解谱,并展望微生物修复技术在农药修复应用前景,以期为该类研究工作提供理论依据。     

山西省主推小麦品种籽粒形态性状分析

旨在研究小麦籽粒相关形态性状与粒重的关系,筛选籽粒形态性状优良品种,为小麦籽粒形态相关性状的遗传改良提供参考。以76个山西省主推小麦品种为试材,对小麦7个籽粒相关性状进行测量,运用主成分分析和聚类分析等方法对其进行分析和评价。供试材料的千粒重与籽粒面积、粒宽、籽粒周长、粒长存在极显著正相关,与籽粒长宽比负相关;依据综合评价值（D值）将参试小麦品种聚为3类,其中第Ⅰ-1类综合评价值最高,包括编号60、72的品种,平均D值达0.896,籽粒性状综合表现最好,尤其是千粒重、籽粒面积和籽粒周长。千粒重、籽粒面积和籽粒周长可作为小麦粒部性状考察的重要指标。     

性信息素技术在高粱鳞翅目害虫发生动态监测中的应用

为研究高粱鳞翅目害虫发生动态,解决防治适期问题,通过3年田间试验,利用性诱技术诱集鳞翅目害虫,探索黏虫、条螟、玉米螟、桃蛀螟、草地贪夜蛾和二化螟的发生动态。研究发现,玉米螟和条螟发生最为严重,占鳞翅目害虫数的70%以上,各类鳞翅目害虫的发生时段在5月初—8月初,其中主要集中在5月底—7月中下旬大量发生。研究结果可为更加科学合理预测高粱鳞翅目害虫的发生危害提供依据,也为本地有机高粱生产过程中的鳞翅目害虫制定防控方法提供实践基础。     

低氮高效红甜菜形态特征分析

筛选低氮高效基因型红甜菜是提高氮素利用效率,减少氮污染的有效途径。采取液体培养方法,设置低氮(1.5 mmol/mL)、正常氮(5 mmol/mL)、高氮(10 mmol/mL)3种氮素水平处理,选用中国农业科学院甜菜研究所育种品系,通过生长指标统计、因子分析、聚类分析来确定评价指标,并筛选出耐低氮基因型。在低氮和高氮条件下,茎叶氮含量、茎叶氮素干物质生产效率、整株氮累积量、氮生理利用效率、整株氮素干物质生产效率差异性显著,变异系数分别为0.169~0.217和0.110~0.271。通过因子分析发现,在低氮和高氮条件下主成分培养情况基本相同,第一主成分是由根系氮含量、根系氮素干物质生产效率、整株氮素干物质生产效率、整株氮含量、氮生理利用效率决定,第一主成分所占的方差贡献率较大。综合红甜菜氮素吸收累积变异特征及因子分析,将茎叶氮含量、茎叶氮素干物质生产效率、整株氮累积量、氮生理利用效率、整株氮素干物质生产效率作为初步筛选红甜菜氮高效综合评价指标。再根据隶属函数法计算出的氮效率综合值和采用欧氏距离平方拟合的分层聚类分析,将整株氮素干物质生产效率作为筛选氮高效综合评价指标。最终筛选出对氮素高效吸收利用的材料（低氮高效型‘YeginaS2’、低氮低效高氮高效型‘CYCLHDAR’）,结合其株高、叶面积、叶柄长、根长等形态特征、干物质量及根冠比等实用特征,分析不同基因型红甜菜对土壤氮素吸收利用特点,进一步验证对增施氮肥反应敏感的低氮高效型、低氮低效高氮高效型品种。     

醇化烟叶表面细菌筛选及增香效应研究

为明确烤烟醇化过程中烟叶表面增香微生物对其品质的作用,以6个不同产地的烟叶为试材,通过菌株分离和产酶能力筛选,对筛选出的细菌进行16S rDNA测序分析,将烟丝发酵样进行感官质量评吸、常规化学成分和多酚化合物分析。结果表明,菌株GY99处理样的感官评吸质量提升最为明显,能有效增加烟叶香气和甜感,其处理后的牡丹江、庆阳烟叶总分分别增加了2.26、2.03分,舒适度提升,香气质和香气量分别增加0.44、0.33分,刺激性和杂气降低。本研究筛选出1株可同时产蛋白酶、淀粉酶和纤维素酶的芽孢杆菌属(Bacillus sp.)菌株GY99。同时还筛选到3株可明显改善烟草品质的菌株,分别是芽孢杆菌属(Bacillus sp.)菌株GY96、假单胞菌属(Pseudomonas)菌株GY72和微球菌属(Micrococcus)菌株GY67。     

铜基营养保护剂对棉花生长和产量的影响

2013―2014年采用盆栽试验研究了不同种类及浓度的铜基营养保护剂对棉花生长、产量及防病效果等的影响。结果表明:4种铜基营养保护剂在喷施质量浓度为1 g·L-1和2 g·L-1时,与喷施清水相比,皮棉产量分别增加4.22%~13.38%和21.89%~38.36%;增加了棉株地上部干物质质量,最高达23.96%;降低了棉花病情指数26.75%~40.91%和22.78%~37.78%,但处理间差异不显著。因此,在棉花上喷施铜基营养保护剂既可促进棉花生长,增加棉花产量,又可提高棉花的防病效果。