实验教学是学生理解掌握理论知识的必要途经,有助于提高学生的学习兴趣、培养学生实践动手能力.植物科学学院农学、植物保护、园艺、资源与环境4个涉农专业开设的机械课程实验课时少、设备少而不全、设备陈旧,并且针对性不强.针对上述现状,研制3套自制教具,并成功应用在植物科学学院4个涉农专业的机械实验课和校开放性创新实验.在实验教学中构建了"引入自制教具的混合教学模式",深受学生欢迎.学生问卷调查表明,学生对教学模式、提高学习兴趣、自学能力、自制教具的适用性等7个问题的提高程度或认可度均在90％以上.自制教具及其混合教学模式大幅提升了课堂效率,教学质量得到显著提高.

针对吉林大学农学、植物保护、农业资源与环境、生物技术、园艺5个涉农专业开设的机械课程中对内燃机的启动原理理解难的问题,研制了柴油机启动系统实验装置.该装置采用液晶显示屏显示,能实现人力启动和电力启动,其中电力启动采用触摸屏操作.该实验装置在实验教学和开放性创新实验中已进行了应用,提高了学生的学习兴趣、实践动手能力、创新意识.

针对《植保机械与应用》实验课课时少、学生没有机械基础等现状,在《植保机械与应用》实验课中构建和应用了混合教学模式.与传统教学模式相比,混合教学模式提高了学生成绩和学生上实验课的积极性与主动性,也锻炼了学生的协作能力和实践能力.

针对开放性创新实验的特点,笔者在开放性创新实验“精量播种的控制与调试”中采用了PBL教学模式.构建了PBL教学模式,设计了实验成绩的考核方式,通过问卷调查的形式调查统计了学生对在开放性创新实验中应用PBL教学模式的满意度.经过统计分析,在开放性创新实验“精量播种的控制与调试”中采用PBL教学模式不仅显著提高了教学质量,而且还提高了学生选做实验的浓厚兴趣、积极性与主动性、实践动手能力、团队意识、合作意识.

Maackia amurensis ,an important kind of medical plant ,mainly distributes in the Northeast of China ..M .amurensis has been used as folk medicine for the treatment of cancer ,cholecystitis ,arthritis ,and hyperthyroidism .This paper reviews and summarize the research progresses in the last ten years ,so as to provide theory basis for further development and utilization of this medicinal plant .

新时期加强农村基层党建工作，需要切实形成齐抓共管合力，应当不断完善体系，加强带头人队伍建设，从严抓好党员教育管理，积极探索发展村集体经济的有效途径，发挥好农村基层党组织的领导核心和战斗堡垒作用，全面提升农村基层党建工作水平。

In order to enhance the timeliness and accuracy of the soft measurement method of the ESC for electric-wheel vehicle, an improved soft measurement algorithm was designed. The improved algorithm was built based on an improved UKF. The improved UKF sampling strategy used scaled minimal skew sampling method to speed up the system sampling rate. The sigma points of the improved UKF were sampling two times to enhance the accuracy. The three degree of freedom vehicle model was built to establish vehicle dynamic relationship. According to the three degree of freedom vehicle model, the vehicle measurement model was built. The verification experiments of improved soft measurement algorithm were made based on the electric-wheel vehicle ESC test platform. The experiments included a step input experiment in 70 kilometers per hour and a step input experiment in 110 kilometers per hour. From the experimental results, it could be seen that the estimated value of yaw velocity and sideslip angle tracked the actual very well. The overshoot of the tracking process was small and the lag time was short. The improved soft measurement algorithm was fit for the ESC of electric-wheel vehicle.

The aim of this study is to improve the convergence speed and accuracy of the filter in the ESC (Electronic Stability Control) of electric-wheel vehicle. A federated filter is designed based on an improved UKF (Unscented Kalman Filter). The federated filter is composed of a vehicle speed filter and a road adhesion coefficient filter. The two filters are connection and correction each other. In the improved UKF, a scaled minimal skew sampling strategy is used to reduce the number of sampling points and avoid the local effects. A tracking adjustment factor and a resisted demission error factor are added to the improved UKF algorithm. These factors are used to enhance the tracking performance and eliminate the outliers of the system measured value. An electric-wheel vehicle dynamics model is established for the federated filter. Simulation experiments of the vehicle speed estimation and the road adhesion coefficient estimation were done. The road adhesion coefficient was 0.8 and 0.2. The initial vehicle speed was 100 and 90 kilometers per hour. The results shown the federated filter could shorten the delay time and reduce the overshoot. The federated filter is fit for the ESC of electric-wheel vehicle.

进步观念是近代以来占据主导地位的历史观,很多思想家的历史理论都是在这一主导性的观念下建构的,这其中也包括马克思的唯物主义历史观。理性主体的形成、稳定法则的信念、线性时间的确立和世俗价值的取向,是历史进步观在近代得以确立的四个基本的理论前提。通过对它们的梳理和分析,不但可以加深对历史进步观念的理解,而且可以确证,只要这些前提性条件存在,进步观念就依然是人类历史的主题。

进步观念作为近代确立的占主导地位的历史观,对人类产生了巨大的影响,但也面临了内在的困境。进步观念有两种解释原则:认知性原则和伦理性原则。从认知性原则出发,进步观念是关于历史运演的规定性知识;以伦理性原则进行理解,进步观念则是关于历史整体的一种反思性理念,仅具有范导性作用。相较于认知性原则,伦理性原则对于理解进步观念更具有优势,它不但解决了进步观念的困境,也尊重了人生存实践的可能性。

Aiming at the problem of testing time consuming and low accuracy of transfer function estimation in the traditional TPA method,an improved TPA method is presented based on a new transfer function estimation method.Adopting the improved TPA method,the three-point suspension of powertrain was analyzed and a contrast simulation experiment was made.Since the new transfer function estimation method can eliminate the influence of the random noise,the estimation accuracy is enhanced.The improved TPA method elides the car body impendence testing and reduces the testing time.The simulation results show that the improved TPA method is viable.

Aiming at the shortcoming of the integral accumulation in the process of CVT ratio adjusting control, which is caused by the general PID control method, a new ratio adjusting control system based on the shift integral PID control method was designed. The theory of CVT ratio adjusting process and the enhanced control method were analized. The enhanced PID parameter tuning principle was presented. The test-bed of CVT ratio adjusting control was devised and adopted to do the CVT ratio tracing experiments. The experiments of step ratio from 0.45 to 1.45 and from 1.7 to 0.7 were made. The experimental results proved that the new ratio adjusting control system and the enhanced PID parameter tuning principle were valid, which made the real ratio trace the object ratio rapidly and steadily. The control performance of CVT ratio adjusting was improved.

Aiming at the complicated structure and the lower reliability of the traditional electro hydraulic CVT ratio control system,a CVT ratio optimal control system is designed.The generally proportion valve is replaced with the PWM high speed on-off valve,and a mathematical model of PWM valve is built taking the magnetic characteristics of the valve into consideration.Then the CVT ratio control system is simplified to build a mathematical model of control cylinder for PWM valve.By applying optimal controls parameter of quadratic form theory of the discrete system,an optimal controller is designed.The simulation experiments for starting up and accelerating and decelerating are made under Matlab,which results show that the steady and the dynamic characteristics of the designed CVT ratio optimal control system are good with safeguarding of the effective track of the real ratio to the object ratio.

Aiming at the problems of the general CVT ratio electro hydraulic control system,which are the lower control accuracy and the integral saturation,an improved CVT ratio electro hydraulic control system was designed.The control theory of the improved control system was analyzed.Based on the magnetic material saturation characteristic and the leakage flux,a new modeling method of PWM high speed on-off valve was presented.Based on the gearshift integral algorithm,the traditional CVT ratio PID controller was improved.CVT step ratio following simulation contrastive experiment was made,which adopted the general control system and the improved control system.The results shown that the improved CVT ratio electro hydraulic control system made the overshoot be reduced and made the delay time be shortened,the CVT ratio control character was enhanced.

Aiming at integral saturation and interference sensitivity of the general PID algorithm during the course of CVT ratio control,the CVT ratio control theory and its general PID algorithm were analyzed.Based on the analysis of integral anti-windup algorithm and incomplete differential algorithm,an CVT ratio control improved PID algorithm was proposed.Adopting the improved PID algorithm and the general PID algorithm,an contrast simulation experiment was made.The experiment included the speed up of 6%～55% throttle opening,and the urgent acceleration of 55%～80% throttle opening,and the deceleration of 80%～25% throttle opening.The results shown that the overshoot and the delay of the control system were reduced by the improved PID algorithm,and the CVT ratio control system performance was enhanced.

通过对该区一种流塑态粉质粘土或粘土的的物理性质、工程地质特性、塑性分区研究,并且与该区软土的物理性质、结构特征以及土中矿物成分、化学成分的比较,参照黄土状土的命名方式将此类土定义为软土状土,并给出软土状土的相关定义条件,为以后本区的工程提供指导.

There is a large area of soft soil in distribution in Yingkou—Liaobin Economic Area.The authors divided the studied area into the grade Ⅰ—engineering suitability good area,grade Ⅱ—engineering suitability general area and grade Ⅲ—engineering suitability less area,according to the bearing capacity calculation of soft soil layer and settlement calculation of normative method for shallow foundation,with 55 mm as the boundary of foundation's additional settlement and combining with indexes of engineering risk.The grade Ⅰ zone mainly distributes in the west of Yingkou City and the south of salt region,grade Ⅱ mainly distributes in southwestern Yingkou City and the areas except the south of Liaobinxiang and salt areas and the grade Ⅲ mainly distributes in eastern Yingkou City.The areas of the grates Ⅰ,Ⅱ,Ⅲ are accounted 10.6%,86.2% and 3.2% of total area of soft soil in this Economic Area,respectively.

孔多塞对进步观的论证和阐述,使得进步观作为一种历史观在启蒙运动以后得到确立和发展。如果我们对孔多塞的进步观进行充分的梳理和分析,就会发现孔多塞的进步观存在着自身所无法克服的内在矛盾。一方面,孔多塞的进步观是一种理性的进步观,是对基督教末世论的一个批判,充分彰显了启蒙运动的精神;另一方面,孔多塞的进步观又有着时代所赋予的内在局限性,这种局限性不但表现在它是以精神进步为主导的进步观,更突出表现为在它以抽象理性主导下的反宗教意识中,依然有挥之不去的神学阴影。

<正> 走进桐庐横村镇小山村,满目绿色的一座座山头上,碗口粗、十几米高的毛竹成片、成林;风吹过,竹涛阵阵让人心旷神怡。横村,这个以发达的针织业享誉全国的工业强镇,为了让青山常绿、让山民钱袋鼓起来,计划今年内建成5万亩毛竹基地。目前,4万亩毛竹基地已先期形成规模,直接产生的经济效益达到600多万元,乐得山民一个个眉开眼笑。多年来,横村镇众多山民都是以种稻、种植水果为主,一些农户所种的少量毛竹,不是稀稀拉拉,就是种不高、养不粗,年收成