乡土社会中雇佣契约的效力机制分析

乡土社会①的熟人特色和近代国家法的西方面向,使得乡村中雇佣契约的实施主要依赖于社会力量。雇工与雇主既是达成雇佣契约的主体,同时也是雇佣契约实施所分别作用的对象。雇佣契约的效力机制主要体现为,社会力量通过对于雇工的压制机制和雇主的惩罚机制迫使雇佣双方安于遵循所达成的契约规范。

可饱和脉冲变压器及其在脉冲调制器中的应用

提出了采用多路绕组分组并联结构和同轴结构的两种新型可饱和脉冲变压器(SPT),用来取代寿命较短的气体开关,作为脉冲电容器或几百kV级脉冲调制器的充电变压器兼主开关。采用磁芯自动复位机制的新型SPT,初步解决了普通SPT难以兼具高升压倍数和绕组低饱和电感的问题,实现独立脉冲变压器和磁开关的集成紧凑化。采用初次级绕组间反向互感压制的物理机制,实现SPT次级绕组饱和电感降低到其固有饱和结构电感以下水平的重要特性,为实现低饱和电感磁开关探索了一条新技术路线。新型SPT已在螺旋Blumlein脉冲形成线(HBPFL)型高功率脉冲调制器中获得了应用:其作为变压器实现HBPFL充电200kV的目标;其作为HBPFL主开关形成了幅度为180kV、脉宽135ns、前沿时间60ns的准方波电压脉冲。此外,提出并验证了新型SPT应用于百kV级集成紧凑化Marx发生器及多路高电压脉冲ns同步等领域的新技术路线。

雇佣契约的效力基础——以乡土社会为场域

乡土社会的熟人特色和近代国家法的西方面向,使得乡村中雇佣契约的实施主要依赖于社会力量。雇工与雇主既是达成雇佣契约的主体,同时也是雇佣契约实施所分别作用的对象。雇佣契约的效力机制主要体现为,社会力量通过对于雇工的压制机制和雇主的惩罚机制迫使雇佣双方安于遵循所达成的契约规范。

Active control of structural sound radiation in an acoustic enclosure consisting of flexible structure

The active control of structural sound radiation in an acoustic enclosure is studied by using distributed point force actuators as the secondary control force, and the control mechanisms for the radiated noise in the cavity are analyzed. A rectangular enclosure involving two simply supported flexible plates is created for this investigation. The characteristics of the primary and secondary sound field and the structural-acoustic coupled system are analyzed, and the optimal control objective for reducing the sound pressure level （SPL） in the cavity is derived. The response of the SPL in the cavity is analyzed and compared when the secondary point force actuators with different locations and parameters are applied to the two flexible plates. The results indicate that the noise in the cavity can be better controlled when some point force actuators are applied to two flexible plates for cooperative control rather than the point force actuators being only applied to the excited flexible plate.

论火力毁伤集团目标的任务

近年来，俄军十分重视对火力毁伤的研究。本文作者根据历史的经验和现代目标的特点，论述了目标丧失战斗力的标准，以及火力压制机制的有关问题，并提出了确定火力突击和射击任务的方法。

Novel Approach for Fault Detection and Diagnosis of Sensors in Air Handling Units Using Wavelet Energy Entropy

A novel fault diagnosis method for sensors in air handling unit（AHU） using wavelet energy entropy was presented. Instead of directly comparing the numerous data under noise conditiom, the wavelet energy entropy residual was compared in the proposed method. Three.level wavelet analysis was used to decompose the measurement data under both fault-free and faulty operation conditions. The concept of Shannon entropy was referred to define wavelet energy entropy of the wavelet coefficients. The sensor faults were diagnosed by comparing the deviation of the wavelet energy entropy of the measured signal and the estimated one with the preset threshold. Testing results showed that the wavelet energy entropy was sensitive to diagnose the biased faults. The wavelet energy entropy residuals exceed the threshold significantly when faults occur. In addition, the severer the faults were, the larger the residuals would be. The results prove that the proposed method is feasible and effective for the fault detection and diagnosis of the sensors.

Identification and optimization for hydraulic roll gap control in strip rolling mill

In order to improve the control performance of strip rolling mill, theoretical model of the hydraulic gap control(HGC) system was established. HGC system offline identification scheme was designed for a tandem cold strip mill, the system model parameters were identified by ARX model, and the identified model was verified. Taking the offline identified parameters as the initial values, online identification using recursive least square was carried out with model parameters changing. For the purpose of improving system robustness and decreasing the sensitivity due to model errors, the HGC system based on generalized predictive control(GPC) was designed, and simulation experiments for traditional controller and GPC controller were conducted. The results show that both controllers acquire good control effect with model matching. When the model mismatches, for the traditional controller, the overshot will increase to 76.7% and the rising time will increase to 165.7 ms, which cannot be accepted by HGC system; for the GPC controller, the overshot is less than 8.5%, and the rising time is less than 26 ms in any case.

Application of Aspen to Lithium Bromide Refrigerator

By transforming the original interstage compression cooling system of nitrogen fertilizer plant and adding lithium bromide refrigerator, the paper designs a new compressor interstage cooling system which leads interstage heat in lithium bromide refrigerator and uses the obtained cooling capacity to reduce the temperature of compressed gas. And aspen is used to simulate the new process. Lastly, the paper makes economical and feasible conclusion.

Microstructural evolution and mechanism of grain growth in magnesia ceramics prepared by high pressure and temperature with ultra-high heating rate

The fast densification method of combustion reaction plus quick pressing was adopted to prepare nanocrystalline ceramics.The densification process of magnesia compact with a particle size of 100 nm was investigated,under the applied pressure of up to 170 MPa,and the temperature range of 1740–2080 K with ultra-high heating rate(above 1700 K/min).High-purity magnesia ceramics with a relative density of 98.8%and an average grain size of 120 nm was obtained at 1740 K,and the grain growth during the densification process was effectively restrained.The characteristic morphology of evaporation-condensation was observed in the compact prepared at 2080 K,which revealed the actual process of mass transfer by gas diffusion.Moreover,the investigation on the microstructure evolution and mechanism of grain growth was carried out,on the basis of as-preserved nanocrystalline ceramics.The result indicated that the grain growth of the nanocrystalline MgO was controlled by the mechanism of evaporation-condensation rather than surface diffusion.Furthermore,the pressure had an influence of restraining the grain growth based on solid diffusion and strengthening the effect of gas diffusion with the increasing temperature.Under the particular conditions,there existed an appropriate temperature for the densification of nanocrystalline magnesia,while the excessive temperature would exaggerate grain growth and impede densification.