人力资源任用的边界

“彼得原理”告诉我们,要让合适的人做合适的事,应根据每个人个性心理特征的不同,安排与之相适应的事情,以利于工作效率及效能的提高。组织合适的人做适合的事,重视能力素质模型的应用,是管理工作者的应有之义。     

Theoretical Investigation of the Viscous Damping Coefficient of Hydraulic Actuators

The viscous damping coefficient(VDC) of hydraulic actuators is crucial for system modeling,control and dynamic characteristic analysis.Currently,the researches on hydraulic actuators focus on behavior assessment,promotion of control performance and efficiency.However,the estimation of the VDC is difficult due to a lack of study.Firstly,using two types of hydraulic cylinders,behaviors of the VDC are experimentally examined with velocities and pressure variations.For the tested plunger type hydraulic cylinder,the exponential model B=αυ~(-β),(α0,β0)or B=α_1e~(-β_1υ)+α_2e~(-β_2υ)(α_1,α_20,β_1,β_20),fits the relation between the VDC and velocities for a given pressure of chamber with high precision.The magnitude of the VDC decreases almost linearly under certain velocities when increasing the chamber pressure from 0.6 MPa to 6.0 MPa.Furthermore,the effects of the chamber pressures on the VDC of piston and plunge type hydraulic cylinders are different due to different sealing types.In order to investigate the VDC of a plunger type hydraulic actuator drastically,a steady-state numerical model has been developed to describe the mechanism incorporating tandem seal lubrication,back-up ring related friction behaviors and shear stress of fluid.It is shown that the simulated results of VDC agree with the measured results with a good accuracy.The proposed method provides an instruction to predict the VDC in system modeling and analysis.     

含氮、磷有机配体对(CdSe)_2量子点结构和电子性质的影响

使用密度泛函理论方法研究了量子点(CdSe)2与配体L(L=PH3、PH2Me、PHMe2、PMe3、NH3、NH2Me、NHMe2、NMe3)之间的相互作用及其产物的结构和性质。配体中的P或N原子与Cd原子上分别形成较强的Cd—P和Cd—N配位键,从而影响(CdSe)2的结构和电子性质。配体作用下,(CdSe)2的几何结构、电荷分布、轨道能级、吸收光谱等均发生变化,但2类配体的影响,尤其是甲基数目的影响,存在较大差异。     

Formation and thermal stability of amorphous Ni-Mo-P alloys

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.     

Electroless deposition of Ni on template of halloysite and its magnetic property

Halloysite template, a ceramic substrate, is of a hollow cylindric structure, on which the fine Pd nanoparticles are uniformly formed by the reduction of palldate chloride to initiate electroless deposition. The electroless deposition of Ni is catalyzed by the Pd particles, which results in a uniform layer of Ni-P alloy on halloysite. The alloy is of a nanocrystalline structure, of which the average diameter is about 6 nm. After being heat-treated at 400 ℃, it contains both Ni and Ni12P5 crystal, meanwhile, the Ni crystal gets larger with an average size of 51.9 nm.The content of phosphorous in the Ni layer has a great influence on crystal structure. The metallized halloysite has a higher inherent coercive force, and a much lower saturation magnetization in its as-plated state, while after heattreatment, the inherent coercive force decreases drastically. These magnetic properties have great relationship with the superparamagnetism of Ni nanocrystalline and the stress anisotropy in Ni layer.     

一种新型气硬冷芯盒树脂砂工艺试验及其在生产中的应用

原砂加入2．5％水溶性酚醛树脂，固化剂为甲酸甲脂，加入量占树脂的30％～40％。先把甲酸甲脂在气体发生器中气化，然后再与40％的压缩空气混合，吹气硬化制芯，最高抗拉强度1．2MPa，抗压强度0．32MPa，发气量12mL／g。生产浇注试验表明：砂芯表面光洁，轮廓清晰，尺寸精确，铸件缺陷少，无毒或低毒，和一般冷硬树脂砂比较，成本降低30％。     

网络机房的故障诊断与排除

目前,计算机网络课程已成为职业院校各专业的必修课。为了加强实践教学,培养实用型人才,网络机房使用的频率越来越高,随之产生的故障也越来越多。只有通过机房管理员及时发现故障,准确定位故障,彻底排除故障,才能延长网络机房使用寿命,确保实践教学高效、顺利进行。本文从实践出发,分析了网络机房的故障、原因、诊断和排除。此外,本文还介绍了网络常用命令和仪器。