强化供应商资格审查提高企业物资采购质量

在市场经济不断完善的进程中,运用公开招标方式优选设备,材料,备品备件供应商是衡量一个企业专业化程度的标尺,强化对供应商资格审查、甄别是决定能否科学地确定满足本企业物质采购需求合作伙伴的重要环节。是企业规避采购风险,降低生产成本、完成经营目标、实现经济效益的有效保障。     

Effects of quenching treatment on the structure and electrical property in doped V2O3 system

The effects of quenching treatment are examined in terms of the phase present, microstructure and electrical properties for doped V2O3 system, in this paper. The results indicate that the specimens transform to the PM phase and show microcracks in the structure after quenching. The room temperature (RT) resistivities become low and the resistivity ratios increase remarkably. There are optimum values for the RT resisitivity and resisitivity ratio under a certain quenching time. The electrical properties of quenched specimens containing Fe metal phase become stable after subsequent thermal cycles. This revised version was published online in November 2006 with corrections to the Cover Date.     

球墨铸铁材料对激光的吸收率

球墨铸铁因其优良性能而被广泛用作模具材料。对球墨铸铁冲压模具的激光表面处理已成为改善其耐磨性、提高使用寿命的重要方法。一定激光参量下吸收率的大小又直接影响到表面处理的质量。因此,确定球墨铸铁材料对激光的吸收率十分必要。通过热电偶测温,计算机数据采集系统进行定点温度采集,并结合数值模拟方法,对吸收率进行了标定,即首先根据预置的吸收率计算,预测被测点处的温度响应,并与实测响应比较,不断修正吸收率值,使预测温度响应和实验值吻合,由此获得吸收率。采用这种方法获得了球墨铸铁材料在大气条件下对激光的吸收率为23.3%。为激光处理球墨铸铁材料时工艺参量的选择和优化提供了一定参考。     

In-situ Formed AIN Particulates and TiN Whiskers Mixture Reinforced Al Composite

The TiNw-AINp/Al composite has been successfully fabricated by gas-liquid reaction method in an intensive electromagnetic mixing and casting in an appropriate cooling condition. The as-cast samples of the composite exhibit a homogeneous distribution of TiNw and AINp, and the in situ formed TiN whisker has a mean diameter of 0.5 μm and mean aspect ratio of 5.8~7.5, and the diameter of the AIN particulates is less than 5 μm. TEM observation indicates that there exist some submicron and nanometer sized in situ formed TiNw-AINp in α-Al matrix. The formation mechanism of in situ formed TiNw and AINp is also discussed     

安启华签约网域万通

日前,来自美国硅谷的高科技公司北京安启华科技有限公司(Anchiva)与专业的安全产品渠道商北京网域万通科技有限公司(网域万通)合作签约仪式暨新闻发布会在京举行。Anchiva中国区总经理李松先生和网域万通总经理邱召强出席了此次活动。根据协议,网域万通将正式成为Anchiva在中国的总代理,Anchiva将为网域万通提供完善的技术支持和丰富的渠道机制,     

架桥机支腿缸爆缸分析及解决办法

在分析900T架桥机支腿油缸使用中爆缸原因的基础上，归纳出一类可能出现爆缸的工况，提出一种简易的解决办法。     

Energy efficiency maximization resource allocation algorithm in wireless-powered backscatter communication network

In order to alleviate the energy consumption problem caused by the increasing number of Internet of things (IoT) nodes,an energy-efficient (EE) maximization based resource allocation algorithm was proposed for multi-carrier wireless-powered backscatter communication network.Firstly,a multivariable and nonlinear resource allocation model was formulated to jointly optimize transmit power,transmission time,reflection coefficient,and energy-harvesting allocation coefficient,where the maximum transmit power constraint of the power station and the minimum harvested energy constraint at the backscatter device were considered.Then,the original non-convex optimization problem was transformed into a convex one which was solved by using Dinkelbach’s method and the variable substitution approach.Furthermore,the analytical solution of the resource allocation problem was obtained based on Lagrange dual theory.Simulation results verify that the proposed algorithm has better EE by comparing it with the existing algorithm under pure backscatter mode and algorithm under the harvested-then-transmit mode.     

双抽机组工况图的画法分析

双抽机组热-电负荷关系非常复杂，运行人员难于分配。介绍一种较精确的工况图画法，可以为电厂运行人员提供可靠的基础。     

聚氧乙烯化大豆油脚硫酸钠的合成

以大豆油脚为原料,经聚氧乙烯化、硫酸化合成出一种新型的表面活性剂。