麦克斯韦散度方程和法向边界条件的非独立性

证明了麦克斯韦方程组中两个散度方程不独立;同时也证明了时谐场法向边界条件不独立。     

双孢蘑菇软包装罐头加工工艺研究

对双孢蘑菇软包装罐头加工工艺进行了研究,确定了不合亚硫酸盐的护色剂配方及汤汁配方,并对制成的双孢蘑菇软包装罐头进行了感官评定和微生物指标检测。试验结果表明,采用不含亚硫酸盐的护色剂处理蘑菇,并用汤汁填充罐头能有效抑制双孢蘑菇的褐变,使菇体色泽浅黄,汤汁鲜味突出,较好地保持了双孢蘑菇的原有品质。     

发酵剂的添加量对奶豆腐品质影响研究

研究发酵剂的添加量对奶豆腐品质的影响,以确定其最佳添加量。采用单因素试验设计,发酵剂添加量分别为1.5%、2.0%、2.5%、3.0%、3.5%(w/w),分别加工一批奶豆腐,测定奶豆腐的性能指标。结果表明,随着发酵剂添加量的增加,奶豆腐的感官评分先增加,然后逐渐降低;奶豆腐pH4.6和12%TCA(w/w)可溶性氮含量、游离氨基酸总量逐渐增加;而pH值和水分含量逐渐降低。以感官评分为主指标,结合其他性能指标,确定发酵剂的最佳添加量为2.0%～3.0%。     

PLC在农村排灌机站控制系统中的应用

针对中、小型排灌机站控制系统运行的一般特点,提出了采用PLC为控制核心的控制方素。该方案成本低,管理、维护和操作简单易行,便于在广大农村中、小型排灌机站中推广。     

基于故障树分析的电控汽油机无法起动的故障诊断

故障树分析法是一种将系统故障形成原因按树枝状逐级细化的图形演绎方法,常用于系统的故障分析、预测和诊断。对电控汽油机的启动控制分析,构建电控汽油机无法起动的故障树。根据底端事件出现的频度和工作对象的接近性,设计电控汽油机无法起动的故障诊断流程图。     

Design of Ex Soft Starter Control System Based on TMS320LF2407A

针对煤矿井下隔爆兼本质安全型交流电动机软起动器的使用要求,介绍了1种以TMS320LF2407A芯片为核心的矿用防爆软起动控制系统的设计原理及方法,描述了软起动控制系统的硬件设计及软件设计;系统具有可靠性高,电机启动平滑,降低了起动电流等优点,取得了相当好的起动效果。     

皖西欠发达地区返乡农民工创业问题研究

农民工返乡创业对于解决"三农"问题,促进城乡一体化,建设社会主义新农村,贯彻落实科学发展观意义重大。但由于国家政策扶持力度不够等原因,导致农民工返乡创业在取得一定成绩的同时,存在诸多困难。在深入调查研究皖西欠发达地区返乡农民工创业现状的基础上,分析返乡农民工创业的原因以及存在的问题,并就如何科学引导和扶助返乡农民工创业提出对策。     

The USLE soil erodibility nomograph revisited

The nomograph by Wischmeier et al. (1971) for calculating the K-factor in the USLE was extremely useful when there was low access to calculators. However, the generalised calculation of this factor requires the development of analytic procedures. This paper presents a detailed analysis of the nomograph and its underlying equation, which is applicable only when the silt plus very find sand fraction does not exceed 70%. We also examined the quality of fit on the nomograph of the adaptations to the equation that have been proposed, as a means of dealing with those areas where the original equation is not applicable. All models are shown to have areas where the fit is deficient or even unacceptable. Besides, the family of curves on the nomograph for the various values taken by the organic matter are not coincident with the mathematical function from which they presumably derive. The study also identifies those areas of the textural triangle in which the soils originally used in developing the USLE are located, with a view to according a lower predictive value to the contrasting areas in which calculations of the K-factor will necessarily be extrapolations. Finally, a new equation for calculating the K-factor is presented, which accurately reproduces the different sections of the nomograph, and allows the poorly functioning graph to be dispensed with. The paper ends with a link to a tool in R for simplifying the procedure for calculating the K-factor, taking into account varying situations of data availability.