浅析图书馆有色金属公共信息服务平台的建设

为了充分发挥图书馆的技术资源优势,缓解企事业单位文献信息资源不足的矛盾,我馆提出建设一个有色金属公共信息服务平台,使图书馆更好地为我市地方经济建设服务,提升图书馆的服务能力和服务水平;更好地发挥图书馆的窗口作用和纽带作用,与地方搭起一个连接的桥梁,更好地为市政府和我市各企事业单位服务。     

An improvement to the simulation of phase-change heat-transfer during soil freezing and thawing

A new variable time step method, which is called the backwards calculating time step method, is presented in this paper. It allows numerical simulation of soil freezing and thawing while avoiding "phase change missing and overflowing". A sensitive heat capacity model is introduced through which the calculation errors are analyzed. Then the equation using the self-adjusted time step is presented and solved using finite differences. Through this equation, the time needed for a space cell to reach the phase change point temperature is calculated. Using this time allows the time step to be adjusted so that errors caused by "phase change missing and overflowing" are successfully eliminated. Above all, the obvious features of this method are an accelerated rate for adjusting the time step and simplifing the computations. An actual example proves that this method can accurately calculate the temperature fields during soil freezing and thawing. It is an improvement over traditional methods and can be widely used on com- plicated multi-dimensional phase change problems.     

米曲霉在牛乳中最适生长条件的研究

利用米曲霉对牛乳进行发酵,通过单因子及正交试验以菌丝体干重为指标对其在牛乳中的生长进行了研究．结果表明：接种量为4％,装液量为30mL,摇床转速为180r／min时菌丝体干重可达到最大．此外测得最大菌丝体干重时的蛋白质分解率可达35．6％．     

管井降水施工技术

文章介绍了管井降水的施工工艺,指出了关键工序和技术要点.     

论《背影》的感恩主题对学生的教育作用

我国现代著名的作家朱自清先生的《背影》成功地刻画了父亲送儿子时爬铁道去买橘子的背影,这一"背影"是中国现代文学史上第一位正面父亲形象。对这一形象的准确理解和感知,在当今对学生进行感恩教育有促进作用。     

关于体育教学改革的问题探讨

分析体育课教学中的主要任务、教材内容、教学方法、成绩考核等几个问题,并对此进行初步的研究和探讨,提出改革意见和措施,以改善体育课的教学效果。     

石油企业财务风险评价神经网络模型的建立

石油企业财务风险评价是石油行业的重要课题.在确立石油企业财务风险评价指标体系的基础上,建立了基于模糊神经网络的石油企业财务风险评价模型.该评价模型分为模糊量化模块和模糊神经网络(FNN)模块,可根据实际问题进行具体调节,具有学习的功能.经过对200多家石油企业的实证分析,结果表明该模型网络预测误差小,是一种可靠、有效的...     

论瞿秋白的调和思想——以《多余的话》为中心

受自身教育、家庭背景的影响,瞿秋白从内心深处接受了调和思想。他强调宽容节制,提倡求同存异,并将这一思想运用到对党内分歧的解决中。但随着革命斗争的日趋激进,他的这一思想与时代产生了错位,因此受到了错误批判。     

Formation mechanism of subtrenches on cone-shaped patterned sapphire substrate

In this paper, the cone-shaped patterned sapphire substrates (PSS) were etched by an inductively couple plasma with BCl 3 as the reacting gas. The influence of the operating pressure and the RF bias power on subtrenches of the cone-shaped PSS and the formation mechanism of subtrenches were investigated. The profiles of patterns were characterized by FESEM (field emission scanning electron microscope). It showed that the subtrench size varied with the operating pressure and the RF bias power. As the operatin...