药厂洁净室两级过滤系统探讨

依据调研、实测及理论分析，针对当前药厂使用较多的１０万级洁净室的现状，提出采用末级为高中效的两级过滤系统替代现在普遍采用的末端为高效过滤器的三级过滤系统，以节约投资和节能，对药厂的除尘系统也建议了节能的方案。     

等截面门式刚架塑性设计方法的讨论

将我国等截面门式刚架塑性设计方法与英国门式刚架的设计方法进行了比较和讨论 ,内容包括应用情况、内力计算、强度计算、塑性设计应满足的条件和整体稳定的计算方法等。通过比较和分析 ,对今后我国等截面门式刚架塑性设计方面进一步研究和发展提出了建议。     

集中供热系统中热水供应用户的工况分析

分析集中供热管网与热水供应热用户水力或热力工况变化时的相互影响规律。     

The influence of low atmospheric pressure on carbon monoxide of n-heptane pool fires

Qualitative theoretical analysis about air pressure influence upon the gas concentration of a fire plume was given, different scale n-heptane pool fires were conducted in a small and a standard compartment room in Lhasa and Hefei, respectively. The experimental results show that, in Lhasa, the average mass burning rates in the small room and the standard room both decrease, burning time increases at about 53% in small room and 45% in standard room more than in Hefei. Whereas for maximum changes of CO concentration, in the small room, in Lhasa, CO concentrations reach about twice bigger peak values at larger increase rates than in Hefei. While in the standard room, in Lhasa and Hefei, there are no significant changes for CO concentration, which agrees well with the theoretical analysis results.     

The prediction of the dissolution rate constant by mixing rules: the study of acetaminophen batches

The purpose of this article is to promote two simple and scalable methods to accelerate the formulation development of formulated granules using acetaminophen as a model system. In method I, formulated granules made from the batch of small particle-sized acetaminophen (1) by ball milling the batch of large particle-sized acetaminophen (2), and the mixture of the two batches at equal weights (mix) gave the dissolution rate constants (k) of k(1) = 0.43 +/- 0.15 minutes(-1), k(2) = 0.18 +/- 0.01 minutes(-1), and k(mix) = 0.30 +/- 0.03 minutes(-1) for 75 wt percent formulation; k(1) = 0.75 +/- 0.01 minutes(-1), k(2) = 0.18 +/- 0.01 minutes(-1), and k(mix) = 0.34 +/- 0.03 minutes(-1) for 62 wt percent formulation; and k(1) = 0.28 +/- 0.01 minutes(-1), k(2) = 0.16 +/- 0.01 minutes(-1), and k(mix) = 0.22 +/- 0.02 minutes(-1) for 30 wt percent formulation. In method II, the mixture of the formulated granules produced by mixing the formulated granules from the two batches at equal weights gave dissolution rate constants of k(mix) = 0.30 +/- 0.03 minutes(-1), 0.30 +/- 0.02 minutes(-1), and 0.22 +/- 0.01 minutes(-1) for 75 wt percent, 62 wt percent, and 30 wt percent formulations, respectively. After fitting the three data points of k(1), k(2), and k(mix) to the 10 mixing rules in materials science--series mixing rule, Hashin and Shtrikman upper bound, logarithmic mixing, Looyenga mixing rule, effective media approximation (EMA), three-point lower bound, Torquato approximation, three-point upper bound, Maxwell mixing rule, and parallel mixing rule--we found that the selection of the best suited mixing rules based on k(1), k(2), and k(mix) was solely dependent on the formulations under a given operating condition and regardless of whether the system was a powder mixture or a granular mixture. The values of k(1), k(2), and k(mix) in both the 75 wt percent and 30 wt percent formulations were enveloped by the parallel mixing rule and Maxwell mixing rule, whereas the values of k(1), k(2), and k(mix) for the 62 wt percent formulation were encompassed by the logarithmic mixing rule, Hashin and Shtrikman upper bound, and the series mixing rule. Apparently, the best suited mixing rules could be used to predict the right proportions of either the powder mixture (Method I) or the granular mixture (Method II) for obtaining any other desired dissolution rate constant, k(mix), whose value fell in between the values of k(1) and k(2).     

Built-in surface electric field, piezoelectricity and photoelastic effect in GaN nanorods for nanophotonic devices

Novel behaviors arising from the coupling between the built-in surface electric field, piezoelectricity, electron-hole pairs and external light beam were observed in GaN nanorods. An increase in the optical excitation density resulted in a blueshift in the photoluminescence spectra and a redshift in the frequency of the GaN A(1)(LO) phonon. The underlying mechanism was attributed to the screening of the built-in surface electric field by photoexcited carriers and, through the converse piezoelectric effect, a reduction in the internal strain. The existence of the built-in surface electric field in GaN nanorods was confirmed by scanning Kelvin probe microscopy. Our results firmly establish the existence of the photoelastic effect in GaN nanorods. In addition to underpinning the principle for applications in nanophotonic devices, this discovery also draws attention to the novel effects arising from the inherent large surface-to-volume ratio of nanostructures, which is possibly applicable to many other nanomaterials.     

25MVA矿热炉功率自动调节控制的设计与实践

阐述了矿热电炉功率自动调节控制的设计、硬软件配置及PID调节工作原理,在25MVA矿热炉的实践中,将人机界面与PLC结合应用,提高了系统的自动化程度,基本达到了电气系统免维护的要求,功率因数、电耗、产量都取得较好效果.     

38MnVS5钢连铸坯中硫化物形貌及形成机制的研究

用扫描电镜观察分析了38MnVS5钢320mm×300姗连铸坯中硫化物的三维形貌,结果显示,从铸坯表面到心部硫化物类型由球状变成杆状,并且在偏析严重区域呈片状或片状-杆状共存.球状硫化物是由包晶反应生成的,杆状硫化物为稳态共晶反应的产物.当合金元素含量较高时,由于过冷导致硫化物生长速度较快,杆状硫化物向片状硫化物转变.     

彩色等离子体显示器寻址功耗等效电路模型

彩色等离子体显示器中引起的容性电流构成了寻址IC中MOS管开关电流的主体,以此为基础建立了寻址功耗等效电路模型,得到寻址功耗计算公式。典型图案寻址功耗的实验结果表明,寻址功耗和各子场图像数据在列方向上的变化率,以及相邻列之间寻址数据差在列方向上的变化率成正比,和图像信号的平均强度没有关系。寻址功耗的理论计算值和实验结果一致,寻址等效电路模型能够对不同图案的寻址功耗进行合理的解释,解决了寻址功耗检测对象不确定和检测的准确性问题。