南方杂木浆和竹浆混合浆中浓打浆生产试验

对南方杂木浆和竹浆混合浆进行了中浓度(6%～8%)打浆试验,并与传统的低浓度(4%～5%)打浆工艺比较,结果表明:中浓打浆通过提高打浆浓度,减少了磨齿对纤维的切断作用,同时磨区中纸浆纤维浓度的增加使纤维之间的摩擦作用力增加,有利于增强纸浆的细纤维化作用;中浓打浆有利于改善纸张的物理性能,且打浆能耗有较明显的下降。     

复合凹凸棒介质对Cr（Ⅵ）吸附动力学和热力学研究

研究了复合凹凸棒介质（CAM）对Cr（Ⅵ）的吸附行为,拟合了吸附等温线,探讨了吸附动力学和热力学性质。结果表明,在实验范围内,CAM对Cr（Ⅵ）的吸附可以用Langmuir和Freundlich吸附等温方程来描述,但更符合Freundlich方程,相关系数均在0.98以上;二级动力学方程可以更好地描述吸附动力学规律;分别计算了热力学参数△G0、△H0、△S0,表明该吸附为熵驱动、吸热、自发的过程。     

硫乙醇酸盐流体培养基的特点及问题分析

文章对硫乙醇酸盐流体培养基的成分及特点进行归纳,对该培养基在使用中出现的问题进行小结,并对硫乙醇酸盐流体培养基在药品无菌检查过程中的局限性进行了分析讨论。     

食用菌产生微生物絮凝剂最佳培养条件的研究

从食用菌中筛选出一种絮凝效果较佳、环保、安全的微生物絮凝剂,开拓废渣再利用的新途径,特开展了该研究。试验采用6种食用菌,经培养后进行培养条件和絮凝条件的优选实验。实验表明,鸡腿菇是最佳的微生物絮凝剂产生菌。在培养过程中确定小麦粉培养基为最佳培养基,最佳的培养基配方组合为小麦粉20mg·L^-1,蔗糖20mg·L^-1,酵母粉6mg·L^-1。实验剩用鸡腿菇对高岭土水样进行絮凝实验,絮凝率为69.39％。     

AP/HTPB复合推进剂用纳米Co粉的制备

以CoCl_2·H_2O和水合联氨(N_2H_4·H_2O)为主要原料,采用化学还原法制备了纳米Co粉.在不同工艺条件下制备了树枝状纳米Co粉和球形纳米Co粉,用TEM和XRD对产物进行了表征,同时用DTA测试了加入球形纳米Co粉后AP的热分解性能.结果表明,反应介质的黏度和分散剂性质对纳米Co粉粒度及形貌影响较大,在最佳工艺条件下制备了颗粒尺寸均匀、粒度为50~60 nm的球形纳米Co粉;球形纳米Co粉能使AP热分解反应的高温分解峰温度显著下降;添加质量分数2%的球形纳米Co粉,复合推进剂的燃速明显提高,压力指数大幅降低.     

水溶性高分子分散聚合技术的开发及其在废水处理中的应用

有机高分子絮凝剂是目前国内外普遍采用的高效污水处理剂,被广泛应用于循环用水、工业废水的处理及污泥脱水等过程。用于絮凝技术的有机高分子絮凝剂与无机絮凝剂相比,具有用量少,絮凝速度快,受共存盐类、pH值及环境温度影响小,生成污泥量少且易处理等优点,在节约用水、强化水质处理和提高水的回用率等方面带来显著的经济效益。聚丙烯酰胺类（PAM）各种离子型有机高分子絮凝剂,由于具有分子量大、官能团多等特点,在市场上占有的份额较大,特别是近些年国内环保执法力度的加强和有关企事业单位对其认识的提高,     

钢铁中温锌-钙系黑磷化液研制

为了改善锌一钙系黑色磷化膜的外观和性能,配制了锌-钙系中温黑磷化液,研究了配位剂、总酸度、磷化时间对黑磷化膜厚度、金相形貌和耐蚀性的影响,采用X射线荧光光谱法(XRF)分析了磷化膜的成分.结果表明,采用柠檬酸三钠作配位荆,控制总酸度为50～100,磷化时间15～20 min,能够获得防护性能良好的黑色磷化膜.     

Analysis of permeability and effective viscosity by CFD on isotropic and anisotropic metallic foams

Hydrodynamic properties of open-cell metallic foams are analyzed at the pore scale on a microtomographied sample from creeping flow to unsteady inertial flow. The influence of the anisotropy, obtained by shearing the initial sample, is also analyzed. The simulations show that the Darcy-Forchheimer law is valid at Re_dl>1 and that the inertial coefficient tensor can be asymmetric as proved by Whitaker [1996. The Forchheimer equation: a theoretical development. Transp. Porous Media 25, 27-61] and checked by the lattice Boltzmann method. Despite this property, the eigen vectors are nearly orthogonal to each other and their orientation follows the shear angle. To evaluate the accuracy of the results, the analysis of the REV leads to a REV size lower than 2.5d_p for the velocity and is lower than 4.5d_p for the inertial flow permeability tensor. It is shown also that the CFD approach, validated by MRI investigation [Graf von den Schulenburg et al., 2007. Flow through an evolving porous media-compressed foam. J. Mater. Sci. 42 6541-6548], matches the 3D-Brinkman-Forchheimer model if the effective viscosity is close to two.     

Influence of the initial gas pressure on the detonation limits and parameters of low-density secondary explosives in an inert porous medium

This paper reports the results of an experimental study of the detonation of low-density (3–40 mg/cm³) secondary high explosives (HEs) in evacuated and gas-filled inert porous media. A convective-jet mechanism of detonation propagation was found to occur under all conditions studied. The effects of the type of HE and initial gas pressure on the critical density of the HE and detonation parameters were elucidated. It is shown that, in the presence of air, detonation can occur at a lower volume-averaged density of the HE than in the case of the evacuated media and there are two limits (minimal and maximal) for the initial gas pressure. As the volume-averaged density HE decreases, the limits approach each other and, for a certain critical density of the HE, detonation exists only at one value of the initial pressure. __________ Translated from Fizika Goreniya i Vzryva, Vol. 45, No. 3, pp. 106–117, May–June, 2009.     

Oxygen reduction reaction on carbon-supported CoSe2 nanoparticles in an acidic medium

We investigated the effect of CoSe₂/C nanoparticle loading rate on oxygen reduction reaction (ORR) activity and H₂O₂ production using the rotating disk electrode and the rotating ring-disk electrode techniques. We prepared carbon-supported CoSe₂ nanoparticles with different nominal loading rates and evaluated these samples by means of powder X-ray diffraction. All the catalysts had an OCP value of 0.81 V vs. RHE. H₂O₂ production during the ORR process decreased with an increase in catalytic layer thickness. This decrease was related to the CoSe₂ loading on the disk electrode. H₂O₂ production also decreased with increasing catalytic site density, a phenomenon related to the CoSe₂ loading rate on the carbon substrate. The cathodic current density significantly increased with increasing catalytic layer thickness, but decreased with increasing catalytic site density. In the case of 20 wt% CoSe₂/C nanoparticles at 22 μg cm⁻², we determined that the transfer process involves about 3.5 electrons.