物理化学实验课教学模式的改革与实践

分析了目前物理化学实验课的教学现状和教学中存在的主要问题,并对物理化学实验教学进行了改革和探索。改变了传统的实验教学模式,搭建了物理化学实验教学网络平台,增强了学生学习的主动性,提高了学生的实验效率和实验质量,培养了学生的创新意识和创新能力,收到了良好的教学效果。     

患者住院费用明细在临床中的应用

住院费用明细的实施,让患者真正明白了医疗费用的每一笔开支,增加了医院的透明度,密切了医患关系,维护了医患双方的利益,赢得了患者及家属的信任,减少了医疗纠纷,树立了医院良好的社会形象。     

中学有机化学实验环己烯制备的改进

指出了中学有机化学实验环己烯的制备实验方法中存在的系列问题,并给出了相应的改进措施,改进后实验条件得到了优化,提高了产品的产率和纯度。同时实验改进后一方面减少了环境污染,实现了实验的绿色化,提高了广大师生的环保意识;另一方面减少了实验消耗和试剂用量,提高了人才的培养质量和效益。     

无功补偿装置扩容后的效益分析

介绍了电容补偿的原理,分析了陕西北元化工集团有限公司化工分公司供电系统的概况,提出了无功补偿的方式,总结了增加高压动态无功补偿装置后的改进效果:降低了电压,减少了电缆发热现象及电能、线路等损耗,提高了功率因数,并改造成根据功率因数自动切换,进而提高了设备的使用效率、供电效率和电路电压的稳定性,减少了对电网的冲击,改善了供电环境。     

带式过滤机在多品种氢氧化铝生产中的应用

介绍了带式真空过滤机的工作原理及其在多品种氢氧化铝生产方面的应用情况,并对带式真空过滤机使用过程中存在的问题进行了改造。改造之后,提高了洗涤过滤效率,降低了滤饼水分,降低了能耗,提高了产量,确保了产品质量,取得了较好的经济效益。     

MTBE装置催化精馏塔捆包催化剂的应用

催化蒸馏塔内的催化剂进行了更换,弃用了原有的散装催化剂,采用了捆包催化剂,抑制了催化剂的副反应,减少了催化剂对催化精馏塔的腐蚀,有效延长了催化精馏塔的使用周期,也进一步满足了扩能改造的要求。     

整流机组节能技术改造总结

介绍了整流机组的技术改造内容。通过改造,提高了装备技术水平,简化了操作,提高了供电的平稳性和安全性;降低了电力损耗;节约了能源。     

《天然药物化学》实验教学改革与实践

通过引入先进的提取技术、色谱分离技术以及结构鉴定的光谱技术,节省了时间与化学试剂,提高了实验效率。鼓励学生参加创新性实验增加了学生的学习兴趣,拓宽了学生的专业视野,增强了学生的动手操作能力,培养了学生的创新能力,提升了学生的综合实力,取得了较好的教学效果。     

1万t/a异戊烯装置的设计与运行优化

对1万t/a异戊烯装置设计的优化项目进行了考察,验证了设计的有效性;分析了装置运行情况,提出了不同负荷下醚化操作的优化条件;优化了醚解催化剂的投用条件,减少了二甲醚的生成,降低了装置的甲醇单耗;控制异构化反应器的温度和叔戊醇含量,保证了2-甲基-1-丁烯的转化率,提高了产品中的2-甲基-2-丁烯的含量;异戊烯侧线出料口下方增加了1米填料后改善了产品的品质,降低了产品中其他组分的含量;装置的标定表明:装置能稳定运行,数据可靠,达到了设计指标。     

氯化钾三效蒸发工艺

氯化钾采用三效蒸发,充分利用了热能,改变了沿用多年的落后工艺、降低了生产成本,为氯化钾生产开辟了新思路;自动控制系统的引用大大降低了工人的劳动负荷,且提高了操作的精度,使氯化钾生产首次实现自动化;三效蒸发系统的成功运行不仅降低了生产成本还为下游产品提供了优质充足的原料.     

注流孔结构对中间包流场影响的物理模拟

针对某钢厂十流中间包紊流抑制器注流孔结构不合理引起流场分布差、各流铸坯质量不均的问题,运用相似原理,使用相似比为1:3的物理模型进行水模型实验,设计不同的注流孔结构研究流体在中间包的平均停留时间曲线及流场显示特征,明晰注流孔结构对中间包流场的影响规律,优化紊流抑制器注流孔结构,达到中间包流场优化及浸入式水口各流一致性提高的目标。结果表明,长距离多流中间包在无堰坝结构条件下,紊流抑制器的注流孔内径尺寸、数量及开孔方向对中间包流场都有影响,注流孔内径的影响最为显著,数量次之。设计的最佳注流孔内径由原型的53 mm缩小至30 mm,死区比例由54.05%降至34.69%,F曲线最大标准差由0.0154降低至0.0035,中间包流场得到改善,各流一致性显著提高。当注流孔数量由1个增加至3个,死区比例由34.69%增大至46.05%,F曲线最大标准差由0.0035增大到0.0062,注流孔数目越多,流场死区比例反而越大,各水口流场的一致性越差。对长距离多流中间包,建议主要通过适当改变注流孔内径及减少孔数来改善中间包流场,提高各流一致性。     

Influence of capillary condensation on heat and mass transfer in the grain of a Fischer-Tropsch synthesis catalyst

A mathematical model of heat and mass transfer processes in the grain of the Fischer-Tropsch synthesis catalyst is presented that takes into account the effect of the capillary condensation of the products of the synthesis in the pores of the catalyst. The influence of capillary condensation on the processes of the diffusion transfer of heat and mass in the catalyst grain is analyzed using the proposed model. Dependences of the efficiency factor of the grain on the pressure and temperature of the process and the partial pressure of various components of a mixture are presented. The possibility of determining the optimum pressure and temperature of carrying out the process for the catalyst of a certain structure is shown.     

含缩水甘油基／氨基丙烯酸酯共聚物乳液的聚合稳定性

研究了乳胶粒组成对含有缩水甘油基,羧基和胺基的丙烯酸酯多层核壳型乳液聚合稳定性的影响规律,探讨了聚合过程的凝聚机理。研究表明：官能团间的交联凝聚作用和水溶性聚合物的架桥凝聚作用是本体系凝聚物形成的主要原因。     

An increase in thermodynamic efficiency and compactness of contact apparatuses via spatially organized structure of the active material bed

The possibility of filling the hollow input (diffuser) and output (confuser) sections of contact apparatuses by an active material is analyzed. The equation determining the distribution function of the sizes of material particles along the axis of a conelike apparatus, which provides the minimum volume of the bed of particles at the specified values of the total surface area of the interfacial contact in the bed and total flow resistance of the bed, is derived. It is shown that the change in the conventional shape of the apparatus to a construction in the form of a junction of two truncated cones filled with the active material allows one to decrease the total volume of the apparatus by 30%. The dependence of the thermodynamic efficiency and compactness of the regenerative facility on the particle size of the active material bed is numerically analyzed. The existence of a critical particle size which determines the minimum necessary volume of the bed providing high thermodynamic efficiency of the process is shown.     

Manifestation of the Urbach rule in the fundamental electronic absorption spectra of halide salt melts: I. Tails of the absorption edge of alkali metal halide melts

The long-wavelength tails of the fundamental electronic absorption spectra of alkali metal halide melts have been investigated. The obtained values of the absorption characteristics of the alkali metal halide melts have confirmed the assumption that, over a wide temperature range (600–900°C), the exponential tail of the absorption coefficient of these disordered systems is associated with the presence of the spectrum of fluctuating electronic levels extended to the band gap in the melts under investigation. The fulfillment of the Urbach rule is the limiting case of the general exponential dependence of the optical absorption coefficient in the ultraviolet region of the fundamental absorption edge. In the studied series of melts of alkali metal halide salts, the absorption coefficient in the region of tails of the spectral curves of the halide systems decreases from LiCl to CsCl and from LiCl to LiI. An analysis of the results obtained from the investigation of alkali metal halides has revealed an interrelation between the main parameters of the Urbach rule and between these parameters and the temperature coefficient of the band gap.     

玻璃纤维增强制件注射成型过程的模具磨损原因及规律

玻璃纤维增强聚醚酰亚胺（PEI）薄壁制件注射成型过程中,易对模具型芯产生磨损,从而严重影响制件成型品质。以某型号手机听筒薄壁制件为例,根据生产实践分析了型芯表面的微观磨损特性,采用数值计算方法研究了型腔近壁面的熔体流动行为以及型芯表面材料的冲蚀破坏形式与磨损规律。结果表明,注塑过程中型芯表面材料发生冲蚀磨损形成月牙形凹槽,型腔近壁面上的熔体流速决定了月牙形凹槽的形貌和尺寸,玻璃纤维粒子的入射角和倾角决定了型芯表面材料的冲蚀破坏形式,冲蚀磨损量随着玻璃纤维粒子侧倾角的增大不断增加,随着入射速度的增大呈指数型增加。     

The electrochemistry of alloys

The features of the dissolution of the components of alloys forming solid solutions were examined. It was shown on the example of the anodic dissolution of alpha-brass that the process of the selective dissolution of zinc observed in the initial period is limited by the stage of its non-stationary diffusion from the bulk of the alloy and is subsequently replaced by uniform dissolution. During prolonged corrosion of brass, secondary selective dissolution is observed, which is due to the re-deposition of copper.It was established that intensive preferential dissolution of iron from Fe-Cr alloys takes place in the passive region and leads to the enrichment of the passivating chromium film. The results obtained from an investigation of the dissolution of the components of Fe-Cr-Mo alloys in the active region permit the conclusion that the favourable effect of small additions of molybdenum on the corrosion stability of alloys is due to the fact that this element, in view of its great inclination to passivation, blocks the most active centres of the surface in the process of its dissolution.In order to establish the mechanism of the active dissolution of Fe-Cr, alloys, the effect of the potential and pH of sulphate solutions on the partial dissolution rates of iron and chrome from these alloys in the active state was established. It was shown that the Tafel slopes and the order of magnitude of the reaction for the H⁺ ions for both components were the same and close to the corresponding values for pure iron (at low concentrations of chromium in the alloy) or for pure chromium (when the chrome content in the alloys was 13% or more). A mechanism was suggested for the active dissolution of alloys that explained the discovered regularities.     

Mathematical description of the synthesis of butadiene rubber with allowance for the branching of a polymer under conditions of the separate supply of a reaction mixture to the reactors of a cascade

Mathematical modeling of the synthesis of butadiene rubber on a neodymium-based catalytic system under conditions of the separate supply of a reaction mixture to the apparatuses of a cascade is performed. Expressions are derived for calculating the characteristics of the branching of the polymer with allowance for the additional supply of the reaction mixture to the second apparatus of the cascade. An analysis of the influence of the flow rate of an additional stream of the reaction mixture to the second apparatus of the cascade and operating parameters on the molecular weight characteristics and branching of the polymer is performed.     

水泥预粉磨装备及技术发展现状的分析

重视预粉磨装备及技术的发展,就是重视水泥联合(半终)粉磨工艺系统的粉磨效果。联合(半终)粉磨系统中充分利用了料床预粉磨段粗处理的技术特性,同时发挥了管磨机段独有的磨细与整形功能,真正实现了“分段粉磨”过程中两段之间的优势互补。预粉磨段主机的吸收功耗越大,管磨机段主电机电耗降低越多,系统的总节电效果越显著。随着预粉磨段主电机功率与管磨机主电机装机功率比值的增加,预粉磨段处理能力进一步增大,投入的功耗越多,整个粉磨系统电耗降低的幅度也更大。在水泥粉磨生产线改造过程中,将高压力多辊外循环立磨用于预粉磨段,是降低粉磨电耗的发展方向之一。辊压机联合(半终)水泥粉磨系统中辊压机的吸收功耗至少应≥9.0 kWh/t,高值可以达到12.0 kWh/t,在此范围内越高越好。辊压机联合(半终)粉磨系统中,辊压机运行常常表现为不够平稳、时有偏辊现象发生、液压系统压力输出不稳定、操作不灵敏、液压系统现场“跑冒滴漏”严重、控制关键元器件购置困难等。建议采用辊压机SPC控制系统进行改造,以确保辊压机应保持稳定和较高的工作压力,确保良好的挤压做功能力,确保有更多的细粉产出,有利于系统高效低耗运行。     

Die differentielle Doppelschichtkapazität an der Phasengrenze Quecksilberanorganischer Elektrolyt—II. Das Kapazitätsminimum

In the negative range of charge, the differential double-layer capacitance at the interface of mercury and an inorganic electrolyte solution shows a characteristic minimum. This minimum is independent of the nature of the ion, of the concentration of electrolyte and of the temperature. However, the solvent strongly influences the capacitance of the minimum. The metal charge at which the minimum occurs is uninfluenced only by the temperature. Changes of the concentration of the electrolyte as well as of the nature of the anion are able to cause a shift of the minimum.