Quaternary Structure and Hetero-Oligomerization of Recombinant Human Small Heat Shock Protein HspB7 (cvHsp)

In this study, a reliable and simple method of untagged recombinant human HspB7 preparation was developed. Recombinant HspB7 is presented in two oligomeric forms with an apparent molecular weight of 36 kDa (probably dimers) and oligomers with an apparent molecular weight of more than 600 kDa. By using hydrophobic and size-exclusion chromatography, we succeeded in preparation of HspB7 dimers. Mild oxidation promoted the formation of large oligomers, whereas the modification of Cys 126 by iodoacetamide prevented it. The deletion of the first 13 residues or deletion of the polySer motif (residues 17–29) also prevented the formation of large oligomers of HspB7. Cys-mutants of HspB6 and HspB8 containing a single-Cys residue in the central part of the β7 strand in a position homologous to that of Cys137 in HspB1 can be crosslinked to the wild-type HspB7 through a disulfide bond. Immobilized on monoclonal antibodies, the wild-type HspB6 interacted with the wild-type HspB7. We suppose that formation of heterodimers of HspB7 with HspB6 and HspB8 may be important for the functional activity of these small heat shock proteins.     

汽轮机叶片用1Cr12Mo钢成分与热处理工艺对冲击韧度的影响

1Cr12Mo钢属于马氏体不锈钢,被广泛用于汽轮机亚临界机组的低压叶片。该钢在生产过程中由于冶炼方法的不同其化学成分会在一定范围内变化。对大量生产和试验数据进行分析的结果表明,成分的波动和热处理工艺参数的变化对钢的冲击韧度都有重要的影响。     

空调铜翅片冲压模工艺分析与设计

从企业生产实际出发，在进行冲压成形理论探讨和各种冲压工序变形特性分析的基础上，采用子模分立结构的设计思想，设计了一副适用于铜翅片冲压的专用模具。     

深井泵的研究现状与发展趋势

简要回顾了深井泵的发展历史.针对深井泵的研究情况,分别从其结构演变、水力设计方法、轴向力平衡方法等方面进行了较为详细的介绍.通过分析国内外深井泵的研究现状,指出了格兰富公司生产的冲压不锈钢井泵是具有广阔发展前途的产品,而采用专利技术"一种叶轮自身平衡轴向力的多级离心泵"生产的新型井泵代表了深井泵一个更新换代的优秀品种.同时指出利用数值模拟来进行平衡轴向力研究是一种有效的方法.     

大型纸机油站油温高的解决措施

北方大型纸机的油站热交换器因结垢、灰尘和菌泥沉积等原因造成热交换效率低,当油站油温高时可能引起纸机意外停机,成为影响纸机效率的主要因素之一。通过对油站冷却水系统的工艺优化（加过滤器和过滤网、使用抑垢剂、使用去离子水、使用杀菌防腐剂和定期清洗等措施）,基本解决了上述问题。     

Effect of a mixture of steam-flaked corn and soybeans on health, growth, and selected blood metabolism of Holstein calves

The objective of the experiment was to evaluate the effects of steam-flaked corn grains and soybeans on calf health, growth, and selected blood parameters. Holstein bull calves (n = 30, approximately 7 ± 3 d of age) were purchased from local dairy farms and offered milk, starter diets, and hay, and were then assigned to the experiment at 21 ± 3 d of age. Calves were blocked into 3 treatments by birth date and body weight and randomly assigned to receive fresh milk and a commercial pelleted starter containing extruded corn and soybeans (ECS), steam-flaked corn and soybeans (SFCS), or ground corn and soybeans (GCS). The experiment was conducted with calves from 3 to 13 wk of age. Body weight, calf starter intake, milk intake, total dry matter intake, and body structural growth were not significantly influenced by corn and soybean processing during the study; however, feed efficiency was significantly improved by the SFCS treatment. Average daily gain generally decreased during the weaning week for all treatments, but did not differ significantly among treatments. Health incidences for calves fed the SFCS starter were lower than those fed the other 2 treatments. The blood hematocrit was higher for calves fed the SFCS starter than for those fed the GCS and ECS starters during wk 6 to 11. The concentration of plasma β-hydroxybutyrate was higher for the calves fed the GCS and SFCS treatments than for those fed the ECS treatment during wk 6 to 13, but lower during wk 4 and 5. Plasma glucose concentrations decreased remarkably with increasing calf age but were not affected by corn and soybean processing. Plasma nonesterified fatty acids were influenced by calf age, and higher NEFA concentration was observed in the SFCS treatment than in the other 2 treatments during wk 5 to 9. Calves consuming the SFCS starter had similar average daily gain, milk intake, starter intake, total dry matter intake, and body structure, but had improved feed efficiency when compared with animals consuming the GCS and ECS starters. The SFCS starter decreased incidence of diarrhea during the postweaning period and required less veterinary treatment. These data suggest that the steam-flaking of corn and soybeans can influence the growth performance and the selected blood parameters of calves and that, in this study, the extrusion of corn and soybeans had no beneficial effect on the growth performance of calves.     

造纸过程中水对水环真空泵性能的影响和合理控制的建议

水环真空泵是纸机湿部真空系统最常用的真空发生装置[1]。它以水为工作液,又是纸页脱水的辅助设备。因此,水对它的影响不容忽视。通过对水环真空泵的工作原理和特点的分析,说明在纸的抄造过程中,不同途径的来水对水环真空泵性能的影响,并指出现在纸厂普遍存在的使用问题。提出了合理控制各种途径的来水,从而减少不必要的能量和水资源浪费的方法和建议。     

Thermal breakthrough analysis for determination of energy equilibrium data in a fluidized bed

The aim of this work was to predict energy equilibrium values in a bench-scale fluidized bed (FB: 105 × 200 mm), using a thermal breakthrough analysis (TBA). For this purpose, a simple “unsteady state” energy balance was proposed by harnessing dynamic model approach on the basis of heat exchange between the bed and the gas. To investigate thermal behavior of the bed, low temperature runs at different flow rates (5.2 ≤ Q₀, m³ h⁻¹ ≤ 7.4) and heating rates (97 ≤ q, kJ h⁻¹ ≤ 765) were carried out. FB was heated by means of an electrical heater (10 × 50 mm) horizontally immersed into the bed particles for heating period and then the power input was terminated for cooling period. The bed temperatures (T_B) were continuously measured for obtaining thermal breakthrough curves for all periods. Temperature-time data were used for extracting bed-to-gas heat transfer film coefficients (h_BG) from linear forms of proposed model. The model was also employed for calculating amounts of shared energies by fluidized bed phases (q_y − q_x). A good agreement between experimental values and model values of T_B was found. The results were thus confirmed by proposed model. The latter may be successfully used to predict energy equilibrium data for e.g. drying or combustion.     

热管换热器的计算机辅助设计

介绍了用计算机进行热管换热器辅助设计的基本方法.软件的需求分析以及程序模块的划分和实现;还着重介绍了几个重要模块的实现方法.这几个模块使热管换热器的设计及软件本身的使用具有它独自的特色.这些方法以前未见实现过。使用计算机给热管换热器的设计带来了很大的效益。