NUMERICAL AND EXPERIMENTAL STUDY ON LIQUID-SOLID FLOW IN A HYDROCYCLONE

Hydrocyclones are widely used in industry, of which the geometrical design using CFD techniques is gaining more popularity in recent years. In this study, the Euler-Euler approach and the Reynolds stress model are applied to simulate the liquid-solid flowfield in a hydrocyclone. The methodology is validated by a good agreement between experimental data and numerical results. Within the research range, the simulation indicates that the liquid-solid separation mainly occurs in the conical segment, and increasing conical height or decreasing cylindrical height helps to improve the grade efficiencies of solid particles. Based on these results, two of the same hydrocyclones are designed and installed in series to establish a liquid-solid separation system. Many experiments are then conducted under different conditions, in which the effects of the water cut and the second hydrocyclone on the separation are investigated. The results also confirm that smaller solid particles are more susceptible to the inlet conditions, and the second hydrocyclone plays a more important role as the water cut reduces.

Large Eddy Simulation of Complex Turbulent Flows: Physical Aspects and Research Trends

In the current paper, we have primarily addressed one powerful simulation tool developed during the last decades-Large Eddy Simulation (LES), which is most suitable for unsteady three-dimensional complex turbulent flows in industry and natural environment. The main point in LES is that the large-scale motion is resolved while the small-scale motion is modeled or, in geophysical terminology, parameterized. With a view to devising a subgrid-scale(SGS) model of high quality, we have highlighted analyzing physical aspects in scale interaction and-energy transfer such as dissipation, backscatter, local and non-local interaction, anisotropy and resolution requirement. They are the factors responsible for where the advantages and disadvantages in existing SGS models come from. A case study on LES of turbulence in vegetative canopy is presented to illustrate that LES model is more based on physical arguments. Then, varieties of challenging complex turbulent flows in both industry and geophysical fields in the near future-are presented. In conclusion; we may say with confidence that new century shall see the flourish in the research of turbulence with the aid of LES combined with other approaches.

酿酒酵母和运动发酵单胞菌木薯乙醇发酵条件研究

本文结合我国燃料乙醇发展的方针政策，以酿酒酵母和运动发酵单胞菌为菌种研究其在非粮能源作物木薯中乙醇发酵的情况，为木薯原料更好地应用于生产中提供了理论依据。 酿酒酵母木薯高浓度乙醇发酵的研究。实验采用的木薯干淀粉含量约70-75%。以酿酒酵母为菌种进行高浓度乙醇发酵的工艺条件研究，最佳条件为：木薯干粉碎细度为35目，料水比1：2，α-淀粉酶用量0.09 KNU/g淀粉，蒸煮温度85 ℃，蒸煮时间15 min。采用30 ℃同步糖化发酵工艺，糖化酶用量为3.4 AGU/g淀粉，发酵时间30 h。在10 L发酵罐中，乙醇质量比达127.88 g/kg，发酵效率为88.28%，发酵强度4.263 g/kg/h，100 L中试研究中乙醇浓度为127.75 g/kg，发酵强度4.258 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析，证明葡萄糖、果糖等单糖已完全被菌体利用，剩余糖为二糖，三糖等不可发酵的低聚糖。 运动发酵单胞菌快速乙醇发酵的研究。对实验室保藏的8株运动发酵单胞菌进行比较，选择发酵速度最快的Zymomonas mobilis232B进行研究。该菌在纯葡萄糖中的最佳发酵条件为：葡萄糖浓度18%，起始pH 6-7，发酵温度30 ℃，发酵时间18 h，乙醇浓度88 g/kg。在以木薯为底物同步糖化快速乙醇发酵中，采用Full Factorial设计和最速上升实验确定了培养基成分中的2个显著性因子及其最适浓度：酵母粉4 g/kg，硫酸铵0.8 g/kg。在最适培养基条件下，对木薯料水比和糖化酶用量进行了优化，得到Z.mobilis232B木薯乙醇发酵最佳料水比1：3，糖化酶浓度4 AGU/g淀粉，乙醇发酵4.915 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析，剩余糖为二糖，三糖等，但成分较酵母发酵后复杂。 According to the fuel ethanol development plans and policies in our country, the ethanol production from cassava by Saccharomyces cerevisiae and Zymomonas mobilis was studied. It provided theoretical basis for ethanol fermentation by cassava in industry. Part 1 is the study of VHG (very high gravity) ethanol fermentation by Saccharomyces cerevisiae. The content of starch in cassava was 70-75%. Compared with the performances under different experimental conditions, the following optimal conditions for VHG fermentation were obtained: Granule size of dry cassava 35 mashes, hydromodulus of cassava to water at 1:2, α-amylase enzyme dosage 0.09 KNU/g starch, cooking temperature 85 ℃ for 15 min, using the SSF process (simultaneous saccharification and fermentation) and the amount of glucoamylase 3.4 AGU/g starch. Accordingly, the final ethanol concentration was up to 127.88 g/kg; the ethanol yield reached 88.28%, and ethanol productivity was 4.263 g/kg/h after 30 h. When the fermentation scale expanded to 100 L, the final ethanol concentration was 127.75 g/kg, and the ethanol productivity was 4.258 g/kg/h in 30 h. The residual sugar was analyzed by high performance liquid chromatography, and proved that there was no glucose and fructose. The residual reducing sugar was some unfermentable oligosaccharide Part 2 is the study of the rapid ethanol production by Zymomonas mobilis. Compare with other seven stains, Zymomonas mobilis 232B was selected for research. The optimum condition in glucose medium was as follow: glucose concentration 18%, initial pH 6-7, and fermentation temperature 30 ℃. The ethanol concentration was 88g/kg in 18 h. After that, rapid ethanol production from cassava in SSF by Zymomonas mobilis 232B was studied. Through a series of experiments aided by Full Factorial Design and steepest ascent search, the optimal concentration yeast extract and ammonium sulfate were determined: 4 g/kg and 0.8 g/kg, each. Under optimum medium conditions, the optimal hydromodulus of cassava to water and glucoamylase dosages were obtained: hydromodulus of cassava to water at 1:3 and glucoamylase dosages 4 AGU/g starch. The ethanol production reached 4.915 g/kg/h. The residual sugar was analyzed by HPLC, and proved that the residual reducing sugar was some unfermentable oligosaccharide，but the components were more complex than that fermentation by Saccharomyces cerevisiae.

用面向对象方法分析、设计、实现工业远程监控系统

较早时期的实时监控应用软件，从分析设计到代码实现，采用的都是结构化方法，有的甚至没有经过分析设计阶段，直接进行编程。也曾有过分析和设计阶段采用结构化方法，编程实现采用面向对象语言的尝试。但由于分析设计的缺陷导致在软件生命周期的维护阶段出现许多问题，如存在较多的缺陷(bug）、结构性错误、修改困难、功能扩展工作量太大等等。统一建模语言(UML)的出现是面向对象建模领域的一个里程碑，它将面向对象方法和以往的面向过程的结构化方法做了较为完善的结合，使在分析、设计、实现阶段都采用面向对象方法完成实时系统成为可能。这次在开发新系统的过程中首次尝试了采用面向对象分析设计语言（UML)和面向对象语言（MS VC++）相结合，在整个软件生命周期均采用面向对象方法和工具实现工业远程实时监控系统，在解决以上问题及优化系统性能、结构方面皆取得了很好的效果。得到了结构良好、高内聚、低藕合、容易理解、易于扩展、维护的系统。这个系统主要实现工业现场仪表的调控，数据的采集、直观图实时监控生产状况，利用电话网及计算机技术自动实现输油管线远程实时监控、统计与处理等功能。

Isobutane/butene alkylation over supported heteropoly acid catalysts: I. Influence of the structure of silica

Catalysts consisting of heteropoly acids (HPAs) supported on different silica and mesoporous molecular sieves have been prepared by impregnation and the sol-gel method, respectively, and their catalytic behavior in fixed-bed alkylation of isobutane with butene has been investigated. The activity, selectivity and stability of the supported-HPA catalysts could be correlated with the surface acidity of the catalysts, the structure of supports as well as the time on stream (TOS). In the fixed-bed reactor, the acidity of the heteropoly acid is favorable to the formation of dimerization products (C-8(=)); especially, the pore size of supports was seen to have an important effect on activity and product distribution of the catalysts. Contrary to the traditional solid-acid catalysts, the supported-HPA catalysts own an excellent stability for alkylation, which makes it possible for these supported catalysts to replace the liquid-acid catalysts used in industry.

雨生红球藻Rubisco在虾青素积累过程中的表达分析

虾青素因其具有极强的抗氧化性及优越的着色作用，被广泛应用于营养保健和水产养殖中，备受国内外研究者的关注。红球藻是目前虾青素的生物来源中较有优势的一条途径。 我们选取雨生红球藻作为研究材料，收集其生长过程中四个不同的阶段，分别为绿色游动细胞阶段，绿色不动细胞阶段，绿褐色不动细胞阶段（开始积累虾青素），以及红色不动孢子阶段。本研究中提取了核酮糖-1,5-二磷酸羧化/加氧酶（Rubisco）的粗提液，并测定了酶活。其编码基因rbcL的mRNA表达量也被测定。另外，光合速率与呼吸速率的比值（P/R）通过测定与计算得出，各个阶段藻细胞中虾青素的含量由分析得出。本研究还应用了叶绿素荧光测定方法，确定了光系统II潜在最大活性（Fv / Fm），光系统II实际活性（ΦPSII），电子传递速率（ETR）和非光化学淬灭参数（NPQ）。 结果表明，绿色游动细胞的生长状态最佳，其P/R、Fv / Fm、ΦPSII均为最大，NPQ为最小。这说明在此状态的细胞中，光系统II的活性最强；但是其Rubisco活性与rbcL表达量均为最小。相比之下，在绿褐色不动细胞中，P/R和NPQ的值较低，Fv / Fm、ΦPSII和ETR值都最小，但Rubisco活性与rbcL表达量均为最高。 结合工业生产虾青素的方法，我们认为，Rubisco或许参与了虾青素的合成，而非Calvin循环为色素合成提供前体和能量。因此，在生产过程中适当加入碳源，比如CO2，可以有效增大虾青素的产量。

藻体对水环境中N、P及重金属Cu2+、Pb2+、Cd2+、Cr6+的吸附特征研究

随着全球生态环境的恶化，各国日益重视对水体中各种污染物的治理。利用藻类的吸收、富集和降解作用，可以去除污水中的营养物质、重金属离子和有机污染物，与其他物理、化学及工程的方法相比，该技术具有以下优点：成本低、能耗小、治理效果较好，对环境污染小，有利于资源化，有利于整体生态环境的改善，是治理水质污染的新途径。 本文利用几种大型海藻对富营养化海水进行处理，结果发现孔石莼、刚毛藻均有很强的吸收N、P的能力，吸收能力依次为褶曲刚毛藻>束生刚毛藻>孔石莼。水体中褶曲刚毛藻3 g/L含量，在3～5小时之内，可把中等以上富营养化海水中的N、P降低至一类海水水平。利用刚毛藻处理富营养化地下海水和养殖废水，进行海参和大菱鲆养殖试验，探索藻类净化水质和废水循环利用的新模式，使水体保持较低的营养盐状态，减轻养殖废水对环境的影响，实现了海水养殖业与环境的可持续发展。 刚毛藻在我国近海滩涂分布广泛，利用它来处理富营养化水体，并和水产养殖业相结合，既净化水体，使养殖废水能循环利用，满足水产养殖的需求，又改善水产业生态环境。同时，将回收藻体生产优质饲料、食品和药物等，实现藻类资源的高值利用。刚毛藻营养丰富，用其替代鼠尾藻作海参饲料，资源丰富，成本低，效果好，是一种值得加以开发利用的宝贵资源，具有广泛的应用前景。 生物吸附法是一种经济有效的移除废水中有害重金属离子的方法。由于藻类细胞壁中的多聚糖可提供吸附重金属的位点，廉价而蕴藏丰富的海藻对多种重金属表现出很强的吸附能力。所以本文通过分批实验，研究了非活体刚毛藻对水体中重金属Cu2+、Pb2+和Cd2+的吸附影响因子、吸附热力学、吸附动力学及吸附机理，得到了平衡等温线及动力学数据。吸附过程的最佳pH值为5.0，吸附量随温度的升高而增加，水体中常见的Na+、K+、Ca2+、Mg2+阳离子及Cl-、NO3-、SO42-、C2O42-等阴离子的存在对吸附的影响并不显著。EDTA存在时，吸附百分率大大降低。吸附等温线符合Langmuir和Freundlich方程。刚毛藻对重金属Cu2+、Pb2+和Cd2+的吸附容量很高，25℃时，对Cu2+、Pb2+和Cd2+的最大吸附容量分别为1.61 mmol/g、0.96 mmol/g和0.98 mmol/g，且吸附过程为吸热反应。刚毛藻对重金属Cu2+、Pb2+和Cd2+的吸附过程为化学吸附，在吸附过程中藻体表面的官能团可能与金属离子发生了螯合作用。吸附动力学过程符合pseudo-二级动力学模型，在初始的30min内，吸附速率很快，随后速率逐渐降低。解吸试验表明，用EDTA可以对重金属进行回收，刚毛藻可以循环利用。实验结果表明刚毛藻是一种高效、经济实用的生物吸附材料，可用来吸附回收水体中的重金属Cu2+、Pb2+和Cd2+等。 通过非活体刚毛藻对重金属Cr6+的吸附影响因子、吸附动力学、吸附机理的研究发现，刚毛藻对Cr6+具有很强的还原能力，对电镀废水中的Cr6+的还原去除提供了非常好的方法。吸附过程的最佳pH值为2～3，实际电镀废水通常在此pH范围，因此处理实际废水时，首先在原酸性条件下，对Cr6+进行还原去除，然后调废水pH至5.0，继续进行吸附，去除其他二价离子及被还原的三价Cr离子，实现了利用同一材料还原Cr6+为Cr3+，并将Cr3+和其他重金属离子同时去除。通过对机理的讨论，认为刚毛藻对Cr6+的生物吸附过程不是一个简单的“离子交换过程”，而是一个“吸附还原过程”。在海藻量足够的前提下，只要时间足够长，Cr6+可被彻底还原去除。 利用工业废弃物褐藻渣，对水体中重金属离子Cu2+、Pb2+、Cd2+及Cr6+的生物吸附特性分别进行了讨论，结果表明褐藻渣对重金属离子的吸附特性与刚毛藻一致，吸附等温线符合Langmuir和Freundlich方程，在25℃时，pH为5.0时，由Langmuir方程求出褐藻渣对Cu2+、Pb2+和Cd2+的最大吸附容量分别为4.20 mmol/g、3.13 mmol/g和2.97 mmol/g。褐藻渣对低、高浓度的重金属Cr6+都具有很强的吸附能力，且移除效果比较彻底。实际应用结果表明，褐藻渣是一种高效、经济实用的生物吸附材料，可用来吸附回收水体中的重金属离子，具有广泛的应用前景。

现代技工培训的心理模拟教学研究

The research of psycho-simulation training on modern operators was raised with the new demands of the technological revolution and the revolution in traditional industries in China. Having reviewed the history and current situation about psychological researches in personnel training in West, Soviet Union, developing countries, including China, the author hold that the principal problems in perssonel technical training in China was that the theoretical exploration of technical ability was neglected. For the solution of the above problems, the overall conception of this research was designed as follows. The intellectual skill plays a more and more important role in elements of technical abilities of workers due to the evergreater progress in modern science and technology, the higher automatic degree in industry. If the intellectual skill in training was emphasiged, the formation of technical ability in whole would be accelerated. For this purpore, the research adopted psycho-simulation method to realize the conception.