产蛋白酶菌株的筛选及其在固态发酵豆粕中的应用

目的:筛选高产蛋白酶菌株,探究微生物发酵对豆粕抗原蛋白的影响,以期提高豆粕在水产饲料中的使用价值。方法:从土壤样品中筛选出1株蛋白酶酶活为1 390.6±12.5 U/mL的菌株LX-6,经生理生化特性和16S rDNA分子鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。通过B.amyloliquefaciens LX-6不同时间发酵豆粕,分析SDS-PAGE中大分子抗原蛋白降解情况、发酵样品总蛋白以及水溶性蛋白含量。结果:在37℃、物料含50%水的条件下,发酵24 h豆粕中大分子抗原蛋白全部降解,48 h时水溶性蛋白含量达到最高44.45%。结论:B.amyloliquefaciens LX-6发酵后有效提高了豆粕的蛋白含量,此发酵豆粕有望今后开发成水产饲料。     

产淀粉酶菌的筛选和诱变

淀粉酶在造纸工业中被广泛利用,淀粉酶的需求量越来越大,获得高产淀粉酶菌株是解决该问题的重要途径。采用透明圈法筛选获得 3 株产淀粉酶的细菌,并对它们进行紫外光和超声波诱变研究,探究其产淀粉酶的最佳诱变条件。实验结果显示,菌株紫外光诱变的适宜照射时间为 30 s,最佳照射距离为 15 cm,C1 菌和 S 菌的诱变效果较好,在此条件下的比透明圈都为 3.00。超声波诱变的适宜时间为 20 min,C1 菌和 S 菌的比透明圈都为 2.50。 研究表明,紫外光和超声波诱变都能提高产酶量,紫外光诱变的效果较超声 波诱变更稳定,超声波诱变后的产酶量低于紫外光诱变。     

海洋弧菌几丁质酶的产酶条件及分离纯化研究

将产几丁质酶的海洋弧菌CY01菌株进行发酵培养，对产酶的培养条件等进行了优化。发酵液经硫酸铵分级盐析，几丁质亲和层析，Sephadex G-100、Sephacryl S-200凝胶分离纯化，分离出三种几丁质酶Chi1，Chi2，Chi3，采用SDS－PAGE测得三种酶的分子量分别为27kD，39kD和46kD。     

敲除Ras1基因对裂殖酵母生长及产孢影响

目的:探究Ras1基因对裂殖酵母生长及产孢的影响。方法:培养将野生型与基因敲除的突变株,分析其生长情况;野生型与突变菌株交配,探讨其产孢情况。结果:在25℃及37℃培养条件下,敲除基因后的突变菌株其生长慢于野生型菌株。产孢实验结果表明,野生型100%产生4个孢子,而突变菌株75%产生1个孢子、25%产生2个孢子,且突变菌株的孢子略小于野生型。结论:敲除基因Ras1会影响裂殖酵母的生长和产孢。     

淀粉酶产色链霉菌1628发酵培养基及发酵条件的优化

淀粉酶产色链霉菌1628(Streptomyces diastatochromogenes)是一株具有广阔应用前景的生防菌株,其合成的主要活性物质为核苷类抗生素——丰加霉素.为了提高淀粉酶产色链霉菌的发酵水平,本研究采用单因素和正交实验设计,对菌株1628的发酵培养基和发酵条件进行了优化,优化后的最佳培养基配方为:可溶性淀粉1.5%、黄豆粉5%、FeSO40.1%、CaCO30.5%、NH4NO3 0.3%、KH2PO4 0.3%,最适初始pH7.0.在供试的发酵条件内,装液量60mL/250mL,发酵温度28℃,摇床转速180r/min,发酵时间为92h.活性物质丰加霉素的产量最高156.17mg·L-1,比优化前提高了3.3倍.     

一株产香兰素的海洋放线菌的筛选及发酵条件的研究

本文以漳州古雷半岛潮间带沉积物作为研究对象,筛选出能够发酵代谢产香兰素的高产菌株。为海洋放线菌发酵代谢进入工业化生产做出理论依据。     

南极产低温几丁质酶菌株的16S rDNA序列分析及其发酵条件及酶学性质研究

从南极深海沉积物中筛选到一株产低温几丁质酶的菌株AC444,经细菌形态观察及16S rDNA序列分析,该菌株属于假交替单胞菌属（pseudoalteromonas）,其最适与最高生长温度分别为15℃和30℃,属于兼性嗜冷菌。AC444菌株能利用多种碳源产酶,在含胶体几丁质和蛋白胨的培养基中产酶最高,达13．47U,最适产酶温度为20℃。酶的最适反应pH为7．0,最适作用温度为35℃,属中性低温酶。     

表面活性剂对栗褐链霉菌(streptomyces badius)产酶的影响

用固态发酵的方法研究了表面活性剂Tween-80和鼠李糖脂对堆肥中常见的放线菌栗褐链霉菌(Streptomyces badius)产酶及底物中挥发性有机质降解的影响.结果表明:添加0.05%的Tween-80能使微生物淀粉酶、蛋白酶和半纤维素酶最高酶活分别提高46.5%、65.9%和70.5%;添加0.15%的Tween-80能使微生物淀粉酶、纤维素酶和半纤维素酶最高酶活分别提高10.6%、51.3%和75%.添加0.006%的鼠李糖脂能使菌体产蛋白酶和半纤维素酶酶活分别提高14.6%和37.6%;鼠李糖脂浓度为0.018%时对微生物产酶有显著抑制作用.表面活性剂通过影响菌体产酶最终显著地影响了有机质的降解,对照组和添加了0.05%的Tween-80、0.15%的Tween-80、0.006%的鼠李糖脂、0.018%的鼠李糖脂的4组样品中挥发性有机质降解率分别为5.66%、7.65%、6.91%、5.07%、4.62%,表明表面活性剂对微生物产酶及有机物降解有显著影响.     

海洋产蛋白酶细菌发酵液防污活性研究

传统的防污剂对海洋环境造成严重污染,随着环保意识的增强以及相关规定的制订,各国竞相开展新型无毒防污剂的研究。本文以海洋产蛋白酶菌株发酵产物为活性物质,研究蛋白酶粗提物对污损生物硅藻(navicula sp.)和贻贝(mytilus edulis)附着行为的影响。结果表明,所研究菌株的发酵液对硅藻(navicula sp.)和贻贝(mytilus edulis)的附着有明显抑制作用。贻贝(mytilus edulis)毒性实验显示,细菌发酵液对贻贝无毒。因此,海洋微生物蛋白酶产生菌粗酶提取物可以作为环保型防污功能添加剂。     

厦门海域产蛋白酶浮游细菌的多样性研究

从厦门海域分离筛选到33株产蛋白酶浮游细菌,并通过对其16S核糖体RNA(16S rRNA)基因进行聚合酶链式反应(PCR)扩增和限制性片段长度多态性(RFLP)分析,初步研究了该海域产蛋白酶浮游细菌的多样性.研究发现,这33株菌可分为12种操作分类单元(OTU),其中OTU-Ⅰ和OTU-Ⅱ分别包含8株和12株菌株,分别占总菌数的24.2%和36.4%,为优势分离类群.分别从12种OTU中随机选取1株细菌作为代表进行16S rRNA基因测序.序列分析结果显示,属于OTU-Ⅶ的细菌为假交替单胞菌属(Pseudoalteromonas sp.),而包括OTU-Ⅰ和OTU-Ⅱ在内的9种OTU 都属于弧菌属(Vibrio sp.),表明弧菌在厦门海域产蛋白酶浮游细菌中占优势.初步的生理检测显示,这些细菌的适宜生长温度为16℃左右,适宜生长盐度范围为3%～5% NaCl.     

热交换器的分类及优缺点分析

热交换器是将不同温度介质之间的热量通过热传导的形式,由高温介质传递给低温介质,使介质达到生产所需温度的工艺设备,也可作为一种节能设备使用.通过对不同热交换器的结构分析,总结不同热交换器的优缺点、适用环境,为生产工艺设计人员及设备制造单位在选择可降低能耗、提高效率的设备上提供参考.     

聚苯胺及其复合物的制备和结构及形貌分析

通过化学氧化法分别制备盐酸,盐酸和十二烷基苯磺酸,碳纳米管(MWNTs-COOH)掺杂的聚苯胺,利用红外光谱,紫外光谱,扫描电子显微镜和透射电子显微镜对所制备聚苯胺的结构和形貌进行分析。分析不同掺杂物对聚苯胺的结构和形貌的影响;同时研究了超声波作用对聚苯胺形貌以及聚苯胺包裹MWNTs-COOH情况的影响。     

Thermodynamic similarity and prediction of the properties and characteristics of substances and processes

Principles of the theory of thermodynamic similarity are considered in application to all aggregate states of a substance, including phase transitions, and to the change in dissipative structures in open systems.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 5, pp. 709–716, November, 1987.     

Modelling and computation of curing and damage of thermosets

The curing of thermosets is a complex process involving the transition from a fluid into a (visco-) elastic solid. This phase transition comes along with an increase in stiffness and a volume shrinkage of the polymer. The latter may lead to severe residual strains and stresses, which in turn can cause damage in the final, usually quasi-brittle material. In this contribution a constitutive model is developed which takes into account the curing of a thermosetting material together with the process-induced damage as resulting from curing shrinkage. The curing of the material is governed by a phenomenological hypoelastic constitutive equation which includes temporal evolutions for stiffness and volume shrinkage. Thermal and viscous effects are neglected in the present study. An isotropic gradient-enhanced damage model is adapted to describe the damage evolution. The curing-damage model is implemented into a finite element code and numerical examples for thermosetting materials demonstrate that the proposed model is capable to predict cure-induced damage in thermosets.     

碳化硼陶瓷增韧补强和致密化研究现状及其展望

碳化硼陶瓷具有极高的硬度,然而其低韧性、低抗弯强度、难以致密化限制了它的广泛应用.已有一些研究集中于碳化硼陶瓷增韧补强和致密化,对这一方面国内外研究进展进行了归纳与评述,阐明各种增韧补强和致密化方法的优缺点,提出碳化硼陶瓷增韧补强和致密化研究值得发展的一些方向.     

Measurement and analysis of elastic and anelastic properties of alumina and silicon carbide

Measurements of dynamic Young's modulus, E, and damping as a function of temperature, T, were made for alumina and silicon carbide. The Young's modulus data were compared with some from the literature, and analysed in terms of a theoretical framework relating the Debye temperature, θD, with the elastic constants. For both materials this analysis yielded a ratio T₀/θ_D which was near 0.4, where T₀ is an empirical fitting constant for the plot of (E(0)−E)/T versus 1/T (E(0) is the value of E at 0 K). The analysis of the damping data in terms of an Arrhenius type dependence led to effective activation energies near kT, where k is Boltzmann's constant. This revised version was published online in November 2006 with corrections to the Cover Date.     

Mechanisms of Corosion and Oxidation of Metals and Alloys

Selected topics in field of the study of the mechanisms of corrosion and of oxidation of metals or alloys are presented. The first part reports a new model for the mechanism of the breakaway oxidation of ferritic stainless steels in water vapour. The second part is devoted to the physico‐chemical aspects of oxidation and presents experimental methods useful in the kinetic modelling applied to two alloys, the zircalloy‐4 and an AlMg5 % in the liquid state. In the third part the physical and numerical modelling of the stress corrosion cracking behaviour in face‐centered cubic (fcc) alloys is detailed, which enables the study of the influence of macroscopic parameters (such as the temperature or hydrogen activity) on the fracture process.     

Surface-charge density and potential of coal-liquid mixtures and control of their stability and fluidity

The preparation conditions of concentrated (>70%) aqueous suspensions of coal were optimized, as were the surface charge density and the surface potential of the coal-water suspensions. The theoretical study showed that (1–3) or (2–3) electrolytes such as Na₂SO₄ or Na₅P₃O₁₀, greatly increase the surface charge density and the surface potential of the coal particles in water. This study has led to the interesting result that thinners and stabilizing agents of concentrated clay suspensions, such as lignosulphonates, tripolyphosphates, polynaphtalene sulphonates, etc., must also be good thinners and stabilizing agents for ground coal-water suspensions. Two parameters were controlled: the stability and the fluidity of the suspensions. A penetrometry technique revealed the importance of the resistance coefficient,C _r that can be used as a criterion for the evaluation of coal-water mixture stability and fluidity. Concentrated coal suspensions (about 75% of solid by weight) were prepared in water by using different additives, for instance sodium tripolyphosphate (NaTPP) and surfactants like lignosulphonates (by coupling of the dispersion and stabilizing effects) with the optimum concentration ratio of these two products equal to 1.9. The stability of the suspensions was then greater than 2 months and the viscosity was 1900 cP.     

SARS传染病数学建模及预测预防控制机理研究

首先，利用疾病传播的一般规律及人口守恒统计法则建立了四类人的SARS传染病数学模型，然后运用数学方法对四类人的SARS传染病数学模型进行分析，得出了其生理意义和预防、控制机理。其次，利用人工神经网络理论建立了SARS的预测模型，以北京市的SARS数据为例进行了预测和分析，预测结果显示该模型简单易行，预测精度高。