关于一类积分型压缩映射不动点的研究

分析了在完备度量空间下,映射满足一类积分型压缩不等式的不动点的存在性和惟一性．具体构造了压缩条件∫d（f（x）,f（y）） 0 g（t）dt≤b ∫d（x,f（x）） 0 g（t）dt＋b∫d（y,f（y）） 0 g（t）dt ∫d（f（x）,f（y））0 g（t）dt≤c∫d（x,f（y）） 0 g（t） g（t）dt＋c∫d（y,f（x）） 0 g（t）dt,其中定义映射f：X→X,b,c∈[0.1/2）,g：[0,＋∞）为有限非负勒贝格可积映射,非负即任意ε〉0都有∫k 0 g（t）dt〉0.     

比生长速率与细菌增代时间

1比生长速率与td(增代时间)h 1.1 M=1/x dx/dt=1/x △x/△t 式中X为菌体量,t为时间[小时]h (1)比生长速率的计算 M=[排气CO2@t1/排气CO2@t2]÷(t2-t1)     

基于气相色谱法的油酸甲酯和亚油酸甲酯热氧化降解特性研究

利用气相色谱法分别测定油酸甲酯和亚油酸甲酯在不同温度下的氧化曲线,同时采用微分法和积分法对热氧化降解反应方程的参数进行了计算,进而确定了反映油酸甲酯和亚油酸甲酯热氧化降解历程的宏观反应动力学方程。微分法动力学分析结果表明:油酸甲酯热氧化降解反应的平均反应级数为1.37,活化能为5.48 k J/mol,反应动力学模型为rA=-dcA/dt=7.06exp(-5.48/RT)c1.37A;亚油酸甲酯热氧化降解反应的平均反应级数为2.49,活化能为392.73 k J/mol,反应动力学模型为rA=-dcA/dt=1.13×1047exp(-392.73/RT)c2.49A。积分法动力学分析结果表明:当反应级数n=1时,油酸甲酯热氧化降解反应的活化能为27.68 k J/mol,反应动力学模型为rA=-dcA/dt=1 690.55exp(-27.68/RT)cA,亚油酸甲酯热氧化降解反应的活化能为107.04 k J/mol,反应动力学模型为rA=-dcA/dt=2.20×1013exp(-107.04/RT)cA;当反应级数n≠1时,油酸甲酯热氧化降解反应的平均反应级数为1.45,活化能为31.29 k J/mol,反应动力学模型为rA=-dcA/dt=369.19exp(-31.29/RT)c1.45A,亚油酸甲酯热氧化降解反应的平均反应级数为1.60,活化能为108.90 k J/mol,反应动力学模型为rA=-dcA/dt=9.27×1013exp(-108.90/RT)c1.60A。积分法得到的活化能数值更为接近,因此更适合研究油酸甲酯和亚油酸甲酯的热氧化降解反应动力学。     

响应曲面法优化琼胶水解条件

采用酸水解法对琼胶进行降解并结合苯酚- 硫酸法测定琼胶低聚糖的含量。在单因素试验的基础上,利用响应曲面法优化水解工艺,建立盐酸浓度(X1)、水解时间(X2 ) 和固液比(X3 ) 与水解率( Y ) 之间的数学模型：Y =81.5933＋0.7175X1＋1.8938X2＋2.7313X3－3.1567X12－3.3042X22－3.3092X32－0.6625X1X2＋0.0475X1X3－0.8000X2X3,确定琼胶水解的最佳工艺条件,即盐酸浓度0.105mol/L、水解时间96min、固液比4.5:100(g/mL),在此最佳工艺条件下进行水解,琼胶水解率为81.43%。     

分散剂对醇溶性磷脂浸出的动力学研究

针对含水醇类、较高温度和较小料液比时以粉末磷脂为原料浸出醇溶性磷脂,浸出过程中常有磷脂分散不好的情况,采用分散剂分散粉末磷脂来提高醇溶性磷脂的传质效率,考察了不经分散剂分散和经分散剂分散的磷脂浸出动力学行为,并分别得到了它们的动力学方程:-dq/dt=0.00719e -0.055t(不加分散剂),-dq/dt=0.00491e -0.0742t(砂-100为分散剂),-dq/dt=0.02208e-0.0522t(糊精为分散剂).研究结果表明,经分散剂分散的磷脂可大大提高醇溶性磷脂的浸出速率和有效浸出时间.     

马铃薯多酚氧化酶酶学特性及热稳定性模型的研究

目的：研究马铃薯中多酚氧化酶（polyphenol oxidase,PPO）的部分酶学性质及热稳定性并拟合数学模型预测酶活变化过程。方法：采用紫外可见分光光度计测定马铃薯多酚氧化酶活力,利用Matlab软件拟合二元多项式热稳定性数学模型,SPSS软件对多项式模型回归分析。结果：马铃薯多酚氧化酶的最适pH为5.5,最适反应温度为40℃,最适底物浓度为8.33mmol/L,加工温度、时间与酶活残存率的函数关系为：Z=24.5439＋6.1163X＋3.4064Y-0.0269X2-0.2361XY-0.0351Y2-0.0002836X3＋0.001326X2Y＋0.0012XY2,其中R2=0.981,F=100.695,p〈0.001。结论：二元三次多项式模型能够较准确的反映并预测马铃薯多酚氧化酶在热加工过程中酶活的变化趋势。     

华东纺织工学院一九八一年攻读硕士学位研究生试卷自动控制理论试题

招生专业:纺织工程、自动化一、(15分)画出右面校正网络的方块图或 信号流图,求出其传递函数卜一一._!斗一“几U。(S)U‘(S)依反I二、(20分)控制系统的方块图结构如下,其中I、I、l、万表示四个环节。园对于I,对于l,已知X出I二X入I+2dX入I dt已知它的单位阶跃响应为(t》o) 0 .8八出l、‘夕=U .6一一下不==井于二于=二匕。.万111 Vl一0 .25对于l,已知其一张伯德图如下:了z一0 .25·10t+tg一1叮l一0 .25气黔丝)创1对于F,已知其奈魁斯特图如下:试求系统的开环传递函数GH(S)下转封三)三、(20分)求作一F列控制系统的根轨迹图(每小题5分) …     

线性回归模型的一种有偏的可容许估计

对于线性回归模型Y=Xβ＋,εE（ε）=0,Cov（ε）=σ2V,V〉0,给出了回归系数的有偏估计βh＊=（XTV-1X＋hI）-1（XTV-1Y＋β＊）（h〉0）优于岭估计的条件以及在二次损失下可容许的充要条件.     

基于气相色谱的植物油特征脂肪酸高温热氧化特性研究

利用自制高温热氧化装置和气相色谱法分别测定棕榈酸、油酸、亚油酸、亚麻酸在不同温度下的氧化降解曲线,同时采用微分法对热氧化降解反应动力学方程的参数(氧化活化能Ea,反应级数n,反应速率常数k,指前因子A)进行了计算,进而确定了反映棕榈酸、油酸、亚油酸、亚麻酸在高温下热氧化降解历程的宏观反应动力学模型。结果表明:棕榈酸热氧化降解反应动力学模型为r_A=-dcA/dt=9. 292×10~(66)exp(-648. 492/RT) c_A~(6. 504);油酸热氧化降解反应动力学模型为r_A=-dc_A/dt=3. 213×10~(59)exp(-548. 724/RT) c_A~(5.201);亚油酸热氧化降解反应动力学模型为r_A=-dc_A/dt=2. 865×10~(57)exp(-515. 468/RT) c_A~(3.220);亚麻酸热氧化降解反应动力学模型为r_A=-dc_A/dt=4. 451×10~(39)exp(-350. 851/RT) c_A~(2.108)。4种脂肪酸的动力学方程分别反映了其化学反应速率与反应温度和底物浓度的关系,同时揭示出不同脂肪酸热氧化的特性:随着不饱和度的升高,脂肪酸的热氧化稳定性降低;不饱和度越高,脂肪酸热氧化受自身浓度的影响越小;不饱和度越高,温度对其反应速率的影响越大。     

白茶超声波浸提过程的数学模拟

文章以福建政和白茶为原料,通过二次正交旋转组合实验设计,将白茶的超声波浸提过程中的参数（超声波提取温度X3、超声波提取时间X2、茶水比例X3）同固形物含量（Y）间的动态关系进行数学模拟,并在仅=0．05显著水平下剔除不显著项,得出回归方程：Y1=319．592＋63．002X1＋79．491X2—115．329X3＋49．022X3：23．850X2X3,经数学检验后证明,该模型拟合成功。     

蛋白质水解度测定方法综述

对目前国内外常用的蛋白质水解度测定方法进行了综述，其中pH—state方法是通过滴定水解过程中释放的质子测定DH；OPA、TNBS及国内常用的水合茚三酮和甲醛等测定方法是利用游离氨基的反应测定DH。     

聚多元羧酸盐的合成及应用

研究了聚多元羧酸盐的合成方法及反应机理,将其应用于洗涤剂和PVC制品中分别代替三聚磷酸钠和邻苯二甲酸二丁酯,证明有良好效果。     

BASIS OF STABILITY OF AMINE SALTS OF LINOLEIC ACID

SUMMARY— The mechanism and generality of the known stabilization against autoxidation conferred on linoleic acid by certain basic amino acids, such as lysine and arginine, was investigated. Basic amino acids were the only class of compounds found to confer the effect. However, the smallest basic amino acid, 2,3-diaminopropionic acid, was not effective, nor was αβω-diaminc acid, 3,6-diaminohexanoic acid, although a simple isomer of lysine. The stabilization was observed only in the solid phase. Inclusion of sodium chloride in the solid matrix was deleterious to the effect. A large number of physical and chemical observations were made and correlated but it has not been possible to draw detailed conclusions about the mechanism of stabilization, nor can a detailed structure of the stabilized complex be suggested. The cause of the phenomenon appears to be closely associated with the physical arrangement of the ions in the crystal lattice.     

棉浆粕制备条件对粘胶生产适用性的影响

本文论述了过低的棉短绒成熟度会引致粘胶生产过程压榨困难和过滤障碍。描述了在蒸球内设置中通管、来用重蒸轻漂、稳定漂白聚合度、以及漂后的除杂疏解等先进的工艺制造棉浆粕，有助于反应性能的提高，改善粘胶的过滤性能。但打浆时过分切断使纤维长度过短，会影响碱纤维素的压榨。采用干毯抄浆、浆粕存放（一段时间）均有助于浆粕水份均匀性的提高。     

基于复合运动理论推导求点的速度及加速度的球坐标法

本文基于点的复合运动理论,用球坐标法推导出点的速度及加速度的计算公式,进一步论证了理论力学中点的速度,加速度公式的正确性。     

EFFECTS OF TYPES OF FAT AND OF RATES AND TEMPERATURES OF COMMINUTION ON DISPERSION OF LIPIDS IN FRANKFURTERS

ABSTRACT— The effect of time, temperature and rpm of comminution of emulsions was determined on the dispersion of approximately 25% of beef fat, pork fat or cottonseed oil in frankfurters. The numbers of lipid particles 5 μ or less in diameter increased in frankfurters containing either beef or pork fat as comminution was continued to higher temperatures, with pork fat dispersed more thoroughly. Fat tended to separate from frankfurters containing beef fat in particles 200 μ or more in diameter. In contrast, no specific degree of dispersion of particles 5 μ or less in diameter consistently indicated emulsion stability, or its lack. Increased rpm during comminution produced an increased dispersion of beef or pork fat. Under the same conditions pork fat was dispersed more finely than beef fat. Dispersion of cottonseed oil produced finely dispersed particles beyond the resolution of light microscopy, as was confirmed by electron microscopy which showed a substantial number of particles to be less than 1 μ in diameter.     

高速纺丝设备预紧联接螺栓断裂原因的分析

针对我厂涤纶高速纺丝生产中多次发生设备预紧联接螺栓断裂现象，以螺杆挤压机计量头紧固螺栓预紧力炬计算为例，推导出预紧联接的一般计算方法，同时对使用国产螺栓替代进口预紧联接螺栓进行了简述。     

ANALYTICAL CHARACTERIZATION OF THE PRODUCTS OF NONENZYMATIC GLYCOSYLATION OF LYSOZYME

The quantitative analysis of the reaction products of the water activity dependent nonenzymatic glycosylation of lysozyme was not straightforward. Difficulties arose in the determination of the number of bound glucose molecules because glycosylation leads to glucose mediated protein aggregation, and the likely presence of a mixture of relatively labile Schiff-base intermediates, and the more stable ketoamine products generated by Amadori rearrangement. Polyacrylamide gel electrophoresis was used to monitor protein aggregation; periodate oxidation, nuclear magnetic resonance (NMR), and oxalic acid hydrolysis combined with HPLC, emerged as the most promising methods to quantitate the degree of glycosylation. Possible interpretations are advanced to explain the apparent discrepancies in degree of glycosylation suggested by the different analytical methods evaluated.     

灵芝不同部位多糖含量测定

采用苯酚-硫酸法对灵芝菌盖表皮层、木栓层、菌柄、孢子粉、发酵菌丝体等部位中的灵芝多糖进行了测定,结果发现,灵芝发酵菌丝体中的多糖含量明显高于灵芝的其它部位,其含量顺序分别为：发酵菌丝体〉菌盖表皮层〉孢子粉〉菌柄〉木栓层。     

STABILITY OF ESSENTIAL OIL OF HOPS

The stability of hop essential oil in beers, in hops and in aqueous emulsions has been investigated. Hop character of beers treated with hop oil emulsion has stability on pasteurization and storage similar to that of dry hopped beers. When bottled with high levels of headspace air, beers lose hop character. Beers dry-hopped with stored hops or with hops damaged during pelleting tend to develop sulphury flavours. However, hop oil emulsions prepared from such hops give rise to a sound hop character in beer. Hop oil emulsion produced by the new process shows good stability physically, chemically and biologically, particularly when mechanically homogenized and stored under an inert atmosphere. The extent of any chemical alteration due to contact with air may be estimated spectrophotometrically.