Feasibility of fishmeal replacement by shrimp head silage protein hydrolysate in Nile tilapia (Oreochromis niloticus L) diets

This study provides information on the use of shrimp head silage protein hydrolysate (SPH) as an alternative protein source for tilapia feeding. Six diets (28% protein, 12% lipid) were prepared where fishmeal protein was replaced at levels of 0 (control), 10, 15, 20, 25 and 30% with the hydrolysate. The diets were supplied to Nile tilapia fry (338 mg initial weight) stocked in plastic recirculating 20 l tanks (10 animals per tank), with three replicates per treatment. After an 8 week experimental period, fish fed the diets containing 10 and 15% SPH showed significantly better performance in terms of final body weight, weight gain (%), mean daily weight gain (mg day^?1), specific growth ratio and feed conversion ratio than those fed the control diet (fishmeal as protein source) and higher‐SPH diets. It is concluded that shrimp head hydrolysate is a promising alternative protein source for tilapia feeding, improving growth ratio at dietary inclusion levels as high as 15%. In addition, the diets with added shrimp silage protein were well accepted by the fish, which avidly consumed the feed during the experiment. © 2002 Society of Chemical Industry     

分光光度法测定微量茴香醛的研究

研究了测定微量茴香醛的光度分析新方法。在盐酸介质中,硫代巴比妥酸与茴香醛发生缩合反应,生成棕色产物,可用于微量茴香醛的测定。最大吸收波长为415nm,茴香醛浓度在2×10-6-1×10-4mol/L范围内符合比尔定律。该法具有灵敏、准确、操作简便、快速等特点。用于测定食品中茴香醛的含量,结果满意。     

脱落酸、乙烯和赤霉素对豌豆苗采后品质的影响

为了解植物生长调节剂对幼苗类蔬菜采后品质变化的影响，用脱落酸、乙烯、赤霉素处理豌豆苗（Pisum Satu-vum L.）。结果表明：脱落酸和乙烯处理加速了叶绿素、蛋白质、可溶性糖含量的下降和纤维素含量的升高。而赤霉素处理则显著延缓了叶绿素、蛋白质和可溶性糖含量的下降和纤维素含量的增加。     

磷钨酸乙醇染色法在嗜铬颗粒电镜X射线显微分析中的应用

通过比较常规透射电镜制样法、快速冷冻固定－冷冻超薄切片法及磷钨酸乙醇（EPTA）染色法在嗜铬颗粒透射电镜X射线显微分析中的应用，发现磷钨酸乙醇染色法能使嗜铬颗粒电子着色，从而较好地显示嗜铬颗粒的超微结构。同时磷钨酸乙醇染色法也以在一定程度上原位保留生物样品中元素，可以应用于检测样品元素含量的变化或比较样品元素含量的组间差别，提示磷钨酸乙醇染色法是一种可应用于透射电镜X射线显微分析的经济简便的生物样品制备方法。     

腐殖酸对烤烟根系生长和生理活性的影响

对腐殖酸和基肥混施进行了烤烟盆栽试验。结果表明 ,腐殖酸能有效刺激根系的生理活性 ,提高根系抗坏血酸氧化酶、多酚氧化酶等呼吸酶的活性 ,增强根系的活力 ,并能有效促进烤烟根系生长 ,根干重、体积和长度均有提高。     

Efficient mixed Timoshenko–Mindlin shell elements

The precise representation of rigid body motions in the displacement patterns of curved Timoshenko–Mindlin (TM) shell elements is considered. This consideration requires the development of the strain–displacement relationships of the TM shell theory with regard to their consistency with the rigid body motions. For this purpose a refined TM theory of multilayered anisotropic shells is elaborated. The effects of transverse shear deformation and bending‐extension coupling are included. The fundamental unknowns consist of five displacements and eight strains of the face surfaces of the shell, and eight stress resultants. On the basis of this theory the simple and efficient mixed models are developed. The elemental arrays are derived using the Hu–Washizu mixed variational principle. Numerical results are presented to demonstrate the high accuracy and effectiveness of the developed 4‐node shell elements and to compare their performance with other finite elements reported in the literature. Copyright © 2002 John Wiley & Sons, Ltd.     

Efficiency of repeated batch penicillin fermentation using two fermentors. Computer simulation and optimisation

Repeated batch operation using two fermentors (RBTF) to penicillin fermentation was demonstrated by computer simulation to improve productivity. Three operation modes were compared: chemostat, repeated batch operation using a single fermentor (RBSF) and RBTF; in each case account was made of the lag period before growth. The simulated fermentor performances were assessed on the basis of the penicillin productivity and concentration; the simulation was based on published batch fermentation data. It was shown that RBTF was superior to RBSF and chemostat. The advantage of RBTF increased as the lag period became greater.     

SO2转化温度异常情况分析

结合凤山实业总公司硫酸车间 SO2 转化系统的具体工艺流程 ,分析近几年转化系统出现温度不正常的原因 ,提出解决方法     

用菱锌矿制取轻质氧化锌的研究

介绍了以菱锌矿为原料生产轻质氧化锌的方法，论述了反应酸浓度，煅烧温度，溶液PH值对实验的影响，并对生产工艺条件进行了研究。其工艺流程是将粉碎后的菱锌矿进行循环酸浸，净化后再直接和碳化母液反应，经沉降后再煅烧分解为轻质氧化锌，产品质量符合国家标准，视比容大，活性强，成本低，经济效益显著。     

从菜西瓜中提取果胶的最佳工艺研究

为确定从菜西瓜中提取果胶的最佳工艺条件,以山西省临汾市菜西瓜为材料,采用酸法进行了提取果胶的试验研究。正交试验结果表明:在萃取时间为45min的前提下,从瓜瓤中提取果胶的最佳工艺条件是加水量为原料重量的4倍,85℃下,添加原料重量0.3％的多聚磷酸钠,果胶得率可达2.03％;从外果皮中提取果胶,加水量为原料重量的4倍,75℃下,添加原料重量0.7％的多聚磷酸钠,果胶得率可达2.98％。