Abstract:本文对近年来发生在浙江一带的条斑紫菜病烂进行了研究，通过对发病症状和病源体形态构造、生长繁殖的显微和超微显观察，以及菌丝体的培养结果表明，病源为紫菜腐霉，属赤腐病。在不同培养温度条件下试验结果表明，２０－２４℃时菌丝繁殖蔓延得最快；而且高盐度对菌丝体有抑制和杀灭作用。

Abstract:The vitellogenesis of the oocytes from the Chinese mitten-Tianded crab, Erlocheir sinensis, was examined by light and electron microscope. The results show that previtellogenic oocy1es belong to prirnary oocytes in a slow developrnent. Each oocyte is surrounded by a 1ayer of follicle cells. The surface of the oolemma show no specializations and is smoth. The ooplasm, containing no yolk granules,possesses the basophilic property.The numbers of the organelles such as endoplasmic reticulum are much greater than in the oogoniuru. One to two condensed nucleolus are prcsent in the nucleus. The vitellogenic oocytes grow fast and their volurne increase significantly. Lipid vesicles and numerious yolk granules appear throughout the ooplasm. The endoplasmlc reticulum, Golgi complex,ribosornes and lysosnles are involves in the formation of yolk granuios. The nucleus become germinal vesicle in which one to threc descontlensed nucleolus are seen. The surface of oocytes forru a few microvilli that proJect into periv1telline space in which electron-dense material are present, but no absorbed by the oocytes. The postvitellogemic oocytes contain a fewer numbers of the organelles. The intra-oocytic synthesis are modified. The layer of follicle cells become very thin. The perivitelline spdce fills with electron-dense material that are ingested by the oocytes by pinocytosis.

Abstract:This paper deals with the toxic effects of NO2 - N and NH3 - N on Macrobrachium rosenbergii larva. The 24h, 48h, 72h, and 96h LC50 values of NO2-N and NH3-N for Z5, Z7 and Z9 were obstained. The safe concentrations of No-2-N and NH3-Nt (NH3-Nm) for Z5, Z7 and Z9 were 0. 64, 1. 38, 1. 68mg/L and 2. 04(0. 287), 2. 26(0. 318),2. 55 (0. 358)mg/L respectively. The Larva of Z7 and Z5 poisoned subacutely for 12-day showed that the larval developement, metaborphosis and survival rate decreased with the concentration. The toxic effects of the toxicant strengthen obviously when the toxicant concentration exceeded the safe concentration.

Abstract:使用孕酮、前列腺素、利血平三种药物，对罗氏沼虾注射以研究其催产效果。结果表明，三种药物以每属注射１μｇ催产效果最好，产卵率可达６５－８５％，比对比组（３５％）有明显提高，且孵出幼体与自然条件下孵出的幼体在生长上无明显差异。三种药物中，孕酮的效果最好。

Abstract:There are many causes to make the vibration of reciproeating internal combustion-engine. The main causes are as follow: (1) no balanced reciprocating inertial force; (2) no balanced centrifugal inertia1 force; (3)twist changing in four processes; (4) press changing of gas in the cylinder. Because single cylinder internal-combustion-engine has no balance parts as multiple cylinder internal-combustion-engine, it is more clear in no balancing. The major affecting factors are no balanced reciprocating inertial force and centrifugal inertial foree. After analysing the no balanced inertial force of single cylinder internal-combustion-engine, the balanced equation were obtalned and several usual balancing methods were analysed. In these mainly analysing and discussing the over weight method is the simplest one. The results are about the balance weight in the opposite and leaning opposite direction to balance the first grade no balanced inertial force as well as about strongness and direction of the minimal force left no balanced. Otherwise, the problem of the first and the second grade inertial force is solved through data calculated mothod.