Juvenile hormone titre and regulation in the cockroachDiploptera punctata

Summary Titres of juvenile hormone (JH) have been determined in both hemolymph and whole body extracts of femaleDiploptera punctata during the first gonotrophic cycle using a method employing gas chromatography/mass spectrometry for qualitative and quantitative analysis. JH III is the sole JH found in both adult and last instarD. punctata. Maximum values of 1500 ng/ml (6M) were observed at the middle of the gonotrophic cycle, when basal oocyte growth rate was greatest. Changes in rates of JH release in vitro by corpora allata paralleled closely the changes in JH titre, suggesting that biosynthesis is a major regulator of titre. JH levels per animal were calculated from observed JH titres, and at certain time points in the gonotrophic cycle JH levels obtained from analysis of whole bodies were significantly greater than those predicted from hemolymph titres. These results suggest the existence of a nonhemolymph JH pool inD. punctata. Decay in JH titre after allatectomy of 5 day females has also been studied. Following a rapid initial decline, the rate of decay slowed appreciably 4 h post-operation. Thus, use of a first-order rate constant to estimate half-life of JH significantly underestimated the longevity of the hormone. The apparent persistence of JH following allatectomy may be due to the existence of a nonhemolymph JH pool.     

稳定非线性动力系统周期的计算机分析

提出采用后继函数法来确定非线性动力系统的周期,并编制计算机程序对Ｖａｎ ｄｅｒ Ｐｏｌ方程实例计算周期和绘制相图,结果表明,该方法计算结果准确且实用性强,本方法不但适合于求解保守系统和具 周期解非线性动力系统的周期,也适合于耗散系统和不稳定系统的分析。     

一种使用非线性循环数列解决堆栈问题的算法

提出了一种使用非线性循环数列解决堆栈问题的算法,对研究栈的性质和求解栈的输出序列具有一定的实用价值。     

Discovery and character of the Kunlun-Yellow River Movement

Based on geomorphological, tectonic and sedimentary data, a Kunlun Yellow River Tectonic Movement has been recognized in 1 10-0 60 Ma B.P. This tectonic movement, which leads to uplift of the Qinghai_Xizang (Tibet) Plateau from 1 500 to 3 000-3 500 m, is periodic, abrupt and changeable in the movement rate of uplifting and slide slipping.     

福州陶江中国淡水蛏Novaculina chinensis生殖周期的研究

采用活体性腺观察和组织切片法对福建闵候尚干陶江中国淡水蛏的生殖腺进行了初步研究,淡水蛏的性腺发育分为５期,增殖期,生长期,成熟期,排放期和休止期,一年只有一个繁殖周期,繁殖期为３月下旬至４月,雌雄异体,有雄性早熟现象,较晚期的卵母细胞和成熟卵子有双质核仁现象。     

普通物理实验教学改革的探索与实践

剖析了传统普通物理实验教学的缺陷,论述了“两循环三层次”教学模式的内容和实施过程,科学总结了教学改革取得的成果。     

剪切型建筑结构抗共振抗震设计

通过将剪切型建筑结构的固有频率调离场地的卓越频率区域,提出一种抗共振抗震设计方法。数值算例说明该方法是很有效的。     

清洁生产的热力学循环探讨

通过对工业系统和热力系统的对比分析，提出运用热力学原理来诠释清洁生产的理论．在此基础上．对工业生产的三种模式和清洁生产的评价体系进行热力学解释，并将热力循环运用于清洁生产，试图从热力学原理中找到清洁生产理论的新突破。     

关于图的Ramsey数的几个下界

推广了3个C4对完全图的R am sey数下界以及一个经典R am sey数下界问题,得到了3个C4对完全图的R am sey数的线性下界,以及一个关于多项式的经典R am sey数下界.