桑叶的化学成分、药理活性及应用研究进展

目的：为合理开发利用桑叶资源提供依据。方法：采取查阅文献资料及实地考察相结合的方法。结果：桑叶中含N－糖化合物，芸香甙、，槲皮素，挥发油，氨基酸，维生素及微量元素等多种活化学成分，具有降血糖，降血脂，降血压，抗菌和抗病毒多种药理活性，结果：桑叶资源丰富，在药品和功能性食品领域研究开发前景广阔。     

菊酯类杀虫的研究和开发

介绍了菊酯类杀虫剂开发的进展，讨论了拟除虫菊酯杀虫剂生物活性与化学结构的关系，探讨了拟除虫菊酯类杀虫剂在我国发展中的若干问题。     

五员杂环化合物的芳香性和亲电取代活性

本文从结构的观点,用符合芳香性的四个判据判别了五员杂环化合物的芳香性,并从杂原子的电炙性及其参与的正离子的共轭体系稳定性的大小两方面,解释了它们的亲电取代活性。     

北卡罗莱纳大学招生规划探析

科学的招生规划对于提高高等教育的质量,保障高等教育的多样化有重要的意义,同时也是高等院校实现其战略规划的基础.北卡罗莱纳大学一直把招生放在学校战略规划的重要位置,制定符合学校特色的招生计划,即招生计划以入学预测为基础,具有客观性;各学院根据自身特点制定招生计划,具有灵活性;招生计划符合社会发展要求,具有针对性.北卡罗莱纳大学制定招生规划的原则,特点及其意义,为我国各个高等教育机构制定招生规划提供了有益的启示.     

让手机电池更长命

手机已经不仅仅是一种时尚产品,而是以基本的通讯工具出现在每个人手中。当我们在尽情享受它带来的便利时,也正在接受它带给我们的尴尬。你正在用手机与她讲着那些肉麻的情话,突然,电池电量不足,一切就此结束。也许只有吃过“苦头”的人,才会真真切切地感受到延长电池使用寿命的重要性。下面笔者就介绍几招。     

Short Report： Cyclic patterns of incidence rate for skin malignant melanoma： association with heliogeophysical activity

Background: Our previous studies revealed cyclicity in the incidence rate of skin malignant melanoma (SMM; ICD9, Dx: 172) in the Czech Republic (period T=7.50～7.63 years), UK (T=11.00 years) and Bulgaria (T=12.20 years). Incidences com-pared with the sunspot index Rz (lag-period dT= 2, 4, 6, 10 or 12 years) have indicated that maximal rates are most likely to appear on descending slopes of the 11-year solar cycle, i.e., out of phase. We summarized and explored more deeply these cyclic variations and discussed their possible associations with heliogeophysical activity (HGA) components exhibiting similar cyclicity. Methods: Annual incidences of SMM from 5 countries (Czech Republic, UK, Bulgaria, USA and Canada) over various time spans during the years 1964～1992 were analyzed and their correlations with cyclic Rz (sunspot number) and aa (planetary geomagnetic activity) indices were summarized. Periodogram regression analysis with trigonometric approximation and phase-correlation analysis were applied. Results: Previous findings on SMM for the Czech Republic, UK and Bulgaria have been validated, and cyclic patterns have been revealed for USA (T=8.63 years, P<0.05) and Canada (Ontario, T=9.91 years, P<0.10). Also, various 'hypercycles' were established (T=45.5, 42.0, 48.25, 34.5 and 26.5 years, respectively) describing long-term cyclic incidence patterns. The association of SMM for USA and Canada with Rz (dT= 6 and 7 years, respectively) and aa (dT=-10 and 9 years, respectively) was described. Possible interactions of cyclic non-photic influences (UV irradiation, Schumann resonance signal, low-frequency geomagnetic fluctuations) with brain waves absorbance, neuronal calcium dynamics, neuro-endocrine axis modulation, melatonin/serotonin disbalance and skin neuro-immunity impairment as likely causal pathways in melanoma appearance, were also discussed. Conclusion: The above findings on cyclicity and temporal association of SMM with cyclic environmental factors could not only allow for better forecasting models but also lead to a better understanding of melanoma aetiology.     

植物性雌激素的生物学特性

植物性雌激素是一类广泛存在于植物中的即具有雌激素样又具有抗雌激素样活性的化合物，在治疗激素依赖性疾病中有广阔的应用前景．     

β-受体阻断药的心血管药理作用

主要从β受体阻断药的功能及分类为出发点,对β受体阻断药降血压的作用进行了阐述,分析该类药对机体的副作用及评价来引起注意.     

工业重整催化剂在低温下的环己烷脱氢性能

以环己烷—苯—氢气 (CBH贮氢系统 )为例 ,研究了低温下几种典型重整催化剂和自制 0 .5 %Pt/γ -Al2 O3催化剂在除Cl- 前后的环己烷脱氢性能 .结果表明 ,除Cl- 后这些催化剂在低温下的脱氢活性 ,尤其是脱氢稳定性得到了显著的改善 ,但其初脱氢活性和相应低温下的理论脱氢活性相比仍有很大差距     

金龙胆草化学成分的研究

对金龙胆草所含化学成分进行研究.利用硅胶柱层析、ODS柱层析等方法提取分离,利用核磁共振并结合薄层色谱分析确定各化合物结构,得到5种化合物,分别为苦蒿素、19-羟基-苦蒿素、大黄素、咖啡酸、槲皮素.19-羟基-苦蒿素为首次从该植物中分离得到.