筛选与杨树抗云斑天牛基因连锁的RAPD标记

筛选与杨树抗云斑天牛基因连锁的ＲＡＰＤ标记王京兆，王斌，卞学瑜，韩一凡（中国科学院遗传研究所北京１００１０１）（中国林业科学研究院林业研究所北京１０００９１）关键词杨树，云斑天牛，ＲＡＰＤ，多态性产物植物抗虫基因工程是当前比较活跃的研究领域，但真正能...     

林业科技论文写作格式及规范

简要概述了林业科技论文规范化写作格式，包括：论文类型、中文摘要的写法及注意事项、正文的写法、图表的使用、法定计量单位的使用、结论和参考文献等，供读者参考。     

二灰碎石抵抗冻融破坏作用的研究

针对黑龙江省寒冷的气候特点,对已建公路二灰碎石半刚性基层的使用状况进行调查,分析破坏的原因,并与研究成果进行比较。利用低温实验室模拟自然环境进行冻融循环试验,确定二灰碎石在一定的冻融循环作用下的强度衰减系数,为冻融循环作用下的基层设计提供有一定可靠度的基层强度设计值,保证基层在使用周期内具有一定的冻融耐久性,从而可以提高道路使用质量和延长道路使用寿命,降低维护费用。     

山东黄河沿岸防护工程景观建设分析

通过对山东黄河沿岸防护工程、自然环境、人文历史等资料的简要介绍,从景观、生态、游憩的角度对山东黄河沿岸景观建设现状进行分析,同时对其景观规划建设原则提出相应的建议。     

达里诺尔国家级自然保护区游憩服务功能价值评估

对自然资源价值的评估是监测自然资源的保护与可持续开发利用效果的理论基础。文章以内蒙古赤峰市克什克腾旗达里诺尔国家级自然保护区为研究对象,运用旅行费用法对达里诺尔国家级自然保护区的游憩服务功能进行了价值评估,计算出其游憩总价值为7517万元。这一结果可为达里诺尔国家级自然保护区的资源决策和资源补偿提供一定的参考。     

新体制下我国城市交通规划工作者所面临的任务

市场经济的迅速发展,推动了城市的发展。作为城市规划重要组成部分的交通规划工作内容亦日益广泛。由于我国的交通规划学科是在计划经济模式下发展起来的,而市场经济的兴起不仅使整个社会生活面貌发生了巨变,也给交通规划创造了新的课题。本文就此问题探讨了城市交通规划师在社会主义市场经济条件下应当注意的一些问题。     

山西太岳山辽东栎夏季树干液流通量研究

树干液流指蒸腾在植物体内引起的上升液流。土壤液态水进入根系后 ,由茎输导组织向上运送达冠层 ,经由气孔蒸腾 (包括角质层及皮孔蒸腾 )转化为气态水扩散到大气中去。根部吸收的水分有 99 8%以上消耗在蒸腾上 (王沙生等 ,1 991 )。通过精确测算茎流量 ,可以基本确定植株蒸腾失     

The pH change in rhizosphere ofPinus koraiensis seedlings as affected by different nitrogen sources and its effect on phosphorus availability

Root mat method described by Kuchenbuch and Jungk was used to study the rhizosphere processes. The experiment was carried out on two years oldPinus koraiensis seedlings. Soil samples collected from the upper 20-cm soil layer in Changbai Mountain were treated with three different forms of nitrogen fertilizers: NO₃ ⁻−N, NH₄ ⁺−N and NH₄NO₃. The results showed that the soil pH and available P near the roots were all lower than in the bulk soil in control treatment. NH₄ ⁺−N application greatly decreased the soil pH near the roots compared to the control treatment and promoted the absorption of phosphorus, which led to a more remarkable depletion region of available P. On the contrary, the rhizosphere soil pH was higher than in the bulk soil in treatments with NO₃ ⁻−N and retarded the P absorption, which led to a nearly equal available P contents to the bulk soil. In treatment with NH₄NO₃, the rhizosphere soil pH was only a little lower than that in the control treatment and its effects on P absorption is mediate between the treatments with NH₄ ⁺−N and NO₃ ⁻−N. Foundation item: This paper was supported by National Natural Science Foundation of China (Grant No. 30170167). Biography: Chen Yong-liang (1969-), male, Ph. Doctor, lecture of Northeast Forestry University, Harbin 150040, Post-doctor in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P.R. China. E-mail: ylchin@sohu.com Responsible editor: Seng Funan     

桥面垫层混凝土破坏与补强技术

该文在旧桥改造维修中,对桥面垫层混凝土破坏机理及补强技术提出了一些看法和措施建议,可供工程实际应用参考。     

The pharmacokinetical study of plant alkaloid tetrandrine with a simple HPLC method in rabbits

A simple HPLC method was developed to quantify rabbit plasma tetrandrine (Tet) with propranolol (Pro) as internal standard. Based on the established method Tet and Pro were eluted at 7.1 and 12.0 min, respectively. It was shown that the concentration-time data of Tet fit the classical two-compartment model, no matter the drug was administered intravenously or orally to rabbits. The values of AUC_0 → ∞, clearance (Cl_0 → ∞), volume of distribution (Vd), and elimination half-life (t_1/2β) of Tet were 59861.149 ± 26962.196 μg/L ? min, 0.503 ± 0.173 L/min/kg, 179 ± 76.185 L/kg, and 283.808 ± 162.937 min for intravenous injection of 5 mg/kg, or 18986.217 ± 7462.308 μg/L ? min, 0.805 ± 0.267 L/min/kg, 110.284 ± 94.176 L/kg, and 732.919 ± 847.32 min for gavage administration of 10 mg/kg , respectively. The results indicate that Tet displays a limited absorption in intestinal tract, even though it has a favorable pharmacokinetic profile after oral or intravenous administration.