茶秆竹生物量模型研究

在标准地调查的基础上，应用多种数学模型对茶秆竹各器官生物量进行相关性分析，建立了茶秆竹各器官间的咽归模型。可用于一定立地条件下的茶秆竹的生物量估测。     

住宅卫生间渗漏的原因和控制措施

本文分析了住宅卫生间渗漏原因,并提出了预防措施与治理办法。     

北京低山地区土壤酶活性与土壤理化性质的关系

通过对北京低山地区土壤的理化性质和脲酶、过氧化氢酶以及多酚氧化酶的分析，探讨了供试土壤中３种酶活性状况及其与土壤理化性质的关系。研究结果表明：３种土壤酶活性均表现出随土壤深度增加而降低的规律性；３种土壤酶活性间具有良好相关性，显示了３种酶在土壤生物化学过程中的共性关系；土壤酶活性同多种土壤性质呈现良好相关性，其中，土壤有机质含量和土壤全氮量对酶活性影响最大。     

Simulating responses of Northeastern China forests to potential climate change

IntroductionItissurethatpresentelevatiollsofCO2a11dotllergrcc11-housegasesinducedbyhumanactivitiesaren1akli1gglobalclimategothroughinexperielICedcl1anges(Scl1le-subgerl987).Thecurrentquasi-equilibriulllstatesofbio-sphereecosystCm,esPeciallyterrestrialecosystems,wouldbebrokenbecausetl1estructure,fu11ction,distributio11andtlledynamicsofanyexistedecosystemsareIberesultsoflongtermadaptationofbio-systemtocurrentclin1ate.Theec()systemsdistributedinhighlatitlldeareawouldhavemuchbiggerchai1ge(Bona…     

HPLC法同时测定皖贝母两种生物碱成分含量

建立皖贝母生物碱测定方法。采用高效液相色谱仪-蒸发光散射仪对皖贝母中的贝母甲素、贝母乙素含量进行测试。高效液相色谱仪-蒸发光散射仪测试贝母甲素、贝母乙素结果分别为0.203~0.251mg/mL、0.472~0.508mg/mL平均加样回收率分别为98.74%及100.34%,RSD分别为1.08%及0.95%。本法准确可靠,重现性好,可用于皖贝母的质量控制。     

贵州亚热带地区的野生香花类观赏植物资源

贵州亚热带地区有野生香花类观赏植物23科39属（1亚属）70种（含新分布种和变种）。分布垂直带谱为海拔160－1000m。花色分为白色、黄色、紫色、黄绿色和红色5类。生境类型分为森林湿地型、疏林灌丛型、山坡草地型和附生型，以森林湿地型和疏林灌丛型的种类居多。银钟花、大叶木莲、尖叶木、云川醉鱼草、紫萼、香槐、两粤黄檀、单性木兰、苍白秤钩风和扭肚藤处于濒危状态。     

Cucubalugenin A, a new triterpenoid from Cucubalus baccifer.

A new triterpenoid, cucubalugenin A (1), has been isolated from the whole plant of Cucubalus baccifer. Its structure was elucidated by spectral methods.     

Relationships of climate change and tree ring of Betula ermanii tree line forest in Changbai Mountain

Based on the tree-ring growth characteristics of Erman＇s birch （Betula ermanii charm.） and the relationships between it and climatic ）＇actors at elevation of 1950m, the sensitivity of tree lines in Changbai Mountain to climatic factors was assessed. The results indicated tree line forest in Changbai Mountain had an obvious sensitivity to climate factors. However, difference from other study sits is that the main climatic control factor on tree-ring growth was not current growth season temperatures, as might be expected, but previous winter and current March temperature. Although the precipitation in the region was quite abundant, the tree-ring growth was still significantly correlated with the precipitation during previous winter and current spring. Additionally, climatic factors which influenced the Erman＇s birch growth were not the yearly variables, but seasonal and monthly variables. Therefore, the reported increase in yearly mean temperature and total yearly precipitation since 1980s was not responded by sustained increase in ring widths in recent decades.     

Ultrastructural and Extracellular Protein Changes in Cell Suspension Cultures of Populus euphratica Associated with Low Temperature-induced Cold Acclimation

Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A cell suspension culture was initiated from callus derived from plantlets of Populus euphratica. Cold acclimation was induced (LT50 of-17.5 ℃) in cell suspension at 4-5 ℃ in the dark for 30 days and the freezing tolerance increased from LT50 of-12.5 ℃ in nonacclimated cells to LT50 of-17.5 ℃ in cold-acclimated cells. Microvacuolation, cytoplasmic augmentation and accumulation of starch granules were observed in cells that were cold-acclimated by exposure to low temperatures. Several qualitative and quantitative changes in proteins were noted during cold acclimation. Antibodies to carrot extracellular (apoplastic) 36 kD antifreeze protein did not cross react on immunoelectroblots with extracellular proteins in cell suspension culture medium of Populus euphratica, indicating no common epitopes in the carrot 36 kD antifreeze protein and P euphratica extracellular proteins. The relationship of these changes to cold acclimation in Populus euphratica cell cultures was discussed.     

青钱柳研究进展

青钱柳是我国独有珍稀植物。对青钱柳的开发利用价值及国内外的研究现状进行概述,并就青钱柳开发利用及研究方向进行了探讨。