不同施肥模式对下辽河平原水稻生态系统生产力及养分收支的影响

采用田间肥料试验,研究了不同施肥模式对稻田生态系统的生产力和养分收支的影响。结果表明:随养分配施均衡程度的增加,系统的生产力逐渐提高,其中氮磷钾处理的生产力最高;氮肥对水稻生产力的贡献最大(对生物量的贡献约20%,对籽实产量的贡献约34%),磷肥和钾肥的贡献相当;在水稻各部位对氮、磷、钾养分的吸收中,氮的吸收主要集中在籽实和秸秆中,磷的吸收则主要集中在籽实中,钾的吸收主要集中在秸秆中;在各施肥处理中,土壤全量养分和有机质的变化不大,而速效养分的变化较大,特别是速效磷库和速效氮库;单施化肥处理的土壤,其速效养分含量不高,而施有机肥处理土壤的速效养分含量较高,表明有机肥较有利于土壤养分的积累。

甘肃省苔类植物初步研究

通过对甘肃省所采集苔类植物标本的鉴定和统计整理,共报道苔类植物18科30属78种及变种,其中包括3个新记录科,分别为:扁萼苔科(Radulaceae)、魏氏苔科(Wiesnerellaceae)、带叶苔科(Pallavicinaceae),11个新记录属和35个新记录种;区系分析表明北温带成分占据优势(占总种数的43.24%),其次是东亚成分(占总种数的22.97%),甘肃省苔类植物区系具有明显的温带性质。

固定化微生物降解土壤中菲和芘的研究

Immobilized with PVA,sodium alginate and activated carbon,both Zoogloea sp. and Fusarium sp.strains could degrade phenanthrene and pyrene efficiently.The optimal carrier was made of 100ρ·g -1 L PVA,5 sodium alginateρ·g -1 L and 50 activated carbon ρ·g -1 L.The degradation rates of phenanthrene and pyrene in 10 days were 87.48% and 75.34% by the immobilized bacterium,37.04% and 20.85% higher than those by the free bacterium,and the rates in 15 days were 84.36% and 74.87% by the immobilized fungus,5.35% and 11.23% higher than those by the free fungus.

森林景观界面研究概况

文章对森林景观界面的概念、由来、分类、结构与功能等进行了介绍与论述,对森林景观界面与边缘效应的关系进行了阐明,特别对森林景观界面的生态过程研究进展作了概括。森林景观界面生态过程研究主要集中在以下几个方面:生物多样性研究、土壤水分、土壤养分、光照辐射与温度、风及其他领域。文章还对森林景观界面的未来研究方向与趋势作了展望:未来的森林景观界面研究将主要聚焦于界面的结构、功能及形成维持机制的研究,景观界面与气候变化的研究,景观界面的生态过程研究。

外来杂草入侵的化学机制

由外来杂草入侵引发的严重生态和经济问题已倍受关注 .外来杂草在新生境成功入侵 ,除了具备一些基本的生物生态学特征外 ,还应具备一些特有的入侵机制 .阐明外来杂草的各种入侵机制可以为入侵杂草的预测和控制提供科学依据 .外来杂草只有在新生境中与原产地生物种间的相互作用中取得优势 ,才能定植并扩增种群而成功入侵 .在这些外来杂草和原产地生物种间的相互作用关系中 ,化学关系是不可忽视的方面 .目前研究已经证实 :植物的化感作用在外来杂草成功入侵中发挥着重要的作用 .事实上 ,植物也可以通过合成和释放特定的化学物质防御或抑制新生境的动物、植物和微生物 .外来杂草入侵的化学机制涉及到植物化学生态学的各个方面 .因此 ,外来杂草的化学生态学特征应作为入侵种预测的重要指标之一 ,外来杂草入侵的化学机制应是今后重要的研究方向

中国多孔菌名录

本文中的多孔菌系指广义非褶菌目中具有孔状子实层体的种类,按照现代分类系统包括担子菌门中多孔菌目、锈革孔菌目、褐褶菌目、糙孢孔目、革菌目、糙孢革菌目和红菇目中孔状子实体的种类,还有伞菌目、阿太菌目、鸡油菌目和木耳目中个别属,如网孔菌属、胶孔菌属、榆孔菌属、牛排菌属和纵隔孔菌属等的种类。基于作者采集的1万余号标本和国内主要标本馆标本的研究,对中国多孔菌的种类进行了系统总结,目前有604种多孔菌发现于中国,多孔菌数量位居世界第一。对中国多孔菌的名称按新近研究成果和最新命名法规(维也纳法规)进行了订正。对121种新拟了汉语学名。

Five supramolecular compounds of water-soluble sulfonylcalix[4]arenetetrasulfonate showing two calixarene conformations

Five new compounds of sulfonylcalix[4]arenetetrasulfonate (SC4AS), [H7Na(H2O)(3)(SC4AS)(phen)(5)](H2O)(11.9) (1), [H6Mn(H2O)(4)(SC4AS)(phen)(5)] (H2O)(12.7) (2), [Cu-4(SC4AS) (phen)(6)] (H2O)(4.5) (3), {[Cu (2)(SC4AS) (bpy)(2)][Cu(bpy)(2)(H2O)](2)} (H2O)(6.6) (4), and {[Zn-2(SC4AS) (phen)(2)][Zn(phen)(2)(H2O)(2)](2)} (H2O)(7) (5) (where phen 1,10-phenanthroline and bpy = 2,2'-bipyridine), were synthesized by a hydrothermal method and structurally determined by single crystal X-ray diffraction. The SC4AS ligand adopts partial cone conformation in compounds 1 and 2 and 1,2-alternate form in compounds 3-5. According to the structural analysis and density functional theory (DFT) calculations, we suggest that the metal can affect the conformation of SC4AS.

Enhanced charge collection in polymer photovoltaic cells by using an ethanol-soluble conjugated polyfluorene as cathode buffer layer

We report enhanced polymer photovoltaic (PV) cells by utilizing ethanol-soluble conjugated poly (9, 9-bis (6'-diethoxylphosphorylhexyl) fluorene) (PF-EP) as a buffer layer between the active layer consisting of poly(3-hexylthiophene)/[6, 6]-phenyl C61-butyric acid methyl ester blend and the Al cathode. Compared to the control PV cell with Al cathode, the introduction of PF-EP effectively increases the shunt resistance and improves the photo-generated charge collection since the slightly thicker semi-conducting PF-EP layer may restrain the penetration of Al atoms into the active layer that may result in increased leakage current and quench photo-generated excitons. The power conversion efficiency is increased ca. 8% compared to the post-annealed cell with Al cathode.

The preparation of sol-gel materials doped with ionic liquids and trialkyl phosphine oxides for Yttrium(III) uptake

A new material (IL923SGs) composed of ionic liquids and trialkyl phosphine oxides (Cyanex 923) for Y(III) uptake was prepared via a sol-gel method. The hydrophobic ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate (C(8)mim(+)PF(6)-) was used as solvent medium and pore templating material. The extraction of Y(III) by IL923SGs was mainly due to the complexation of metal ions with Cyanex 923 doped in the solid silica. Ionic liquid was stably doped into the silica gel matrix providing a diffusion medium for Cyanex 923, and this will result in higher removal efficiencies and excellent stability for metal ions separation. IL923SGs were also easily regenerated and reused in the subsequent removal of Y(III) in four cycles.

离子液基萃取金属离子的研究进展

室温离子液体作为一种新型绿色溶剂,因其具有不挥发、不易燃等重要特性,故近年来在各种金属离子液/液萃取领域的应用日益受到关注。本文系统评述了离子液基萃取金属离子的分配规律、萃取机理、缺陷和克服方法,并展望了该分离方法在环境分析化学领域的应用前景。