流域生态系统管理研究

本文在对流域生态系统及生态系统管理的概念进行阐述的基础上 ,指出流域生态系统管理是流域开发和流域社会经济可持续发展的有效途径 ,并对流域生态系统管理中的热点问题进行了论述

溪流粗木质残体的生态学研究进展

粗木质残体 ( CWD)是森林或溪流生态系统中残存的超过一定直径大小的站杆、倒木、枝桠及根系等死木质物的总称 ,溪流 CWD对于溪流生态系统的稳定、水生生物多样性、河槽形态及其变化过程有着重要的作用。对溪流 CWD的产生和分类 ,溪流 CWD贮量、分布和动态 ,以及溪流 CWD的功能和管理分别进行了总结。并指出应尽快在国内开展溪流CWD的研究和管理。

江汉平原农田生态系统B素循环及平衡分析

以江汉平原农田生态系统为研究对象 ,通过对当地农户小麦 -稻、稻 -稻、油菜 -大豆、油菜 -花生、小麦 -芝麻、小麦 -棉花、青椒 -大白菜、萝卜 -茄子 8种种植模式农田 B素的输入、输出和平衡研究。结果表明 ,B素的输出主要是作物收获 ,占 B素总输出量的 4 4.8%～ 6 4 .7% ;其次是淋溶损失占 2 5 %～ 4 1 .4 % ,B素流失占总输出量的 9.2 %～ 1 7.4 %。B素的主要输入途径是施有机肥和 B肥 ,此外 ,降雨也是 B素输入的主要途径 ,该区域各种类型农田生态系统

湖北地区稻田甲烷排放量及控制措施的研究

通过田间试验 ,比较研究了施用有机肥 ,硫铵 ,包膜复合肥 ,尿素 +淹灌 ,尿素 +间歇落干5种处理对早、晚稻甲烷排放量的影响。测得5种处理的早、晚稻甲烷平均排放通量为:早稻4.39～15.6mg/m2·h ,平均值8.03mg/m2·h ;晚稻5.65～22.0mg/m2·h,平均值10.7mg/m2·h。从各种措施的效果来看 ,5种处理间存在显著差异 ,其中以施包膜复合肥处理效果最佳 ,与施有机肥比较 ,年甲烷排放总量减少73.4 %。包膜复合肥处理比施尿素处理年甲烷排放总量减少48.6 %。

饲料中土豆蛋白替代鱼粉对虹鳟摄食率、消化率和生长的影响

通过生长试验探讨了饲料中土豆蛋白浓缩物替代鱼粉后对虹鳟摄食率、消化率、生长和饲料利用的影响。对照饲料全部以鱼粉为蛋白源，其它饲料分别含土豆蛋白2．2％，5．6％，8．9％和11．1％，另一饲料含5．6％土豆蛋白和1．7％蛋氨酸。在12℃下饲养4周，试验结果表明，随着饲料中土豆蛋白使用比例的增加，虹鳟的摄食率下降，饲料的干物质、蛋白和灰分的表观消化率上升，脂肪的表观消化率无显著影响；当饲料中含5．6％土豆蛋白时，虹鳟生长率明显下降；当饲料中土豆蛋白含量为8．9％，生长率和饲料效率均下降。饲料中添加蛋氨酸后，

太平湖水库藻类演替与营养侦别研究

本文报告了1992～1993年间对安徽省太平湖水库藻类的演变以及库水营养侦别试验的研究结果。与1985～1986年资料相比,整个水库的藻类种类多样性下降,总种类数由175种降为112种,减少了1/3。藻类种类小型化现象十分明显,相隔6～7年,小型藻类的种类及其数量越来越多,单个藻细胞鲜重的平均值在敞水区和库湾区分别减少了63.6％和75.4％;平均细胞密度则分别增长了3.6和5.6倍;生物量的变化不大,增长不足1倍。营养侦别试验结果表明,磷仍然是该水库的主要限制因子,库水的藻类生长潜力约为对照培养基的1/

草鱼胸腺组织学的研究

草鱼胸腺位于鳃腔背上角,紧贴在鳃腔膜之下,突起部分伸入到下颞凹,整个胸腺形态形似菱角。其组织结构可分为外区、中区和内区。中区和内区主要由淋巴细胞和网状上皮细胞构成,在组织结构上分别类似于高等脊椎动物胸腺的皮质和髓质区。胸腺淋巴细胞可分大、中、小三型,小淋巴细胞约占78％,中淋巴细胞约占15％,大淋巴细胞约占4％。在Ⅰ龄草鱼,每毫克胸腺约有3.6×10~6个胸腺淋巴细胞,Ⅱ龄草鱼约为2×10~6。Ⅰ至Ⅱ龄草鱼胸腺重量明显地随鱼龄增加,Ⅱ龄以上草鱼胸腺重量变化无规律,成鱼胸腺表现出明显的退化。草鱼胸腺除年龄性

中华血簇虫的生活史研究(复顶门:孢子纲) Ⅱ.中华血簇虫在中华鳖中的发育

中华血簇虫在其无脊椎动物寄主中的发育已另有文描述。这里报道的是中华血簇虫在中华鳖中的发育。这一时期包括三个阶段:组织细胞内裂体增殖、深部血红细胞内的裂体增殖和外周血红细胞内的裂体增殖。组织细胞内裂殖体产生14—32个裂殖子。深部血红细胞内的裂殖体分为两类:一类是X裂殖体,它产生14—18个小裂殖子;另一类是Y裂殖体,它产生4—6个大裂殖子。外周血红细胞内的初期裂殖体可产生多至14个裂殖子,而随后的裂体增殖却产生越来越少的裂殖子,且裂殖体和裂殖子的大小也渐趋变小。外周血晚期的裂殖体只形成2个裂殖子。配子母细

四川西南部小相岭东坡更新世冰川地貌与冰川沉积特征的初步研究

该地更新世冰川地貌类型有三级冰斗,槽谷、角峰、刃脊、4—6道侧碛堤、2—3道终碛垅等。冰碛成分全部来自冰川作用区,组构不发育。冰碛中砂含量较高,粉砂含量较少。电镜观察到石英砂上有压坑、“阶步”和擦痕。不同时代冰碛物的化学元素迁移不很明显。伊利石是冰碛中的主要粘土矿物。

Peridiniopsis niei sp nov (Dinophyceae), a new species of freshwater red tide dinoflagellates from China

A new freshwater phototrophic species of the dinoflagellate genus Peridiniopsis, P. niei sp. nov., is described based on morphology. The new species appeared during spring with densities up to 1.48 x 10(7) cells L-1 in some tributaries and gullies of Three Gorge Reservoir and Lake Donghu, China, forming red tides. Peridiniopsis niei is a cyst-producing freshwater dinoflagellate that belongs to the group Penardii. The plate tabulation is po+x+4 '+0a+6 ''+5c+5s+5 '''+2 '''' and the plate pattern is symmetric. The cells of P. niei are pentagonal in ventral view, the epitheca is larger than the hypotheca, making up about 2/3 the length of the cell. Plate 3 ' is hexangular. The closest species to P. niei is P. penardii (Lemmermann) Bourrelly, but cells of the former are pentagonal, very compressed dorsoventrally, and the hypotheca is truncated with one transparent, robust spine on each antapical plate.

Reproductive seasonality and maturity of male Neophocaena phocaenoides asiaeorientalis in captivity: A case study based on the hormone evidence

To provide hormone evidence on reproductive seasonality and maturity of the Yangtze finless porpoise, the authors monitored the monthly variations of serum reproductive hormones of a male Yangtze finless porpoise in captivity via radioimmunoassay from 1997 to 2003. It was demonstrated that the immature animal had a serum T level of 28-101ngdL -1 (6552ngdL -1 ), reached puberty with the serum T concentration ranging between 250 and 590ngdL -1 (390130ngdL -1 ), and attained reproductive maturity when the serum T level went beyond 1120180ngdL -1 in the breeding season. The body length growth of the animal showed a pattern similar to the serum T variations during its adolescent period from the age of 4 to 6 years. Moreover, the serum T concentration of the male porpoise exhibited significant seasonal variations, indicating that its breeding season may start as early as March and end as late as September.

Effects of solar UV radiation on morphology and photosynthesis of filamentous cyanobacterium Arthrospira platensis

To study the impact of solar UV radiation (UVR) (280 to 400 nm) on the filamentous cyanobacterium Arthrospira (Spirulina) platensis, we examined the morphological changes and photosynthetic performance using an indoor-grown strain (which had not been exposed to sunlight for decades) and an outdoor-grown strain (which had been grown under sunlight for decades) while they were cultured with three solar radiation treatments: PAB (photosynthetically active radiation [PAR] plus UVR; 280 to 700 nm), PA (PAR plus UV-A; 320 to 700 nm), and P (PAR only; 400 to 700 nm). Solar UVR broke the spiral filaments of A. platensis exposed to full solar radiation in short-term low-cell-density cultures. This breakage was observed after 2 h for the indoor strain but after 4 to 6 h for the outdoor strain. Filament breakage also occurred in the cultures exposed to PAR alone; however, the extent of breakage was less than that observed for filaments exposed to full solar radiation. The spiral filaments broke and compressed when high-cell-density cultures were exposed to full solar radiation during long-term experiments. When UV-B was screened off, the filaments initially broke, but they elongated and became loosely arranged later (i.e., there were fewer spirals per unit of filament length). When UVR was filtered out, the spiral structure hardly broke or became looser. Photosynthetic 0, evolution in the presence of UVR was significantly suppressed in the indoor strain compared to the outdoor strain. UVR-induced inhibition increased with exposure time, and it was significantly lower in the outdoor strain. The concentration of UV-absorbing compounds was low in both strains, and there was no significant change in the amount regardless of the radiation treatment, suggesting that these compounds were not effectively used as protection against solar UVR. Self-shading, on the other hand, produced by compression of the spirals over adaptive time scales, seems to play an important role in protecting this species against deleterious UVR. Our findings suggest that the increase in UV-B irradiance due to ozone depletion not only might affect photosynthesis but also might alter the morphological development of filamentous cyanobacteria during acclimation or over adaptive time scales.

Xenobiotics removal from polluted water by a multifunctional constructed wetland

Removal efficiencies on xenobiotics from polluted water in a twin-shaped constructed wetland consisting of a vertical flow chamber with the crop plant Colocasia esculenta L. Schott and a reverse vertical flow one with Ischaemum aristatum var. glaucum Honda, were assessed by chemical analysis and bioassays. After a four-month period of application, removal efficiencies of the applied pesticides parathion and omethoate were 100%, with no detectable parathion and omethoate in the effluent. For the applied herbicides, the decontamination was less efficient with removal efficiencies of 36% and 0% for 4-chloro-2-methyl-phenoxyacetic acid and dicamba, respectively. As shown by toxicity assay with duckweed Lemna minor L., growth retardation may occur if the water treated for herbicide removal is used in irrigation of sensitive cultivars in agriculture or horticulture. In contrast to I. aristatum var. glaucum Honda, the crop C esculenta L. Schott has a high yield in biomass production as a valuable source of renewable energy. (C) 2002 Elsevier Science Ltd. All rights reserved.

低温晶片键合的方法

一种低温晶片键合的方法，其特征在于，包括如下步骤:步骤1:将单面抛光的Si外延片和InGaAs外延片用有机溶剂清洗，去除表面的有机物，该InGaAs外延片的底层为InP衬底;步骤2:再分别对Si外延片和InGaAs外延片进行表面处理，以去除表面的杂质离子、除碳和亲水性处理;步骤3:将Si外延片和InGaAs外延片进行贴合，贴合后的晶片对置于真空键合机内键合，进行第一次热处理，以驱除键合界面的水气;步骤4:对键合后的晶片进行减薄;步骤5:再对减薄后的晶片进行第二次热处理;步骤6:最后腐蚀掉键合晶片的InP衬底，完成低温晶片键合的制作。

一种单模高功率垂直腔面发射激光器及其制作方法

本发明是一种单模高功率垂直腔面发射激光器，属半导体光电子领域。其特征在于，包括P型电极(1)，P型Si衬底(2)，金属键合层(3)，P型分布布拉格反射镜(DBR)(4)，氧化限制层(5)，有源区(6)，N型DBR(7)，SiO2掩膜(8)，聚酰亚胺或苯并环丁烯(BCB)(9)，N电极(10)，光子晶体(11)，出光窗口(12)。在该结构的垂直腔面发射激光器中引入光子晶体，可增大氧化孔径，提高单模输出功率，同时采用键合技术将传统VCSEL外延片转移到Si衬底上和采用底部出光的设计，便于拉近VCSEL外延片有源区与Si衬底的距离，改善器件热学特性，进一步提高单模输出功率。