水泵选型专家系统研究与开发

在对水泵选型方法、判别准则、评价模型等分析研究的基础上 ,建立了泵产品样本和水力模型数据库 ,研制开发了水泵选型专家系统。该系统具有水泵选型、综合评价、装置推荐等功能 ,是一个稳定、开放的系统 ,有较大应用价值     

春石斛兰类原球茎分化过程中抗氧化酶活性和可溶性蛋白的变化

以春石斛兰(Dendrobium nobileSw.)为试材,研究了类原球茎在分化芽和根系发生过程中抗氧化酶系统中多种酶活性及可溶性蛋白的变化规律。结果表明,在分化过程中抗坏血酸过氧化物酶(APX)、愈创木酚过氧化物酶(POD)、多酚氧化酶(PPO)和过氧化氢酶(CAT)的活性和可溶性蛋白含量均呈现先降后升的趋势;超氧化物歧化酶(SOD)活性则呈现先升后降的变化。对过氧化物酶同工酶和可溶性蛋白进行SDS-PAGE电泳发现,在分化过程中均有新谱带的产生或原有谱带的消失。     

新疆地区牧户对退牧还草政策的认知程度及其影响因素调查分析

[目的]选取新疆自治区布克赛尔县为研究的样本区,对该区牧户退牧还草政策进行调查分析,以期为该地区草原生态环境与社会经济的协调发展提供科学依据。[方法]通过问卷调查的方式对样本区150户牧民参与退牧还草工程的情况进行调查,并采用最优尺度分析法对问卷数据进行建模分析。[结果]牧户的文化程度、家庭收入水平、从退牧还草政策中的获利程度和对草场退化的认知程度对牧户参与退牧还草政策的积极性存在显著正向影响;而牧户的年龄、家庭人口规模对牧户参与退牧还草的积极性存在显著负向影响。[结论]在退牧还草政策影响下,文化程度和家庭收入水平高的、从政策中获益多的牧民更愿意调整生产结构、转变生产方式;牧户参与退牧还草积极性的高低主要取决于参与退牧还草能否能获利和是否有能力承担转变后的风险。     

Variability of communities and physiological characteristics between free-living bacteria and attached bacteria during the PAH biodegradation in a soil/water system

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) via free-living and attached micro-organisms in soil/water systems was observed in order to examine the variability in the community dynamics and physiological profiles of the micro-organisms. As determined by fluorescence in situ hybridization (FISH), the Domain Bacteria, consisting of three phyla α-, β- and γ-Proteobacteria, reached 41.27–56.05% of all organisms in the soil/water system for PAH biodegradation. Among the free-living species, Proteobacteria, including Brevundimonas (Pseudomonas) diminuta, Caulobacter spp., Mycoplana bullata, Acidovorax spp. and Pseudomonas aeruginosa were found to be dominant—making up 93.51–99.80% of the population—and therefore seem to be associated with PAH biodegradation. Total plate count numbers and the count of Pseudomonas sp. present in the free-living population increased to between 10³ and 10⁶ CFU ml⁻¹ when clay with very low organic matter content was used as the matrix for PAH degradation. However, total plate count microbial numbers increased to only 10¹–10² CFU ml⁻¹ using natural soil from Taichung containing 1.883% organic matter. The soil organic content (SOM) seemed to affect the mass transfer of PAH in soil, leading to the difference in PAH biodegradation. Two different approaches, which included community-level physiological profiling (CLPP) and ectoenzymatic activities, were used to explain the functional diversity between free-living and attached bacteria. The free-living and attached bacterial communities from the clay system showed proportionately greater differences using CLPP. Relatively high levels of esterases, aminopeptidases and some specific glycolysis-gluconeogenesis enzymes gave an identifiable correlation with PAH biodegradation. The differences in bacterial composition, numbers and physiological characteristics show that free-living and attached micro-organisms may play different biochemical roles in PAH degradation in soil.     

Antioxidant properties of methanolic extracts from several ear mushrooms.

Five kinds of ear mushrooms are commercially available in Taiwan, including black, red, jin, snow, and silver ears. Methanolic extracts were prepared from these ear mushrooms, and their antioxidant properties were studied. For all methanolic extracts from ear mushrooms, the antioxidant activities in the 1,3-diethyl-2-thiobarbituric acid method were moderate (38.6 approximately 74.6%) at 1.0-5.0 mg/mL. Methanolic extracts from red, jin, and snow ears showed excellent antioxidant activities in the conjugated diene method at 5.0 mg/mL. At 5.0 mg/mL, reducing powers of methanolic extracts were in the descending order of snow > black approximately red approximately jin > silver ears. The scavenging effect of methanolic extracts from ear mushrooms on 1,1-diphenyl-2-picrylhydrazyl radicals was excellent except for that from silver ears. Ear mushroom extracts were not good scavengers for hydroxyl free radicals but were good chelators for ferrous ions. Naturally occurring antioxidants, including ascorbic acid, tocopherols, and total phenols, were found in the methanolic extracts. However, beta-carotene was not detected. Total antioxidant components were 15.69, 30.09, 27.83, 49.17, and 31.70 mg/g for black, red, jin, snow, and silver ears, respectively.     

高产水稻土结构特性的初步研究

随着稻、麦的持续高产,高产稳产水稻土的土壤条件日益受到重视,不少单位进行了专门研究(上海市农业科学院土肥植保研究所土壤组,1975;广东省农业科学院土肥所土壤组,1976;中国科学院南京土壤研究所苏南调查组,1977).但研究的内容多偏重于土壤的农业化学性状或土壤形态的描述,而较少进行土壤结构性的研究.     

脂肪组织RNA提取的三种方法比较与改进

脂肪组织单位体积细胞数少,且单位细胞富含脂类RNA含量相对较少（Mersmann,2002）,这增加了从脂肪组织提取RNA的难度.本研究以脂肪组织为材料,比较了几种商品化的总RNA提取试剂盒,优化和改进某些提取步骤,从而得到了符合实验要求的总RNA.     

糠醛渣生态肥对风沙土理化性质和茄子效益的影响

采用田间试验方法,研究了糠醛渣生态肥对河西内陆灌区风沙土改土培肥效应和茄子效益的影响。结果表明:糠醛渣生态肥原料间的效应是:茄子专用肥糠醛渣5406生物菌肥,糠醛渣生态肥配方比例为:5406生物菌肥0.0103:茄子专用肥0.1291:糠醛渣0.8606。施用糠醛渣生态肥与传统化肥比较,风沙土体积质量、pH、EC和可溶性盐分别降低了13.85%、1.07%、6.22%和6.92%;Hg、Cd、Cr和Pb离子分别降低了21.21%、40.00%、18.70%和21.94%;总孔隙度、团聚体和饱和持水量分别增加了13.35%、16.98%和13.35%;CEC、有机质、碱解氮、速效磷、速效钾、有效锌和有效钼分别增加了19.20%、25.93%、0.29%、1.89%、0.17%、2.08%和8.33%;真菌、细菌和放线菌分别增加了59.00%、41.94%和24.32%;蔗糖酶、脲酶和磷酸酶分别增加了57.51%、5.88%和10.35%;茄子单果重、单株果重、产量和施肥利润分别增加了5.27%、5.35%、3.01%和0.51×104元/hm~2。糠醛渣生态肥施用量与风沙土总孔隙度、团聚体、饱和持水量、有机质、速效养分和茄子产量呈显著的正相关关系;与体积质量、pH呈显著的负相关关系;糠醛渣生态肥施用量与茄子产量间的线性回归方程为y=51.2300+1.5151x–0.0408x2,经济效益最佳施用量为17.40 t/hm~2,茄子理论产量为65.24 t/hm~2。在风沙土上施用糠醛渣生态肥,有效的改善了土壤理化性质和生物学性质,提高了土壤有机质和番茄产量。     

碳酸钙和根际作用对酸性红壤解磷微生物丰度的影响

选用玉米品种郑单958为试验材料,设置不添加碳酸钙(CK)、每千克土添加0.3g碳酸钙(Ca-0.3)和0.5g碳酸钙(Ca-0.5)3个碳酸钙处理,以相应处理未种植物土壤为非根际对照土壤,研究了碳酸钙和根际作用对酸性红壤磷酸酶活性及解磷微生物相关功能基因phoC和phoD丰度的影响。结果表明:碳酸钙添加能有效改善玉米生长,促进地上部氮、磷、钾和钙的吸收。土壤酸性磷酸酶(ACP)活性显著高于碱性磷酸酶(ALP)活性,表明酸性土壤中ACP在矿化有机磷方面占主导地位。根际土壤ACP、ALP活性和phoD基因拷贝数均显著高于非根际,而仅Ca-0.5处理ALP活性和phoD基因拷贝数显著高于CK,说明根际效应强于碳酸钙处理。phoC基因拷贝数与土壤铵态氮、硝态氮含量存在显著相关性,ALP活性和phoD基因拷贝数与土壤pH及铵态氮、硝态氮、有效磷、交换性钙含量均存在显著相关性。可见,碳酸钙和根际作用均影响酸性土壤解磷微生物功能和丰度,但根际效应更加明显,这些作用与土壤理化因子的改变密切相关。     

填埋复垦侵蚀沟的导排水功能和秸秆腐解速率

秸秆填埋复垦技术主要用于修复东北地区耕地中的侵蚀沟，研究复垦后原沟道的导排水能力以及秸秆的腐解速率，旨在为沟毁耕地修复提供科学依据。该研究在黑龙江省海伦市光荣村选取一条复垦后的侵蚀沟为试验区，对土壤入渗能力、渗井入渗能力、秸秆层的持水能力、复垦后的土体排水能力系统测定分析，评价复垦后的导排水能力；对填埋不同年限的秸秆取样分析，评价秸秆腐解速率。结果表明：1）复垦后原沟道位秸秆层储水量为463 kg/m3，雨季产生径流能够完全被秸秆层储存，复垦后耕地能承受44～80 mm/h的均匀降雨，95%的地表汇流转为地下径流，大大减少径流对地表的冲刷，实现了变地表径流为地下导排水，复垦后未二次冲刷成沟。2）秸秆捆的厚度平均每年下降1.4 cm，秸秆层下降部分可被春季翻耕以及雨季汇流带来的泥沙沉积填充，复垦后原沟道位未出现塌陷。3）经过20 a的填埋，秸秆不同组分的腐解速率不同，其中半纤维素与纤维素腐解较快，木质素几乎不发生腐解，其占比由26.8%上升至38.8%。填埋的秸秆长期处于厌氧环境，且被水浸泡，约半年处于冻结状态故腐解缓慢。秸秆填埋侵蚀沟，可以修复沟毁耕地，实现复垦和地块的完整，可广泛用于东北黑土区约20万条耕地中侵蚀沟的修复。