多级沉淀与生物净化结合模式的水质净化特征分析

对北京市一企业园区一处4个串联水池(A-D池)的多级沉淀与生物净化相结合的净化系统的水样进行了实地采样和水质分析,测定了pH、COD、TN、NH4+-N、NO2--N等5项水质指标。结果表明,各项主要污染指标去除率为68.9%~87.6%,净化后水质清洁,达到地表环境水质量标准Ⅱ类水质标准,净化后的水体可用于一般景观水体的补水。物理沉淀与生物净化具备协同作用,其中A、B池沉淀作用更明显,并主要针对TP净化,C、D池生物净化作用更明显,并主要针对COD和N类污染。但两类净化作用表现并不独立,沉淀具初期快速净化作用,生物净化具彻底净化作用。     

红豆杉多糖的提取与结构初探

红豆杉枝叶经热水浸提、浓缩、醇沉、透析等工序制得一种红豆杉多糖,采用SephadexG-100凝胶渗透法测定分子质量,采用气相色谱法测定其单糖组成,并测定了不同纯度红豆杉多糖的红外光谱。所得红豆杉多糖分子质量约为59.2 ku,可视为由约365个糖残基构成的高分子化合物,其单糖残基鼠李糖、阿拉伯糖、甘露糖、葡萄糖、半乳糖数量比约为4∶6∶1∶1∶4。该红豆杉多糖分子结构中含有普通单糖、糖醛酸或氨基酸残基等,单糖主要以吡喃环形式存在、通过β-(1,3)苷键结合形成一种糖蛋白缀合物,Sevag法处理不能完全除去分子中的肽链。     

转基因抗虫玉米对亚洲玉米螟的抗性评价

采用田间人工接虫鉴定方法,根据玉米抗螟性田间鉴定评价标准,研究转基因玉米Bt799和NC6304YGRR对亚洲玉米螟的抗性.心叶期接虫试验结果表明,以食叶级别作为评价参数,2种转基因玉米对亚洲玉米螟具有良好的抗性,食叶级别均为1级;2种非转基因玉米食叶级别均大于7级.吐丝期接虫试验结果表明,以单株虫孔数、单株活虫数、单株隧道个数及单株隧道长度作为评价参数,2种转基因玉米对亚洲玉米螟抗性均显著高于各自对应的非转基因玉米.转基因抗虫玉米Bt799和NC6304YGRR田间抗虫效果良好,均能保护玉米在整个生育期内不受亚洲玉米螟危害.     

亚洲玉米螟自然种群数量变动研究

通过虫期生命表方法,对亚洲玉米螟自然种群数量变动进行了Var-ley-Gradwell K-图示分析和Morris-Watt相关回归分析。结果表明影响亚洲玉米螟自然种群数量变动的关键虫期,1代为低龄幼虫潜藏期,2代为卵期。影响亚洲玉米螟自然种群数量变动的主导致死因子,1代为低龄幼虫潜藏期的天敌捕食及自然死亡因子,2代为卵期的中华草龄捕食因子。     

辽宁省春玉米主要病虫为害损失之研究

采用在植株上接种不同浓度的丝黑穗病菌、弯孢菌叶斑病菌和玉米大斑病菌,以及不同玉米螟虫量,研究不同病级和虫量对玉米的产量构成因素及产量损失的影响,同时对玉米螟(A)、弯孢菌叶斑病(B)、大斑病(C)、丝黑穗病(D)的复合发生为害(ABCD)损失和经济阈值进行简单探讨。研究表明,病虫为害主要影响穗粗、行粒数和百粒重产量构成因素,病级和虫量与产量损失呈显著正相关;病虫之间存在复合为害关系,复合产量损失率占四者单独造成产量损失率之和的41.48%,其大小依次为:A相似文献   

基于心率变异指标研究木材良好接触感的生理机制

以人在接触材料时的电生理学指标心率变异(HRV)为参量，从时域、频域以及非线性动力学角度加以分析，深层反映人在接触这些材料时的交感神经和副交感神经的活动变化情况，揭示材料材性因子与人体生理、心理变化之间的关系。实验结果表明，当人接触木材时，交感神经活动兴奋性增强，但增强程度低于金属、石材；副交感神经活动性略降低，降低程度低于其它材料；说明木材时人体自主神经系统的影响较小，且不危及人体健康。从心率变异指标恢复到正常水平的时间看，木材所用时间较短。主观调查结果显示，木材的接触感良好，人们时它的喜爱程度较高。综合分析，结合木材的热学基本物理量、心理量与人体心率变异生理指标可以解释木材的艮好接触感。     

水青冈木材构造和利用的研究

对水青冈木材构造和利用进行了研究，结果表明：水青冈木材为半环孔材，具宽木射线，射线组织异形Ⅲ型，纤维长度和长宽比大，差异壁厚和微纤丝角小；木材不变形，材质优良，花纹美丽，为建筑、家具、地板、装饰、贴面板、造纸和纤维工业及种的鉴定提供了理论依据。     

Preparation of polyols from methyl-α-d-glucoside and cyclic esters for design and fabrication of biodegradable polyurethane foams

A ring-opening polymerization of cyclic esters -caprolactone (CL) and/or l-lactide (LACD) was carried out in the presence of methyl--d-glucoside (m-Glc) as an activated substrate and tin(II) 2-ethylhexanoate (SnEht₂) as a catalyst. This led to successful synthesis of an armed polyester polyol with m-Glc as the core. These polyols were characterized through gel permeation chromatography, hydroxyl value assessment, differential scanning calorimetry, and viscosity measurements. It was clarified that the thermal properties and tractability of the synthesized polyols are closely related to the structural characteristics of the side chain polyesters, such as their length and chemical composition. Polyurethane foams were also prepared by mixing an appropriate amount of the polyols with diphenyl methane diisocyanate, a foaming agent (water), and other additives, and their mechanical properties were examined. Two polyurethane foams manufactured from polycaprolactone-polyols that were synthesized at a CL/m-Glc ratio of 2 or 5, were used in a biodegradation test in a closed system of activated sludge suspension. Evidence of their biodegradation is presented based on data showing oxygen consumption by the pulverized samples.     

Cellular composition of granulomatous lesions in gut-associated lymphoid tissues of goats during the first year after experimental infection with Mycobacterium avium subsp. paratuberculosis

Mycobacterium avium subsp. paratuberculosis (MAP) causes lesions in naturally and experimentally infected ruminants which greatly differ in severity, cellular composition and number of mycobacteria. Morphologically distinct lesions are already found during the clinically inapparent phase of infection. The complex local host response and number of MAP were characterized at the initial sites of lesions, organized gut-associated lymphoid tissue, in experimentally infected goats. Tissues were collected at 3, 6, 9 and 12 month post-inoculation (mpi) from goat kids that had orally received 10 times 10 mg of bacterial wet mass of MAP (JII-1961). The cellular composition of lesions in Peyer's patches in the jejunum and next to the ileocecal valve was evaluated in 21 MAP-inoculated goats, where lesions were compared with unaltered tissue of six control goats. CD68⁺, CD4⁺, CD8⁺, γδ T lymphocytes, B lymphocytes and plasma cells, MHC class II⁺ and CD25⁺ cells were demonstrated by immunohistochemistry in serial cryostat sections.At 3 mpi, extensive granulomatous infiltrates predominated, consisting of numerous epitheloid cells admixed with many CD4 and γδ T lymphocytes. Only single MAP were detected. This indicates a strong cellular immune reaction able to control MAP infection. γδ T lymphocytes were markedly increased in this type of lesion which may reflect their important role early in the pathogenesis of paratuberculosis. At 9 and 12 mpi, divergent lesions were observed which may reflect different outcomes of host–pathogen interactions. In five goats, minimal granulomatous lesions were surrounded by extensive lymphoplasmacytic infiltrates and no MAP were detected by immunohistochemistry. This was interpreted as effective host response that was able to eliminate MAP locally. In three goats, decreased numbers of lymphocytes, but extensive granulomatous infiltrates with numerous epitheloid cells containing increased numbers of mycobacteria were seen. This shift of the immune response resulted in uncontrolled mycobacterial multiplication. Focal and multifocal circumscribed granulomatous infiltrates of mainly epitheloid cells may represent sites of new infection, since they were observed in goats at all times after inoculation. Their presence in goats with minimal granulomatous lesions surrounded by extensive lymphoplasmacytic infiltrates may indicate that despite the local clearance, the infection may be perpetuated.The complex cellular immune reactions postulated for the pathogenesis of paratuberculosis were demonstrated at the local sites of infection. These early host–pathogen interactions are most likely essential for the eventual outcome of the MAP infection.     

重庆地区板栗园桃蛀螟发生与为害调查及药效试验

2001-2002年，对桃蛀螟在重庆地区板栗园的生活史、发生规律、生活习性、为害特点及其化学防治进行了研究。结果显示，桃蛀螟在重庆地区的生活史为每年发生4代，是重庆地区板栗园引起果实减产最主要的蛀果性害虫；7种药剂的药效试验表明，5.0％抑太保乳油和2.5％功夫乳油对桃蛀螟的防效较好。