新型甜菜碱型沥青乳化剂的合成与研究

以月桂酸、二甲胺水溶液、环氧氯丙烷和氯乙酸钠为原料合成出一种新型甜菜碱型沥青乳化剂.在最佳反应条件下,第一步合成月桂酸-2-羟基-3-氯丙酯的酯化率为97.1%.利用红外光谱对产物结构进行了表征.对第一步合成月桂酸-2-羟基-3-氯丙酯的反应提出了合理的反应机理.该乳化剂对沥青具有很好的乳化能力,制备的乳化沥青储存稳定性良好,该乳化剂属于快裂型沥青乳化剂.     

姚桥煤矿外因火灾隐患分析及对策

分析和梳理了姚桥煤矿不同地点的外因火灾隐患,在对比全矿井反风和区域性反风并对后者进行可行性分析后,提出了采用区域性反风以及调整通风系统应对外因火灾突发事故的对策。笔者根据姚桥煤矿的实际情况,并结合自己从事"一通三防"多年的工作经验整理成文,可为现场工程人员进行矿井抗灾、避灾、救灾提供一些参考和帮助。     

基于压力测试的我国某商业银行房贷违约率评估

运用带外生变量的自回归模型和向量误差修正模型对房价下跌背景下商业银行的不良贷款率问题进行了研究. 以房地产不良贷款率度量信用风险，以居民消费价格指数、贷款利率、商品房平均销售价格、汇率、仿泰德利差和 广义货币供应量作为压力指标变量，建立了合适的房贷压力测试模型. 在贷款利率上升、商品房销售价格下跌的 压力情境下，分别预测了房地产不良贷款率的变化路径. 实证结果表明，在压力情景下，不良贷款率先急剧上升，然后逐渐降低并趋于稳定，在影响因素中，房价对房地产不良贷款率的影响程度最强，持续时间最长.     

商标代理业信用机制建立的博弈分析

商标代理行业中不诚信的现象非常普遍,尽快建立起诚信机制对于行业健康发展至关重要。可以通过动态博弈的方法分析商标代理行业信用机理,分析内生信任和外生信任机制中委托人和代理人的博弈过程。通过内生信用和外生信用两种途径建立起完善的商标代理业信用机制。     

Distinct but parallel evolutionary patterns between alcohol and aldehyde dehydrogenases: addition of fish/human betaine aldehyde dehydrogenase divergence

Alcohol dehydrogenases (ADHs) of the MDR type (medium-chain dehydrogenases/reductases) have diverged into two evolutionary groups in eukaryotes: a set of 'constant' enzymes (class III) typical of basal enzymes, and a set of 'variable' enzymes (remaining classes) suggesting 'evolving' forms. The variable set has larger overall variability, different segment variability, and variability also in functional segments. Using a major aldehyde dehydrogenase (ALDH) from cod liver and fish ALDHs deduced from the draft genome sequence of Fugu rubripes (Japanese puffer fish), we found that ALDHs form more complex patterns than the ADHs. Nevertheless, ALDHs also group into 'constant' and 'variable' sets, have separate segment variabilities, and distinct functions. Betaine ALDH (class 9 ALDH) is 'constant,' has three segments of variability, all non-functional, and a limited fish/human divergence, reminiscent of the ADH class III pattern. Enzymatic properties of fish betaine ALDH were also determined. Although all ALDH patterns are still not known, overall patterns are related to those of ADH, and group separations may be distinguished. The results can be interpreted functionally, support ALDH isozyme distinctions, and assign properties to the multiplicities of the ADH and ALDH enzymes.     

The processing and presentation of endogenous and exogenous antigen by Schwann cells in vitro

The expression of major histocomatibility complex class II in vitro and in vivo by Schwann cells indicates a potential facultative role of Schwann cells in the presentation of antigen to neuritogenic T cells during inflammatory demyelinating neuropathies. Using a T cell proliferation assay, this study demonstrated that processing and presentation of endogenous and exogenous antigen by Schwann cells influences T cell proliferation. Statistical analysis of proliferation and its relation to processing and presentation of antigen by Schwann cells had not been previously addressed. Different combinations of factors including treatment of cultures (untreated, irradiated or fixed), concentration of exogenous antigen (0 or 40 μmg/ml), the presence of interferon-γ and the timing of exogenous antigen addition influence the proliferation P₂-specific, non-mammalian protein ovalbumin-specific T cell lines and naive T cells. Received 25 July 2002; received after revision 9 September 2002; accepted 7 October 2002     

Genomic cloning and sequencing of betaine aldehyde dehydrogenase gene in spinach

A genomic library derived from leaves of spinach was constructed with the λGem11_BamHI Arms as the vector. The library was screened using the BADH cDNA of mountain spinach as a probe and six positive clones were obtained through three rounds of screening. One of the positive clones named D, which was hybridized with the 5′600 bp fragment of mountain spinach BADH cDNA, was selected and further analyzed. The size of the insert in clone D was about 12 kb. 8 856 nucleotides of the insert were sequenced which contained 2 459 nucleotides of 5′ noncoding region, 6 111 nucleotides of the complete sequence of the BADH gene, and 286 nucleotides of a 3′ noncoding region. The result of sequence analysis indicated that the BADH gene contained 14 introns and the junction sequences at splicing sites followed the GT_AG rule basically.     

外源有机碳浓度对藻菌关系及氮磷去除的影响

采用实验室一次培养法,以葡萄糖为有机碳源,对地衣芽孢杆菌和丝藻进行单独及混合培养,研究了外源有机碳浓度对藻菌相互关系及氮磷去除效率的影响。结果表明,当水体中葡萄糖质量浓度不高于20mg/L时,地衣芽孢杆菌能显著促进丝藻的生长。尤其当葡萄糖质量浓度为20mg/L时,藻菌体系叶绿素荧光强度最大可达5227,较纯丝藻体系相应值提高约15%;当葡萄糖质量浓度为50 mg/L时,藻菌体系对水体中NH_4~+-N和PO_4~(3-)-P的去除率分别达到27%和60%,显著高于纯丝藻及纯菌体系相应值;当葡萄糖质量浓度高于50mg/L时,藻菌体系和纯丝藻体系对氮磷的去除率无显著差异;当葡萄糖质量浓度高于100mg/L时,地衣芽孢杆菌明显抑制丝藻的生长。     

甜菜碱石墨涂膜电极的研制

电极法在医学、环保等领域具有较广泛应用，如对生物碱的测定方面￣［１，２］具有广阔的前途，本文介绍了四苯硼钠－甜菜碱－石墨涂膜电极的制作。实验结果证明，电极性能在１０￣（－１）～１０￣（－５）ｍｏｌ·Ｌ￣（－１）浓度范围内符合Ｎｅｒｎｓｔ方程，可用标准加入稀释法直接对甜菜碱进行定量测定，方法简便、快速。