Application of cationic polymer prepared from sulfuric acid lignin as a retention aid for usual rosin sizes to neutral papermaking

Cationic polymers that acted as the retention aids for usual rosin sizes in neutral papermaking were prepared from sulfuric acid lignin (SAL), one type of acid lignin. To convert SAL to the cationic polymer (MP-SAL), SAL was phenolated and then treated by the Mannich reaction to introduce the amino groups. In the MP-SAL single system, MP-SAL exhibited high sizing effectiveness in neutral papermaking with the rosin emulsion size. However, MP-SAL showed no sizing effectiveness when soap rosin size was used. MP-SAL showed increased sizing effectiveness as the pK _a of the introduced amino group increased. From this and comparison of the sizing degrees of MP-SAL and polyethylenimine, which possesses a linear structure, it was suggested that the sizing effectiveness was not only affected by the charge density and molecular weight, but also by the basicity of the introduced amino groups and the molecular structure of the retention aid. In the alum–MP-SAL dual system, alum and MP-SAL synergistically enhanced the sizing effectiveness in the rosin emulsion sizing at neutral pH. In turn, this allowed a decrease in the MP-SAL dosage and resulted in a small decrease in brightness.Part of this report was presented at the 48th Lignin Symposium, October 2003, Fukui     

黄麻DNA提取与RAPD反应体系的建立

以假黄麻、假长果、越南圆果 (圆果种黄麻 )等为材料 ,研究了黄麻 DNA的提取方法以及对 RAPD分析的影响因素 ,包括模板浓度、Mg2 + 、d NTP、引物和 Taq酶等 ,建立了适于黄麻种质 RAPD分析的 PCR反应体系 .即在 2 5μL反应体积中 ,Tris- HCl(p H8.0 )、KCl、Mg Cl2 、d NTP、随机引物的浓度分别为 10 mmol· L-1、5 0mmol·L-1、2 .5 mmol· L-1、15 0 μmol· L-1、0 .2 μmol· L-1,并含有 30 - 60 ng DNA与 1.5 U Taq DNA聚合酶 .扩增程序为 :94℃预变性 5 min;然后 94℃ 30 s,37℃ 1.5 min,72℃ 1min,4 1个循环 ;最后 72℃延伸 7mi     

茶汤组分与金属离子的络合性能

用直接观察法、酒石酸亚铁法和铬黑 T 祛对绿茶茶汤组分与23种金属离子的络合性能进行了研究,结果表明,有22种金属离子可与茶汤组分发生络合或还原络合反应,其中有10种金属离子参与了茶多酚的络合。钙离子可与茶汤组分生成低溶解度的络合物,其溶解度及稳定性可随反应溶液 pH 升高而下降。钙络合沉淀中的主要茶汤组分是茶多酚,其中以酯型儿茶素含量最高。     

红椿SRAP反应体系优化及引物筛选

[目的]优化相关序列扩增多态性(SRAP)体系内的不同组分,建立适用于红椿SRAP分子标记的反应体系,并进一步从SRAP引物组合中筛选出稳定、多态性好的引物组合,为红椿遗传多样性研究奠定试验基础。[方法]针对SRAP-PCR反应体系中5个因素各设置8个水平,先利用单因素试验确定浓度梯度,后在确定的梯度范围内选定4个水平,按照正交试验L16(45)进行优化,结合正交直观分析法和新复极差法对各因素进行优化筛选。[结果]确定最优体系为总体系25μL,模板DNA 25 ng,上下游引物各0.3μmol·L~(-1),Taq DNA聚合酶1U,Mg2+2.5 mmol·L~(-1),d NTP 0.3 mmol·L~(-1)。利用稳定的SRAP-PCR体系,从1 505对SRAP引物组合中筛选出30对优质引物组合。[结论]通过不同种源红椿基因组DNA的重复验证,获得了稳定清晰、多态性较强的扩增条带,表明所确定的最优体系稳定可靠,适用性较强,可用于不同种源红椿遗传多样性研究的后续实验。     

Utility of diagnostic tests used in diagnosis of infection in dogs experimentally inoculated with a North American isolate of Leishmania infantum infantum

Eight female beagles were infected with 1 x 10(7) (low dose, LD) or 2 x 10(8) (high dose, HD) promastigotes of a North American isolate of Leishmania infantum infantum (LIVT-1 strain) isolated from naturally infected Virginia Foxhounds. Two female beagles served as negative controls and 2 male beagles chronically infected (> 3 years) with Leishmania infantum chagasi were positive controls. Bone marrow (BM) and lymph node (LN) aspirates were collected every 6-8 weeks for cytologic evaluation, parasite culture, and polymerase chain reaction (PCR). Serum samples were collected monthly for determination of serologic responses by indirect fluorescent antibody test (IFAT) and diagnostic rK39 antigen. Cultures of BM and LN aspirates and cytology evaluation were consistently positive in positive control dogs during the course of study. Negative control dogs were negative on BM and LN cultures and on cytologic evaluation of aspirates. Amastigotes were present on cytological examination of BM aspirates in 2 experimentally infected dogs. Cultures of LN aspirates were positive on 22 samples, whereas BM cultures were positive on 12 samples for all dogs. IFA titers ranged from 0 to 1 :400 in experimentally infected dogs during the course of the study. Recombinant K39 immunoassay tests were consistently positive in positive control dogs and in the HD dogs by approximately 8 weeks after infection. BM PCR products were identified more consistently in the HD dogs compared with the LD dogs. Kappa statistics indicated PCR correlated better with cultures and cytology than did IFAT or the rK39 immunoassay results in the experimentally infected dogs.     

抗滑桩优化设计在滑坡治理中的应用研究

基于传统剩余推力法，提出了新的抗滑桩优化方法。以位于凉山彝族自治州某县城南的滑坡体为例，说明了主要治理方法。采用剩余推力法和新的抗滑桩优化方对该滑坡体天然状态工况进行了稳定分析。结果显示，在设计安全系数为1．15的情况下，该滑坡处于临滑状态，因此，须采取相应的加固措施，最后推荐了抗滑桩设计方案，已在凉山州某县城滑坡工程中成功实施。     

The Method of Diagnosing Brain-dysfunction Based on Membership Function and BP Neural Network

Membership functions.formed with the characteristic values obtained by applying the continuous reaction time (CRT) theory from controls and heptic encephalopthy and proposedin this paper.whith these membership functions,the CRT data to be diagnosed are calculated in advance,and then discriminated by BP meural network to differentiate patients with or without braindysfunction.The troubles of low accuracy and efficiency,encountered in training BP network withfuzzy samples.scattered data and extended samples,are solved.     

氘标记稻瘟酯的合成及其杀菌活性

氘标记农药作为探针或者内标在农药代谢、毒理研究或者农药残留分析中发挥着重要作用。由于动力学同位素效应,C-D键比C-H键更为稳定,因此氘标记农药可能具有更长的半衰期,以及对非靶标生物更小的毒性。稻瘟酯是一种对水稻恶苗病和稻瘟病有良好防治效果的农用杀菌剂。本项研究利用单电子转移还原氘化反应和氘标记中间体,成功合成了4个不同位点被选择性氘代的稻瘟酯,其中3个化合物未见文献报道,并对其进行了杀菌活性测试。离体杀菌活性测试结果显示,上述4种氘代稻瘟酯对水稻稻瘟病菌和水稻恶苗病菌均具有良好的生物活性,与未被标记的稻瘟酯无显著差异。氘标记稻瘟酯未来可作为代谢、毒理研究的探针及农药残留分析中的内标。     

响应曲面法优化美拉德反应以制备蘑菇酪氨酸酶活性抑制组分

MRPs作为天然抗褐变剂,可抑制引起果蔬酶促褐变的酪氨酸酶的酶活。为进一步优化美拉德反应以制备酪氨酸酶活性抑制组分,本研究采用响应面法对MRPs制备工艺进行研究。在单因素实验基础上,确定美拉德反应初始pH、反应温度、反应时间、底物浓度比(糖∶氨基酸)4个因素,设计4因素5水平的二次回归中心组合试验。经响应面法分析,为方便实际操作,确定最佳工艺条件为:初始pH为2.94,反应时间为1.9 h,反应温度为110.09℃,底物浓度比(糖∶氨基酸)为0.57。经实验验证,得出结果与理论值相对误差较小,故采用二次回归中心组合设计得到的最优MRPs制备条件参数准确可靠。     

红壤坡地雨水产流及其土壤流失的垫面反应

通过4年(1998～2001年)径流场定位观测研究,探明了不同植被垫面雨水产流过程中系统水土流失有显著性差异。水流失量为农作区>常绿灌木区、针叶林区>常绿果园区>退化区、恢复区。坡地不同垫面间雨水地表径流的差异存在,为坡地雨水利用和利用坡地集雨支持农田灌溉提供了依据和可调控性。土壤流失量受人为干预、耕作强度的影响很大,坡地从自然保护到作物栽培,系统的土壤流失量提高20倍。茶果林地的土壤流失低于作物耕种的2～3倍,而高于自然利用和自然保护的6～12倍。养分流失在数量和质量上皆取决于垫面构成。提出了利用坡地集雨优势,构建与单元生态系统水循环平衡相适应的坡地农林复合生态系统,并通过水平衡生态建设来维系生态系统的水分平衡。