催干剂对氨基环氧树脂阴极电泳漆的影响     

邓光辉  石晓红  蓝虹云  雷福厚 《林产化学与工业》2001,21(2):62-66

以氨基环氧树脂为基体树脂，Co^2 ,Pb^2 盐为催干剂合成了阴极电泳漆，并对膜性能进行考察，结果表明，所合成的阴极电泳涂料在PH值为6－7、电泳时间2min的条件下。加入不同的催干剂，在不同的烘干温度下，得到性能不同的漆膜。经过膝膜综合性能试验，结果表明，加入钴和铅复合催化剂，在160℃左右烘干20min，可得到完全固化，硬度较高、耐潮、耐盐、耐酸碱性较好的漆膜。  相似文献   

猪血浆蛋白(酶)多态性与杂种优势的关系   总被引：2，自引：0，他引：2  

王忠华  柳小春  施启顺 《湖南农业大学学报(自然科学版)》2002,28(5):421-424

为探讨血浆蛋白 (酶 )多态性与杂种优势的关系 ,测定了杜洛克、长白、大白、杜×长大、大×长大、长×大、大×长共 7个品种 (组合 )的 8个血浆蛋白 (酶 )位点的多态性及部分生长和胴体性状 ,计算了平均基因杂合度与部分经济性状实测值和杂优率的相关关系 .结果表明 ,平均基因杂合度与遗传距离呈正相关 ,与日增重、屠宰率、背膘厚、后腿比例的实测值或杂优率呈正相关 ,与眼肌面积的实测值和杂优率呈负相关 .平均基因杂合度和亲本间遗传距离可为预测杂种优势提供依据 .  相似文献   

对《中图法》(第四版)类目注释的系统认识     

杨衡 《农业图书情报学刊》2005,17(3):154-157

本文从语言特点、编排体例及内容特点出发,对《中图法》(第四版)类目注释进行了系统的认识,并就此提出了自己的一些看法。  相似文献   

基于果实相关性状的桃品种初级核心种质取样策略研究   总被引：5，自引：1，他引：4  

李银霞  高其洁  李天红 《果树学报》2006,23(3):359-364

以国家种质资源圃(北京)编目的558份桃品种的18个形态学和农艺学性状为基本数据,研究了桃品种初级核心种质构建的取样策略,包括总体取样比例的确定及取样方案的选择,以获得最佳的初级核心种质。本试验共设10%～90%9个总体取样比例;取样方案研究包括分组原则和组内取样比例的确定。结果表明,桃初级核心种质的适宜总体取样比例为10%;按品种类群分组结合多样性比例取样为构建桃初级核心种质的最佳取样方案;利用此取样策略从558份桃品种中提取56份作为核心样本,对其代表性进行检测表明所构建的初级核心种质能够很好地代表桃原始种质的遗传多样性。  相似文献   

干旱区20个紫花苜蓿品种抗旱性研究   总被引：4，自引：0，他引：4  

徐秀梅  杨万仁  刘东宁 《种子》2004,23(11):21-24

该试验测定了20个苜蓿品种的水势、总含水量、自由水量、束缚水量、束/自比以及渗透调节物质.从植物水分生理与生化方面,测试各品种的抗旱性,并结合产草量、品质进行综合评价.从中选出5～6个抗旱性较强、产草量高、品质较好的苜蓿品种,为干旱区选择适宜的苜蓿品种提供具有实用价值的基础资料.  相似文献   

Effect of various plant factors on the expression of creeping-rootedness in lucerne (Medicago sativa L. complex)     

L. Pecetti  E. Piano  M. Romani 《Euphytica》2004,135(1):89-97

Although agronomically interesting, selection of creeping-rootedness inlucerne, that is, the ability to form adventitious shoots on horizontal,spreading roots, remains difficult because of the complex and still unclear geneticcontrol of this character, coupled with the possible occurrence of external factorsthat affect unpredictably its expression. Two experiments were undertaken onprogenies of creeping-rooted plants, to verify previous findings and inferences,and test novel hypotheses, concerning the effect of various plant factors on theexpression of creeping-rootedness. The ultimate aim was to provide information onthe most appropriate germplasm, procedures, or indirect selection criteria, that wouldimprove the efficiency of breeding for this character. The factors here examinedincluded genotype, age, kind of progeny, vigour, spreading ability, and undergroundmorphology. Some genotypes appeared to be good donors of the character, whereasothers did not. The proportion of creeping-rooted plants increased in allcases with the plant age. Selfing consistently depressed the expression ofthe character compared with clonal propagation or crossing. It is suggestedthat the effect of age and selfing on the penetrance of creeping-rootedness ismediated through their effect on plant vigour. Both aerial and root vigour showedindeed an effect per se on the presence of the character. Beside thevigour, possible indirect selection criteria were identified in the frequenciesof swollen zones and latent stem primordia on horizontal roots. Proportion ofcreeping-rooted plants in progenies after one year of growth appeared as a simple anduseful criterion to predict future trends. Consistent with previous conclusions, theresults provided evidence that a combination of family and individualselection may enhance the character expression.  相似文献   

陆地棉功能叶不同生育时期酶活性及脂质过氧化作用的研究   总被引：5，自引：0，他引：5  

王新望  王惠萍 《作物学报》1995,21(2):215-222

对不同熟性棉花品种功能叶几种酶活性及脂质过氧化水平（以丙二醛含量表示）的研究结果表明，超氧物歧化酶（ＳＯＤ）活性在吐絮前呈波动上升，吐絮盛期争剧下降；丙二醛（ＭＤＡ）含量吐絮前缓慢上升，吐絮后明显增加；过氧化氢酶（ＣＡＴ）活性在结铃以前随叶片发育而上升，结铃后急剧下降；过氧化物酶（ＰＯＤ）活性始终呈上升趋势。进一步对ＰＯＤ同工酶进行电泳发现，其酶谱构成随生育进程而变化，早熟品种在开花期酶带条数最多  相似文献   

离子选择电极法测定NBPG与银、镉、汞的配合物组成和稳定常数     

孙桂珍  阎早婴  宁开桂 《河北北方学院学报(自然科学版)》1995,(1)

本文用离子选择电极法测定了N,N—二甲基膦酸基甘氨酸(NBPG)与银、镉、汞的配合物组成和稳定常数。结果表明,NBPG与Ag~ 、Cd~(2 )、Hg~(2 )均生成组成为1:1的多齿质子型配合物。其lgK_稳值分别为:AgL5.28、CdH_3L3.63、CdH_2L5.16、CdHL7.30、CdL11.56、HgH_3L6.06、HgH_2L7.55、HgHL8.24、HgL12.58。  相似文献   

应用生物素标记的NDV－cDNA探针检测感染尿囊液中NDV－RNA的初步研究     

陈书琨  何云生  李观娣  钟安清 《畜牧兽医学报》1995,(4)

本文应用聚合酶链反应（ＰＣＲ）技术从构建的新城疫病毒（ＮＤＶ）ｃＤＮＡ文库中扩增含编码Ｆ糖蛋白前体──Ｆｏ酶切位点序列的３５９ｂｐ的Ｆ蛋白基因ｃＤＮＡ片段。将此３５９ｂｐｃＤＮＡ片段经光敏生物素标记后,即成ＮＤＶ－ｃＤＮＡ探针。该探针能特异性地从感染的尿囊液中检测出ＮＤＶ强毒株和疫苗毒株的基因组ＲＮＡ,而不与ＩＢＤｖ－ｄｓＲＮＡ、ＡＩＢｖ－ｓｓＲＮＡ、ＥＤＳ７６－ｄｓＤＮＡ、ＭＤＶ－ｄｓＤＮＡ,ＦＰＶ－ｄｓＲＮＡ及ＡＩＬＶ－ｄｓＤＮＡ发生交叉杂交反应。试验结果表明：尽管该探钎含有编码Ｆｏ蛋白酶切位点序列的碱基顺序,但它还是不能把ＮＤＶ的强、弱毒株区分开。这说明ＮＤＶ强、弱毒株比区域内的碱基存在着相当大的同源性。不过,此探针对ＮＤＶ来说具有特异性,这就为ＮＤＶ的诊断技术开创了基因水平检测的新途径。  相似文献   

Unsaturated vitamin b(12) binding capacity in human and ruminant blood serum - a comparison of techniques including a new technique by high performance liquid chromatography     

Schultz WJ 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1987,16(3):67-72

A new technique by High Performance Liquid Chromatography (HPLC-gel permeation) shows promise as a tool to separate and quantitate the Unsaturated Vitamin B(12) Binding Capacity (UBSC) of the individual Vitamin B(12) binders in blood serum. This method, although not as rapid as protein-coated charcoal or cellulose separation techniques, is more applicable for use with large numbers of samples than gel filtration. The use of a radioactivity detector to monitor the eluant from the column permitted automation of the method. Comparable results for UBBC and for the UBBC of individual binders were obtained when samples were analyzed by gel filtration and HPLC. The HPLC method proved suitably precise and the recovery of added cyanocobalamin was acceptable. It is proposed that HPLC be the method of choice for measurement of the USBC of binders of Vitamin B(12) in blood serum.  相似文献