草坪草种(品种)的筛选及利用   总被引：3，自引：0，他引：3  

额木和  哈斯其其 《草原与草坪》2000,(3):12-14

以绿色期、质量、抗逆性及建植效率为指标 ,对国内外的优良草坪草进行了引种筛选工作。筛选出了适宜内蒙古气候条件的 9个品种 ,培育出了冷季型草坪草品种—大青山草地早熟禾。同时对优良的地被植物进行了引种驯化  相似文献   

烷基锡酸催化松香酯化反应的研究   总被引：16，自引：5，他引：11  

常东亮  哈成勇  袁金伦 《林产化学与工业》1999,19(3):21-24

以松香树脂酸的酯化反应为例，研究了烷基锡酸为酸化反应的催化作用，系统的探讨了影响反应的各种因素，研究表明烷其锡酸具有很高的催化活性，可以高效地催化合成系列松香酯，大大缩短了反应时间。  相似文献   

都市型薄皮甜瓜品种比较试验     

张静  哈雪姣  贾文红  乔媛媛  郝敬虹  李婷 《蔬菜》2021,(4):69-72

为筛选出适宜在北京种植的优质都市型薄皮甜瓜品种,选取8个品种的薄皮甜瓜为试验材料,对比分析其田间长势及果实品质。结果表明:8个参试品种田间长势及果实品质均有显著差异,其中梨形瓜中丘比特果实大,外观好,果肉最厚,心糖最高,综合果实品质最优秀;长筒形瓜中博洋9号果实外观及品质较优秀,单果质量最大,果形指数好,心糖最高。综合看来,丘比特和博洋9号这2个品种可在北京地区进一步推广种植。  相似文献   

富含硒钴锌的苜蓿青干草在牛羊饲喂中的效果     

李明  哈斯  介晓磊  郭孝  李建平  蒋士传 《家畜生态》2011,(4):34-37

通过在荷斯坦奶牛和杜泊羊日粮中添加5%高硒型、高硒钴型、高硒钴锌苜蓿青干草,研究3种苜蓿青干草对牛羊饲料转化和生产特点的影响。结果表明,功能型苜蓿青干草能够显著提高牛羊的饲料转化率,其中高硒钴和高硒钴锌苜蓿青干草有利于提高羊和牛的日增重,而高硒型青干草有利于提高荷斯坦奶牛的产奶量。  相似文献   

Frequency Hydraulic Aperture about Fracture Seepage in Rock Mass     

XU Guang xiang  HA Qiu-ling  ZHANG Yong xing 《保鲜与加工》2001,(5):50-55

The frequency aperture given in this paper is a new method that describes the fracture aperture composition. The aperture curve plays a role in describing the aperture distribution and uniformity. In particular, the frequency hydraulic aperture is of great importance in seepage analysis. It overcomes limitations of hydraulic aperture and mean aperture. Based on existing information, the result of example calculation shows that the hydraulic aperture e h equals to the median aperture e 50 . This paper also obtains that the frequency hydraulic aperture e sh equals to e 48 through finite element numerical modeling for various type of random fracture.  相似文献   

Connect Technique of Laminated Object Manufacturing Using Metallic Materials as Modeling Materials     

YI Shu ping  HA Jin  LIN Li hong  ZHANG Jin 《保鲜与加工》2002,(2):1

To solve some key problems existed in the manufacturing of metallic functional part via Laminated Object Manufacturing (LOM), a new technique using vacuum solid-state pressure diffusion weld technique to connect the metallic slice sheets is presented in this paper. The following conclusions can be draw from the experiments introduced specially: the size in the stack direction shrink at the rate of less than 1% and the shrinking is owed to regularly error, the atom-diffusion between two combined interface occurred clearly and new crystallites shaped meanwhile, shearing intension of well connected diffusion section is more than 100 MPa and micro hardness of well-knit portion is the same to matrix's. It can be proved from the result above that the vacuum solid-state pressure diffusion technique weld is a perfect technique for connecting metallic slice sheets used in the manufacturing of metallic functional part via LOM.  相似文献   

Trypanosomosis prevalence in cattle on Mafia Island (Tanzania)     

Goossens B  Mbwambo H  Msangi A  Geysen D  Vreysen M 《Veterinary parasitology》2006,139(1-3):74-83

During two consecutive surveys (February and August/Sept 2002), a total of 970 cattle from the cattle population of Mafia Island (United Republic of Tanzania) were blood-sampled. All blood samples were microscopically screened for the presence of trypanosomes and a portion of these were checked for antibodies with an Ab-ELISA and for the presence of trypanosomal DNA with PCR. Microscopic evidence of trypanosomes of the congolense group (sub-genus Nannomonas) was found in 0.8% of the animals (8/970) and in two cases the species identified was confirmed by PCR as Trypanosoma congolense savannah type. Non-pathogenic Trypanosoma theileri were detected in 3.2% (31/970) of the samples using the Dark Ground-Buffy Coat (DG-BC) technique. For survey 1 (S1), detection of antibodies (Ab-ELISA) against pathogenic trypanosomes indicated a seroprevalence of 14.2% (68/480). Of the samples, either DG positive or with a PCV lower then 25, examined by PCR, a total of 8.4% (5/59) (selected from 970 samples), were found positive for T. congolense. The low prevalence of pathogenic trypanosomes on Mafia Island is intriguing, especially in view of the omnipresence of the tsetse fly Glossina brevipalpis. Although the presence of detected trypanosomal antibodies does not necessarily indicate a current infection, the combination of serological/parasitological examinations and the results of the PCR do support this low prevalence of trypanosomosis in cattle. Despite the low prevalence, pathogenic trypanosomes are present on Mafia Island and possible reasons for this low infection rate, taking account of the relation between Glossina species present, transmission risk and trypanosomes found in cattle, are discussed also in view of a future appropriate intervention strategy.  相似文献   

糖水龙葵果罐头制作工艺研究     

韩天龙  金明晓 《保鲜与加工》2006,6(2):33-34

通过单因素多水平、多因素多水平的正交实验对龙葵果实罐藏工艺进行研究,结果表明,加工条件为烫漂温度60℃,烫漂时间10min,糖水浓度60%,排气温度40℃,排气时间15min.在此条件下罐头产品感官与品质最佳.  相似文献   

动物溶菌酶基因的研究进展   总被引：1，自引：0，他引：1  

孙国庆  哈福  苗永旺  李大林 《中国牛业科学》2012,38(3):51-54,59

溶菌酶[Lysozyme(EC3.2.1.17),LYZ]是机体先天免疫系统中一个重要的效应分子,参与机体多种免疫反应,在溶菌过程中形成一个水解体系,破坏和消除侵入动物体内的病原,从而实现机体的免疫防御。它可以有效抑制葡萄球菌、大肠杆菌等一系列病原菌,是重要的奶牛乳房炎抗性因子之一。本文综述了溶菌酶基因的研究进展,包括其结构与进化、变异及应用前景等。  相似文献   

Arginine Levels Affect Growth and CSN3 Gene Expression of Dairy Cows Mammary Epithelial Cells in Vitro     

XU Bolin  WANG Mengzhi  ZHANG Xingfu  HA Si  WANG Chunyan  AO Changjin  WANG Hongrong 《动物营养学报》2012,24(5)

本试验旨在研究培养基中添加不同浓度的精氨酸( Arg)对乳腺上皮细胞体外增殖及κ-酪蛋白(CSN3)基因表达的影响.选用中国荷斯坦奶牛乳腺上皮细胞进行体外培养,以无Arg的培养基(0.00 mg/L)为对照(0组),试验培养基分别添加69.50(0.25组)、139.00(0.50组)、278.00(1.00组)、556.00(2.00组)、1 112.00(4.00组)和2 224.00 mg/L(8.00组)的精氨酸.结果表明:Arg能促进乳腺上皮细胞的增殖,24 h时,0.25～4.00组与0组相比均差异显著(P＜0.05),8.00组与0组相比差异不显著(P＞0.05);48和72 h时,各试验组与0组相比均差异显著(P＜0.05).Arg能促进CSN3基因的表达,各试验组与0组相比均差异显著(P＜0.05),当Arg浓度为556.00 mg/L时,CSN3基因表达量最高.结果提示,Arg对乳腺上皮细胞增殖及CSN3基因表达均具有明显的促进作用,且在Arg浓度为69.50～1112.00 mg/L时促细胞增殖效果较佳,在Arg浓度为556.00 mg/L时促CSN3基因表达作用最强.  相似文献