兰考泡桐苗木顶芽越冬特性初步研究   总被引：19，自引：2，他引：17  

侯元凯  翟明普  张俊昌  何建涛 《河南农业大学学报》2000,34(2):196-197,200

对兰考泡桐一年生苗木 芽休眠期进行不同的平埋处理，结果表明，１０月下旬至１１月下旬实施平埋是可行的，苗木面芽越冬率无显著性差异；平埋覆土类型（粘土、沙土、两合土）对顶芽越冬率无显著性差异；平埋方式（顶芽不埋，其它部位平埋；干部不埋，其它部位平埋；整株平埋）对苗木顶芽越冬率影响差异显著；平埋深度对苗木顶芽成活率的影响差异极为显著，兰考泡桐苗木体面 芽失水速率高于侧芽和枝条，顶芽相对含水素与旬平均气温  相似文献   

超级电容器用活性炭的研究     

王仁清 《山东饲料》2008,(22)

以石油焦为活性炭原料,运用化学活化法制备了超级电容器用高比表面积活性炭。利用SEM和BET对实验制备的活性炭进行了分析和表征。以实验制备的活性炭为超级电容器电极材料,利用恒流充放电测试对其电容特性进行了研究。结果表明,实验研制的活性炭的比表面积为1674m2/g,中孔含量达到40%,在10mA/cm2的电流密度下其比容达到285F/g,而且基于实验研制的活性炭的超级电容器具有低内阻和良好的功率特性。  相似文献   

有机,无机肥料配合施用对地膜棉田土壤微生物及生化特性的影响   总被引：7，自引：0，他引：7  

罗明  文启凯 《新疆农业大学学报》1997,20(4):45-48

主要研究了有机、无机肥料的配合施用对地膜棉田土壤微生物及生化特性的影响，结果表明：施肥对地膜棉田土壤微生物有较大影响，其中，有机、无机肥料配合施用的影响尤为显著，可增加微生物总数，有益的氮素生理群微生物的数量，降低反硝化细菌的数量。土壤呼吸强度、纤维素分解强度等体现微生物活性的生化过程强度指标均有所增长。  相似文献   

毕节地区林业有害生物普查     

刘正忠  郑红军  曾宪勤  万艳  吴军 《贵州林业科技》2007,35(3):57-64

对全区林业有害生物进行普查,初步查出林业有害生物共七大类147种,病害53种,虫害83种,鼠(兔)害8种,寄生性种子植物3种,蜱螨3种,软体动物2种,有害植物1种.发现林业外来有害生物松材线虫病1种,有害植物紫茎泽兰1种,本土有害生物145种.  相似文献   

草鱼巨噬细胞的集结及相关的组织变化     

张奇亚  李正秋 《中国兽医学报》1999,19(5):504-507

给草鱼腹腔注射细微炭粒（墨汁）后不同时间取样，比较观察了草鱼胸腺、肝、脾、头肾和肾组织中巨噬细胞集结（ｍ ａｃｒｏｐｈａｇｅ ａｇｇｒｅｇａｔｉｏｎ ， Ｍ Ａ）状况及相应组织的变化。结果表明，在头肾和脾组织中， Ｍ Ａ 的数量和体积均较肝和肾中的多而大，胸腺中所产生的 Ｍ Ａ 数量较肝和肾中的少，体积也小；注射墨汁后 １～３ 周内，在胸腺、头肾、肝和脾组织中， Ｍ Ａ 的数量和体积均有不同程度的增加，但在注射墨汁后第 ４ 周的肾组织中， Ｍ Ａ 的体积缩小而且密度降低，同时肾组织结构有逐渐恢复的趋势，可能是由于 Ｍ Ａ 分解后通过肾小球和肾小管排泄到膀胱或体外的缘故。对草鱼 Ｍ Ａ 的组织分布、排除等分析认为， Ｍ Ａ 可作为草鱼非特异细胞防御作用的解剖学和细胞学的一种生物标记。  相似文献   

Failure of passive transfer in foals: incidence and outcome on four studs in New South Wales     

CM TYLER-McGOWAN  JL HODGSON  DR HODGSON 《Australian veterinary journal》1997,75(1):56-59

Objective To determine the regional incidence and effectiveness of treatment of failure of passive transfer (FPT) in foals. Design A study of disease incidence. Animals Eighty-eight foals and 57 mares from four studs in the practice area of the Rural Veterinary Centre were tested. Procedure Foals were tested for their serum IgG and total serum protein (TSP) concentration within the first 72 hours of life. Colostrum was collected from mares and specific gravity determined. FPT and partial failure of passive transfer (PFPT) of immunoglobulins was diagnosed when serum IgG concentrations were < 4 g/L and 4 to 8 g/L respectively. Owners of foals diagnosed with FPT were offered treatment with 1 to 2 L plasma (TSP > 70 g/L); 9 (64%) of the affected foals were treated. Results Fourteen foals (16%) had FPT whereas 15 (17%) had PFPT. There were significant differences between the mean TSP concentration in foals with FPT (42.6 ± 4.2 g/L), PFPT (48.1 ± 3.9 g/L) and those acquiring adequate passive immunity (58.9 ± 5.5 g/L) (P < 0.01). Sixteen (29%) mares had pre-suck colostral specific gravity < 1.060 and 12 (71%) foals raised by these mares had FPT or PFPT. The incidence of severe disease (categorised by a sepsis score > 11, positive culture of bacteria from blood or disease requiring hospitalisation) in all foals in the first 2 months of life was 10%. However, none of the nine foals with FPT that received plasma experienced severe disease. In contrast, foals with PFPT had an increased susceptibility to severe disease (P < 0.001) when compared with normal foals. Conclusion Treatment of foals with FPT may reduce the subsequent incidence of severe disease. Pre-suck colostral specific gravity and foal TSP may be used to predict the likelihood of FPT and PFPT. Even though the number of foals studied is small the results highlight the importance of optimal management practices in reducing the incidence of FPT and disease associated with this process.  相似文献   

Morphogenetic Effects of Different Mineral N-compounds on Roots of Maize (Zea mays L.), Spring Barley (Hordeum vulgare L.) and Broad Bean (Vicia faba L.)     

G. Geisler 《Journal of Agronomy and Crop Science》1986,157(1):67-71

Plants of maize ( Zea mays L.), spring barley ( Hordeum vulgare L.) and broad bean ( Vicia faba L.) were raised in tubes filled with a soil-sand mixture and supplied with nutrient solution. The nutrient supply was varied with regard to concentration and typ of compound of "N". Due to the relatively high concentrations of "N", dry matter of shoots and roots was reduced in comparison to the control; root morphology was affected in terms of root length and root thickness. The N-compounds, used in the experiment, exerted quantitatively different influences on dry matter production and root morphology, NH₄NO₃ being the N-form which had the weakest detrimental effects. There was no specific response to NH⁺₄ or NO⁻₃ but a strong influence could be shown for NH₄Cl and N_aNO₃. Probably not only the concentration of "N" and the form of "N" have a specific influence, but also the cations and anions associated with the N-containing ion are effective.  相似文献   

绵羊FecB突变检测方法的建立及高繁滩羊核心群的构建     

周世卫  吴庭杰  王倩  蔡蓓  韩赛铮  吴彦虎  王小龙  陈玉林 《畜牧兽医学报》2022,53(9):2920-2929

旨在建立快速、高效、精准检测FecB突变的荧光qPCR技术,为滩羊多羔性能研究、群体改良及肉用多羔滩羊新品系培育提供技术支撑。基于荧光qPCR技术基本原理,设计特异性引物对,开发基于荧光qPCR检测绵羊FecB突变的方法;对85只已知FecB基因型的健康、适繁雌性滩羊血液基因组DNA样品分别采用PCR-Sanger测序法、TaqMan探针法和荧光qPCR法进行FecB基因分型,统计3种方法的准确率;采用开发的荧光qPCR方法对939只健康、适繁滩羊进行FecB基因分型,统计不同FecB基因型经产母羊的产羔率。结果表明,使用TaqMan探针法、PCR-Sanger测序法和开发的荧光qPCR法对已知FecB基因型样品检测的比较中,荧光qPCR法对各基因型鉴定的准确度均达100%,高于前两者。939只滩羊FecB基因分型结果显示,6只滩羊为FecB突变纯合型（BB）、57只为杂合型（B+）、876只为野生型（++）,BB型、B+型和++型滩羊的基因型频率分别为0.64%、6.07%和93.29%,其中B等位基因频率为0.04,+等位基因频率为0.96;监测母羊群体的产羔数发现,FecB突变纯合型滩羊产羔率为166.67%,突变杂合型滩羊产羔率为153.12%,野生型滩羊产羔率为105.78%,纯合突变型和杂合突变型母羊群体的产羔率极显著高于野生型群体（P<0.01）。综上所述,与TaqMan探针法及PCR-Sanger测序法相比,本研究建立的绵羊FecB突变荧光qPCR分型方法具有简便易行、廉价高效的优点,在绵羊的分子选育中具有较高应用价值;同时本研究证实了滩羊FecB突变可显著提高母羊产羔率,为多羔滩羊的分子选育提供了坚实的技术支撑。  相似文献   

黄土高原果园不同覆盖模式对土壤酶活性的影响     

田玉莉  吴小苹  陈欣佛  郭亚茹  李泽林  倪新华  张嘉涛  李会科 《草地学报》2022,30(10):2581-2589

为探究土壤绝对酶活性和相对酶活性在果园不同覆盖模式下的变化特征及相关影响因素,为果园土壤质量评价提供理论依据,本试验以传统清耕(Conventional tillage,CT)为对照,研究秸秆(Corn stalk,CS)、黑麦草(Lolium perenne L. Ryrgrass,RE)和白三叶(Trifolium repens L. White clover,WC)处理下α-葡萄糖苷酶(α-glucosidase,AG)、β-葡萄糖苷酶(β-glucosidase,BG)、β-木糖苷酶(β-xylosidase,BXYL)、纤维二糖苷酶(Cellobiosidase,CBH)、乙酰氨基葡萄糖苷酶(Acetylglucosaminidase,NAG)、亮氨酸氨基肽酶(L-leucine aminopeptidase,LAP)和碱性磷酸酶(Alkaline phosphatase,ALP)变化特征及影响因素。结果表明,覆盖措施不同程度提高了0~40 cm各土层土壤绝对酶活性。AG,BG,BXYL,CBH,NAG和ALP活性表现为CS>RE>WC>CT,LAP表现为WC>CS>RE>CT。不同覆盖下土壤相对酶活性变化与绝对酶活性基本一致。冗余分析表明,土壤酶活性与有机碳、全氮、全磷等土壤理化因子含量正相关,而与pH值和容重负相关,有机碳、硝态氮和铵态氮含量是影响土壤酶活性的关键环境因素。  相似文献   

锥栗干制研究Ⅰ.锥栗鲜果中坏粒剔除研究   总被引：3，自引：0，他引：3  

陈钦  邹双全 《经济林研究》2002,20(2):84-86

对锥栗干制品制作中所产生的原料坏粒剔除进行了研究。实验结果表明 ,通过对原料抽样比较 ,测定坏果率的含量 ,得出最佳抽样数量 ,使样品的检测结果具有代表性 ;通过对个体坏果比重的测定 ,得出总体坏果的比重 ,能最大限度剔除坏果 ;通过盐水浓度的选择 ,剔除鲜果中的坏果 ,从而保证了成品的质量。  相似文献