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41.
以京秀、早黑宝、白鸡心、克伦生4个鲜食葡萄品种的1年生枝为试材,通过对生根促进剂吲哚丁酸浓度的筛选试验,选择吲哚丁酸(2 000mg/L)对葡萄硬枝进行扦插成活率的影响试验。结果表明:克伦生、白鸡心生根情况较好,早黑宝居中,京秀最差。  相似文献   
42.
采用问卷法对160名北京本科一年级的学生进行调查,对大学生的学习成绩与智力、人格特征的关系进行讨论。学习成绩用高考成绩表示。问卷包括团体IQ测验量表和青年人格问卷(CPI),分别对智力和人格特征进行测量。结果表明,大学生的学习成绩不仅跟智力有关,而且还跟人格特征有着紧密的相关。因此,我们不仅要重视学生智力的培养,也要要关注学生健康人格的培养。  相似文献   
43.
黄颡鱼(Pelteobagrus fulvidraco)是较为典型的淡水刺毒鱼类,本研究结合宏观毒棘骨骼标本制作和微观组织切片等方法,深入探究黄颡鱼的毒棘结构。研究结果表明,黄颡鱼的胸鳍和背鳍均具有尖锐的倒刺棘骨,棘骨外包围着皮膜,皮膜拥有能分泌毒液的毒腺细胞,它们共同组成了黄颡鱼毒棘装置。毒棘骨骼宏观结构表明,黄颡鱼的背鳍和胸鳍毒棘均具有贯穿全棘骨的中央管和包围棘骨的皮膜;背鳍棘骨细长、锥形,且轻微拱起,顶部骤尖,后缘为弱锯齿;胸鳍棘骨前后缘均有锯齿,但后缘为强锯齿。背鳍和胸鳍毒棘基部结构的髁突形状、大小、位置全然不同。微观结构显示,皮膜中的毒腺细胞聚集成层,位于鳞状上皮与色素层之间,未见导管与之相连,背鳍和胸鳍毒棘的分支性骨管中均未发现毒腺细胞。胸鳍和背鳍锁紧装置可让毒棘保持倒伏或者直立的锁定状态,降低猎物挣脱几率。本研究可深入了解黄颡鱼的毒棘结构和特征,增强人们对刺毒鱼类的认知,同时为淡水刺毒鱼类深入研究奠定基础。  相似文献   
44.
杜辉  李华 《中国乳业》2020,(7):21-23
在现代经济社会中,每个企业都需要树立自己的品牌,而树立自身品牌首先要了解目标顾客,分析目标顾客,从而拿出更好的服务与产品来服务目标顾客,所以对消费者的行为研究至关重要。以回龙观地区为例,以蒙牛低温酸奶为切入点,研究居民对低温酸奶消费行为的影响因素,对了解国内低温酸奶市场,促进国内低温乳业健康发展具有一定的作用。  相似文献   
45.
OBJECTIVE: To determine effect of diets with variable n-6-to-n-3 fatty acid (FA) ratio on CD4+ and CD8+ T-lymphocyte subpopulations, and on results of routine laboratory analyses (CBC and total WBC count, serum biochemical analyses, and urinalysis). ANIMALS: 20 healthy, aged (9.5 to 11.5 years old) female Beagles. PROCEDURE: Dogs were fed 1 of 3 diets that contained 6% fat by weight but differed in amounts of n-6 and n-3 FA. For 11 weeks, 6 dogs were fed a low concentration of n-3 FA (ratio, 31:1), 7 were fed a medium concentration (5.4:1), and 7 were fed a high concentration (1.4:1). Preprandial blood and urine samples were collected before beginning the study and at 8 weeks for evaluation of laboratory variables. Before and at 3, 6, and 8 weeks during the study, blood was drawn for total WBC and lymphocyte counts and for characterization of T-cell subpopulations. At 8 and 10 weeks, dogs were vaccinated with keyhole limpet hemocyanin suspension. Blood was drawn 4 days after each vaccination, and lymphocytes were isolated for flow cytometry. Effects of diet and vaccination on each variable were determined. RESULTS: After vaccination, total lymphocyte count increased and CD4+ T lymphocyte count and the CD4(+)-to-CD8+ ratio decreased in dogs consuming the diet with n-6-to-n-3 FA ratio of 1.4:1. CONCLUSION: Feeding a diet with n-6-to-n-3 FA ratio of 1.4:1 had significant effects on CD4+ T lymphocytes in healthy, aged Beagles after vaccination.  相似文献   
46.
为了帮助我国北方旱区或半干旱区绵羊度过草枯严寒的漫长冬、春季,开发研制一种能够提高现有草料利用率的绵羊中草药饲料添加剂。根据中兽医药学的辨证施治理论,采用小鼠日粮添加倍量秸秆粉和不同中草药复方的方法,在120只小鼠上进行了增重率和重料比的中草药复方的筛选研究。结果表明,以益气养血和消食健胃为主的两个中草药复方能够较好地改善小鼠的增重率和重料比。  相似文献   
47.
The objective of this study was to evaluate the effects of supplemental magnesium (Mg) on the performance of gilts and parity 3 sows and their piglets. Fifty-six gilts (Trial 1) and 56 sows (Trial 2) were assigned to one of 4 treatments according to their mating weight, respectively. The treatments comprised corn-soybean meal based gestation and lactation diets (0.21% magnesium) supplemented with 0, 0.015, 0.03, or 0.045% Mg from mating until weaning. The results showed that magnesium supplementation significantly (P < 0.05) reduced the weaning to estrus interval in both gilts and sows. There were significant effects (P < 0.05) of supplemental magnesium on the total number of piglets born, born alive and weaned in sows. In late gestation and lactation, the digestibility of crude fiber (quadratic effects, P < 0.05), and crude protein (P < 0.05), were significantly influenced by magnesium in gilts and sows, respectively. There were differences among the 4 groups in terms of the apparent digestibility of dry matter and crude fiber in sows (P < 0.05) during both early and late gestation. The apparent digestibility of gross energy was increased for sows in late gestation (P < 0.05), and lactation (quadratic effects, P < 0.05). At farrowing and weaning, serum prolactin levels and alkaline phosphate activities linearly increased in sows as the Mg supplementation increased (P < 0.05). Serum Mg of sows at farrowing and serum urea nitrogen of sows at weaning was significantly influenced by Mg supplementation (P < 0.05). The Mg concentration in sow colostrum and the serum of their piglets were increased by supplemental magnesium (P < 0.05). In addition, growth hormone levels were linearly elevated (P < 0.05) in the serum of piglets suckling sows. Our data demonstrated that supplemental magnesium has the potential to improve the reproduction performance of sows, and the suitable supplemental dose ranged from 0.015% to 0.03%.  相似文献   
48.
The present study developed and validated a species-specific loop-mediated isothermal amplification (LAMP) assay for the rapid detection and discrimination of two benign bovine Theileria species – T. sergenti and T. sinensis. The LAMP assay is inexpensive and easy to perform and involves a rapid reaction-the amplification can be performed in 55 min or 50 min under isothermal conditions of 61 °C or 63 °C, respectively, by employing a set of four species-specific primer mixtures. The results can be checked using agarose gels. The optimal assay conditions, under which the assay exhibited with no cross-reaction with other closely related tick-borne parasites (T. annulata, Babesia bovis, B. bigemina, B. major, B. ovata, B. U. sp., Anaplasma marginale) or between the two Theileria species of interest, was established. The assay is approximately 10-fold more sensitive than the conventional specific PCR assay. The LAMP assay was validated using DNA from 6 standard stocks in the laboratory and was evaluated for its diagnostic utility using blood samples collected from experimentally and naturally infection cattle or yaks in China. These findings indicate that this Theileria species-specific LAMP assay may have potential clinical applications for the detection and differentiation of two benign bovine Theileria species – T. sergenti and T. sinensis, especially in endemic countries.  相似文献   
49.
菜粉蝶绒茧蜂种群空间分布型及其应用   总被引:2,自引:0,他引:2  
杜予州  任顺祥 《昆虫天敌》1989,11(3):130-135
本文应用频次分布x~2检验法,Iwao法,Taylor幂法则以及其它聚集指标等方法,分析研究了菜粉蝶绒茧蜂种群(茧块)的空间分布型。结果表明:菜粉蝶绒茧蜂茧块在甘蓝上呈聚集分布,分布的基本成分是以个体群形式存在,个体群之间是随机的,茧块的聚集是由寄主等环境因素引起的。此外,利用分布型参数确定了理论抽样数及序贯抽样。  相似文献   
50.
稻秆潜蝇是浙南山区水稻生产的重要害虫.通过推广薄膜育秧、绿肥田除草、选用抗性品种、实行健身栽培、生态控制等一系列综合防治技术,可达到经济有效的防治效果.在水稻整个生长期可减少用药1~2次,稻秆潜蝇穗被害率减轻41.03%,病虫害损失控制在3.6%以内,稻谷增产9.2%,稻田害虫天敌蜘蛛和黑肩绿盲蝽分别增加38.1%和26.3%,获得了明显的生态、经济效益.  相似文献   
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