混凝土结构表面蜂窝麻面成因及其防治措施     

吴春华  徐岩峰 《林业科技情报》2009,41(1):56-57

随着建筑业的飞速发展和科技水平的不断提高,工程对混凝土的各种性能要求越来越高,不仅要求混凝土工作性能好、强度指标高、耐久性好等,而且还要求混凝土结构表面无蜂窝麻面光洁如镜的外观,尤其是清水混凝土结构要求更为严格,为此我们必须加以防范,给予重视。  相似文献   

压力实时监测法在管道泄漏检测中的应用   总被引：2，自引：0，他引：2  

靳春义  宋春花 《油气储运》2001,20(8):48-49

检测输油管道漏油的方法很多，介绍了通过压力实时监测确定输油管道漏油点方法，以及实际应用情况。实践证明，通过压力实时监视确定输油管道漏油点的方法在实际输油运行中是切实可行的。  相似文献   

日光温室内外金太阳杏光合特性的比较研究   总被引：12，自引：0，他引：12  

王鸿  王发林  牛军强  班明辉 《果树学报》2005,22(5):479-482

为了探明杏对设施栽培的生理反应,对日光温室内外金太阳杏光合特性进行了比较研究。结果表明,日光温室栽培条件下,金太阳杏单位重量叶片的叶绿素含量增加;光(CO2)饱和点和光(CO2)补偿点降低鸦露地晴天净光合速率Pn日变化呈明显的双峰曲线,温室内也呈双峰线,但双峰出现原因不同。并且研究了影响光合作用的主要生态因子及变化规律,发现净光合速率与胞间CO2浓度、蒸腾作用、气温、叶温、光合有效辐射等因子相关。  相似文献   

连农923菜豆胚培养技术及愈伤组织诱导研究     

孙丽娜  王淼  吴春华 《长江蔬菜》2016,(4):56-57

以连农923菜豆种子为试验材料,探讨不同外植体取材部位对胚培养的效果,并探索不同激素配比及接种方法对连农923菜豆愈伤组织诱导效果的影响。试验结果表明,在菜豆胚培养过程中,完整胚芽、胚根接种法最适合胚培养;愈伤组织诱导的最佳接种方式为胚芽、胚根切段接种法,最佳培养基为MS基本培养基+2 mg/L 2,4-D,pH值5.8。  相似文献   

自动车床工序调整卡的计算机辅助设计     

卞鲁平  赵春花 《山东农机》2014,(1):62-67

“经验式”和“创成式”是计算机辅助工艺过程设计的两种基本的技术方法.后一种技术方法虽然还不够成熟,但它在CAPP系统的设计与实现上具有很多的优势.描述了计算机辅助设计在自动车床加工中的一些应用,它涉及到工艺方案的制定和加工工序的安排.另外,它描述了一些特有的计算机算法和编程原理.  相似文献   

植物组织培养技术发展现状及方向     

齐春华 《农业科技与装备》2011,(4)

植物组织培养技术是农业生物技术中最早实现产业化并取得显著经济效益和社会效益的领域,在理论研究和生产实践中具有广泛的应用价值.通过对国内外组培技术发展现状、存在问题和发展趋势的分析,指出植物组织培养技术的优点和我国在该技术领域的发展方向.  相似文献   

产蛋期蛋鸡不同类型玉米净能研究     

班志彬  张芳毓  武斌  杨琳  张鑫  杨华明  李立佳  梁浩  李柏浩  郎朝丽  闫晓刚 《动物营养学报》2020,(4):1650-1657

本试验利用禽用开放式呼吸测热装置进行能量代谢试验,通过间接测热法结合替代法测定不同类型玉米在产蛋期蛋鸡饲粮中的表观代谢能和净能。选用34周龄产蛋期海兰褐蛋鸡180只,随机分为6组,每组30只。试验选用1种玉米-豆粕型基础饲粮和5种待测饲粮。待测饲粮由5种待测玉米(3种2018年10月收获的正常玉米和2种2016年收获储存3年的陈化玉米),分别以50%比例替代基础饲粮构成。试验鸡在舍内笼养,预试期7 d,正试期27 d,其中正试期分为3期,每期9 d(适应3 d、呼吸测热3 d、绝食测热3 d)。每期试验中,从每组中选择4只试验鸡,称重后分别放入呼吸测热装置的12个代谢室(每个代谢室2只),每2个代谢室对应1种饲粮,测定气体交换和排泄物总量,呼吸测热的同时进行消化代谢试验。结果表明:与基础饲粮相比,5种玉米待测饲粮的表观代谢能显著提高(P<0.05),3种正常玉米待测饲粮的净能显著高于基础饲粮和2种陈化玉米待测饲粮(P<0.05);2种陈化玉米的表观代谢能和净能显著低于3种正常玉米(P<0.05)。本试验中,3种正常玉米的表观代谢能分别为16.19、15.85、16.17 MJ/kg,2种陈化玉米的表观代谢能分别为15.12和15.06 MJ/kg;3种正常玉米的净能分别为12.39、12.57、12.25 MJ/kg,2种陈化玉米的净能分别为11.29和12.05 MJ/kg。  相似文献   

Green tea polyphenols supplementation alters immunometabolism and oxidative stress in dairy cows with hyperketonemia     

Yanfen Ma  Ying Feng  Liwen Song  Muyang Li  Hongyu Dai  Hua Bao  Guijie Zhang  Lei Zhao  Chunhua Zhang  Jing Yi  Yusheng Liang 《动物营养（英文）》2021,7(1):206

Peripartal cows often experience negative energy balance, and are therefore prone to suffering from metabolic diseases such as hyperketonemia, which causes financial losses in dairy farms. This study aimed to investigate the effect of green tea polyphenol (GTP) supplementation during the periparturient period on production performance, oxidative stress and immunometabolism in dairy cows with hyperketonemia. One hundred Holstein cows were assigned to GTP (0.2 g/kg DM; n = 50) or control (without GTP; n = 50) group based on body weight, previous milk yield, and parity on d 15 before expected parturition. Subsequently, 10 cows with hyperketonemia were selected from each group, according to blood β-hydroxybutyric acid (BHBA) concentration between 1.2 and 2.9 mmol/L from 2 to 3 d postpartum. All cows were fed a close-up diet and a lactation diet with or without GTP supply from 15 d prepartum until 30 d postpartum. Milk and blood samples were obtained from 20 cows selected with hyperketonemia on 10, 20, and 30 d postpartum. Compared with control cows, greater milk yield and lower somatic cell count were observed in GTP cows. The GTP group had lower concentrations of BHBA, free fatty acids, cholesterol, triglyceride, reactive oxygen species, malondialdehyde, and hydrogen peroxide, greater concentrations of glucose, lower activities of aspartate aminotransferase, alanine aminotransferase, and glutamyl transpeptidase, alongside greater activities of superoxide dismutase, glutathione peroxidase, and total antioxidant capacity. Additionally, GTP supplementation up-regulated concentrations of interleukin-6 and interleukin-10, but down-regulated concentrations of tumor necrosis factor-α, interleukin-1β, interleukin-2, interleukin-8, and interferon-γ in plasma. Greater concentrations of plasma immunoglobulin G were also detected in the GTP group. Overall, the data suggested that GTP supplementation from 15 d prepartum to 30 d postpartum improved the milk yield and health status in cows with hyperketonemia during early lactation.  相似文献   

手持式电动绿篱修剪机的研究与设计   总被引：1，自引：0，他引：1  

杨天兴  赵春花  安虎平  柴昌盛 《中国农机化学报》2015,(3):67-69,73

通过对目前市场上绿篱修剪机结构和使用特点的详细分析,设计了一种用220V照明电为电源、手提砂轮机作为主机,用专门制作的切割器替换砂轮片实现快速修剪成形的手持式电动绿篱修剪机。试验表明,该修剪机有很好的实用价值和推广前景。  相似文献   

Model of Survivable Architecture     

BAN Xiao-fang  Xiang Hong 《保鲜与加工》2005,(8):56-59

Critical information system in Interact is in face of increasingly security problems. More attention has been focused on the survivability of information system, which is the capability of system to continue its mission even in the presence of damage to the system. The authors first introduce the definition of survivability. According to four function properties of survivability, which are Resistance, Recognition, Recovery, and Adaption, the authors design a model of survivable system structure and then explain survivability requirement, survivability strategy in this model. Additionally, they provide possible technical solutions for the survivability of systems, categorized by different aspects of our survivability strategy.  相似文献