城市公交车制动能量回收方式综述

文章在分析城市公交车运行工况的基础上,说明了城市公交车能量回收系统的必要性。分析了三种制动能量回收方式的结构原理,对三种制动能量回收系统在城市公交车上的应用进行了分析比较。     

渗灌对日光温室番茄栽培环境的影响

研究了渗灌和漫灌对日光温室番茄栽培环境及番茄产量的影响。结果表明,渗灌下,土壤密度比漫灌低7.59%,差异极显著;土壤总孔隙度比漫灌高9.72%,差异显著;土壤黏粒和粉粒高于漫灌,而砂粒和细粗砾低于漫灌;观测时段内,渗灌下平均气温、10cm处土壤平均温度较漫灌分别高1.55℃、0.86℃,地表平均温度比漫灌低0.14℃;渗灌下温室空气相对湿度较漫灌低11.86%,以10:00—20:00差值最大;渗灌下番茄产量比漫灌高8.60%,且差异显著。     

Expression Analysis of THBS3 Gene in Different Tissues and Skeletal Muscles at Different Periods from Landrace and Tongcheng Pigs

To study the expression pattern of THBS3 gene in different tissues and during skeletal muscle development, the THBS3 gene expression in different tissues and skeletal muscles during prenatal periods (33, 45, 65, 70 and 90 d) and postnatal periods (0, 9, 30, 60, 120 and 160 d) from Landrace and Tongcheng pigs were detected by Real-time quantification PCR.The results showed that THBS3 gene widely expressed in all tissues examined, exhibiting similar spatial expression patterns with expression peaks in lung in both pig breeds except in stomach and intestine.Moreover, although THBS3 gene showed a significant higher expression level in gestation than after birth in Landrace and Tongcheng pigs (P<0.05), it exhibited different expression patterns between Landrace and Tongcheng pigs, the expression peak was detected at gestation day 45 in Landrace pig, while was detected at gestation day 65 in Tongcheng pig.The results suggested that THBS3 gene involved in skeletal muscle growth and development in pigs, as well as the regulation of asynchronization of skeletal muscle development in different pig breeds.     

麦草畏、水杨酸对西洋参成熟种胚体细胞胚发生的影响

以西洋参成熟种胚为试材,以不加激素和添加0.5mg/L 2,4-D的MS培养基为对照,研究了不同浓度(0.05~2.00mg/L)麦草畏、水杨酸对西洋参体胚发生的影响。结果表明:未添加激素的空白培养基没有愈伤和体胚发生;在附加2,4-D的培养基中愈伤和体胚发生率为100%;5个浓度的麦草畏和水杨酸均能诱导出体胚,其中1.00mg/L麦草畏的效果最佳,体胚发生率为56.60%,水杨酸处理下体胚发生率最高为7.50%;在各种浓度的水杨酸中种胚生长量比对照小且褐化严重。说明麦草畏、水杨酸均可诱导西洋参成熟种胚体细胞胚发生,诱导能力2,4-D麦草畏水杨酸;水杨酸对种胚生长有抑制作用。     

不同浓度多效唑和比久浸种对甜瓜幼苗质量的影响

为解决新疆吐鲁番地区甜瓜工厂化育苗当中遇到的容易出现徒长苗,不易培育出适龄壮苗等问题,选用甜瓜品种"西州密十七号"为试材,研究不同浓度植物生长延缓剂多效唑(PP333)和比久(B9)浸种处理对甜瓜幼苗质量的影响。结果表明:甜瓜幼苗发芽势随着PP333溶液浓度的增大而降低,幼苗的株高和下胚轴长显著小于对照;浓度为60mg/L的PP333溶液浸种处理下的幼苗叶片厚度和幼苗壮苗指数最大;60mg/L和80mg/L的PP333溶液浸种处理下幼苗根冠比最大。PP333溶液浸种处理对甜瓜幼苗的株高、下胚轴长、叶片大小和厚度的抑制作用大于B9溶液,可以用于防止幼苗徒长,培育壮苗。     

黄瓜棒孢叶斑病菌的毒力分化及AFLP分析

以6个黄瓜品种(系)为试材,以来自山东、辽宁、黑龙江的200个黄瓜棒孢叶斑病菌为供试菌株,采用苗期接种鉴定及AFLP分子标记技术,研究了黄瓜棒孢叶斑病菌的毒力分化。结果表明:黄瓜棒孢叶斑病菌存在生理小种分化现象,并将200个菌株分为4个生理小种,初步筛选出D0330、D1306、D0649和D2025作为研究黄瓜棒孢叶斑病菌生理小种分化的鉴别寄主备选材料;AFLPs与菌株的地理来源无关,与毒力存在相关性。     

香葱连作障碍的成因及其修复试验

选取不同连作年限(0、2、4、6、10、15 a)的葱田土壤,测定土壤的养分、微量元素和重金属含量,发现不同连作年限土壤中的铁、硼、镁等微量元素含量丰富,但是连作葱田土壤的容重、有机质含量和铵态氮含量有不同程度降低,硝态氮含量显著提高。用5种土壤改良剂对连作年限为15 a的葱田进行土壤淋施处理,试验结果表明,奥普尔冲施肥使土壤中的硝态氮含量降低11.57%,铵态氮含量提高50.27%,香葱产量提高2.66%,是最佳的土壤改良剂。     

Loser cows in Danish dairy herds: definition, prevalence and consequences

During the last few years, many Danish dairy farmers have expressed increasing concerns regarding a group of cows, which we have chosen to term ‘loser cows’. Until now, a loser cow has not been described scientifically. We defined a loser cow on the basis of a clinical examination of the cow. A total of 15,151 clinical examinations were made on 6,451 individual cows from 39 randomly selected, large Danish dairy herds with loose-housing systems using a clinical protocol. Scores for the clinical signs lameness, body condition, hock lesions, other cutaneous lesions, vaginal discharge, condition of hair coat and general condition were converted into a loser cow score. Cows with a loser cow score of 8 or more were classified as loser cows. The overall prevalence of loser cows was 2.15%, 4.50% and 2.98% during the first, second and third round of herd visits, respectively.

The associations between the loser cow state and milk production, mortality, morbidity, culling and workload for the farmer were evaluated using data from herd visits and from the Danish Cattle Database and a number of different statistical techniques. It was concluded that the loser cow state has significant negative consequences for both the farmer and the cow. On average, loser cows yielded 0.61 to 2.24 kg energy corrected milk less per day than non-loser cows depending on parity. Hazard ratio for death or euthanasia was 5.69 for loser cows compared to non-loser cows. Incidence rate ratio for disease treatments was 0.69 for non-loser cows compared to loser cows. Loser cows were often culled in an ‘unfavourable’ way and generally caused extra workload for the farmer.

A simplified version of the loser cow score was evaluated and is recommended for future research and use in practice.     

陆地棉一个丝氨酸/苏氨酸激酶蛋白基因的克隆与表达分析

通过RT-PCR获得一个编码棉花丝氨酸/苏氨酸激酶类似蛋白全长的cDNA片段,其编码的氨基酸序列与拟南芥ATPK3的相似度达到82%,这个基因暂被命名为GhPK1。基因全编码区包括1038个核苷酸,编码346个氨基酸的蛋白。GhPK1的编码产物在265~270个氨基酸处有一个跨膜区并可能结合在内质网膜上。GhPK1在种子和纤维中的表达水平较其它组织高。另外,GhPK1的表达量在受到盐胁迫后上升,说明GhPK1可能参与了盐胁迫反应。     

GA3和PP333对萝卜生长及产量的影响

通过研究不同浓度的GA3和PP333及两激素不同浓度的互作对萝卜叶面积、叶重量、叶子叶绿素含量及根冠比的影响。结果表明，两者对叶子叶绿素含量没明显影响，但GA3在促进叶子的生长，叶面积的增大上以10~30ppm效果最好，而PP333虽然能抑制叶子的生长，但在肉质根生长中后期试用50ppm浓度的PP333，抑制了叶子的生长，反而促进了光合产物输送到肉质根，起到增产的作用。适当浓度的GA3和PP333及两者结合增产效果明显