低温胁迫对葡萄品种梅鹿辄和贝达活性氧代谢的影响

以抗寒性不同的2个葡萄品种梅鹿辄和贝达为材料,研究不同温度下其1年生枝条叶片的细胞膜相对透性、丙二醛(MDA)含量、超氧化物歧化酶(SOD)等抗氧化酶活性变化,并用组织化学定位方法检测氧自由基(O2·-)和H2O2水平,以期分析各指标与葡萄抗寒性之间的关系并了解其抗寒机制。结果表明,随温度降低,两个葡萄品种叶片的细胞膜相对透性、MDA、O2·-和H2O2含量显著升高,并且抗寒性弱的梅鹿辄增大幅度显著大于抗寒性强的贝达;贝达叶片中SOD、过氧化物酶(POD)和过氧化氢酶(CAT)活性随温度降低显著提高且POD和CAT活性增大幅度显著高于梅鹿辄。推测POD和CAT活性及O2·-和H2O2形成速度与葡萄品种的抗寒性关系密切。     

乳腺特异表达载体缺失片段的鉴定与修复

通过对pBC1中的乳腺特异表达启动子成分进行分析,鉴定了位于β酪蛋白启动子上游两个EcoRⅠ位点(-89~-94和-120~-125)之间的缺失片段,31bp的缺失使得该载体中的一个乳控盒元件(-112~-141)和一个乳腺因子识别序列(-92~-102)遭到破坏,并使得位于TATA框上游的所有启动子成分发生了位置改变。通过与山羊β酪蛋白启动子序列进行比较,设计并合成了缺失片段,经一系列的酶切和连接处理,使得该缺失得到了修复,修复后的载体具有所有乳蛋白表达需要的启动子调控原件。本试验结果为利用修复后的乳腺特异高效表达载体进行乳腺生物反应器的研究奠定了分子生物学基础。     

蜜腺发达Ogura晚抽薹不结球白菜雄性不育系的鉴定

本试验以Ogura晚抽薹不结球白菜薹ms等为材料,通过观察和比较熊蜂对不同白菜品种访花次数和访花滞留时间的差异,选择出能吸引熊蜂访花且访花滞留时间长的Ogura薹ms植株。对选择出植株的蜜腺大小和开花结实特性进行了进一步鉴定,结果表明选出的薹ms株蜜腺发达,开花结实正常,为选育优良晚抽薹胞质不结球白菜雄性不育系奠定了基础。     

烟台市拉美斑潜蝇发生规律及控制技术研究

通过 1 998～ 2 0 0 0年对拉美斑潜蝇的研究结果表明 :①寄主植物有伞形花科等 1 6科 68种 ,温度是制约其发生的主要因子 ,不能在自然环境条件下越冬 ,但可在冬暖大棚内越冬和继续发生为害 ,成为露地发生主要虫源 ,通过自然传播扩散 ;②控制为害的关键技术是 ,选用以生物农药为主的农药品种 ,对冬暖大棚及伞形花科、豆科及葫芦科等受害重的菜田进行集中治理 ,做到早防治和连续防治的综合措施 ;③ 3年共累计防治面积 50 0 0 0hm2 ,其经济、生态和社会效益显著     

南美斑潜蝇幼虫空间分布与抽样技术研究

通过田间调查和计算 ,明确了南美斑潜蝇幼虫呈聚集分布 ,且以负二项分布为主 ,主要分布在植株的中下部。如果防治指标定为每百叶有虫 3 7头 ,则序贯抽样的累积幼虫数量界限 :T0 (N) =0 .3 7N± 0 .83 68N。田间随机取样以平行线和Z字形为好。     

低压电器控制展示柜的设计制作

结合现有电气实验装置的具体教学特点,设计并制作了低压电器控制展示柜,成为辅助性教学设备。展示柜布置了电气元器件和典型电气控制回路,在实践教学中起到了积极的作用。     

ASP平台的Cookie会话攻击及防范措施

Cookie是Web服务器保存在用户浏览器上的文本信息.它相当于网站发给某用户进入该网站的身 份的标识.在许可的时间中,用户可以凭着这个身份标识在该网站中行使自已的合法权限.由于Cookie信息 是被保存在客户端的,这就给恶意攻击者提供了窍取通行证的可能.一旦Cookie信息被窍取,攻击者就可以 伪装成该用户,为其他类...     

局部应用IL-12对小鼠S180实体瘤的抗瘤效应及机制初探

目的研究白细胞介素-12（Interleukin 12,IL-12）对小鼠S180实体瘤的抗肿瘤作用并初步探讨其机制.方法将小鼠左后肢皮下接种S180细胞荷瘤后的BaLB/c小鼠随机分为生理盐水组和IL-12组,分别给予生理盐水和IL-12.接种第28天,眼球取血,流式细胞仪分析外周血T细胞亚群的变化;解剖取瘤称重,计...     

Early-warning Indicators of Acidification in the Single-phase Anaerobic Digestion Process for Food Wastes

The commonly used indicators are often too slow to reflect the operating status in time.Confronted with lacking reliable early-warning indices in the single-phase anaerobic digestion for kitchen waste which is easy to decay,lab-scale experiments of start-up and continuous operation process of anaerobic digestion for kitchen waste were carried out in the single-phase anaerobic reactor which is self-designed under mesophilic conditions.Those values which reflect the capacity of acidity-basicity resistance,including the ratio of bicarbonate alkalinity to total alkalinity (BA/TA),absolute testing value of volatile fatty acid (VFA) and the ratio of total concentration for volatile fatty acid to bicarbonate alkalinity (VFA/BA),are determinated to be the early-warning indices for acidification and imbalance of single-phase anaerobic digestion for kitchen waste.It is considered that,when VFA/BA＞0.8,BA/TA＜0.4 and VFA＞3000mg/L,buffering capacity of the system is very poor,and the system might be out of control.Therefore,an immediately steps must be taken.While,when BA/TA≥0.7~0.8 and VFA/BA＜0.4,the alkalinity of system is relatively better and the process can be operated with higher organic volumetric loading,which can raise the biogas-producing efficiency and get economic benefit.     

Ratio control strategy for solving system response lag of continuously variable transmission system

Generally, there’s a system response lag in the continuously variable transmission system, and this leads to a deviation of the engine work point from the optimal operation line of the minimum fuel consumption. To reduce the influence of system response lag, a new CVT ratio control strategy with the system response lag parameter during computing target ratio is proposed. Simulation results indicate that the proposed control strategy can overcome the effect of system response lag, so as to keep the engine work point on the optimal operation line effectively. A comparison of fuel consumption is made between the proposed control strategy and the traditional one by simulation, and results indicate that the proposed control strategy reduces the fuel consumption of the system by 2.85％.