基于Ansys的泥浆泵连杆的有限元分析

运用刚体平面运动学理论对泥浆泵动力端进行受力分析,结合PROE、ANSYS建立了连杆的几何模型和有限元模型,重点讨论了连杆大、小头载荷和惯性力的处理方法,给出了加载方程及其计算过程,并使用APDL语言实现了复杂载荷的程序化加载。在此基础上,运用有限元理论对连杆进行了静力学分析,得到了连杆在在典型工况下的应力状态及其危险部位,为进一步对曲轴连杆的设计和改进提供了可靠依据。     

茶厂粉尘理化特性、成因及控制

茶厂粉尘指茶叶加工过程中所产生的粉尘、灰尘、烟尘等污染要素。介绍了茶厂粉尘浓度、粉尘成因、粉尘粒度特性以及粉尘理化特性,系统地研究揭示茶厂粉尘的产生、传递和累积效应。考虑到茶叶生产车间物料的特殊性以及茶厂布局优化和清洁化生产具体要求,探讨了抖筛机、平面分筛机、平面撩筛机、切茶机、风选机、匀堆装箱机的尘源控制方法,以及与之相结合的解决粉尘污染具体措施。通过综述近年来有关茶厂粉尘控制的新技术,超声波雾化除尘、袋式除尘、静电除尘、声波清灰等在茶厂除尘中应用的可行性分析,进而提出了茶厂粉尘控制存在的技术难题及相应的解决途径,为进一步明确茶厂粉尘有效控制的系统性方法及相关的评价指标提供了思路和依据,并对该研究领域进行了展望。     

滋味物质在不同交联度鱼糜凝胶中的释放动力学分析

为探讨滋味物质在不同交联度鱼糜凝胶中的释放规律并揭示其释放机制,该研究以氯化钠、蔗糖和谷氨酸钠分别为鱼糜凝胶咸味、甜味和鲜味的代表滋味物质,通过感官评价、释放动力学模型拟合和模拟咀嚼释放等方法,分析滋味物质在不同交联度鱼糜凝胶中的释放规律。结果表明,随着交联度的增加,人体对咸味的感知逐渐降低而对鲜味的感知逐渐增强,并当交联度大于42.2%时,咀嚼破碎显著提高了鱼糜凝胶咸味和鲜味的感知（P<0.01）。氯化钠和蔗糖的释放动力学曲线符合准一级动力学模型,而谷氨酸钠的释放则符合准二级动力学模型。随着交联度的增加,鱼糜凝胶在模拟咀嚼过程中氯化钠和蔗糖的释放量先降后升,分别在交联度为42.2%和51.5%时取得最小值（4.54和3.38 mg/g）;而谷氨酸钠的咀嚼释放量则逐渐增加。相关性分析结果表明,氯化钠和蔗糖在鱼糜凝胶中的释放主要与网络结构和化学作用力相关,谷氨酸钠的释放主要与凝胶质地、凝胶持水性和化学作用力相关。综上,滋味物质在鱼糜凝胶中的释放行为受滋味物质种类、凝胶质地以及凝胶与滋味物质的相互作用等多方面的影响,且凝胶在咀嚼过程中较高的破碎程度增强了滋味物质的释放与感知。     

不同水稻种质中渗透胁迫抗性基因DREB2A的遗传多样性分析

本研究旨在分析转录因子DREB2A基因在不同水稻种质中的遗传多样性,以期为水稻耐渗透胁迫遗传改良提供分子工具。利用单倍型分析、系统进化树、遗传距离和密码子偏好性分析,对85份不同类型水稻种质中DREB2A基因的功能性核苷酸序列变异及遗传多样性进行了研究。共鉴定出55个核苷酸变异位点,其中12个位于编码区,43个位于非编码区;鉴定出12个DREB2A等位基因型,其中来自非洲栽培稻(Oryza glaberrima)的3个等位基因型表现大片段变异;根据DREB2A基因的序列变异鉴定出39个单倍型,其中33个为新单倍型;将所有单倍型分为三组(Group Ⅰ、Ⅱ和Ⅲ),其中非洲栽培稻(Oryza glaberrima)中的10个单倍型单独分为一组(Group Ⅲ);系统进化树、遗传距离和密码子偏好性分析均表明Group Ⅲ与其他两组具有较大差异。对85份不同类型水稻种质中DREB2A基因的序列分析表明,非洲栽培稻(Oryza glaberrima)中的DREB2A等位基因在序列变异、系统进化关系和密码子偏好性方面均明显不同于其他种质材料中的等位基因。     

Union dyeing of the photografted PET/wool blend fabrics with dimethylaminopropyl methacrylamide

Dimethylaminopropyl methacrylamide (DMAPMA) was grafted onto PET/wool blend fabrics by continuous UV irradiation. Union dyeing of the photografted fabrics was investigated using three reactive dyes of α-bromoacrylamide reactive groups. The influence of grafting yield, DMAPMA concentration, NaCl amount, pH value, and dyeing temperature on the dyeability was evaluated. The dyeability of both PET and wool components was improved significantly by the DMAPMA photografting and successive reactive dyeing. Although the dyeability of the PET component in the blend substantially was improved with higher grafting, equal dyeability between PET and wool was difficult to achieve due to more facile grafting and higher reactivity of the wool component compared with the modified PET component. However, the color fastness of the PET/wool blend fabric was excellent for all three colors. This study may offer a way to achieve union dyeing of PET/wool blend fabrics.     

Value-per-recruit analysis of bighand thornyhead <Emphasis Type="Italic">Sebastolobus macrochir</Emphasis> caught off the Pacific coast of northern Honshu,Japan

The yield-per-recruit (YPR) analysis has been used to assess growth overfishing of exploited fish stocks. Since the ex-vessel price per weight widely depends on the size of the fish, the result of the YPR does not imply the revenue. The value-per-recruit (VPR) analysis, which is an economic expansion of the YPR analysis, was conducted for bighand thornyhead Sebastolobus macrochir caught off the Pacific coast of northern Honshu, Japan. The results showed that, for the current age at first capture (t _c = 3), the current fishing mortality (F = 0.12) was close to the optimum level. However, for the current F, optimum t _c in the VPR model was 8 years and would lead to a 47% increase compared to the current revenue. The maximum YPR was obtained at t _c = 6 years, but the revenue at t _c = 6 only gave a 20% increase in the maximum revenue. The difference was caused by the size dependency of the ex-vessel price per weight. The VPR model would generate fisheries management plans with both economical and biological consideration and would help in making general consensus of fisheries management strategies.     

兔眼蓝莓组织培养过程中褐化与生根问题的探讨

以兔眼蓝莓茎尖和茎段形成的愈伤组织和长期继代培养的试管苗为材料,接种于改良的WPM和1/2WPM的培养基中,研究活性炭与Vc液对兔眼蓝莓外植体和愈伤组织形成中褐化的影响以及外源体、活性炭对无根苗瓶内生根的影响。结果表明,当培养基中加入Vc液并含100～200 mg·L-1的活性炭时,能有效防止外植体褐化的发生;当培养基中加入Vc液并含200～500 mg·L-1活性碳时,可有效防止愈伤组织褐化发生。蓝莓继代培养试管苗在1/2 WPM的培养基中添加0.2 mg·L-1IBA,并含100～200 mg·L-1活性炭时生根情况最为理想,经过7 d暗培养,30 d后生根率高达87.8%。     

荷斯坦牛抗热应激候选基因S441的检测

本试验以S441为奶牛假定抗热应激候选基因。在核心母牛场湖南省奶牛原种场测定不同世代的种母牛213头,在核心公牛场湖南省种公牛站,以及北京、上海、南京、安徽等地测定种公牛46头,共检测出具有S441基因的母牛27头,检出率为12．7％（27／213）,公牛15头,检出率为32．6％（15／46）。在湖南省奶牛原种场,有、无抗热应激候选基因的母牛在热应激期间的产奶量分别为1736．75kg和1528．63kg,产奶量下降率分别为3．51％和22．56％,产奶量差异不显著（P〉0．05）,但产奶量下降率差异显著（P〈0．05）,基本肯定该基因为抗热应激候选基因。     

Pharmacokinetics of florfenicol in healthy and Escherichia coli-infected broiler chickens

The aims of this study were to evaluate the effects of a ketamine/propofol anaesthetic protocol in lions (Panthera leo), and to compare it to two commonly used anaesthetic protocols. Seventeen adult lions were anaesthetised using three different protocols. Group XK (n=6) was anaesthetised with intramuscular (i.m.) injections of xylazine and ketamine. Group KD (n=5) was anaesthetised with an i.m. injection of ketamine, followed by an intravenous (i.v.) injection of ketamine and diazepam. Group KP (n=6) was anaesthetised with an i.m. injection of ketamine followed by an i.v. injection of propofol. There was a significant difference in heart rate (P<0.0002), which was lowest in group XK and highest in KD. Jaw tone was significantly lower in Group XK (P<0.05). No undesirable effects were noted following injection of the propofol. Propofol was a suitable and safe drug for maintenance of anaesthesia in adult lions.