鲈流刺网技术研究

对鲈流刺网的不同目大，网线规格，缩结系数进行了研究试验，结果：以目大１５５ｍｍ、网线规格０．６ｍｍ，水平缩结系数０．６为宜。３只１２马力渔船用此网生产一年半，创产值１９８．４元，利税１８０多万元。专家鉴定认为本成果居国内先进水平。     

Quantitative dietary copper requirement of juvenile Siberian sturgeon,Acipenser baerii,and effects on muscle composition and some enzymatic activities

An 8‐week feeding trial was conducted to quantify dietary copper (Cu) requirement of juvenile Siberian sturgeon, Acipenser baerii. Five isonitrogenous diets were formulated to provide actual dietary copper values of 1.8, 5.7, 10.1, 15.9 and 28.3 mg Cu per kg diet. Experimental diets were fed to the Siberian sturgeon (27.57 ± 0.24 g) in triplicate to apparent satiation for 8 weeks. At the end of experiment, weight gain (WG), specific growth rate (SGR) and protein efficiency ratio (PER) were significantly increased with increasing dietary Cu level up to 10.1 mg/kg and then decreased with further increases in dietary Cu level (p < .05). The Cu concentration in the liver and cartilage was positively correlated with the respective concentrations in the diet (p < .05), while muscle and serum Cu concentrations remained significantly unchanged (p > .05). Superoxide dismutase and glutathione peroxidase had the highest activities in serum of fish fed with 15.9 and 28.3 mg Cu per kg diet, respectively. Analysis by the broken‐line regression of SGR, crude protein content and superoxide activity demonstrated that the optimum dietary Cu requirements in juvenile Siberian sturgeon were 9.51, 9.58 and 16.10 mg/kg diet, respectively.     

铜和镉对草鱼肾脏中3种白细胞介素基因表达的影响

为探讨水体铜(Cu)和镉(Cd)污染对草鱼免疫系统的影响,本研究利用实时荧光定量PCR(QRT-PCR)技术,分析在不同时间(2、4、6、8 d)及不同质量浓度的Cu²⁺(0.10、0.20、0.40、0.60、0.80 mg/L)和Cd²⁺(0.05、0.10、0.20、0.30、0.40 mg/L)暴露下,草鱼肾脏中3种白细胞介素——白细胞介素-1β、白细胞介素-8和白细胞介素-10基因表达量的变化。试验结果显示,高质量浓度和长时间的Cu²⁺暴露(0.60、0.80 mg/L, 8 d)和Cd²⁺暴露(0.20、0.30、0.40 mg/L, 8 d)下,草鱼肾脏中的白细胞介素-1β、白细胞介素-8和白细胞介素-10基因表达量与对照组相比显著增加(P<0.05);在0.80 mg/L Cu²⁺,0.30、0.40 mg/L Cd²⁺暴露下的草鱼肾脏中白细胞介素-1β的基因表达量,以及在0.60、0.80 mg/L Cu²⁺暴露下的草鱼肾脏中白细胞介素-8和白细胞介素-10的基因表达量,均随着暴露时间的增加而逐渐升高,且第8 d时的基因表达量均显著高于第2 d时(P<0.05)。本研究揭示了高质量浓度和长时间的Cu²⁺、Cd²⁺暴露会使草鱼肾脏产生炎症反应,为进一步深入研究重金属对鱼类的免疫毒性机制奠定了基础。     

铜离子和食盐控制丝状菌污泥膨胀的试验研究

污泥膨胀不仅影响出水水质,增大污泥的处理费用,而且极易引起大量污泥流失,严重时可导致整个污水处理系统崩溃。药剂法是一种有效的丝状菌污泥膨胀控制技术,可使污泥膨胀在短时间内得到控制,对于污水厂的运行管理具有较大的实用价值。本试验在以前研究的基础上探索了采用铜离子和食盐(NaCl)在抑制丝状菌膨胀的效果,试验结果表明,铜离子浓度在0.75mg/L时对抑制丝状菌污泥膨胀效果良好,食盐(NaCl)浓度为4g/L时对抑制丝状菌污泥膨胀效果良好,为以后抑制丝状菌膨胀提供一些简单的参考。     

The Effect of Dietary Sulphate Copper Supplementation on Growth Performance, Intestinal Digestive Enzymes and Absorptive Transporters in Weanling Pigs

The experiment was conducted to assess the effects of dietary supplementation of Cu on the growth performance, digestive enzymes, tissue minerals and absorptive transporters in small intestinal mucosa of weanling pigs. One hundred crossbred pigs weaned at 28 ± 2 d of age were assigned randomly to one of the following diets with 5 replicates: corn-soybean basal diet with 10, 100, 175, 250 mg/kg of Cu as CuSO₄•5H₂O. The results showed that 250 mg/kg Cu had a positive effect (P < 0.05) on average daily gain, daily feed intake and ratio of gain/feed. Compared to 10 mg/kg Cu, higher Cu had significant effect on the apparent digestibility of protein and fat (P < 0.05). The supplementing of Cu improved amylase and lipase activity in jejunum content and lipase in pancreas (P < 0.05) and had no effect on intestinal morphology. The liver Cu elevated approximately 4-fold in pigs fed diet with 250 mg/kg Cu compared with pigs fed diet with 10 mg/kg Cu, no increases were observed in pigs receiving the lower level of Cu (100 and 175 mg/kg). Both Fe and Zn contents in kidney and liver were not affected by Cu supplementation. There was no positive effect (P > 0.05) of Cu supplementation on PepT1 (peptide transporter 1) and SGLT1 (sodium/glucose cotransporter) mRNA abundance in intestinal mucosa. However, higher supplementing level (250 mg/kg) significantly elevated the DMT1 (divalent metal transporter) mRNA abundance in duodenum mucosa. These results suggested that dietary supplementation with 250 mg/kg Cu could improve growth performance, nutrient digestibility and intestinal enzyme activities of weanling pigs.     

高铜日粮对肉鸡血清抗氧化功能的影响

为了了解高铜日粮对肉鸡血清抗氧化功能的影响,试验将200羽1日龄商品代科宝肉仔鸡随机分为4组,各组日粮中铜含量分别为Ⅰ组(对照组)11 mg/kg、Ⅱ组110 mg/kg、Ⅲ组330 mg/kg和Ⅳ组550 mg/kg,在饲养10,20,30,40,50天时每组各取5只鸡分离血清,检测血清中总抗氧化能力(T-AOC),超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽还原酶(GR)活性以及丙二醛(MDA)含量的变化。结果表明:与Ⅰ组相比,Ⅱ组SOD、GR、GSH-Px的活性升高,T-AOC升高(P<0.05);Ⅲ组、Ⅳ组SOD、GR、GSH-Px的活性及T-AOC先出现代偿性升高(P<0.05),随着饲喂时间的延长,该系列指标降低(P<0.05)。Ⅱ组、Ⅲ组、Ⅳ组MDA的含量均升高(P<0.05)。说明日粮铜含量达到或超过330 mg/kg可引起肉鸡血清抗氧化酶活性降低,致使血清抗氧化功能受损。     

饲料中添加蒙脱石对肉牛组织中镉铅铜铁锌含量的影响

本研究通过在精饲料中添加蒙脱石喂养杂交牛的方法,探讨蒙脱石对动物体内必需微量元素铜、铁、锌及有害元素镉、铅含量的影响。结果表明:与对照相比,喂蒙脱石的杂交牛日增重提高了14.96%(P<0.01),饲料转化率提高了9.22%(P<0.05);肾脏和脾脏中铅含量显著增加(P<0.05),肾脏、肝脏、脾脏和肠中镉的含量极显著增加(P<0.01),而血液中镉含量显著降低(P<0.01),其余组织中镉和铅的含量变化不显著;脾脏铜和铁含量极显著减少(P<0.01),肾脏中锌含量极显著增加(P<0.01),肝脏和肌肉组织中铁含量显著增加(P<0.05),其余各组织中的变化不显著(P>0.05)。结论:在饲料中添加蒙脱石,可在不同程度上改变铅、镉、铜、锌、铁在动物体内各器官和组织中的分布水平,但不能有效降低肉牛各组织中铅、镉的蓄积。     

不同铜源及添加水平对北京鸭生长性能和脂代谢的影响

文章研究了饲粮中不同浓度的无机铜和有机铜对1~56 d北京鸭生产性能和脂质代谢的影响。试验选择360只1日龄北京鸭,随机分为9组,每组4个重复,每个重复10只。试验日粮采用4×2因子设计,共9个组(含1个对照组),对照组铜添加水平为0 mg/kg,试验组在基础日粮中添加3、6、9和150 mg/kg的无机(硫酸铜)和有机铜(氨基酸螯合铜),试验分为1~28 d和29~56 d两个阶段进行。结果显示:日粮添加无机铜显著降低了北京鸭的采食量,改善了料比(P <0.05)。日粮添加铜显著提高了血浆铜水平,显著降低了血浆锌水平(P <0.05)。与无机铜源相比,有机铜源显著改善了肝脏铜水平、铜排泄和沉积量(P <0.05)。日粮添加铜显著影响血红蛋白浓度和脂肪水平(P <0.05)。日粮添加150 mg/kg铜显著降低了肝脏和肉脂肪、胆固醇含量以及肉色和嫩度(P <0.05),同时显著降低了血浆脂肪、甘油三酯、胆固醇含量,提高了谷丙转氨酶和谷草转氨酶活性(P <0.05)。无机铜有提高回肠组织病变的风险,但有机铜对北京鸭组织较安全。结论:铜浓度在150 mg/kg时可以显著改善肉质,增加肉蛋白质含量,同时显著降低肉脂、胆固醇以及血脂、甘油三酯和胆固醇含量。     

林木容器育苗碳酸铜化学修根效果比较

采用不同浓度的碳酸铜与乳胶漆配制成混合涂料涂刷育苗容器内壁,进行8个树种的容器苗化学修根试验研究.结果表明,碳酸铜对抑制苗木侧根长度生长、促进侧根数量增加具有显著效果,但对苗木的质量指数无明显影响.在150g·L-1浓度的碳酸铜处理下,化学修根能提高所有供试树种苗木的根系活力,使其更好地吸收土壤水分和养分利其生长;对马尾松、滇柏、刺槐、喜树、猴樟5个树种苗木的叶绿素含量有较明显的提高.培育马尾松、华山松容器苗,碳酸铜浓度可控制在100～150 g·L-1;培育湿地松、滇柏、刺槐、喜树、猴樟、香椿容器苗,碳酸铜浓度可控制在150～200 g·L-1.     

腐蚀条件下中碳合金钢冲击磨损特性及机理

中碳合金钢经适当热处理后,得到M＋B＋AR复相组织,在冲击腐蚀磨损条件下研究其磨损特性和机理。结果表明：中碳合金钢的耐磨性随冲击功增加而明显下降;剥落裂纹起源于表面,在亚表层中扩展;冲击功由2．0J增至3．5J,中碳合金钢在冲击腐蚀条件下的磨损失效机制由以浅层剥落为主向以深层剥落为主转变。