高效净化污水光合细菌的分离鉴定

研究旨在筛选1株能够高效净化污水的光合细菌。通过对不同来源光合细菌的筛选分离以及比较菌株对水体有机质、氨态氮、可溶性磷的去除作用,综合比较得到1株最优菌株P1,该菌对水体有机质有很强的吸收能力,去除率可以达到66.87%,对水体氨态氮和磷有一定的吸收作用,去除率分别为3.33%和8.03%。经过16S rDNA测序以及生理生化实验鉴定,该菌为粪红假单胞菌(Rhodopseu-domonas faecalis)。药敏试验显示P1菌对常用抗生素均有一定的敏感性,其中对庆大霉素最敏感,其次是氨苄青霉素和链霉素,对卡那霉素最不敏感,显示在应用过程中要注意抗生素对该菌存活能力的影响。     

一种利用电站乏汽余热供暖方式的新方案

提出了一种基于常规供暖模式下采用吸收式热泵吸收汽轮机做功后乏汽和汽水换热器将热网循环回水进行二次加热的新方案。以某2×300MW热电厂机组为例,对新方案进行了可行性分析,并与常规方式进行了对比,结果表明:新方案更加节能环保,供暖成本降低,效果更好。     

断奶仔猪小肠黏膜脂肪酸结合蛋白和二肽转运载体1mRNA表达发育性变化及谷氨酰胺对其的影响

本试验旨在研究断奶仔猪小肠黏膜脂肪酸结合蛋白( Ⅰ-FABP)和二肽转运载体1( PEPT1) mRNA表达的发育性变化及谷氨酰胺对其的影响.以69头(21±3)日龄断奶杜×长×大仔猪为试验动物,断奶当天选取3头猪进行屠宰,剩余66头随机分为2组,每组3个重复,每个重复11头.对照组饲喂基础饲粮,试验组饲喂基础饲粮+1％谷氨酰胺.断奶后第3、5、7、14天试验组和对照组分别选取3头猪进行屠宰(共计27头),取十二指肠、空肠和回肠黏膜组织样品,通过实时定量PCR法测定Ⅰ-FABP和PEPT1 mRNA的表达量.结果表明:1)Ⅰ-FABP和PEPT1 mRNA的表达量各肠段间无显著差异(P＞0.05);2)Ⅰ-FABP和PEPT1 mRNA在十二指肠、空肠和回肠的表达量均在断奶后急剧下降,断奶第3天的表达量最低,显著低于断奶当天(P＜0.05),而后逐渐升高,第14天达到峰值;3)试验组Ⅰ-FABP和PEPT1 mRNA表达量与对照组无显著差异(P＞0.05),但试验组表现出促使十二指肠、空肠、回肠黏膜的Ⅰ-FABP和十二指肠PEPT1 mRNA表达提前恢复至断奶前水平的趋势.结果提示,断奶仔猪Ⅰ-FABP和PEPT1 mRNA表达量随时间而变化,谷氨酰胺对断奶后Ⅰ-FABP和PEPT1 mRNA表达量的恢复有一定的促进作用.     

采用微波消解-火焰原子吸收光谱法测定家蚕幼虫体中6种金属元素的含量

采用微波消解-火焰原子吸收光谱法,测定家蚕幼虫体中Ca、Mg、Fe、Cu、Mn、Zn 6种金属元素含量。结果表明家蚕幼虫体中不仅含有大量的常量元素Ca和Mg,同时也含有丰富的人体必需微量元素Fe、Cu、Mn、Zn,Ca、Mg、Fe、Cu、Mn、Zn 6种金属元素在家蚕幼虫体中的质量比分别为1 907.122、1 319.753、35.109、4.133、6.592、74.116μg/g。因此认为家蚕幼虫体适于作为药食资源进行开发。     

饮用磁处理水制备条件的优化

目的研究磁处理水在常温下的最佳制备条件,设计最佳制备装置。方法常温下,采用强度为4000高斯永磁铁,针对不同水源和磁化时间,分析其磁化前后的紫外吸收光谱,探讨不同条件对水被磁化效果的影响。结果过滤后自来水的紫外吸收强度改变最明显,并且在磁化30min时,其吸收峰达到稳定。结论经过滤后的自来水在场强4000高斯下磁化30min,其磁化效果最佳。     

Dietary phytase increases the true absorption and endogenous fecal excretion of zinc in growing pigs given a corn-soybean meal based diet

We investigated the effect of dietary phytase on the true absorption and endogenous fecal excretion of zinc (Zn) using ⁶⁷Zn in growing pigs given a corn-soybean meal based diet. Ten crossbred barrows were fed the control diet containing 90-mg/kg Zn, 2.3-g/kg phytate-phosphorus and 3.7-g/kg non-phytate-phosphorus or the phytase diet containing similar amounts of Zn and phytate-phosphorus, and 1.4-g/kg non-phytate-phosphorus with 750-PU/kg phytase for 12 h/day. On day 6, the pigs were given 200 g of the corresponding diet labeled by ⁶⁷Zn for 2 h. We measured feed intake, fecal Zn concentration and ⁶⁷Zn abundance for the determination of apparent absorption, true absorption and endogenous fecal excretion of Zn. Although the apparent absorption of Zn did not significantly differ between the dietary groups, the phytase group had significantly more ( P  < 0.05) true absorption of Zn than the control group. The endogenous fecal excretion of Zn tended to be more ( P  = 0.07) in the phytase group than in the control group. These results suggest that dietary phytase improves Zn bioavailability through increasing the true absorption of Zn in growing pigs, which results in stimulating the endogenous fecal excretion of Zn when dietary Zn satisfies its requirement.     

不同吸附剂对黄曲霉毒素B1吸附效果的研究

作者通过体外试验和动物饲养试验,研究3种吸附剂对黄曲霉毒素B₁（AFB₁）的吸附效果。3种吸附剂分别是吸附剂A（主成分为酵母培养物提取物）、吸附剂B（主成分为水合铝硅酸盐）、吸附剂C（为复合物,主成分为酵母培养物及水合铝硅酸盐）。体外试验研究pH为2.0、6.0、8.0的磷酸盐缓冲液（PBS溶液）、人工胃液和肠液环境下3种吸附剂对AFB1的吸附能力,比较pH 8.0条件下3种吸附剂对AFB1的结合速率。结果表明,各种条件下吸附剂B的吸附能力最强。pH 8.0条件下,吸附剂B在10 min内对AFB₁吸附率达到97.69%,且60 min内吸附率一直处在96.03%以上。吸附剂A和吸附剂C对AFB₁的作用效果较吸附剂B弱。动物饲养试验选择240只1日龄健康雄性AA肉仔鸡,随机分为8个处理,每个处理3个重复,每个重复10只鸡,饲养周期21 d。结果表明,与基础组相比较,AFB₁组（污染水平为98.8 μg/kg）肉仔鸡生长性能和肝脏功能发生显著变化,吸附剂A、B、C均能不同程度地缓解AFB₁对肉仔鸡生长性能和肝脏损伤方面的毒性作用,与吸附剂A、C相比,吸附剂B能更有效的防止肉仔鸡黄曲霉毒素B1中毒。结果提示,使用吸附剂B能很好的降低AFB₁对肉仔鸡的危害程度。     

牛奶挥发性成分的GC-MS分析

研究4种牛奶挥发成分,经水蒸气蒸馏所得的油状物,采用GC-MS法对4种牛奶的挥发性成分进行了分离鉴定.经气质连用检出4种牛奶中含有苯并噻唑、丁化羟基甲苯、二苯胺、十二烷、十六烷、十八烷、十九烷、二十一烷、2-壬酮、2-呋喃甲醇、戊酸等.     

盐生植物海蓬子对不同形式的氮源的响应

Salt-affected soils are agricultural and environmental problems on a global scale. Plants suffer from saline stresses in these soils and show nitrogen (N) deficiency symptoms. However, halophytes grow soundly under saline conditions. In order to clarify the N nutrition of the halophyte Salicornia bigelovii, it was grown at several N levels (1, 2, 3, and 4 mmol L^-1), supplied in the form of NO₃^- or ammonium (NH₄⁺), under high NaCl conditions (200 mmol L^-1). NH₄⁺-fed plants showed better growth than NO₃^--fed plants at 1-3 mmol L^-1 N, and plants in both treatments showed the same growth at 4 mmol L^-1 N. Nitrogen contents in NO₃^--fed plants increased with the N concentrations in solution; competitive inhibition of NO₃^- absorption by Cl^- was observed under lower N conditions. In addition, shoot dry weight was significantly correlated only with shoot N content. Therefore, growth of NO₃^--fed plants was regulated by N absorption. Inc ontrast, N contents of shoots in NH₄⁺-fed plants did not change with N concentration. Shoot Na content decreased with increasing N concentration, while K content increased. Dry weight was highly correlated only with K content in NH₄⁺-fed plants. These observations indicated that growth of NH₄⁺-fed plants was mainly regulated by K absorption.     

棉花黄萎病病情严重度的连续统去除估测法

该文利用地面高光谱数据遥感监测棉花黄萎病病情严重度.通过分析黄萎病不同病情严重度下棉花单叶光谱变化特征,筛选对病情严重度识别的敏感波段,利用连续统去除法对光谱反射率进行处理并构建基于光谱特征吸收参量的病情严重度估测模型.红光光谱(650～700 nm)是识别棉花单叶黄萎病病情严重度的最佳波段,且随受害棉叶病情严重度增加,红光光谱吸收波段位置向长波方向移动,吸收波段深度及特征吸收峰面积减小,二者与病情严重度呈极显著线性相关关系.以红光波段特征吸收峰右半端面积为自变量建立的线性模型具有最大决定系数,最小均方根误差,为棉花单叶黄萎病病情严重度估测的最佳模型.研究结果表明,利用高光谱遥感技术能够有效地监测棉花黄萎病病情严重度,为进一步深入研究棉花黄萎病的遥感监测机理提供理论依据.