添加不同剂量锌对固始鸡生长性能与胫骨锌含量的影响

[目的]为制定鸡饲料配方提供科学依据。[方法]以固始雏鸡为试验动物,在基础饲粮含锌量35.3 mg/kg基础上研究不同剂量外源锌(0、30、60、90、120 mg/kg)对其生长性能、腿病率和胫骨锌沉积量的影响。[结果]不同剂量外源锌对固始鸡生长性能与腿部发病率均具有显著或极显著影响;60、120 mg/kg外源锌添加组鸡的日采食量和饲料效率最高,腿病率最低;锌添加量为60 mg/kg时,鸡的生长性能最佳,鸡胫骨中锌的沉积量基本达到最高水平;锌添加量为90 mg/kg时,鸡胫骨中的锌沉积量达到平衡,且腿病率最低。[结论]该试验中,外源锌的添加量以60~90 mg/kg为宜,即固始鸡对锌的需要量为96.3~125.3 mg/kg。     

叶面喷施微肥对冬小麦产量和品质的影响

为给小麦高产优质栽培中微肥施用提供参考,以冬小麦品种石新828为材料,研究了叶面喷施锌、铁、硒3种微肥对小麦产量、籽粒锌、铁、硒和蛋白质含量的影响。结果表明,3种微肥中只有喷硒增产作用显著(P<0.05),但喷锌、铁、硒分别显著增加了千粒重、穗数和穗粒数。3种微肥均能明显提高籽粒中相应的微量元素含量,但对籽粒蛋白质含量影响均不显著。     

不同磷营养水平对2种沉水植物在Cd·Zn复合污染下的影响

[目的]揭示富营养化和重金属污染共同存在时对沉水植物的影响,为水生生态系统的健康评价和治理提供理论依据和手段。[方法]比较研究了不同磷营养水平对Cd、Zn复合污染下伊乐藻（Elodea nuttallii）、黑藻（Hydrilla verticillata）2种沉水植物叶绿素含量和叶绿素a/b比值、MDA含量、GSH含量、POD活性、CAT活性等生理生化指标的影响。[结果]随着培养时间延长,2种植物的叶绿素含量基本呈下降趋势,MDA含量呈先上升后下降趋势,POD活性及可溶性蛋白含量呈先下降后上升趋势,GSH呈缓慢上升趋势,当不存在磷水平时CAT活性无明显变化;但是黑藻比伊乐藻对胁迫更敏感,并且耐性优于伊乐藻。[结论]不同磷营养水平对受重金属胁迫植物的影响不一样,其中低磷水平（0.05 mg/L）可在一定程度上缓解重金属的毒害,与重金属产生拮抗作用;而高磷水平（5 mg/L）则加重了重金属对植物的伤害,产生协同作用。     

固体超强酸SO4^2-/ZrO2/Al2O3催化乙二胺合成哌嗪的研究

采用超声化学共沉淀法制备SO4^2-/ZrO2/Al2O3固体超强酸催化剂,并对该催化剂在常压固定床反应器中催化乙二胺合成哌嗪的性能进行了研究.结果表明,乙二胺的转化率随反应温度升高而增大,哌嗪的选择性和收率在温度超过250℃条件下急剧下降;进料速度超过0.50 mL/min后,乙二胺的转化率和哌嗪的收率急剧降低,而哌嗪的选择性与进料速度没有明显关系;乙二胺的进料质量分数不超过50%,原料转化率、哌嗪收率以及哌嗪选择性没有明显差别;但随乙二胺质量分数进一步增大,原料转化率急剧下降,而哌嗪的选择性和哌嗪的收率则下降更快.     

静脉注射不同锌源与锌水平对肉仔鸡生长性能及组织锌含量的影响

用378只22日龄商品代AA肉公鸡进行静脉注射试验,研究不同锌源与锌水平对肉仔鸡生长性能及组织锌含量的影响。采用4种锌源（ZnSO₄·7H₂O、弱络合强度Zn-AA C、中等络合强度Zn-Pro B和偏极强络合强度Zn-Pro A）与3个日粮锌吸收率（0%、6％和12％）静脉注射锌水平构成的4×3两因子安排的完全随机设计,将22日龄肉公鸡按体重随机分成9个组(每组7个重复笼,每个重复笼6只鸡),分别翅静脉注射生理盐水（对照组）,或在生理盐水中溶解硫酸锌及弱、中等和偏极强络合强度有机锌源的注射液12 d。结果表明,锌源显著影响（P<0.10）注射后6 d胫骨灰锌含量,但对肉仔鸡注射后1～6 d和7～12 d的日采食量、日增重、料重比、第6 天胰脏锌及第12 天胰脏锌和胫骨灰锌均无显著影响（P>0.10）;锌水平显著影响（P<0.10）肉仔鸡注射后1～6 d的日增重和料重比、第6和12天的胰脏锌和胫骨灰锌,而对肉仔鸡注射后1～6 d日采食量和7～12 d的日采食量、日增重和料重比均无显著影响（P>0.10）;锌源与锌水平互作对肉仔鸡注射后以上各观测指标均无显著影响（P>0.10）。偏极强络合强度有机锌源组鸡胫骨灰锌含量显著低于弱络合强度有机锌源组和中等络合强度有机锌源组（P<0.10）,且有低于无机硫酸锌组的趋势（P>0.10）。对照组肉仔鸡的日增重显著低于注射锌吸收率6%组（P<0.10）,其料重比显著高于注射锌吸收率6%与12%组（P<0.10）,其它锌吸收率注射水平组之间鸡的日增与重料重比均无显著差异（P>0.10）;随着注射锌水平的升高,肉仔鸡注射后第6、12天胰脏和胫骨灰锌含量呈线性升高（P<0.10）。本试验结果表明,相对于胰脏锌和生长性能而言,静脉注射后第6天的胫骨灰锌能更敏感地反映出不同锌源对肉仔鸡生物学利用性的差异,而偏极强络合强度的有机锌最不利于肉仔鸡体组织的利用。     

Effects of planting soybean in summer fallow on wheat grain yield,total N and Zn in grain and available N and Zn in soil on the Loess Plateau of China

Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200 m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089 kg ha⁻¹ at the 108 kg N ha⁻¹ rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.     

Chinese urban migrants' sense of place: Emotional attachment,identity formation,and place dependence in the city and community of Guangzhou

In this paper, we study urban migrants' sense of place in Guangzhou, China, focusing on the structural relations between place attachment, identification and dependence as the three key place dimensions. Through both quantitative structural equation modelling and qualitative analysis of in‐depth interviews data, our research suggests that migrants' sense of place demonstrates complex relationships between the three registers of emotional attachment, identity formation and functional dependence. The construction of sense of place is also related to the personal experiences of living as urban ‘outsiders’. Our research also reveals a striking difference between the city and community levels in terms of the ways in which migrants' sense of place is constructed. Urban migrants tend to exploit the functional utilities of microscopic urban spaces to meet their demands for recreation, education and socialisation. On the other hand, their sense of place to the city is largely compromised by their attachment to the hometown and conditioned by their personal identification to the city.     

Accumulation and distribution of Zn and Mn in soybean seeds after nutrient seed priming and its contribution to plant growth under Zn- and Mn-deficient conditions

Nutrient seed priming is a strategy to increase the seed reserves of mineral nutrients as primary source for mineral nutrition during seedling development and early growth. The present study investigates the effects of zinc (Zn) and manganese (Mn) seed priming on growth and nutritional status of soybean under conditions of Zn and Mn limitation. Nutrient seed priming increased the natural seed reserves for Zn by, approximately, sixfold and by fivefold for Mn; however, 40–60% of the primed nutrients were adsorbed to the seed coat. Zinc seed priming was able to maintain plant growth for 5 weeks in the same way as Zn supply via the nutrient solution. It is concluded that nutrient seed priming offers perspectives to improve seed quality of soybean for early seedling development under limited nutrient supply or availability and needs further investigation on performance under various stress conditions.     

原生态从江香禾糯中锌和镍的含量及其生理功能研究

[目的]测定从江香县禾糯中的锌（Zn）和镍（Ni）含量,探讨其在人体内的生理功能。[方法]以产自长寿之乡黔东南林区从江县的原生态香禾糯稻米为样品,用火焰原子吸收光谱法作测定,先采用正交试验确定Zn和M的最佳仪器测试条件,再采用微波消解FAAS法在绘制标准曲线的基础上对从江香禾糯中微量元素锌（Zn）和镍（Ni）的含量进行测定,并研究这2种元素在人体内的生理功能。[结果]标准曲线的绘制表明,Zn的线性回归方程为：c＝0．4946A＋0．0084,相关系数r=0．9996;Ni的线性回归方程为：c=0．0479A＋0．0030,相关系数r=0．99964。锌和镍含量的测定表明,从江香禾糯米含微量元素Zn和Ni分别为11．25和0．41mg／kg。[结论]黔东南林区从江县的原生态香禾糯稻米中含有适量的Zn和Ni,不但可以安全食用,而且还可以补充微量元素,达到延寿安康的效果。