坝下地区寒冷季节不同月份育肥牛舍内、外光照、风速差异化研究

[目的]为了探讨张家口坝下地区寒冷季节育肥牛舍内外光照和风速的变化规律,以期发现该地区寒冷季节这两项指标的变化规律。[方法]在张家口怀安县某肉牛场进行了入冬后不同月份牛舍内外光照和风速的研究,在试验前对开放式肉牛育肥舍的后窗进行了封堵,测试时间为2018年11月至2019年5月,每个月的11日、12日和13日进行测定并记录数据。[结果]结果表明,坝下地区中午时间段光照强度大,育肥牛舍内外与密闭舍对比均有不同程度差异显著性(P<0.05或P<0.01);育肥舍及舍外风速也存在不同程度的差异显著性(P<0.05)变化或差异极显著变化(P<0.01)。[结论]该结果为在张家口坝下地区冬季养好育肥牛,科学合理地修缮及改造牛舍提供理论依据和技术参数。     

Effects of conventional and organic feed on the mineral composition of cultured European sea bass (Dicentrarchus labrax)

European sea bass (Dicentrarchus labrax) is a widely consumed marine fish in Mediterranean areas, and different farming techniques are applied for fish culturing to satisfy the growing demand for seafood. The aim of this study was to investigate the effects of conventional and organic feed on the quality of cultured European sea bass (Dicentrarchus labrax) collected during the growth period. The concentrations of ash, moisture, essential macro‐elements (Ca, K, Mg, Na and P), micro‐elements (Co, Cr, Cu, Fe, Mn, Ni and Zn) and toxic elements (As, Cd, and Pb) were determined in feeds and in fillets of cultured fish. The results were compared to those obtained from wild sea bass. Results showed that the differences between organic diet‐fed and conventional diet‐fed sea basses varied in relation to the specific element measured and the growth period. The former showed higher concentration of Fe, Mg and Cr, and lower Na content. The amount of P, Na, Fe, Cu and Cr in wild sea bass was significantly (P ≤ 0.05) higher than that found in farmed fish. The levels of toxic elements in cultured sea bass were always within the allowed limit for fishery products. Wild samples had significantly (P ≤ 0.05) higher content of arsenic and lead than farmed sea bass. Cultured fish represent a valuable dietary source of essential macro‐ and micro‐elements. Controlled rearing systems and feedings were related to a decrease in the presence of some toxic metals in cultured fish compared with wild fish.     

一种基于传感器的智能谷仓的设计

提出了一套应用于谷物储存的智能谷仓设计方案,通过特定传感器和计算机程序,对进出谷仓的谷物的重量变化和位置分布进行精确估计,并通过无线局域网上传谷仓内谷物或粮食的进仓时间及位置分布到储粮调度服务器,实现谷物进出仓优化调度,通过智能传感器并利用专家知识对谷仓内储存的谷物状态进行评估,调节仓内温度湿度并及时报警,防止谷物霉变和因储存时间过长形成陈化粮,对于保证粮食安全以及优化粮食调度具有积极意义。     

源库调节对常规粳稻花后营养器官碳水化合物及氮磷钾转运的影响

 【目的】阐明抽穗期源库关系对常规粳稻花后营养器官干物质、非结构性碳水化合物（NSC）和氮、磷、钾矿质元素等转运的影响,明确促进水稻植株养分高效再利用的粒叶比。【方法】以淮稻5号和宁粳3号两个常规粳稻品种为材料进行大田试验,分别于抽穗期选择茎生绿叶6片且开花进程一致的单茎,采用剪叶疏花的方法调节源库关系,将处理后当天每穗颖花数与单茎叶面积的比值定义为粒叶比,测定抽穗至成熟期叶片、茎鞘中干物质、NSC及氮、磷、钾的含量,计算相关物质的转运率,并分析其与粒叶比的关系。【结果】与对照（L₀S₀）相比,剪叶处理（L_1/2S₀）通过提高粒叶比,显著降低了结实率和千粒重,其中淮稻5号分别降低了8.6%-10.5％和19.0%-8.0%,宁粳3号分别降低了9.7%-20.4%和5.7%-12.6%;而疏花处理通过降低粒叶比,显著提高了结实率和千粒重,其中淮稻5号平均提高了3.4%-6.7%和1.2%-18.7%,宁粳3号平均提高了2.0%-4.3%和6.9%-17.3%,同一品种不同疏花处理之间的结实率和千粒重无显著的差异,但年份之间的表现并不一致,2014年水稻季的气候条件更有利于籽粒灌浆充实,其结实率和千粒重及提高幅度普遍高于2013年。剪叶处理显著提高了常规粳稻抽穗至成熟期叶片和茎鞘中干物质、NSC及氮、磷、钾等矿质元素的转运率,两品种间差异较小,不同年份间未表现出实质性的差异;而疏花处理则显著降低了抽穗至成熟期叶片和茎鞘中干物质、NSC及氮、磷、钾等的转运率,且疏花越多降低幅度越大,不同品种和不同年份间未表现出实质性的差异,但叶片和茎鞘干物质、NSC转运对疏花的响应存在根本性区别,随着疏花增多,叶片中干物质和NSC转运率下降,而茎鞘中干物质和NSC转运在表观上出现滞留不外运的现象。进一步分析叶片和茎鞘中干物质、NSC及氮、磷、钾的转运率（y）与抽穗期粒叶比（x）的关系,发现上述指标间均存在y=（a+bx）/x曲线相关关系,在粒叶比较小时,叶片和茎鞘中各种物质的转运率均随粒叶比增大而急剧提高,当粒叶比增大至一定程度后,各种物质的转运率均趋近于潜在最大值,不再随粒叶比的增大而显著提高,不同物质潜在最大转运率虽然不同,但都在粒叶比1.5左右接近这一极限值,且淮稻5号和宁粳3号两个品种之间也未出现明显分异。【结论】相对较高的粒叶比有利于促进常规粳稻花后营养器官干物质和非结构性碳水化合物及氮、磷、钾等的转运,粒叶比与常规粳稻花后营养器官干物质、非结构性碳水化合物、氮、磷、钾等的转运率存在着密切的曲线相关关系,并在粒叶比1.5左右达到近似最大转运率,抽穗期粒叶比1.5左右可作为常规粳稻氮、磷、钾矿质养分高效再利用的品种选育与栽培调控指标。     

森林防火隔离带技术的变革与优势

以消减可燃物的方式预防和阻隔森林火灾是林火管理工作的核心。传统阻隔技术向遮荫型防隔火技术的演变已成为近10余年西方多林国家林火管理工作的重要走向。从林火的特点和蔓延基本规律出发, 遮荫型防火隔离带技术通过局部消减可燃物载量和规则化可燃物分布, 显著降低其可能形成的林火强度, 使大多数火灾自行熄灭。该项技术的实施不受区域和气候条件限制; 与传统全光式防火隔离带和生物防火林带相比, 不但工作量较小, 对林分植被和生态环境的干扰也较小。该项技术实现了偶发性林火的防控、森林健康及生态维护的有机结合, 以此替代传统防火隔离带技术效益显著。针对遮荫型防隔火技术的进一步研究工作应包括不同稀化程度林带潜在火行为和其防隔火效能的量化评估、林地局部可燃物稀化的高效作业机具以及伴随该项技术实施产生的大量生物质副产品的有效利用问题。     

甜菜红色素提取工艺研究进展

甜菜红色素是一种水溶性的色素,广泛的存在于以红甜菜为主的石竹目中,甜菜红色素在食品以及制药等方面具有很好的应用前景,因此建立一种快速、高效以及环保的甜菜红色素提取工艺尤为重要。笔者分别介绍了传统提取甜菜红色素的方法以及最新提取工艺研究进展,并指出传统方法由于需要加热以及加入有机溶剂,容易造成甜菜红色素降解、溶剂污染以及产量低等问题。而以γ射线、高压脉冲电场、超声波辅助萃取技术、超临界萃取技术以及膜处理技术为代表的最新提取技术,可以在非热情况下达到提取色素的目的,并且具有环境友好、安全、一致性好以及回收率高等特点。并指出未来的发展不管使用哪种新技术,都需要对提取的每一步细化,制定提取标准。     

番茄斑萎病毒4种检测方法比较

本研究根据番茄斑萎病毒(TSWV)S RNA上的核衣壳蛋白(N)基因保守序列设计特异性引物,比较了4种检测方法的灵敏度。结果表明,特异性引物可扩增出397bp的片段,序列和已发表的TSWV核苷酸序列同源性高达99%,可用于常规PCR和荧光定量RT-PCR(qRT-PCR)检测。qRT-PCR的灵敏度比快速检测试纸条、双抗体夹心酶联免疫吸附法(DAS-ELISA)和常规PCR分别高出15 625倍、3 125倍和125倍,且能够准确定量;常规PCR灵敏度较高,但不能准确定量;DAS-ELISA方法适用于批量定性测定,但检测时间较长;试纸条法检测速度最快,但灵敏度最低,使用时可根据症状程度和试验条件选择适宜的检测方法。     

网式散叶密集烘烤下部烟叶失水规律与烘烤效应关系研究

为明确网式散叶密集烘烤过程中不同装烟层烟叶的失水规律及其与烟叶烘烤效应的关系,采用称重器对气流上升式密集烤房网式烟框装烟下部叶烘烤过程中失水量进行了实时测定,并考查烘烤过程中烟叶外观性状变化及烤后烟叶质量性状。结果表明:(1)烘烤过程中上、中、下三层烟叶失水率均呈Logistic曲线变化规律,在干筋期以前烟叶失水率下层明显大于中层,中层明显大于上层;(2)不同层次烟叶失水速率均呈"先上升后下降"的"∧"型变化趋势,全炕烟叶的平均失水率与中层烟叶接近;(3)各层烟叶失水变化规律及烟叶外观性状变化与烘烤过程中温湿度变化、烘烤时间的关系密切,对烟叶外观质量和内在质量都有影响。     

新陆早棉花品种DNA指纹图谱的构建及遗传多样性分析

以新疆2013年前审定的51个新陆早常规棉花品种为材料, 从5000对SSR引物中筛选出多态性高、稳定性好、且定位在棉花26条染色体上(每条染色体上选择2~3对)的75对核心引物,检测到多态性位点226个, 每个标记检测到的基因型位点数在2~12之间, 平均为3.01个;引物多态信息量(PIC)值介于0.0799~0.8752之间, 平均值为0.6624。结果显示, 在51份新陆早棉花常规品种中, 可利用特征引物将21份品种一次性区分开。利用40对引物可以完全区分开新陆早51份常规品种, 并构建供试品种的指纹图谱。同时利用NTSYS-pcV2.10软件聚类分析表明, 51个新陆早棉花品种遗传相似系数变化范围为0.4269~0.9873, 平均值为0.7071, 说明新陆早棉花品种之间遗传多样性较狭窄;遗传相似系数矩阵和聚类分析将51个新陆早品种分为4大类型, 与原品种选育系谱高度吻合。     

Effects of different soil management practices on total P and Olsen-P sediment loss: A field rainfall simulation study

Field rainfall simulations were conducted in 2002 and 2005 to study the effects of different soil management practices on the total phosphorous (TP) and Olsen-P losses by soil erosion and redistribution along a 15 m long slope in Luoyang, Henan province, China. Field plots were set up in 2001 and included the following soil management practices: subsoiling with mulch (SSM), no-till with mulch (NTM), reduced tillage (RT), and a conventional tillage control (CT). The results showed that there were no significant differences in TP and Olsen-P content in the sediment load between different plots after 6 years uniform tillage practices. The enrichment of TP and Olsen-P at the lower slope showed a clear redistribution along the slope. Effects of tillage practices on the temporal pattern of the enrichment ratio (ER) of TP and Olsen-P was not uniform. ER_TP values were initially high and diminished after a short period of time and leveled to the end of the rainfall test in CT and RT plots, but remained ≥ 1. The ER of Olsen-P at the end of rainfall simulation showed a significant difference when compared to the initial stage, 0.78 to 1.60, respectively. However, the temporal loss rate of TP and Olsen-P showed a similar pattern because it was more depending on the sediment loss rate than on the concentration in the sediment. SSM resulted in 96% less TP and Olsen-P erosion loss compared to CT in 2002. Also, SSM showed the highest reduction in TP and Olsen-P loss after 4 years consistent practice. RT reduced TP and Olsen-P loss by 30%, although the runoff reduction was not significant. NTM was the best alternative with respect to TP and Olsen-P conservation, when considering its lower operational costs.