高职农业类专业"订单教育"实践初探

“订单教育”是市场经济形势下,企业的订单经济向教育界渗透的一种表现,它作为一种新型教学模式,表现出强大的生命力.阐述“订单教育”的概念及其特点,重点介绍岳阳职业技术学院农业类专业实施“订单教育”的几点措施,并分析其实施过程中存在的几点问题.     

浅谈高校学生管理工作的"三思四勤"方法

本文分析了新时期高校学生思想政治表现状况及其存在问题的原因,得出了学生管理工作存在四种困难,提出了加强高校学生管理工作的新措施和新方法即"三思四勤".     

沼泽湿地局地小气候"冷湿岛"效应

利用沼泽湿地及其周围旱田对比观测的方法,对沼泽湿地的局地小气候效应进行了研究。结果表明:与周围旱田相比,沼泽湿地近地层(0.5—5.0m)气温低,湿度大,具有显著的冷湿岛效应,且不同高度冷湿效应表现不同,越靠近地面,冷湿效应越明显。6—9月的野外试验结果表明,沼泽湿地的冷湿岛效应在7、8月比较明显;比较沼泽湿地和旱田温度、湿度的日变化发现,沼泽湿地在12:00—14:00的日间午后时段呈现出较明显的冷湿岛效应。     

"三高"农业与土肥作用及对策——以梅县为例

"三高"农业与土壤和肥料有密切关系。地力是作物产量和质量的重要基础,要取得高产、优质、高效,就必须坚持不懈地培肥地力。土壤中营养元素的含量,肥料类型和施肥技术,都对农产品产量和品质有很大的影响。因此,培肥地力、因土种植、合理施肥能提高经济效益、生态效益和社会效益。忽视土肥工作,将影响"三高"农业的发展。     

ICS-3000离子色谱系统

ICS-3000离子色谱系统在使用效率和应用能力上，都比以前的系统有大幅的增长，所有模块的彻底改良使其在应用中的表现更加出色，系统的多功能性、多种功能的综合性以及其卓越的表现将离子色谱的优势发挥到了极致。     

班主任工作"六字诀"

班主任工作在培养和教育当代大学生过程中起着重要的作用,本文从理解、引导、激发(六字诀)三个方面探讨了班主任工作的有效模式.     

洱海流域水质时空变化特征

依据2009年洱海流域62个样点的水质调查数据,应用聚类分析对洱海流域水质时空变化特征进行分析,将样点在空间上分为4组,分别为无干扰的苍山林区源头溪流(A1)、受到一定程度人类干扰的流经农业区和城镇区溪流的中上游段及湖泊(A2)、干扰较严重的流经农业区和城镇区溪流的下游段(A3)以及干扰最为严重的洱海岸边带(A4),判别分析结果表明聚类准确率达95.2%。应用主成分分析方法得到影响洱海流域水质的4个主成分为:第1主成分,Alk、Ca2+、Mg2+、HS;第2主成分,TP;第3主成分,TN和NO3--N;第4主成分,DOC和TOC,这些主成分空间差异明显。在时间尺度上,Alk表现为丰水期高于枯水期;Ca2+表现为枯水期高于丰水期;TP没有表现出明显的季节性变化规律;TN在A1和A3组表现为丰水期高于枯水期。     

重庆四面山杉木群落物种多样性研究

通过对重庆四面山杉木(Cunninghamia lanceolata)林样地的调查,运用丰富度指数、Shannon-Wiener多样性指数、Simpson多样性指数和Pielou均匀度指数,分析了该地区杉木群落物种多样性特征,将该地区现存杉木群落划分为2个群系组(杉木林和杉木针阔混交林),8个群系,10个群丛。结果表明,杉木群落可分为乔木层、灌木层和草本层。在杉木林群系组中,丰富度指数、多样性指数和均匀度指数均表现为灌木层>草本层>乔木层。在杉木针阔混交林群系组中,丰富度指数表现为灌木层>乔木层>草本层;多样性指数多数表现为灌木层>乔木层>草本层;均匀度指数变化较为复杂,没有统一规律。杉木群落各层的丰富度指数随海拔高度的升高总体上呈下降趋势。群落各层的多样性指数随海拔高度的升高在特定区间内表现出一定规律性:在海拔1180m以下低海拔区域,随海拔高度的升高呈下降趋势;在海拔1180～1351m范围内,随海拔高度的升高呈波动状态;而在海拔1351m以上高海拔区域,又呈下降趋势。群落各层的均匀度指数随海拔梯度变化较为复杂,未表现出明显规律。     

微囊藻毒素-LR对罗非鱼鳃组织活性氧自由基含量及相关抗氧化酶活性的影响

应用腹腔注射的方式,研究了微囊藻毒素MC-LR对罗非鱼（Oreochromis niloticus）鳃组织活性氧自由基含量（ROS）及过氧化氢酶（CAT）、超氧化物歧化酶（SOD）活性的影响。结果表明：在MC-LR的胁迫下,罗非鱼鳃组织产生了大量的ROS,并引起了SOD和CAT 2种抗氧化酶活性的变化。SOD和CAT在清除过量的ROS时表现出的动态变化过程不同,SOD的变化曲线是多阶段的,而CAT则表现为先诱导后恢复的趋势。SOD和CAT在变化趋势上有所不同,但均表现为明显的时间与效应的正相关关系和剂量与效应的正相关关系。这也为将鳃组织中SOD和CAT作为抗氧化生物标志物来监测微囊藻毒素对罗非鱼胁迫作用提供了一定的参考。试验为研究微囊藻毒素对罗非鱼的生态毒理学作用提供相应的资料,并为罗非鱼质量安全问题的研究打下一定的基础。     

农村森林防火存在"五缺"、亟待"十改"

经实地调查发现,农村森林防火工作中存在"不管、不扑、不报、不查、不恢复"五个现象,其原因主要在于农村森林防火存在"五缺",即缺人管、缺钱管、缺健全的法制、缺责任制的真实约束和缺激励机制,缺先进扑火设备.由此笔者认为农村森林防火亟待"十改",即,改"五长负责制"为"各级党政一把手负责制"、改"防盗为主"为"防火为主"、改"入海战术"为"精兵上阵"、改"死拼硬打"为"确保生命安全为前提的灵活战术"等等.     

香芋高产、优质栽培技术与产品分级及加工

香芋是多年生宿根草本植物,属天南星科(Araceae)一年生栽培,是我省重要的特种蔬菜之一,随着农业结构调整步伐的加快,香芋的种植面积也在不断扩大,为了提高香芋的产量和品质,达到绿色蔬菜的标准,该文提出了香芋高产、优质栽培技术与产品分级及加工.表3,参5.     

Nanosensors and nanobiosensors in food and agriculture

The food and agriculture sector controls the economic growth of a developing country. The food industries have practices of growing crops, raising livestock and sea foods, food processing and packaging, regulating production and distribution with quality and safety. The process control and monitoring quality are crucial steps. Here we review nanosensors and nanobiosensors as alternative of classical quantification methods. Nanoscale dimensions of metal nanoparticles, metal nanoclusters, metal oxide nanoparticles, metal and carbon quantum dots, graphene, carbon nanotubes, and nanocomposites expand the sensitivity by signal amplification and integrate several novel transduction principles such as enhanced electrochemical, optical, Raman, enhanced catalytic activity, and superparamagnetic properties into the nanosensors. The electrochemical nanosensors, optical nanosensors, electronic nose and electronic tongue, nanobarcode technology, and wireless nanosensors have revolutionized the sensing in food and agriculture sectors with multiplex and real-time sensing capabilities. Despite previous success stories of the remunerative health sector, the approaches are transferred subsequently to food and agriculture sector; with potential application in detection of food contaminants such as preservatives, antibiotics, heavy metal ions, toxins, microbial load, and pathogens along with the rapid monitoring of temperature, traceability, humidity, gas, and aroma of the food stuff.     

市场经济与土肥科技

土肥的基础地位是不随社会性质或社会经济类型的变化而变化的，它既具重要性，又具长久性．市场经济是仍然需要土肥科技的．土肥科技的教学、科研和推广的力度必须加大，局面必须改观，且宜快不宜迟．土肥科技工作者一定要将培肥地力作为中心工作．根据广东的实际，增施有机肥是培肥地力的主要措施，因而抓秸秆还田和发展冬绿肥是我们工作的重点．     

基因污染与生态环境安全

论述了基因污染可能对生态环境安全造成的影响。转基因作物有可能污染天然物种的基因库；有可能破坏传统农作物品种的遗传多样性，加速作物种植品种的单一化及基因资源的流失；使抗除草剂作物的基因向野生或半野生植物漂移的可能性加大，有可能创造出“超级杂草”；带有病毒型转基因作物的基因重组，有可能创造出新的植物病毒，导致新的病害；BT转基因抗虫作物分泌的毒素，在食物链中传递，很难加以控制，对非目标生物造成危害，并最终破坏自然生态系统的平衡。文章还从不同角度分析了基因污染的严重性。     

1株贫营养好氧反硝化菌的分离鉴定及其脱氮特性

从水库底泥样品中,以硝酸盐为唯一氮源进行驯化、分离筛选出1株能在贫营养及好氧条件下进行高效反硝化的菌株PY8,经过电镜形态学观察、生理生化和16S rDNA序列分析,并基于16SrDNA序列结果,构建了该菌株的系统发育树,最终确定菌株PY8为根瘤菌Rhizobiumsp.。考察了初始pH值、温度、C/N、初始硝酸钠质量浓度、投菌量对菌株PY8硝酸盐还原活性的影响,以及该菌株的异养硝化性能。结果表明,在pH6.0～10.0,温度25～30℃,C/N1.0～9.0,初始硝酸钠质量浓度0.01～0.50g·L-1,投菌量1%～15%时,菌株PY8培养72h后的硝氮去除率可达到95%以上。另外,该菌株具有同时硝化-反硝化作用,在培养过程中氨氮去除率可达到58%左右。实验结果表明,菌株PY8在微污染水体生物脱氮领域中具有很大的应用潜力。     

Indoor and outdoor air pollution and lung cancer in New Hampshire and Vermont

Indoor and outdoor air pollution is known to contribute to increased lung cancer incidence. This study is the first to address the contribution of home heating fuel and geographical course particulate matter (PM₁₀) concentrations to lung cancer rates in New Hampshire, USA. First, Pearson correlation analysis and geographically weighted regression were used to investigate spatial relationships between outdoor PM₁₀ and lung cancer rates. While the aforementioned analyses did not indicate a significant contribution of PM₁₀ to lung cancer in the state, there was a trend towards a significant association in the northern and southwestern regions of the state. Second, case-control data were used to estimate the contributions of indoor pollution and secondhand smoke to the risk of lung cancer with adjustment for confounders. Increased risk was found among those who used wood or coal to heat their homes for more than 10 winters before the age of 18, with a significant increase in risk per winter. Resulting data suggest that further investigation of the relationship between heating-related air pollution levels and lung cancer risk is needed.     

Characteristics of dispersions and water-soluble extracts of crude and refined oils and their toxicity to estuarine crustaceans and fish

The quantitative hydrocarbon composition and behavior in seawater of water-soluble fractions (WSF) and oil-in-water dispersions (OWD) of 4 oils was investigated. Two crude oils, South Louisiana crude and Kuwait crude, and two refined oils, No. 2 fuel oil and bunker C residual oil, were used in these investigations. The WSFs of the crude oils had higher total oil-hydrocarbon concentrations and were richer in light aliphatics and single-ring aromatics than were the WSFs of the refined oils. The WSFs of the refined oils contained significantly higher concentrations of naphthalenes than did those of the crudes. The hydrocarbon composition of the aqueous phase of OWDs closely resembled that of the parent oils. Gentle aeration of the OWDs resulted in a loss of 80 to 90% of the aqueous hydrocarbons in 24 h. Alkanes disappeared from the dispersions more rapidly than aromatics. The WSFs and OWDs of the refined oils were considerably more toxic to the 6 test species than were those of the crude oils. The test species can be ranked according to increasing sensitivity to oil as follows: Cyprinodon variegatus, Menidia beryllina, Fundulus similus, Penaeus aztecus postlarvae, Palaemonetes pugio and Mysidopsis almyra. The results of this investigation are discussed in relation to the potential impacts of oil spills on the marine and estuarine environments.