Flowering pattern of biodiesel plant Jatropha in frost- and drought-prone regions of Botswana

Jatropha has gained interest as a potential biodiesel feedstock. Nevertheless, its oil production decreases significantly in frost- and drought-prone regions. In this study, we characterized the flowering pattern of Jatropha in Botswana in the 2014/2015 season. Extensive springtime pruning synchronized Jatropha regrowth in summer and effectively stimulated growth after frost damage. Flowering started in February 2015 and peaked in April and May. Wide variations in flowering frequency were observed among different Jatropha accessions. Trees flowering in February and March produced fruit in May, but most trees only flowered in April and May and did not yield fruit because of cold snaps. These observations suggested that harvesting seed before wintertime is the key to improve Jatropha production in the Botswana climate. This study highlighted the importance of inducing early flowering by developing new agricultural managements. These may include frost cover and sun shades to prevent stress-induced damage, canopy control by pruning, optimization of fertilization practice, and/or introduction of superior Jatropha varieties.     

Climate Change and Population Growth in Timor Leste: Implications for Food Security

The climate in Timor Leste (East Timor) is predicted to become about 1.5 °C warmer and about 10 % wetter on average by 2050. By the same year, the population is expected to triple from 1 to 2.5–3 million. This article maps the predicted changes in temperature and rainfall and reviews the implications of climate change and population growth on agricultural systems. Improved cultivars of maize, rice, cassava, sweet potato and peanuts with high yield performance have been introduced, but these will need to be augmented in the future with better adapted cultivars and new crops, such as food and fodder legumes and new management practices. The requirements for fertilizers to boost yields and terracing and/or contour hedgerows to prevent soil erosion of steeply sloping terrain are discussed. Contour hedges can also be used for fodder for improved animal production to provide protein to reduce malnutrition.     

产油微藻培养与回收的关键技术研究进展

寻找廉价而高效的替代原料是实现生物柴油产业化的关键所在.微藻以含油量高、生长周期短、环境适应能力强、生物产量高等优点,有望成为一种极具潜力的生物柴油生产原料.然而,目前尚存在微藻培养低效成本高和微藻回收效率低两大难题.综述了微藻培养与回收过程中的关键技术,并对存在的两大难题及其改进技术进行了详细的探讨.最后,总结并展望了微藻培养、回收技术未来的发展趋势.     

两晋以来气候变化对太湖流域稻麦两熟复种的影响

太湖流域的稻麦两熟复种大约产生于东晋南朝时期（317～589年）,此后这一种植制度长期存在,并不断有所发展。考察发现,此一区域的稻麦两熟在历史上的大多数时候并无突出的季节矛盾,只是有两个时期例外。这两个时期一是明末清初,一是19世纪。太湖流域历史上突出的季节矛盾不由人口、品种等社会原因引起,而由气候变化这一自然因素导致。明末清初和19世纪分别是历史上最为寒冷的时期,是气候变冷造成了这一区域稻麦两熟突出的季节矛盾     

The Dual Model for Tourism Resource Productivity Improvement

For natural resource science, resource productivity studying is an important subject. But researches on tourism resource productivity are limited. The most significant influencing factor on tourism resource productivity is the potential market scale of tourist locations, and second most important influencing factor is the resource endowment. Regional urban population is significantly correlated with region tourist numbers, being the decisive factor of region potential tour market scale. In tourism development, the dual model should be adopted: on one hand to enhance tour spot attractiveness, on the other hand to cultivate the potential market by improving urbanization level and other means. In the situation of tourism development fever spreading, the dual model for improving tourism productivity helps to avoid the "Great Leap Forward" which means that too rapid tourism construction divorces from actual market demand.     

工科学生工程安全素质培养的探索与实践

高等学校工科学生的社会职业定位是工程师,工程师的主要工作是从事工程的规划、设计、实施、运行和管理,其工程行为对工程安全具有至关重要的影响。随着现代工程向大型化、综合化和复杂化方向发展,工程安全已成为人类社会面临的重大问题,解决工程安全问题的根本途径之一是加强和改进高等工程教育,致力于提高工科学生的工程安全素质培养。对工科学生的工程安全素质培养,各高校可根据自己的专业优势和服务需求面而独具特色,以适应社会对工程安全人才多样性要求。湖南科技大学在工科学生的培养中,从培养目标的改革中加强了对工程安全素质的要求;从培养内容的改革中加强了对工程安全知识的传授;从培养方法的改革中加强了对工程安全技能的训练;各项改革中的措施在实践中取得令人满意的效果。     

设施菜地土壤重金属累积及影响因素研究

为了解设施菜地土壤重金属累积规律及影响因,通过在全国8个省具有代表性的设施蔬菜产区采集土壤和肥料样品,系统研究了设施栽培年限、肥料施用、土壤性质对设施菜地土壤重金属Cu、Zn、Cd累积量及活度的影响.结果表明:与露天栽培相比,设施条件下随着栽培年限的延长,土壤Cu、Zn和Cd的全量和有效态浓度均呈明显的累积趋势,栽培年限>15a时的设施土壤Cu、Zn和Cd的全量和有效态浓度分别是露天栽培土壤的1.57、2.16、1.67、3.28、1.96、2.00倍.Pearson分析表明设施菜地土壤Cu、Zn、Cd均与土壤SOM呈极显著相关,说明其在来源上较强的相似性,进一步对设施栽培土壤主要投入品中Cu、Zn、Cd含量分析表明,猪粪、商品有机肥及土壤调理剂中Cu、Zn均超过了100mg/kg,Cd超过了1.0mg/kg,且投入量较大,是设施栽培土壤中Cu、Zn、Cd的主要贡献者,而秸秆和部分化肥(如尿素、硫酸钾)中的Cu、Zn、Cd含量均极低,对设施栽培土壤累积贡献微乎其微.pH值和CEC是影响Cu、Zn、Cd在土壤中累积活度的关键因素,其中随着pH值的升高土壤Cu活度表现了先升高后下降的趋势,而土壤Cd活度则表现了持续下降的趋势,仅在pH<6.26时达到了显著相关水平;土壤CEC的升高对土壤Cu活度表现了先下降后升高再下降的趋势,土壤Cd活度表现了先升高后缓慢下降再升高的趋势,而土壤Zn活度仅在CEC<5.83时随着CEC升高表现下降显著线性相关趋势.因此,防止设施栽培土壤Cu、Zn、Cd的累积与污染,选择重金属含量低的肥料和调控土壤理化特性(尤其是pH值、CEC)则是缓解设施栽培土壤重金属累积速率进而确保蔬菜质量安全的有效途径.     

Organic farmers in islands: Agricultural management and attitude towards the environment

SUMMARY

This study explores differences among organic farmers who live in islands and have isolated small-size operations. The relationships between farmers' characteristics and attitudes and farm management were interpreted by studying how they manage their land, their attitudes towards the environment and alternative farming systems, and their involvement in organic farming. The research was carried out using questionnaires addressed to organic farmers on the island of Thassos. Nonlinear canonical correlation was applied for data analysis. This information could contribute to adjustment of policy decisions for on-farm diversification. Agricultural policy makers should approach organic farmers in northern Thassos (productive irrigated olive orchards with gentle slopes) by enacting standards to reduce the cost of alternative plant protection methods and promoting their products in order to maintain and expand organic farming. They should also approach organic farmers in southern Thassos (less productive, dry cultivated olive orchards with steep slopes, overgrazed and often abandoned) by providing them with the necessary information and appropriate agricultural know-how to effectively manage their farms. Organic farmers with stable off-farm income are more aware of environmental values and consider that they risk less than others in order to gain the benefits of alternative farming systems. However, they should attend training programmes to achieve economic success to allow them to continue farming organically.     

不同物质对铬价态测定结果的影响

采用单波长法和双波长法,分别考察了KH2PO4、H3PO4、H2SO4、KNO3、牛肉膏和蛋白胨对Cr(III)和Cr(VI)质量浓度测定的影响。结果显示,Cr(III)和Cr(VI)在测量中是相互影响的,并且Cr(III)对Cr(VI)影响较显著。在单波长法测定中,牛肉膏、蛋白胨及2种酸对Cr(III)和Cr(VI)的影响较钾盐对其影响更为显著,H3PO4和H2SO4对Cr(III)和Cr(VI)的特征吸收峰值影响最大,降低幅度在20%～50%。这些物质对双波长法测定Cr(VI)几乎没有影响;但对Cr(III)测定中,H2SO4和H3PO4的影响较大,其相对误差分别为14.57%和8.87%,其余物质产生的相对误差均小于1.6%。因此,双波长法可用于生物样品中Cr(III)和Cr(VI)的测定,线性范围分别为0～160 mg/L和0～80mg/L。     

湖南品牌战略的现状与对策刍论

湖南省许多企业由于仍然受计划经济体制的阴影笼罩，缺乏竞争观念，品牌意识淡薄，导致品牌难上档次，知名品牌缺少．因此，必须整合湖南品牌战略、实施企业形象战略、培育品牌文化战略和实施品牌战略．