白色酿酒葡萄品种制汁适性及稳定性研究

由于加工葡萄汁的品种要求出汁率高,风味独特,糖、酸、香味和涩味成分平衡,故品种选择对制汁质量十分重要。本实验根据不同白色酿酒品种的葡萄汁,分析其主要成分及特征指标,来评定该品种是否适合制汁以及其制成汁的稳定性。     

Impact of contracts in high yielding varieties seed production on profits and yield: The case of Nepal

Nepal’s population continues to grow, but the agricultural sector’s performance remains almost stagnant. This has led to a decline in the per capita availability of food. Increasing agricultural productivity is the key to agricultural growth, and one strategy for increasing agricultural productivity is to use improved seeds. This study investigates the impact of contract farming (CF) in high yielding varieties (HYV) of paddy seed production on costs, yield, and profits of smallholder farms in Nepal. Using farm-level data and a non-parametric propensity score matching estimator, the study finds a significant positive impact of contract HYV seed farming on revenues, profits, and yield, and a significant negative impact on total costs of production. Additionally, very small farms (⩽0.43 ha) with CF in HYV paddy seeds tend to gain the most when it comes to yield per hectare. Our estimates reveal that the average smallholder household in Nepal engaged in CF with input conditions receives higher profits. However, farmers engaged in CF with output conditions tend to have higher yields but smaller profits. Finally, farmers engaged in CF in HYV paddy seeds with both input and output conditions have the highest yield gains and significantly higher profits.     

球形锐钛矿TiO_2合成及晶种对TiO_2形貌的影响

成功地采用水解法制备了球形锐钛矿TiO2,研究了空白实验(未引入晶种)、引入10 nm TiO2晶种及菌体晶种对锐钛矿TiO2形貌的影响。结果表明随着引入晶种的颗粒逐渐变大,合成的锐钛矿型TiO2颗粒也在逐渐增大:空白实验中TiO2的颗粒平均直径约为0.5μm,10 nm TiO2晶种中TiO2的颗粒平均直径约为0.6~0.7μm,菌体中TiO2的颗粒平均直径约为0.8~0.9μm;加入晶种的颗粒越大,合成的锐钛矿型TiO2颗粒粒度越均匀,球形越完整、团聚现象越少。     

不同培养时间对决明子芽菜生物学产量和黄酮含量的影响

本文使用控温豆芽机恒温20℃培养决明子芽菜,研究不同培养时间(5 d、7 d、9 d、11 d和13 d)对决明子芽菜生物学产量和黄酮含量的影响。结果表明,决明子芽菜的胚根长度、子叶长度、胚轴长度、单株鲜重和单株净菜重在培养7 d采收时均高于5 d采收,且差异显著,7 d后各指标数值虽呈增加趋势,但是差异不显著。黄酮含量随生长期增加不断增加,但在5 d、7 d、9 d和11 d之间差异不显著,13 d时采收黄酮含量最高为16.17 mg·g^-1,且与之前不同生长期差异显著。综合生物学产量、黄酮含量及时间成本决明子芽菜培养7 d即可以进行采收。     

Do tourists disperse weed seed? A global review of unintentional human-mediated terrestrial seed dispersal on clothing,vehicles and horses

Human-mediated seed dispersal is recognised as an important, but under-researched, issue. To assess the potential for tourists to act as unintentional seed dispersal agents, we reviewed published and unpublished data on seed dispersal via clothing, vehicles (cars) and in/on horses and donkeys, all of which can be used by tourists. Seeds from 754 species of terrestrial plants have been collected from these vectors, 15% of which are internationally recognised environmental weeds. Seeds were collected from personal clothing and equipment (228 species), the fur of donkeys and horses (42 species), horse dung (216 species) and vehicles (505 species). Most were herbs (429 species) or graminoids (237 species) and native to Europe. Annual Poa, White Clover, Kentucky Bluegrass and Yorkshire Fog were the most frequent species. There have been eight studies specifically on tourists, which identified 12 species on clothing, 26 on vehicles and 133 from horse dung. Methods that minimise the risk of tourists as human-mediated dispersal agents may therefore be appropriate for some tourism activities/destinations: suggestions are made. Further sampling using standardised experimental techniques is required to assess the relative risk associated with specific tourist activities and locations and determine which, and how much, seed is transported.     

棉种市场“窜货”现象分析及其防范

近年来，令各棉种生产企业及各级棉种经销商深受其害的“窜货”现象时有发生，“窜货”行为给棉种生产企业带来了一系列危害，从而使得保护市场、打击“窜货”显得尤为重要和必要。本文针对棉种市场出现的“窜货”行为进行了原因分析，并分析了为什么棉种市场成为恶意“窜货”行为重灾区，最后针对原因分析提出了棉种生产企业如何防范和处理市场上出现的窜货行为。     

并购与种子产业发展

并购是现代经济史上一个十分突出的现象,现代种子产业的发展就是一部种子企业的并购史。从微观层次上看,并购是企业发展和追逐利润的内在要求,是实现企业扩张和资本集中的快速有效形式,从宏观层次看,是产业结构调整,合理配置资源的手段。从并购这一企业行为对市场结构和产业发展影响的角度,对世界种子产业发展中的并购过程和并购效应进行实证分析,证实了国际种子产业的并购实践对现阶段国内种子产业的借鉴意义。     

茶皂素提取工艺的研究及应用前景

本文综述了茶皂素的性质、用途、应用前景,着重探讨了利用醇水溶液法,从油茶籽饼中提取茶皂素的方法,通过实验发现,与水溶法及有机溶剂法相比较而言,本方法具有工艺简单,成本较低,所得产品颜色浅,含量及得率较高等优点。能完全适用于工厂生产操作。     

Smallholder Demand for Maize Hybrids in Zambia: How Far do Seed Subsidies Reach?

We add to an emerging body of literature on input subsidies in Africa south of the Sahara. Our analysis focuses on demand for seed, characterising smallholders with a high predicted demand for hybrid seed who were not reached by the subsidy programme. We use cross‐sectional data from the 2010 agricultural season and an instrumented control function approach to test the hypothesis that the subsidy on hybrid maize seed in Zambia is selectively biased. Consistent with other literature, we find that the subsidy is a recursive determinant of seed demand, but in 2010, its recipients had more land, more assets, and lower poverty rates. Findings illustrate the social costs of the programme as currently designed and highlight the need to build alternative supply channels if poorer maize growers are to grow hybrid seed.     

云南松母树林基地发展对策研究——白马河林场案例

优良种子是提高林分质量的重要保障,因此,母树林经营在林业可持续发展中起着重要作用。探讨母树林经营在市场经济条件下的出路,已成为十分迫切的问题。文章对白马河林场云南松母林基地的经营现状进行了分析,找出了其中存在的问题,提出了以云南松母树林为核心、多元化发展、制度创新的发展对策。