菜用枸杞栽培技术研究

通过对菜用大叶枸杞扦插繁育与生长习性的研究，总结了枸杞菜丰产栽培技术。大叶枸杞扦插以８ｃｍ长硬枝插条效果最好。枸杞菜生长受肥水影响最大，扦插前宜施足基肥，在每次采收后，施速效肥以补充肥力，以后每７～１０ｄ用３ｇ·Ｌ－１尿素水溶液喷施叶面追肥。在夏季高温季节（日均温≥２５℃）宜搭建荫棚，以防高温危害。枸杞菜在３０～４０ｃｍ高时采收，采收时茎基部留１．０～２．０ｃｍ，用以萌发更新。收获期５月上旬至１０月下旬，分期采收７次。１１月下旬留种，用原畦留种或埋于土下越冬     

Adoption of small-scale irrigation technologies and its impact on land productivity: Evidence from Rwanda

In an attempt to identify solutions to the effects of erratic rainfall patterns and droughts that limit agricultural production growth, the Rwandan government has recently increased investments in irrigation development. In this study, we analyze the adoption of small-scale irrigation technologies (SSITs) and its impact on land productivity using cross-sectional data from a sample of 360 farmers in Rwanda. The study uses the propensity score matching technique to address potential self-selection bias. Our results reveal that adoption decisions are significantly influenced by factors such as education, farm size, group membership, gender, extension services, access to credit, access to weather forecast information, risk perceptions, access to a reliable source of water for irrigation, awareness of rainwater harvesting techniques, and awareness of subsidy programs. In addition, the results show that the adoption of SSITs has a significantly positive impact on land productivity. The study concludes with policy implications that highlight the need to promote the adoption of SSITs among farmers as a strategy to improve agricultural productivity and food security in Rwanda.     

江淮地形对一次梅雨锋暴雨影响的数值模拟试验

利用WRF-V2.1模式对2007年7月8日至9日一次江淮地区暴雨过程进行数值模拟以及地形敏感性试验。研究表明,大别山地形对这次降水过程中有着重要影响,在迎风坡,地形强迫暖湿气流气旋性辐合上升,降水量增加,至山顶气流辐合上升运动减弱,反气旋性辐散增强,降水量减少;而在背风坡,下坡风和绕山气流影响大气垂直运动,引起降水量变化;同时,地形激发中尺度波动,造成降水阵性分布。     

金银忍冬种子变温催芽处理的研究

[目的]提高金银忍冬种子的发芽率。[方法]设置高温15~25℃、中温5~15℃、低温1~5℃3种温度,对金银忍冬种子采用2段或3段变温处理进行催芽。[结果]金银忍冬种子在两段变温处理中,高温—中温处理的种子最早发芽,发芽势最强,发芽率最高,开始发芽时间是第16天,发芽势25%,发芽率83%;在3段变温处理中,高温—中温—高温处理的种子最早发芽,发芽势最强,发芽率最高,开始发芽时间是第13天,发芽势39%,发芽率86%。变温处理缩短了金银忍冬种子的催芽时间,提高了种子发芽率。[结论]生产中应适当考虑采用高温—中温和高温—中温—高温2种变温处理对金银忍冬种子进行催芽。     

Discarding practices in a Mediterranean small-scale fishing fleet (Patraikos Gulf, Greece)

Abstract  Discarding practices from 110 fishing operations in a Mediterranean small-scale fishing fleet (Patraikos Gulf, western Greece) from August 2004 to July 2005 were analysed. On average, 1 kg of fish was discarded per fishing operation (10% of the catch). The reasons for discarding were: low commercial value (78% of discards), damage at sea before retrieval of the gear (5%), and bad handling on-board (17%). More than half of discards belonged to Spicara flexuosa (L.), Lepidopus caudatus (Euphrasen), Sardinella aurita Valenciennes and Merluccius merluccius (L.). The bulk of discards of each species were associated with a single fishing method (metier). A Generalized Linear Model (Delta-X – error-model) indicated that, when discards were present, significant differences existed in the discard ratio among different métier groups (groups comprising métiers with similar characteristics). Longlines and trammel nets with small mesh-sizes had the highest discard ratios. Discarding practices for the species Diplodus annularis (L.), S. aurita , Squilla mantis (L.), S. flexuosa and Scorpaena scrofa (L.) did not follow a consistent pattern (these species were either fully discarded or fully retained during a fishing operation). The decision seemed to be dependent on market demands rather than fish size. Significant correlation was found between discarded and catch weight, but the presence of many outliers indicated deviance from a case where discards are high when there is an abundant catch. The findings of the study imply that monitoring and management should be carried out preferably on the métier level. Discards could be reduced by technical measures, controlling effort regulations and by improving working conditions on-board fishing vessels.     

6MW小型火力发电厂的优化设计

作者根据设计实践和小型火力发电厂的特点,遵循安全可靠、投资合理、运行高效、绿色低碳的设计原则,就6MW小型火力发电厂的布置形式、电气方案等提出了优化设计建议。     

基质加温对牡丹催花的影响

打破传统牡丹催花技术中单一空气加温的形式,进行催花植株的根际加温,有利于促进牡丹新枝、花蕾的生长发育,在一定时间范围内提早开花.改变传统的土壤盆栽催花,应用无土栽培,且使根际温度保持在12～18℃之间,有利于牡丹萌生新根,从基质中吸收养分,促进开花.     

东亚单层低云特性及其短波辐射强迫的季节变化

利用云与地球辐射能量系统CERES(clouds and the earth’s radiant energy system)资料,对2003-2016年东亚不同区域单层低云物理属性及地面短波辐射强迫的季节时空分布特征进行研究。结果表明:①在空间分布上,辐射强迫与单层低云量在春秋两季有着较好的相似性,而与冰/液态水柱含量在春、夏、秋三个季节有着较好的一致性。②在时间变化上,北方地区夏季的单层低云对短波辐射的削弱作用是最强的;南方地区和西北地区最强的削弱作用发生在春季;东部海域则发生在冬季。在空间分布上,春、秋、冬季最强的低云削弱效应在南方地区。夏季,东亚低云对短波辐射的削弱作用各区域都较弱,大部分区域的负辐射强迫的绝对值小于200 W·m^-2。     

杏黄兜兰和硬叶兜兰在北京的催花比较试验

为确保2011年春节兰展期间能够将从贵州引种的杏黄兜兰和硬叶兜兰及时展出,在春节前对这两种兜兰进行引种催花比较试验。结果表明:(1)杏黄兜兰更适宜换基质栽培,硬叶兜兰是否换基质对其花芽率的影响不大。(2)硬叶兜兰更适宜在11月引种并做低温处理,如果在9月引种也适宜做低温处理;杏黄兜兰对引种的月份要求不高,两个月份引种都不适宜做低温处理。(3)高温温室的催花时间应在春节布展前2～3个月较合适,大约在11月。     

对推进我国农村城镇化主线的思考

目前,我国进入新一轮经济周期,推进中国城镇化是新的经济增长点之一。农村城镇化的本质是农业现代化。只有打破常规,充分利用我国现阶段运用积极的财政政策和稳健的货币政策启动需求的机遇,集中财力,以推进农业现代化为主线,求得农业生产力的跨越式发展;切实依靠农村政治、经济制度和农业生产技术的创新,以农业经济体制的转型和农业经济增长方式的转移,使我国广大农村从传统的自给和半自给的小农经济跃上商品化、专业化、规模化的新台阶;以此奠定城镇的经济基础,切实推进中国农村的城镇化。农业现代化不但可以解决我国"三农"问题中的一系列深层次的矛盾,使我国城镇化得以有序健康地发展,而且也可以使生机勃勃的农村经济板块驱动城市经济板块,形成彼此互动、并驾齐驱的崭新格局,使我们摆脱目前宏观经济运行的困境,推动我国经济持续稳定地增长和繁荣。