青海省海东市不同等级降水和旱涝关系研究

利用1961～2015年青海省海东市5气象站逐日降水资料,根据中国气象局降水等级划分标准和旱涝Z指数的计算方法,分别统计海东市夏、冬半年不同等级雨量和雨日及计算Z指数,利用线性回归法分析海东市55年来不同等级雨日和雨量和Z指数的变化趋势,并采用偏相关系数、相对贡献率和合成分析等方法研究不同等级雨日和雨量对旱涝的影响。得出以下结论：①海东市夏(冬)半年降水以小雨(雪)和中雨(雪)为主,雨日和雨量及占年比例均呈现自南向北递增的空间分布。②夏半年小雨和大到暴雨的雨量及雨日呈减小趋势,中雨雨量和雨日呈增加趋势,冬半年小雪、中雪和大到暴雪的雨量及雨日均呈减小趋势。③夏、冬半年Z指数均表现为不显著的减小趋势。④夏、冬半年不同等级雨量和雨日与Z指数偏相关系数和相对贡献率分析,夏半年中雨和大到暴雨的雨量及雨日对Z指数有显著的影响,冬半年小雪的雨量和雨日对Z指数变化影响最大。⑤采用合成分析法的标准化值,无论是夏半年还是冬半年,在偏涝年,不同等级降水雨日和雨量基本都为正值,在偏旱年,不同等级降水雨日和雨量基本都为负值。在偏涝年,不同等级降水雨日和雨量差异夏半年主要表现在大到暴雨和中雨雨日及雨量,小雨雨日及雨量差异较小,而冬半年主要表现在小雪雨日及雨量,中雪次之,大到暴雪最小；在偏旱年,不同等级降水雨日和雨量差异夏半年主要表现在中雨雨日及雨量,大到暴雨次之,小雨最小,冬半年主要表现在小雪和中雪雨日及雨量,大到暴雪差异较小。     

Bird,weed and interaction effects on yield of irrigated lowland rice

Weeds and grain feeding birds are the two main biological causes of yield losses in irrigated rice in Africa. To quantify the single and combined effect of these biological constraints on rice yields, and to investigate whether weeds attract birds and thereby contribute to increased bird damage, a three-year factorial experiment was set-up in the Senegal River Valley. We tested two management factors (bird and weed management), each with two levels (‘complete’ and ‘absent’), and one crop cycle factor also with two levels (Sahel 202, a medium-cycle and Sahel 108, a short-cycle rice cultivar). Season-long competition from weeds resulted in high but predictable yield losses ranging from 50% to 75%, with lower yield losses for the medium-cycle cultivar Sahel 202 in two of the three seasons. Due to the nature of the pest, season-long exposure to birds resulted in less predictable yield losses ranging from 13% to as high as 94%, with high seasonal variation. In two seasons, much lower bird-inflicted yield losses were observed in the short-cycle cultivar Sahel 108, whereas in one season the medium-cycle cultivar Sahel 202 was much less damaged. When rice was exposed to both weeds and birds, the relative yield losses ranged from 80 to 99%. The yield reducing effect of weeds and birds was never additive. Bird visits to a weedy crop were more frequent compared to a weed-free crop at least in the early rice grain filling stages. This attraction of birds by weeds resulted in an additional yield loss in five of the six cases, ranging from 2 to 62%. Bird-inflicted yield losses in irrigated rice may be reduced by keeping the crop, as much as possible, free from weeds.     

Relative abundance and damage of some insect pests of wheat under different tillage practices in rice–wheat cropping in India

Tillage changes the physical and chemical properties of soil and can also inhibit or enhance useful and harmful fauna. In agriculture, different tillage technologies are being tried to enhance crop productivity, but little concrete information seems to exist on their effects on pest abundance and damage. To address this lack of information, sowing of wheat was investigated under different tillage systems. In order to monitor pest abundance and damage in altered tillage systems, the present studies on the relative abundance and damage due to insect pests viz. pink stem borer (PSB, Sesamia inferens Walker), termites (Microtermes obesi Holmgren and Odontotermes obesus Rambur) and root aphid (Rhopalosiphum rufiabdominalis Sasaki) were undertaken in a rice–wheat cropping system during 2010–11 and 2011–12. Pest abundance and damage was monitored in four tillage systems i.e. conventional tillage (CT), zero tillage (ZT), ZT + mulch and rotary tillage (RT) under insecticide protected and unprotected conditions. The application of insecticide did not affect root aphid incidence or termite damage. However, significant differences in PSB damage in insecticide protected (0.9%) and unprotected (1.2%) conditions were observed. The investigations demonstrated that in CT, damage by PSB (0.6%) was minimum; however termite damage (2.2%) was maximum as compared to all other tillage conditions. In ZT, PSB damage (1.4%) was maximum and root aphid incidence (3.1 aphids/tiller) was minimum in comparison to other tillage conditions. ZT + mulch resulted in inter-mediate insect pest incidence/damage; however, RT was the least effective practice which showed relatively high incidence/damage of these three insects (1.2% PSB damage, 1.9% termite damage and 5.1 aphids/tiller). The insecticide × tillage interaction indicated that insecticide application is needed only in ZT and RT for PSB management.     

田东县气候特征及舒适性分析

选取田东县1954—2010年的气温、风、相对湿度、特殊天气等4个因子,对其气候特征及人体舒适性进行分析。结果表明,田东县雨水充沛,光照充足,气候宜人;全年综合舒适指数总体平均为次舒适以上,气候舒适度高,舒适期长,为适宜旅游观光之地。本研究可以为旅游部门合理开发旅游资源提供参考性建议,以进一步推进田东县旅游业的发展。     

王正非林火蔓延模型改进研究

王正非林火蔓延模型是目前国内比较先进的森林火灾蔓延模型,但是由于林火行为的复杂性,此模型在准确率和普适性方面仍存在许多不足。本文结合已有的成果进一步改进王正非模型,增加了可燃物湿度对林火蔓延速度的影响,改进了林火初始速度的计算方式。针对各种坡度对林火蔓延行为的影响给出了一个计算公式。与改进前相比,改进后的模型使其对林火蔓延情况的预估更为精准。     

基因型和环境对不同生育期花椰菜霜霉病的影响

花椰菜霜霉病是影响其生产和品质的主要真菌类病害之一,为探究基因型、环境,以及基因与环境互作效应对花椰菜霜霉病病情指数的影响,对4个花椰菜品种(厦美80天、雪园80天、830-F、黄80天)进行人工接种,调查了3个生长时期、4个不同田间温湿环境条件处理下花椰菜的发病情况,分析霜霉病病情指数与温度、湿度、昼夜温差、积温和日照时数5个气象因子的相关性。结果表明:对花椰菜霜霉病抗性的贡献率依次为基因型>环境>基因型与环境互作,变异幅度分别为77.52%~87.04%、12.33%~19.94%、0.63%~2.54%;黄80天具有较强的霜霉病抗性,可以作为抗性种质资源;花椰菜霜霉病与日均湿度、昼夜温差呈显著正相关,与日均温度、积温呈显著负相关,与日照时数无显著关系。综上,低温和高湿环境会加剧花椰菜霜霉病的发生,选用抗病品种、秋冬季注意保温、保持通风等措施可以有效降低霜霉病发生。     

养殖模式对冬季商品肉鸭舍温湿指数的影响

选择1日龄健康樱桃谷SM3系商品代肉鸭18 490羽,随机分为网上(N组)和发酵床上(B组)2组进行饲养,监测冬季一个完全生长周期内(42d)鸭舍温度(T)、相对湿度(RH)及温湿指数(THI)变化,探讨不同养殖模式对商品肉鸭舍温湿指数的影响。结果表明:N组和B组舍内平均温度均明显高于平均气温;N组舍内温度全部高于B组,N组平均温度比B组高8.32℃,差异显著(P0.05)。N组和B组舍内相对湿度均明显高于室外;N组舍内平均相对湿度比B组高2.47%,无显著性差异(P0.05)。试验期N组有16d处于热应激状态,B组有6d处于冷应激状态。结果提示,在北方寒冷气候下网上供暖养殖模式能为商品肉鸭提供更舒适的温湿度条件。     

国内外药典相对密度测定法比较研究

通过对比中国兽药典、中国药典、美国药典和欧洲药典中相对密度测定法,了解四部药典的异同点,旨为中国兽药典引入新方法提供参考。分别对四部药典的收载情况、测定法原理、应用范围等进行比较和讨论。四部药典收载的测定法略有差异,中国兽药典收载的测定法在测定黏稠液体时具有一定局限性。建议中国兽药典在充分调研基础上,引入振荡型密度计测定法。     

家具检测用环境舱恒温恒湿系统方案改进

对所研制的第一代环境舱恒温恒湿系统进行实验及分析,分析环境舱内壁结霜凝水以及检测甲醛和TVOC不够准确等问题产生的原因,并提出具有针对性的改进方案。实验表明,改进后的系统可有效解决上述问题,能够精确控制环境舱内部温湿度的恒定,从而保证环境舱在工作过程中对样品分析结果的准确性。     

北极村樟子松与落叶松林区空气负离子浓度及其与气象因子的关系

为了揭示空气负氧离子浓度与林种及相关气象条件之间的关系,笔者于2013年夏、秋两季对北极村地区选取的具有代表性的样地进行负氧离子浓度的观测及研究,通过时间尺度平均值及相关性分析的方法,对采集数据进行统计分析,并得出北极村地区负氧离子浓度的总体水平以及其与林种和气象因子之间的变化关系。结果表明:漠河北极村空气负离子浓度的总体水平处于548~1203个/cm~3,平均值为892个/cm~3,负氧离子浓度大体上与空气温度呈正相关、与空气湿度呈负相关。落叶松样地整体负氧离子水平高于樟子松样地,不同季节对负氧离子浓度也有较大影响。揭示出北极村地区负氧离子浓度与林种、季节以及气象因子之间的变化关系。