敦煌气候条件及对棉花产量因素的影响

甘肃敦煌地区气候条件虽然适宜棉花生长,但热量条件处于棉花正常生长适宜指标的下线,对棉花的产量和质量具有较大影响。利用敦煌市国家基准气象观测站1983~2012年农业气象观测资料,统计分析了敦煌棉花全生育期气象条件对棉花的株铃数、单铃重及僵烂铃率、蕾铃脱落率及产量的影响。结果表明：棉花花蕾期气温、花后热量和花期气温、裂铃吐絮阶段灌水量是造成棉花僵烂铃和蕾铃脱落的主要原因。花铃期的平均气温越高,热量越充足,越有利于棉铃数的增加;7月上旬至8月中旬夜温不足降低了棉株矿物质和贮存物的积累速率,导致花蕾及胚珠发育不良,单铃胚珠数减少;盛夏7月中旬高温造成棉铃代谢紊乱,导致单铃不孕,造成株铃数不足和单铃重下降,进而影响棉花产量。     

不同品种棉田辐射平衡与小气候分析

朝阳县是辽宁省的重点棉区，植棉历史悠久，为本省积累了丰富的植棉经验，但品种单一，技术老化，产量低而不稳，管理繁琐，与当今高速发展棉花生产的要求已不相适应。因此，我们根据气候相似的原理从山西引进了高产适宜简化栽培管理的3008棉花，在朝阳县十二台乡进行栽培试验，并与辽棉10号品种进行对比分析，其产量高，品质好，经济效益比较显著，深受棉农欢迎。本文进行了农田小气候分析研究，从而为朝阳县推广棉花简化栽培管理技术提供了科学依据。     

棉花产量及品质与气象条件的关系

利用1991－1995年地膜棉花分期播种试验资料,分别建立了籽棉产量和霜前花率积温模式,并建立了影响棉花品质的纤维长度、衣分、衣指及子指的温度、耗水量模型。分析了各自的影响机理,并推算了宁夏各地在气候正常年份下新陆早1号的产量及品质范围,发现宁夏存在棉花花铃期冷害,其出现概率为20％。     

充分利用光热资源搞好棉花栽培管理

棉花栽培管理,应采用综合性科学技术措施,在水肥条件具备下,自然界光、热资源在棉花产量形成中起主导作用,提高光热资源利用率,对棉花优质、高产、稳产意义重大,所以,把提高光、热利用率作为棉花栽培管理目标。棉花栽培管理可用两个优势保一个优势的方法,就是用棉株生物学优势与光、热资源优势时段匹配同步,保证棉花产量优势。在作务上,扬长避短,发挥光、热气象因素在棉花生产中的作用,通过人工调控,促进棉株营养生长和生殖生长,减少养分消耗,     

关中东部油直棉种植试验报告

在关中东部棉区进行了夏直棉、油直棉、麦棉套试验,得结论：油直棉在关中东部,生长发育处于光热水富集期,能获较高产量,且管理方便宜于推广。油棉套棉花、油菜共生期短,产量品质高。     

石河子棉花产量与日温度因子的研究

通过对石河子地区棉花产量与日温度因子（日最高气温、日最低气温、日平均气温）的数理统计分析,得出影响本地区玛河流域下游西部团场棉花产量的主导日温度因子及其关键时段均在棉花籽种一现蕾生育期内,影响玛河流域下游东部团场棉花产量的主导日温度因子及其关键时段在现蕾一裂铃及播种生育期内,并建立了相关模式。然后,用炮台、莫索湾、沙湾的日温度日子分别与121团、150团及沙湾县的棉花产量做了一致的分析,建立相关模式,通过比较,得出石河子地区的日温度日子与当地棉花产量的关系具有代表性,影响棉花产量的主导日温度日子及其关键时段与调查情况吻合。     

气候对新疆棉花产量的影响分析

新疆是我国近年发展起来的重要产棉区,在中国棉花生产中占有重要地位,尽管目前新疆棉花单产已达到了较高的水平,但生产仍存在潜在的风险。本文即在前人工作的基础上,根据产量统计资料和历年气象数据,划分气候丰歉年型,用相关分析法分析月平均温度、月总日照时数、月总降水量3个气候因子对棉花产量的影响,从而找出影响棉花产量丰歉的气象指标因子,为新疆棉区棉花产量丰歉年预测提供依据。     

山东棉花产量旱灾损失评估模型

采用统计方法,对棉花气象产量与气候因子进行统计分析,得到了各生育时段影响产量的主要降水因子和需水指标,从而根据当年的降水量对棉花产量因旱灾造成的损失程度进行评估,建立区域、省级棉花旱灾损失评估模型。     

基于灰色关联分析的新疆棉花产量气象影响因素研究

整理了新疆境内2000—2009年的棉花单产、年降水量、年平均相对湿度、年日照时数以及年平均气温等统计数据,对各因素变化趋势及相关性进行了分析,并应用灰色关联分析方法研究各个气象因素对棉花产量的影响程度。结果表明,年日照时数与棉花单产之间相关性最好,对棉花产量贡献最大,基于日照时数建立的棉花产量预测模型具有良好精度。     

风沙灾害对策勒绿洲棉花生物量的影响

为定量评估风沙灾害对策勒棉区棉花生物量的影响,2011—2012年以新陆中21号为供试品种,在中国科学院新疆策勒荒漠草地生态系统国家野外科学观测研究站农民常规栽培模式田内进行有、无防风沙网防护对棉花最终产量影响的对比观测试验,发现频繁的风沙天气对棉花产量形成的影响分两个阶段,前期营养生长阶段,棉花植株抗逆性弱,而此时该地区风沙活动频繁,植被盖度低,平均风速较大,因此该时段棉花遭受风沙危害后其出苗率明显降低,导致后期严重缺苗;棉花营养生长和生殖生长并进时期抗逆性增强,绿洲植被覆盖度增加,起沙风频次减少,从而导致风沙对棉花生长的影响减弱,仅使棉花植株发育期延迟,地上部分单位面积上的生物量在防护网内比网外多52%,但单株生物量仅多4%。     

极限产量权重法分段预报盐城市大、小麦产量

根据盐城市的大、小麦产量，农技措施和气象资料，采用极限产量权重法组建大，小麦产量（ｙ）的预报模式：ｙ＝ｙｍ－ｙ农－ｙ灾－ｙ气或改写为：ｙ＝ｙｍ（１－（∑ａｉ＋∑Ｂｊ＋∑Ｃｎ））对盐城市大、小麦产量进行分段预报，经多年试报，结果与实产的相以误差均在５％以内。     

Comparisons of sulfate and nitrate production in clouds on the mid-Atlantic and Pacific Northwest Coasts of the United States

Measurements are presented of sulfate and nitrate production in clouds on the East and West coasts of the United States. Sulfate production measured on the mid-Atlantic Coast was significantly greater than on the Pacific Northwest Coast. Nitrate production was significant on the mid-Atlantic Coast but, on average, insignificant on the Pacific Northwest Coast. Measurements of sulfate and nitrate scavenging coefficients by clouds are also presented.     

昭平县茶叶生产的气候优势及生产对策

根据茶叶生长发育对气候条件的要求,分析昭平县发展茶叶生产的气候优势,并提出发展茶叶生产的对策。     

贵州省主要粮食作物综合增产潜力

从大气作物土壤系统出发,建立了贵州省主要粮食和物综合生产潜力模式,提出了作物增产潜力指数的概念,分析了在现实条件下和未来条件下作物综合增产潜力的前景。     

气候变暖对盐城市小麦生产的影响及其对策

本文通过对盐城市37年气象资料的计算分析,得出：小麦生育期间气候明显变暖,尤其冬季气温上升最为明显,便得小麦生育进程超前,过早拔节,冻害变重,病虫草害和涝渍害加重。据此,根据本市小麦生产的实际情况,提出了扩大半冬性品种种植面积、适当推迟播期、控制群体结构、适时防治病虫草害等对策措施。     

如何在Windows NT环境下进行远程访问

目前 ,ＷｉｎｄｏｗｓＮＴＳｅｒｖｅｒ 4.0中文版在网络市场比较流行 ,不少单位把它作为局域网最佳的网络操作系统 ,工作站大多选用Ｗｉｎｄｏｗｓ 95和Ｗｉｎｄｏｗｓ 98,各单位也利用Ｉｎｔｅｒｎｅｔ/ｉｎｔｒａｎｅｔ技术开发各类应用服务系统。建立了ＷＥＢ主控服务器、电子邮件服务器、ＦＴＰ服务器等 ,提供网上浏览各类信息及资源的共享。对于局域网管理员来说 ,对本地局域网终端上网网络参数配置都很熟悉 ,但在实践中 ,由于网络终端距本地网有相当一段距离而不能联接 ,就束手无策。这时 ,应考虑使用ＷｉｎｄｏｗｓＮＴＳｅｒｖｅｒ…     

Role of the volatile fraction of submicron marine aerosol on its hygroscopic properties

The hygroscopic growth factor (HGF) of 85 nm and 20 nm marine aerosol particles was measured during January 2006 for a three-week period within the frame of the EU FP6 project MAP (Marine Aerosol Production) winter campaign at the coastal site of Mace Head, using the TDMA technique. The results are compared to aerosol particles produced in a simulation tank by bubbling air through sea water sampled near the station, and through synthetic sea water (inorganic salts). This simulation is assimilated to primary production. Aitken and mode particles (20 nm) and accumulation mode particles (85 nm) both show HGF of 1.92 and 2.01 for particles generated through bubbling in natural and artificial sea water respectively. In the Aitken mode, the marine particles sampled in the atmosphere shows a monomodal HGF slightly lower than the one measured for sea salt particles artificially produced by bubble bursting in natural sea water (HGF = 1.83). This is also the case for the more hygroscopic mode of accumulation mode particles. In addition, the HGF of 85 nm particles observed in the atmosphere during clean marine sectors exhibits half of its population with a 1.4 HGF. An external mixture of the accumulation mode marine particles indicates a secondary source of this size of particles, a partial processing during transport, or an inhomogeneity of the sea water composition. A gentle 90 °C thermo-desorption results in a significant decrease of the number fraction of moderately hygroscopic (HGF = 1.4) particles in the accumulation mode to the benefit of the seasalt mode, pointing to the presence of semi-volatile compounds with pronounced hydrophobic properties. The thermo-desorption has no effect on the HGF of bubble generated aerosols, neither for synthetic or natural sea water, nor on the atmospheric Aitken mode, indicating that these hydrophobic compounds are secondarily integrated in the particulate phase. No difference between night and day samples is observed on the natural marine aerosols regarding hygroscopicity, but a more pronounced sensitivity to volatilization of the 1.4 HGF mode in the accumulation mode is observed during the day.     

Improving Simulation of the Terrestrial Carbon Cycle of China in Version 4.5 of the Community Land Model Using a Revised Vcmax Scheme

The maximum rate of carboxylation(Vcmax) is a key photosynthetic parameter for gross primary production(GPP) estimation in terrestrial biosphere models. A set of observation-based Vcmax values, which take the nitrogen limitation on photosynthetic rates into consideration, are used in version 4.5 of the Community Land Model(CLM4.5). However, CLM4.5 with carbon-nitrogen(CN) biogeochemistry(CLM4.5-CN) still uses an independent decay coefficient for nitrogen after the photosynthesis calculation. This means that the nitrogen limitation on the carbon cycle is accounted for twice when CN biogeochemistry is active. Therefore, to avoid this double nitrogen down-regulation in CLM4.5-CN, the original Vcmax scheme is revised with a new one that only accounts for the transition between Vcmax and its potential value(without nitrogen limitation). Compared to flux towerbased observations, the new Vcmax scheme reduces the root-mean-square error(RMSE) in GPP for mainland China by 13.7 g C m-2 yr-1, with a larger decrease over humid areas(39.2 g C m-2 yr-1). Moreover, net primary production and leaf area index are also improved, with reductions in RMSE by 0.8% and 11.5%, respectively.     

Mapping and modelling trade-offs and synergies between grazing intensity and ecosystem services in rangelands using global-scale datasets and models

Vast areas of rangelands across the world are grazed with increasing intensity, but interactions between livestock production, biodiversity and other ecosystem services are poorly studied. This study explicitly determines trade-offs and synergies between ecosystem services and livestock grazing intensity on rangelands. Grazing intensity and its effects on forage utilization by livestock, carbon sequestration, erosion prevention and biodiversity are quantified and mapped, using global datasets and models. Results show that on average 4% of the biomass produced annually is consumed by livestock. On average, erosion prevention is 10% lower in areas with a high grazing intensity compared to areas with a low grazing intensity, whereas carbon emissions are more than four times higher under high grazing intensity compared to low grazing intensity. Rangelands with the highest grazing intensity are located in the Sahel, Pakistan, West India, Middle East, North Africa and parts of Brazil. These high grazing intensities result in carbon emissions, low biodiversity values, low capacity for erosion prevention and unsustainable forage utilization. Although the applied models simplify the processes of ecosystem service supply, our study provides a global overview of the consequences of grazing for biodiversity and ecosystem services. The expected increasing future demand for livestock products likely increase pressures on rangelands. Global-scale models can help to identify targets and target areas for international policies aiming at sustainable future use of these rangelands.     

基于T213数值产品的安康降水分县预报释用

将临汾市尧都区1954年至2001年小麦产量年增量和其全生育期降水量进行同步统计分析得出：小麦生产全生育期降水量大于同期降水平均值20％，则绝大多数是增产年；小麦生育期降水量少于同期降水平均值50％，则是欠收年；当小麦全生育期降水量在同期降水平均值-50％至20％之间时，小麦是增产?或是减产，由其它影响小麦产量因素决定。