两种河道洪水演进方法在新疆山区的应用比较

以呼图壁河流域石门水文站以上山区河道为研究区域，利用石门站2015—2019年的日流量观测数据和1978—1983年、2008—2019年的年平均流量数据，以GFS降水资料为WRF-Hydro模型的输入，用其内置的扩散波模式、马斯京根-康吉模式两种河道演算方式进行径流模拟，对比分析模拟径流与实测径流的差异，探讨基于WRFHydro模型的洪水演进方法在新疆内陆干旱区的径流模拟效果。结果表明：扩散波模式模拟效果总体优于马斯京根-康吉模式的模拟效果。分析了WRF-Hydro两种河道演算模式模拟洪水的一些特征，其中扩散波模式模拟结果较好，用时较长；马斯京根-康吉模式模拟结果不太理想，但用时短。     

光,温土壤湿度影响玉米生长发育及产量形成的模拟模式

在田间试验的基础上，从光合、呼吸作用出发，建立了光照、温度、土壤湿度影响玉米植株生长、各器官生长的模拟模式；建立了光照、温度影响玉米发育期的模拟模式；从“库源”理论出发，建立了玉米产量形成的模拟模式。结果表明，模式性能良好，可以在玉米产量预测、指导田间管理等方面推广应用。     

塔克拉玛干沙漠周围主要河流水文序列特性分析

本文在利用数理统计方法分析塔克拉玛干沙漠周围主要河流水文特征基础上，重点利用时间序列分析方法，从时间域和频率域上分别分析了这些河流序列内部结构特征，通过分析初步认为本区河流水量是基本稳定的，各河流的年径流序列基本呈独立随机序列。在此基础上建立了随机模拟模型，从而为模拟本区河流径流变化规律，以及本区水资源合理开发利用提供了决策分析基础。     

旱地冬小麦产量与水分及施肥量关系的模拟研究

试验采用通用旋转组合设计，模拟研究了冬小麦产量与降水量，施氮量及施磷量的关系，结果表明，在雨养农业区，冬小麦产量主要受降水量限制，施氮量对产量影响较大，施磷量影响较小，模拟研究得出本试验设计范围内，冬小麦最高产量为５６００．５ｋｇ／ｈｍ＾２，此时需降水为６００ｍｍ，最佳施纯氮量为１５０ｋｇ／ｈｍ＾２，施纯磷量为１０３．８ｋｇ／ｈｍ＾２；模拟还得出在不同降水情况时，获得冬小麦最高产量所需的最佳施肥量     

人工柠条固沙林生长期水量平衡分析

本文通过对人工柠条固沙林水量平衡的实地调查，按照土壤蒸发的水热原理，从统计学的角度，模拟了生长期林分蒸腾、土壤蒸发和土壤蓄水量的季节动态；两种密度的柠条林土壤蓄水量的模拟误差分别为７．３％和６．２％。     

冬小麦叶片和冠层尺度的光合-蒸腾模拟

利用气孔导度-光合-蒸腾耦合模型(SMPT-SB),选取冬小麦关键生育期的典型日，模拟了冬小麦叶片和冠层尺度的光合与蒸腾速率日变化，并借助光合仪和涡度相关系统获得的观测数据进行了验证。研究结果表明：模型模拟的叶片和冠层尺度光合及蒸腾速率与实测值变化趋势具有较好的一致性，光合速率日均绝对误差不超过1μmol·m^-2·s^-1,蒸腾速率日均绝对误差不超过0.41 mmol·m^-2·s^-1;叶片尺度光合和蒸腾速率模拟值与实测值的决定系数R²均在0.90以上，冠层尺度也分别达到了0.96、0.88。此外，模型中水汽响应函数以f(D_s)=RH表示时，相对湿度(RH)变化较大会导致参数m值不能准确量化气孔导度(g_s)的变化，从而降低模拟效果；若分时期率定m值，会大幅提高模拟精度。该模型适用于冬小麦叶片及冠层尺度的土壤-植物-大气之间水碳交换的模拟。     

荒漠土壤成分对陆面过程的影响研究

采集塔克拉玛干沙漠北缘肖塘观测站附近的土壤，应用Mastersizer-2000激光粒度仪测定土壤粒径，按照伍登-温德华粒级标准进行土壤成分分类，发现土壤类型并非均质沙土，在0~30 cm深度的浅层存在10%~24%的黏土,根据土壤成分比例对Noah陆面模式的土壤参数重计算，然后利用肖塘站2011年3月22日至7月25日的观测数据驱动Noah模式，对比修正土壤参数前后的模拟效果。结果表明：更新土壤参数后10 cm土壤温度模拟偏差减少0.62 ℃，土壤热通量偏差减小10.47 W·m-2，感热通量偏差减少7.02 W·m-2，地表净辐射偏差减少5.48 W·m-2，且效率系数达到更高的接受程度。通过泰勒图分析了土壤参数修正对Noah模拟效果的整体作用，表明修正土壤参数后的模式中热量传输扩散有一定的优化作用，10 cm土壤温度和热通量土壤温度模拟效果得到改进。     

不同玉米品种苗期抗旱性研究

用PEG模拟干旱胁迫条件下发芽率伤害程度、离体叶片保水力、细胞膜相对透性及植株自身调节系统的变化，研究了抗旱性不同的3个玉米品种。结果表明，3个品种各项抗旱生理指标都表现不同程度的变化，品种太单32受模拟干旱胁迫条件的影响比忻抗5号、晋单33要小。因此，本项研究将为玉米抗旱品种选育与旱作栽培提供科学依据。     

塔南绿洲优化防护模式风洞实验研究初探

利用大气边界层风洞对不同结构防护林的防风效应进行了初步研究，并依据风洞模拟结果提出了一个优化目标参数，给出了林网优化防护模式的相对最优模型。     

不同矿化度水源膜下滴灌棉田土壤水盐动态和作物生长模拟

为构建适用于干旱区膜下滴灌条件的土壤水盐动态分布和棉花生长模型，基于2020—2021年的田间试验，经过对SWAP模型的土壤、土壤水力功能和作物生长等模块进行率定和验证，对灌溉水矿化度为1、2、3、4、5、6 g·L^-1时的土壤水盐分布特征、作物生长过程和干物质累积分配进行数值模拟。结果表明：（1）土壤含水率与土壤含盐量的模拟精度以20～100 cm土层较好，0～20 cm土层模拟精度较差，其中土壤含水量的模拟效果优于土壤含盐量；随着灌溉水源矿化度的增加，土壤含水率和含盐量的模拟误差逐渐变小。（2）不同矿化度水源膜下滴灌棉花叶面积指数模拟效果较好（R²=90.72%，RMSE=0.35 cm²·cm^-2，NRMSE=8.73%，IOA=0.98）。（3）不同矿化度水源膜下滴灌棉花茎干物质累积量模拟效果较好（R²=89.08%，RMSE=6.12 g，NRMSE=23.16%，IOA=0.96）。研究结果表明，SWAP模型可以较好地对不同矿化度水源膜下滴灌的土壤水盐动态分布和棉花生长过程进行模拟。     

城市化过程中的景观生态环境效应

城市化是人类文明进步的一个重要标志。我国由于工业化起步晚,城市化进程也较慢。2001年全国城市化平均水平仅有36%,远远低于发达国家76%的平均水平。在未来的50年里,我国将经历一个快速的城市化过程,大约3~4亿人口将从农村转移到城镇,城市化的规模是史无前例的。但在城市化过程中,也带来了一系列生态问题。本文着重分析了城市化过程中的景观生态环境问题,并提出了相应的景观生态环境保护对策,以期起到借鉴作用。     

The area under the disease progress stairs: calculation, advantage, and application

The area under the disease progress curve (AUDPC) is frequently used to combine multiple observations of disease progress into a single value. However, our analysis shows that this approach severely underestimates the effect of the first and last observation. To get a better estimate of disease progress, we have developed a new formula termed the area under the disease progress stairs (AUDPS). The AUDPS approach improves the estimation of disease progress by giving a weight closer to optimal to the first and last observations. Analysis of real data indicates that AUDPS outperforms AUDPC in most of the tested trials and may be less precise than AUDPC only when assessments in the first or last observations have a comparatively large variance. We propose using AUDPS and its standardized (sAUDPS) and relative (rAUDPS) forms when combining multiple observations from disease progress experiments into a single value.     

植物激素受体的三维结构及其分子识别机制研究进展

许多研究表明,第一次"绿色革命"与植物激素的相关基因编码是密不可分的。植物激素是一类具有调节植物生长发育功能的有机内源物质,激素受体是植物激素调控生长的中心环节,一直备受关注,而激素受体结构的发现可以使人们更深入地了解其调节植物生长的分子机制。综述了生长素、赤霉素和脱落酸3种经典植物激素受体结构的发现及其作用机制的最新研究成果,旨在为开展基于结构的新型人工植物激素的生物合理设计提供参考。     

Advances in sunflower downy mildew research

This review summarises the progress in research on sunflower downy mildew as reported in publications of the past 10 to 15 years, the period since the last comprehensive review on Plasmopara halstedii. Particular attention is paid to subjects that showed much progress and may be of particular interest to sunflower pathologists, mycologists or molecular biologists. Accordingly, single sections are devoted to the problems of taxonomic and phylogenetic aspects, host specificity, the host—pathogen interaction including resistance phenomena, as well as epidemiology and disease management. Reflecting the progress achieved in some fields and illuminating the deficits in others should stimulate the reader's interest in this very significant pathosystem.     

Simultaneous temporal progress of sorghum anthracnose and leaf blight in crop mixtures with disparate patterns

Field studies were conducted at Alupe in western Kenya in 1995 and 1996 to evaluate the efficacy of crop and species mixtures for the management of sorghum anthracnose (caused by Colletotrichum sublineolum) and leaf blight (caused by Exserohilum turcicum). The progress of these diseases developing simultaneously on a susceptible sorghum cultivar planted in inter- or intra-row mixtures of varying proportions with either maize or resistant sorghum was monitored. The effects of host type and mixture patterns on disease progress were compared by parameter estimates derived from fitted Lotka-Volterra competition equations and nonlinear logistic models. Competition coefficients were not significant and their confidence intervals included zero in most cases, suggesting that interactions between C. sublineolum and E. turcicum did not occur. Mixtures of the susceptible sorghum with either the nonhost maize or the resistant sorghum delayed the time when disease is first observed and reduced the rate of disease progress and carrying capacity for both anthracnose and leaf blight, with a more pronounced effect on the latter disease. The lower efficacy of mixtures in reducing anthracnose was attributed to an aggregated spatial pattern, coupled with higher rates of progress for this disease. Intra-row mixtures were more efficient than inter-row mixtures in reducing disease development in all years. The implications of these observations for the management of sorghum diseases under small-scale farming systems are discussed.     

A time series analysis of brown eye spot progress in conventional and organic coffee production systems

Brown eye spot (BES), caused by Cercospora coffeicola, is an important coffee disease in Brazil. Losses related to this disease have increased over the last few years. Because the factors associated with the disease dynamics are not fully understood, it is important to gather information about this in different cropping systems. BES epidemics were compared from three production systems: organic (OS), organic under shade (OSS) and conventional under full sun (CS). This study was conducted in Ervália‐MG, Brazil, from November 2004 to October 2008. Disease progress was modelled with all 4 years of data in a time series analysis. Disease intensity (severity (SEV) and incidence (INC)), leaf setting (LS) and leaf fall (LF) were assessed on a monthly basis. The highest values for SEV, INC, LF, LS, as well as a larger area under the disease progress curve and maximum disease occurred in CS and in the upper branches, whereas the lowest values for all variables occurred in OSS and in the lower branches. The highest values occurred for SEV and INC from May to July, for LF from July to September, and for LS from October to January. The disease progress was successfully modelled via a time series analysis. The seasonal behaviour of disease progress for all years and production systems was modelled with a nonlinear sinusoidal model with autoregressive moving average (ARMA) errors. Estimated parameters were generated which could be useful for comparative epidemiology, and it was shown that shade could be used in the field for BES management.     

抗除草剂转基因水稻的研究进展

水稻是我国乃至世界上最重要的粮食作物之一,杂草是影响水稻产量和品质的主要因素。近年来,抗除草剂转基因水稻的研究与应用取得了较大进展。本文概述了稻田的主要杂草及防除方法,简述了稻田常用的几种除草剂及其作用机理,介绍了全球抗除草剂转基因作物的现状,着重阐述了抗除草剂转基因水稻的研发进展、应用及未来发展方向。     

Natural products in plant protection

Natural products can be used to control pests and diseases in crops. These products include anorganic compounds, but also a variety of plant extracts. In the beginning of this century active microbial extracts were discovered as well. Synthetic crop protection chemicals were developed from about 1940 onwards and sustained progress in modern agriculture. The first generation chemicals have aspecific modes of toxic action and are in many instances deleterious to the environment. The second generation chemicals have specific modes of action and meet modern environmental requirements. A disadvantage of these chemicals is the potency of target organisms to acquire resistance. This condition urged agrochemical industry to develop chemicals with new modes of action. Such chemicals can be developed by using natural bioactive products as leads in synthesis programmes. This paper decribes the progress that was made in the development of natural bioactive compounds in pest and disease control.