Architecture of stem and branch affects yield formation in short season cotton

The cotton direct seeding after wheat(rape) harvested is under trial and would be the future direction at the Yangtze River Valley region of China.The objective of this study was to quantify the effects of branch and stem architecture on cotton yield and identify the optimal cotton architecture to compensate the yield loss due to the reduction of individual production capacity under high planting density in the direst seeding after wheat harvested cropping system.The characteristics of the stem and branch architecture and the relationships between architecture of the stem and branch with yield formation were studied on eight short season cotton cultivars during 2015 and 2016 cotton growth seasons.Based on the two years results,three cultivars with different architectures of stem and branch were selected to investigate the effect of mepiquat chloride(MC) application on the architecture of the stem and branch,boll retention,and the yield in 2017.Significant differences were observed on plant height,all fruiting nodes to branches ratio(NBR) in the cotton plant,and the curvature of the fruiting branch(CFB) among the studied cultivars.There were three types of stem and fruiting branch structures: Zhong425 with stable and suitable plant height and NBR(about 90 cm and 2.5,respectively),high CFB(more than 10.0),and high boll retention speed and seed cotton yield;Siyang 822 with excessive plant height and NBR,low CFB,and low boll retention speed and seed cotton yield;and other studied cultivars with unstable structure of stem and branch,boll retention speed,and seed cotton yield across years.And MC application could promote the appropriate plant height and NBR and high CFB and thus resulted in high boll retention speed and the yield.The results suggested that the suitable plant height and NBR(about 90 cm and 2.5 respectively),and high CFB(more than 10.0),which was related to both genotype and cultural practice,could promote the higher boll retention speed and seed cotton yield.

The Relationship between Extreme Precipitation Events in East Africa during the Short Rainy Season and Indian Ocean Sea Surface Temperature

The East African short rainy season (October-November-December) is one of the major flood seasons in the East African region. The amount of rainfall during the short rainy season is closely related to the lives of the people and the socio-economic development of the area. By using precipitation data and sea surface temperature data, this study reveals the spatial and temporal variation patterns of extreme precipitation during the East African short rainy season. Key findings include significant rainfall variability, with Tanzania experiencing the highest amounts in December due to the southward shift of the Intertropical Convergence Zone (ITCZ), while other regions receive less than 100 mm. Extreme rainfall events (90th percentiles) are evenly distributed, averaging 2 to 10 days annually. Historical data shows maximum seasonal rainfall often peaks at 15 mm, with frequent occurrences of daily rainfall exceeding 10 mm during OND. Additionally, a positive correlation (0.48) between OND precipitation extremes and Indian Ocean Dipole (IOD) anomalies is statistically significant. These findings highlight the climatic variability and potential trends in extreme rainfall events in East Africa, providing valuable insights for regional climate adaptation strategies.

A preliminary study of the effects of plastic film-mulched raised beds on soil temperature and crop performance of early-sown short-season spring maize(Zea mays L.) in the North China Plain

To identify a strategy for earlier sowing and harvesting of spring maize(Zea mays L.) in an alternative maize–maize double cropping system, a 2-year field experiment was performed at Quzhou experimental station of China Agricultural University in 2014 and 2015. A short-season cultivar, Demeiya number 1(KX7349), was used in the experiment. Soil temperature to 5 cm depth in the early crop growth stage, crop growth, crop yield, and water use of different treatments(plastic film-mulched raised bed(RF) and flat field without plastic film mulching(CK) in 2014; RF, plastic film-mulched flat field(FF), and CK in 2015)were measured or calculated and compared. Soil temperature in the film-mulched treatments was consistently higher than that in CK(1.6–3.5 °C in average) during the early growth stage. Crops in plastic film-mulched treatments used 214 fewer growing-degree days(GDDs) in 2014 and 262 fewer GDDs in 2015. In 2014, the RF treatment yielded 32.7%higher biomass than CK, although its 9.4% higher grain yield was not statistically significant. Also, RF used 17.9% less water and showed 33.1% higher water use efficiency(WUE) than CK. In 2015, RF and FF showed 56.2% and 49.5% higher yield, 15.0% and 4.5%lower water use(ET), and 63.4% and 75.7% higher WUE, respectively, than CK. RF markedly increased soil temperature in the early crop season, accelerated crop growth, reduced ET,and greatly increased crop yield and WUE. Compared with FF, RF had no obvious effect on crop growth rate, although soil temperature during the period between sowing and stem elongation was slightly increased. However, RF resulted in lower ET and higher WUE than FF. Effects of RF on soil water dynamics as well as its cost-effectiveness remain topics for further study.

APPLICATION EXPERIMENT OF ASSIMILATING RADAR-RETRIEVED WATER VAPOR IN SHORT-RANGE FORECAST OF RAINFALL IN THE ANNUALLY FIRST RAINY SEASON OVER SOUTH CHINA

A scheme of assimilating radar-retrieved water vapor is adopted to improve the quality of NWP initial field for improvement of the accuracy of short-range precipitation prediction. To reveal the impact of the assimilation of radar-retrieved water vapor on short-term precipitation forecast, three parallel experiments, cold start, hot start and hot start plus the assimilation of radar-retrieved water vapor, are designed to simulate the 31 days of May, 2013 with a fine numerical model for South China. Furthermore, a case of heavy rain that occurred from 8-9 May 2013 over the region from the southwest of Guangdong province to Pearl River Delta is analyzed in detail. Results show that the cold start experiment is not conducive to precipitation 12 hours ahead; the hot start experiment is able to reproduce well the first6 hours of precipitation, but badly for subsequent prediction; the experiment of assimilating radar-retrieved water vapor is not only able to simulate well the precipitation 6 hours ahead, but also able to correctly predict the evolution of rain bands from 6 to 12 hours in advance.

Characteristics Analysis on Short-Time Heavy Rainfall during the Flood Season in Shanxi Province, China

In order to provide a reference for the correct forecasting of short-term heavy rainfall and better disaster prevention and mitigation services in Shanxi Province, China, it is very important to carry out systematic research on short-term heavy precipitation events in Shanxi Province. Based on hourly precipitation data during the flood season (May to September) from 109 meteorological stations in Shanxi, China in 1980-2015, the temporal and spatial variation characteristics of short-time heavy rainfall during the flood season are analyzed by using wavelet analysis and Mann-Kendall test. The results show that the short-time heavy rainfall in the flood season in Shanxi Province is mainly at the grade of 20 - 30 mm/h, with an average of 97 stations having short-time heavy rainfall each year, accounting for 89% of the total stations. The short-time heavy rainfall mainly concentrated in July and August, and the maximal rain intensity in history appeared at 23 - 24 on June 17, 1991 in Yongji, Shanxi is 91.7 mm/h. During the flood season, the short-time heavy rainfalls always occur at 16 - 18 pm, and have slightly different concentrated time in different months. The main peaks of June, July and August are at 16, 17 and 18 respectively, postponed for one hour. Short-time heavy rainfall overall has the distribution that the south is more than the north and the east less than the west in Shanxi area. In the last 36 years, short-time heavy rainfall has a slight increasing trend in Shanxi, but not significant. There is a clear 4-year period of oscillation and inter-decadal variation. It has a good correlation between the total precipitation and times of short-time heavy rainfall during the flood season.

A Short-Term Climate Prediction Model Based on a Modular Fuzzy Neural Network

In terms of the modular fuzzy neural network (MFNN) combining fuzzy c-mean (FCM) cluster and single-layer neural network, a short-term climate prediction model is developed. It is found from modeling results that the MFNN model for short-term climate prediction has advantages of simple structure, no hidden layer and stable network parameters because of the assembling of sound functions of the self-adaptive learning, association and fuzzy information processing of fuzzy mathematics and neural network methods. The case computational results of Guangxi flood season (JJA) rainfall show that the mean absolute error (MAE) and mean relative error (MRE) of the prediction during 1998-2002 are 68.8 mm and 9.78%, and in comparison with the regression method, under the conditions of the same predictors and period they are 97.8 mm and 12.28% respectively. Furthermore, it is also found from the stability analysis of the modular model that the change of the prediction results of independent samples with training times in the stably convergent interval of the model is less than 1.3 mm. The obvious oscillation phenomenon of prediction results with training times, such as in the common back-propagation neural network (BPNN) model, does not occur, indicating a better practical application potential of the MFNN model.

面向季节性短时高峰负荷的虚拟配电馈线功能架构及协同配置

传统线路增容方式面对季节性短时高峰负荷时存在线路整体利用率低、紧急功率支撑能力差等问题。因此,文中以功能虚拟化为核心,研究了传统配电馈线与储能元件融合的虚拟配电馈线功能架构,利用双端储能元件搭建虚拟电能传输通道,以应对季节性短时高峰负荷、延缓传统线路增容改造工程,并在非高峰时期提供紧急功率支撑和辅助服务功能,提高储能元件整体利用率。为充分挖掘虚拟配电馈线的灵活传输和紧急功率支撑潜力,提出了配电网线路增容优化配置模型,在保证经济性和满足高峰负荷需求的前提下,优化虚拟配电馈线储能配置。算例研究表明,虚拟配电馈线能够有效延缓传统线路增容改造工程、应对季节性短时高峰负荷;对于线路负荷增长较稳定、线路长度较长和设计延缓增容年限较短的配电区域,虚拟配电馈线的优势更加凸显。

面向动态交通分配的交通需求深度学习预测方法

为满足动态交通分配对高精度、高时效性交通需求的要求,本文建立了一种交通需求深度学习预测方法。根据动态交通分配要求确定交通需求数据的时间间隔,构建对复杂交通需求预测性能较优的长短期记忆神经网络预测方法;针对动态交通分配中交通需求的周期性、随机性和非线性等特征,为减少数据噪声的干扰,引入局部加权回归周期趋势分解方法将交通需求数据分解,将其中的趋势分量和余项分量作为深度学习预测方法的输入量,周期分量采用周期估计进行预测;选用具有随机寻优能力强、寻优效率高等特点的布谷鸟寻优算法优化预测方法的隐藏层单元数量、学习速率和训练迭代次数等核心参数。应用西安市长安区的卡口车牌数据验证该方法。结果表明:本文模型的预测结果在高峰及平峰各连续4个时段内相比于自回归滑动平均模型、长短期记忆神经网络模型、支持向量回归模型,平均绝对误差降低了10.55%~19.80%,均方根误差降低了11.20%~17.99%,决定系数提升了8.62%~12.48%;相比遗传算法、粒子群算法优化的模型,平均绝对误差降低了7.36%~13.81%,均方根误差降低了4.23%~10.67%,决定系数提升了3.50%~7.01%,且本文模型运行时间最短。说明与对比模型相比,本文所建立的预测方法在面向动态交通分配的交通需求预测中具有更高的预测精度。

夏播短季栽培对棉花成铃时空分布特征及产量构成的影响

以10个不同基因型棉花品系为试验材料,采用株式图记载棉株各部位蕾铃发生、生长和脱落情况,以探明棉花在夏播短季栽培条件下的棉铃形成时空分布特征。结果表明:在时间分布上,现蕾高峰期为播种后第56天至第80天,开花高峰期为播种后第77天至第96天,成铃高峰期为播种后第85天至第101天,各品系生殖器官(蕾、花、铃)数量积累均有显著差异;在空间分布上,P56-3、07单12、07单6和07单7表现为中部成铃最多,其余品系则表现为下部成铃最多;P56-3、07单6和07单7成铃率分布表现“下部果枝内空形”;各品系产量结构有显著差异,品系2003-29单株铃数较其他品系高19.53%~119.55%,籽棉和皮棉产量较其余品系分别高21.82%~106.32%、22.46%~134.05%,在所有参试品系中表现突出,成铃分布均匀,脱落较少,单株成铃数和产量最高,适宜在夏播短季栽培模式下种植。棉花夏播短季栽培成铃主要集中在8月,不能用传统的“三桃”比例来衡量高产优质栽培的成铃结构。

不同脱叶剂对长江流域夏播短季栽培棉花脱叶催熟效果及产量和品质的影响

【目的】研究棉花在夏播短季栽培模式下对不同脱叶催熟剂的响应,为筛选适宜长江流域棉花栽培的脱叶催熟剂提供理论依据。【方法】以成品脱叶剂欣噻利(50%噻苯隆·乙烯利)为对照(CK),以乙烯利和助剂为通用组分,分别配以98%噻苯隆、98%噻苯隆+50%敌草隆、98%磷酸二氢钾、10%脱落酸制成4种脱叶剂配方(对应标记为S、D、L和T处理),测定不同脱叶剂处理棉株的脱叶率、吐絮率、产量相关性状及棉花纤维品质指标,并通过相关分析和主成分分析比较不同脱叶剂处理对棉花脱叶催熟效果及产量和品质的影响。【结果】随着脱叶剂喷施后时间的推移,棉花脱叶率和吐絮率均呈上升趋势。其中第10 d以CK的脱叶率最高(96.57%),D处理次之(95.76%),L处理的脱叶率显著低于其他处理(P<0.05,下同);吐絮率也呈相似趋势,以CK最高,D处理次之,L和T处理显著低于其他处理。在棉花产量方面,以D处理最高,S处理、CK和T处理次之,L处理最低;后期(8月30日)开花的棉铃产量性状表现也以D处理最优。纤维品质中,各处理对整齐度指数、马克隆值和伸长率无显著影响(P>0.05);上半部平均长度以CK最优、D处理次之;断裂比强度以D处理最高;后期(8月30日)开花的棉铃也同样以CK和D处理的纤维品质最优。相关分析和主成分分析结果表明,D和S处理及CK的脱叶及催熟效果较好,且均能不同程度提高棉花产量,改善棉花纤维品质。【结论】不同脱叶剂以噻苯隆+敌草隆、噻苯隆和欣噻利效果较优,可在长江流域湖南地区夏播短季栽培模式下棉花生产种植中应用。

基于周期特征提取的DLnet预测模型研究

现有的预测方法很少独立分析能源消耗的周期性特征。本文提出了一个短期办公建筑能耗预测模型(DLnet),以解决周期性能耗数据利用效率低下的问题。首先,利用STL对能耗数据的周期成分进行分解,通过网格搜索算法寻找能耗数据的最优周期;然后,根据最优周期构建周期块;再根据周期块的数据形状构建时间序列块数据;之后,利用长短期记忆(LSTM)对时间序列块数据和周期块数据进行训练和学习;最后,通过线性回归将时间序列块数据和周期块数据的预测结果进行融合。事实证明,所提出的模型的4个预测精度指标分别比LSTM模型高7%,21%,25%和26%。

桃源县棉花夏播短季轻简化栽培模式推广研究

我国棉花需求不断增长,但受耕地面积减少和粮食安全压力的影响,棉花种植面积难以大幅提高,因此,提高棉花单产水平对满足国内棉花需求具有重要意义。常德地区作为湖南省棉花生产大市,传统的宽行稀植、大棵壮株、大水大肥精细化栽培模式虽然单产较高,但劳动力投入大,难以适应现代农业发展趋势。为探索提高棉花单产水平的新模式,在桃源县开展了调查和试验研究。对2023年桃源县棉花生产示范点进行调查,了解不同品种、栽培方式、种植密度等情况,并调查了2020—2022年棉农种植成本、产量、收入和机械化程度。在生产示范区开展了常规与短季轻简化模式的对比试验。结果表明:虽然短季模式下单株结铃数较少,但由于种植密度提高,单位面积产量高于常规模式。在8元/kg收购价时,短季模式单位面积净收益比常规高168元。综合来看,棉花夏播短季轻简化栽培模式有望提高常德地区棉花单产和棉农收益,适应了农村劳动力成本上升趋势,兼顾粮棉赛季安排,具有较好的推广前景,但在实际推广中需结合当地实际情况灵活调整。

太阳能跨季节蓄热和短期蓄热供热系统应用对比研究

将集中式系统小型化,尝试设计分布式供热系统。采用太阳能跨季节蓄热和太阳能短期蓄热分别对张家口市某一单体农户住宅进行采暖设计。对于两种蓄热方式分别选取合适的集热器面积,确定合适的蓄热水池体积。通过计算对比采用两种蓄热方式采暖的实用性与经济性。

基于PSO-LSTM模型的平原河网汛期水位预测

基于水位、流量、降水量长序列数据资料,构建了采用粒子群优化(PSO)算法进行超参数寻优的长短期记忆(LSTM)神经网络模型(PSO-LSTM模型),对位于江南运河苏州吴江段平原河网中心的平望站的汛期水位进行了预见期为1~3 d的短期预报,并与基于PSO算法的支持向量机(SVM)、随机森林(RF)、卷积神经网络(CNN)以及门控循环单元(GRU)模型的水位预测结果进行了对比,同时探究了水利工程对水位预报精度的影响。结果表明:对于预见期为1~3 d的短期预报,PSO-LSTM模型具有较高的预测精度,但随着预见期的增长,预测精度逐渐降低;相较于PSO-SVM、PSO-RF、PSO-CNN和PSO-GRU模型,PSO-LSTM模型的平均绝对百分比误差更低,预测效果更好;PSO-LSTM模型能够较有效地进行汛期平原河网的水位预测,且加入水利工程等人工调控影响因素能够提升水位预测效果。

基于DWT-SARIMA-LSTM的流感预测模型研究

为提高流感预测模型的准确率,针对流感数据的季节性与波动性特点,提出利用离散小波分解(DWT)、季节性自回归综合移动平均模型(SARIMA)和长短期记忆神经网络(LSTM)综合建模,构建DWT-SARIMA-LSTM混合预测模型。首先,将流感数据分解为高频成分与低频成分,对低频成分使用SARIMA模型、高频成分使用LSTM模型分别进行预测;其次,将预测值融合得到最终的预测结果;最后,构建流行控制图预警模型。使用从中国香港卫生署官网获得的中国香港地区2010—2019年的流感数据对模型进行预测和验证,其MAE为0.3427,MAPE为8.0973%,RMSE为0.4632,预警模型的准确率为100%,该模型较于如ARIMA-LSTM等其他混合模型有更高的预测精度。

短季棉主要农艺性状的遗传分析

选用5个早熟不早衰的短季棉品种和5 个早衰的短季棉品种进行部分双列杂交。通过对亲本、F1 和F2 代分别于2001 年和 2002 年两年田间试验研究。结果表明:子棉产量、皮棉产量和衣分3个性状以显性效应为主,其次为加性效应,同时还存在极显著的加性上位性与环境的互作效应,单铃重和成铃数以显性效应为主;与早熟有关的诸性状,生育期、始花期、铃期和果枝始节4个性状以加性效应为主,其次为显性效应,霜前花率以显性效应×环境互作效应为主,同时存在显著的加性上位效应,落叶株率以加性与加性互作上位性为主,落叶指数以加性效应为主;与纤维品质有关的诸性状,2.5%跨长、比强度、伸长率3个性状以加性效应为主,其次为显性效应,同时还存在着加性、上位性与环境的互作效应;同时还研究了产量、早熟性和纤维品质各性状之遗传和表型相关关系。

我国短季棉品种的RAPD指纹图谱分析

本文选用了18个随机引物,对25个我国主要的短季棉品种作了RAPD多态性分析。并对各品种的指纹图谱进行了聚类和相似性分析。结果表明,大部分短季棉品种与其系谱吻合。主要从来自美国的金字棉中选育而成,它再次反映了我国现在推广的短季棉品种遗传基础比较狭窄,亟待发掘新的早熟棉基因资源。研究结果可对杂种优势利用的亲本选配提供理论依据。

不同短季棉品种衰老过程生化机理的研究

本文对中棉所16等5个短季棉品种大田栽培条件下的第10叶片和盆栽子叶附体或离体状态下某些生化变化作了研究.结果表明,中棉所16及姊妹系中427的叶绿素和可溶性蛋白质降解慢、幅度小.超氧物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性强.中棉所10的叶绿素和可溶性蛋白质降解快、幅度大.SOD、POD、CAT活性小.辽棉7叶绿素降解速度居中,田间附体叶片蛋白质降解较慢,离体子叶则降解快,SOD、POD、CAT活性居中,在离体子叶后期高于其他品种,可能与晚熟有关,中无268叶绿素和子叶可溶性蛋白质降解慢,SOD、POD、CAT活性有特异之处,如SOD、POD活性明显高于其他品种,CAT则低于其他品种,可能与该品种无棉酚、兼抗枯黄萎病和棉蚜、棉铃虫有关.

清除活性氧酶类对棉花早熟不早衰特性的遗传影响

本研究对父本短季棉早熟早衰类型品种中棉所１０号、母本晚熟类型辽棉７号、子代早熟不早衰类型中棉所１６进行了清除活性氧毒害的酶类ＳＯＤ、ＰＯＤ、ＣＡＴ等进行了分析。母本中棉所１０号ＳＯＤ、ＰＯＤ、ＣＡＴ活性小，不能及时清除体内活性氧的危害，致使未老先衰，过早丧失光合能力，造成低产；父本辽棉７号的ＳＯＤ、ＰＯＤ、ＣＡＴ的活性前期强后期稳而不降，致使晚熟；子代中棉所１６结合了两者优点，生长特性早熟不早衰，青枝绿叶吐白絮、高产稳产，其生化特点与其特性较一致，ＳＯＤ、ＰＯＤ、ＣＡＴ活性强，后期平稳下降，使其早熟不早衰。

短季棉早熟不早衰生化辅助育种技术研究

为解决棉花育种中普遍存在的早熟早衰问题,研究了与短季棉早熟不早衰有关的抗氧化系统酶包括超氧化物岐化酶SOD、过氧化物酶POD 和过氧化氢酶CAT,氧化产物之一丙二醛性MDA,以及生长素IAA 和脱落酸ABA在不同类型短季棉品种中不同生长发育时期的变化规律和遗传特性。CAT 活性、叶绿素含量存在明显的母体效应;SOD 活性、可溶性蛋白含量、IAA 和MDA 含量存在显著的显性效应;POD 活性、ABA 含量存在显著的加性效应。根据不同种类生化物质的变化及其遗传规律,建立了生化辅助育种技术体系,确定了早熟不早衰品种生化物质的相对选择标准:选择范围、选择酶活量和选择时间;应用该技术成功培育出早熟不早衰的短季棉中棉所20、中棉所24、中棉所27 和中棉所36 等品种。