Analysis of Flood Risks Upstream from the Imboulou Hydroelectric Dam on the Léfini River, a Tributary of the Right Bank of the Congo River

The analysis of the risk of flooding upstream from the Imboulou hydroelectric dam on the Léfini River in the Republic of Congo-Brazzaville, focused on the evolution of annual rainfall and flow in the study area during the period from 1970 to 2020 before and after the building of the dam in 2005, by applying statistical methods. These methods were used to analyse the spatial and temporal evolution of rainfall and flow at the unique hydrometric station located at the RN2 (National Road N°2) bridge in the village of Mbouambé in the Pool region. This work has shown that rainfall is not the cause of flooding in the Léfini catchment area. The monthly flow coefficient (MFC) showed exceptional flooding from November and December onwards after the dam was built, resulting in a variability of flows, with periods of high and low water. In addition, the annual average flow (AAF) and the maximum average flow (MAF) increased after the dam was built. Maximum average flows (MAF) were higher than annual average flows (AAF) throughout the period of study (1970-2020). The annual and monthly rainfall-runoff relationship showed changes after the dam was built, particularly from 2009 and during the months of November and December. .

Evolution of Main Characteristics of the Registered Cotton Cultivars in National Cotton Regional Trials in Yangtze River Valley

[Objective] The aim of this study was to characterize the national regis- tered varieties selected from cotton regional trials in Yangtze River Valley （YaRV） in recent years. [Method] Cotton cultivar classification and comprehensive evaluation index were set up based on national cotton registration standard. GGE biplot method was adopted to analyze the correlation of major breeding target characters of 53 national registered cotton varieties in cotton regional trials in YaRV during 1981-2012. According to the shift of check cultivars in cotton regional trials in the past, the cotton regional trial practice since 1981 was divided into five periods. The dynamic of cultivar type＇s proportion and the evaluation index scores was analyzed across the five periods. [Result] There existed intricate interrelationship among cotton breeding target traits, which constrained it necessary to construct indices for com- prehensive evaluation of cotton varieties. The dynamic of cultivar types in the five periods indicated that type II varieties emerged since Simian 3 period and then its proportion decreased gradually; type Ⅲ varieties maintained a certain proportion in each period and kept on the rise overall; type Ⅳvarieties occupied the majority pro- portion of registered cultivars before 1993, but a minor proportion since Simian 3 period. On the other side, the change trend of the evaluation index demonstrated that the varieties registered before 2003 did not pass the qualified line at present. The peak scores appeared in the varieties registered during 2004-2008. The scores of the varieties registered after 2009 were only slightly over the qualified line. [Conclusion] More attention should be paid to the improvement and evaluation of micronaire, so as to guide the simultaneous development of high yielding and fiber quality in cotton breeding and registration procedure in YaRV.

Development and Validation of National Cotton Cultivar Registration Index Model in Yangtze River Valley

[Objective] Based on the cotton variety high yielding potential, fiber quality traits, disease resistance, and early maturity characters, a cultivar registration index model was developed to simplify the tedious calculation process in national cotton registration procedure, and thus to enhance the practical application of cultivar regis- tration index in cotton breeding ancl cotton recommending. [Method] By means of correlation analysis, partial correlation analysis and path analysis methods, the cor- relation of cotton main properties and their effects on cultivar registration index were explored using the dataset of national cotton regional trials in Yangtze River Valley during 1996-2013. The cultivar registration index model was constructed with step- wise regression statistical technique to ascertain the quantitative relationship of main characters with cultivar registration index, and the regional cotton trial dataset in 2013 was used to validate the model. [Result] Several characters with larger deter- minants to cultivar registration index were screened out,ie. lint yield increase ratio, pro-frost yield ratio, verticillium wilt index, fiber strength, fusarium wilt index and mi- cronaire value. The cultivar registration index model defined the functional relation- ship of cultivar registration index with the selected main characters, among which lint yield increase ratio, fiber strength and micronaire value contributed most to culti- var registration index. The model validation with regional cotton trials in 2013 indi- cated the root mean square error, RMSE was only 2.77, and the variation coeffi- cient was 6.77%, which confirmed the model prediction effect was quite perfect. [Conclusion] The developed cultivar registration index model was reliable enough to simulate the complicated scoring system in cultivar registration procedure, also sim- plified cotton registration process, and enhanced the practicability of the cultivar reg- istration index.

Evaluation on the High Yielding, Stability and Comprehensive Performances of Check Cultivars in National Cotton Regional Trials in the Yangtze River Valley

[Objective] This study was to analyze the high yielding, stability, adaptabil-ity and main characteristics of check cultivars in national cotton regional trials in the Yangtze River Val ey in 2000-2013, with the aim to provide theoretical basis for the reasonable selection of check cultivars for cotton regional trials. [Method] GGE biplot analysis method was used to carry out the intensive analysis and comprehensive comparisons on the performances and differences of the 9 major characters of check cultivars, namely, lint cotton yield , stability, and other main traits including bol weight, bol number, lint percentage, fiber length, fiber strength, micronaire val-ue, plant height and seed index. [Result] Ezamian 10 was suitable in the majority of cotton planting regions in the Yangtze River Val ey, with the best high yielding abili-ty and perfect yield stability. The yielding ability of Xiangzamian 8 ranked the sec-ond, but its stability was the poorest. Xiangzamian 8 was of the specific adaptive cultivar with relatively good performance in high yielding but the poorest stability. The suitable planting areas of Xiangzamian 8 were limited to the cotton planting re-gion around Dongting Lake in Hunan province, Poyang Lake in Jiangxi Province, the Coastal region in Jiangsu Province and Wuhan district in Hubei Province. Xi-angzamian 2 performanced poorer in both yielding and stability, while Simian 3 ranked first in stability but the last in yielding ability. The dominant character of Xi-angzamian 8 and Xiangzamian 2 were high cotton plants and big bol s. Simian 3 performanced super in lint percentage and fiber length. Ezamian 10 was strong in cotton bol formation ability, lint cotton yielding, fiber strength and seed size, as wel as high micronaire value. [Conclusion] The outstanding performance of Ezamian 10 in high and stable yield in the Yangtze River Val ey in recent years has effectively promoted the high yielding ability of candidate varieties in cotton regional trials in the area.

Evolution of Nitrogen, Phosphorus and Potassium Fertilizer Application Rates in Cotton Fields and Its Influences on Cotton Yield in the Yangtze River Valley

[Objective] The historical evolution pattern of nitrogen （N）, phosphorus （P） and potassium （K） fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.

金沙江干热区麻疯树(Jatropha curcas L.)杂交育种技术的初步研究

对金沙江干热区麻疯树生物特性、开花特性、结实特性进行观测,并开展不同地理种源麻疯树杂交育种试验。结果表明,麻疯树在本区域生长发育较好,可持续开花结果至1月初,雌雄花比例可达1∶10左右。通过麻疯树杂交育种试验,研究了麻疯树雌雄花分辨、雌花可授粉时间、套袋材料及去袋时间等特性。通过对金沙江干热区麻疯树主要特性和杂交育种技术试验研究,有利于提高育种效果,加速育种进程,提高育种工作的预见性。

基于L-THIA模型的温榆河流域非点源污染负荷变化分析

为研究温榆河流域城市化过程中土地利用变化对非点源污染负荷的影响,基于GIS(地理信息系统)和RS(遥感),利用二次开发改进后的长期水文影响评价(L-THIA)模型,采用实地测得的EMC(事件平均浓度)数据,模拟了1992年和2009年非点源污染负荷量。结果表明,1992—2009年的城市化过程中商业用地、交通用地和住宅用地分别增加了13.95%、20.46%和85.76%,农业用地和水域分别减少40.04%和9.64%,导致非点源污染负荷量(总磷除外)明显增加。其中,总氮增加了3.31%,氨氮增加了12.20%,BOD5(5日生化需氧量)增加了11.87%,CODMn(化学需氧量)增加了7.62%,TOC(总有机碳)增加了15.46%,总磷下降了12.84%。交通用地、商业用地的非点源污染产出能力最强,应该成为非点源污染的重点控制区域。

L-肉碱对黄河鲤鱼生长性能和肌肉品质的影响

研究了饲料中添加不同水平(50、100及200 mg/kg)的L-肉碱对黄河鲤鱼生长性能和肌肉品质的影响。结果表明,在基础饲料中添加不同水平的L-肉碱均能在一定程度上降低饵料系数,显著提高肥满度(P<0.05),降低肝体比和脏体比(P<0.05),添加100 mg/kg的L-肉碱能显著提高黄河鲤鱼的增重率(P<0.05)。添加不同水平的L-肉碱均可以显著提高黄河鲤鱼体蛋白质和脂肪含量(P<0.05),改善肌肉氨基酸组成,能在一定程度上改善鱼体的肌肉品质。综合考虑L-肉碱对黄河鲤鱼生长性能和肌肉品质的影响以及经济效益,认为添加量以100 mg/kg较适宜。

L-矩法在澜沧江流域参数统计中的应用

水文频率分析计算中一般采用矩法作为参数估计方法,国内外许多研究及应用表明,矩法估计时有较大的估计偏差。L-矩是目前洪水频率分析计算的最新发展之一。它的最大特点是对洪水系列中的极大值和极小值远没有常规矩那么敏感,因而根据L-矩求得的洪水频率曲线参数的估计值比用常规矩所求得的值偏差小些。本文在澜沧江流域进行参数统计时运用了L-矩法,效果较好。

生物净化槽中菌群结构在梭鱼草(Pontederia cordata L)不同生长期的动态变化

为探究引入植物对生物净化槽处理黑臭河水的影响及机理，结合水质理化指标的动态变化，采用了ERIC—PCR指纹图谱技术来分析生物净化槽内的微生物群落结构在植物不同生长阶段的变化特征，比较植物与填料不同工艺组合对微生物群落结构的影响．结果发现：引种梭鱼草（Pontederia cordataL）的生物净化槽对主要污染物CODcr，NH3-N和TP的去除率分别提高了19．8％～69．4％，18．2％～68％和23．9％～77．2％；微生物群落结构随植物不同生长发育阶段而变化，分蘖期优势菌群的种类和数量最多，同期净化效果也最好；从三种工艺的运行效果来看，植物＋组合填料搭配最合适．

有限对称逆半群的L-断面

设In是有限集合Xn={1,2,...,n}上的有限对称逆半群.该文定义有限逆半群的L-断面,给出In的所有L-断面的构造和分类.

L形钢骨异形柱的ANSYS有限元分析

为研究L形钢骨混凝土异形柱的受力性能,对五个混凝土异形柱试件进行试验研究和采用ANSYS有限元软件进行数值模拟分析,计算得出了试件各材料的应力分布图和试件的极限承载力。将试验结果与有限元计算结果对比,表明二者显示了良好的一致性。结果表明,可以运用ANSYS有限元数值模拟技术对钢骨混凝土异形柱的受力性能进行深入研究,其模拟结果与实验现象吻合较好,说明了混凝土与钢骨、钢筋能够协同工作,并且试件随着含钢率的提高,其承载力增大。

基于L-THIA和GIS的辽河源头区小流域非点源污染负荷变化分析

农业非点源污染是导致流域水质恶化的重要原因之一。笔者选择了辽河源区域作为研究目标,重点研究辽河流域的小型水系,使用所处位置的土地状况以及日降雨量数据,基于长期水文影响评价模型L-THIA,以GIS空间分析技术为平台,对研究区的总氮、硝态氮、总磷、COD和可溶磷5种非点源污染物的污染输出负荷进行估算,并分析了其空间分布特征。结果表明:总氮、硝态氮和总磷3种污染物的单位网格污染物输出负荷的空间分布较为一致,可溶磷和COD污染输出负荷分布各有特点。区内的农用地域污染一般都是农田抑或是村里闲置的土地。经研究发现,越是干旱的区域会使得调查数据分布影响越大,对总氮、硝态氮和总磷的贡献率分别达到了82.57%、80.02%和92.92%,村镇用地对可溶磷的污染负荷分布影响最大,而水田对COD污染输出负荷作用明显。根据不同污染物输出负荷并结合土地利用现状,采用GIS空间叠加和融合技术,将研究区划分为4个非点源污染控制区,分区结果能够为非点源污染控制提供科学依据。

L型布置内河框架直立式码头结构模态分析

以重庆某平面布置为"L型"的内河框架直立式码头为依托,采用MIDAS建立空间刚架模型并进行模态分析,提取关键模态分析结构的振型特点。初步探讨其动力特性,为结构设计、振动故障诊断以及结构动态特性的优化设计提供依据。

基于L-THIA模型的四川省濑溪河流域非点源污染负荷分析

非点源污染是造成流域水环境恶化的重要原因之一,掌握非点源污染的时空分布特征是流域水环境污染防治和流域综合管理的基础性工作.为落实国家《水污染防治行动计划》,四川省启动了濑溪河等流域综合治理达标方案编制工作,探明濑溪河流域非点源污染负荷及其分布特征是该方案编制的前提.以四川省境内濑溪河流域为研究区域,基于GIS(地理信息系统),利用L-THIA(long-term hydrologic impact assessment,长期水文影响评价)模型,基于2015年土地利用地图数据、土壤水文数据以及长时间序列(2009—2014年)逐日降雨数据,调整模型参数,使模型模拟径流量符合水文站监测数据,进而模拟2014—2015年流域内的非点源污染负荷空间分布.L-THIA模型模拟得到濑溪河流域径流量约为5.10×108m3,和控制水文站实测径流量相比,模型模拟相对误差为5%,表明模型模拟质量较好,模拟结果可信度较高.结果表明,流域内TP、NH3-N、CODCr非点源污染负荷分别为204.10、353.12、5 162.53 t;农业用地对研究区的非点源污染影响最大,林地最小;根据濑溪河水系分布特点将研究区划分为16个控制单元,各控制单元TP、NH3-N、CODCr的空间分布特征及比例相似,研究区非点源污染平均负荷强度为3.72 t/km2,TP、NH3-N、CODCr的输出范围分别为(0.08~0.15)(0.14~0.27)(2.19~3.89)t/km2.研究显示,流域非点源污染产生量的估算和空间分布特征的揭示为编制濑溪河流域水污染治理方案提供了科学参考.

L-M优化改进的BP网络模型在水环境承载力评价中的应用研究

以泾河流域为例,通过对该流域2014-2016年各季节水质与水生态环境指标的提取与测定,构建了能够反映流域水环境整体状况的指标体系和分级标准;然后利用MATLAB语言建立了L-M优化改进的BP网络结构,并科学、准确地评价了泾河流域水环境承载力状况。研究表明:L-M算法不仅克服了经典BP网络训练速度慢、局部陷入极小的缺陷,而且可提高输出结果的有效性与准确性;泾河流域2014-2016年的水环境承载力分别为0.67、0.52、0.48,整体处于基本可承载水平,并表现出逐渐下降的趋势。

Assessment of Habitats according to Groyne Types (Using Pale Chub)

A groyne zone formed by installing groynes functions as habitat or shelter for aquatic organisms during a flood. Since flow characteristics over a groyne zone are affected directly by groynes, understanding flow patterns due to shapes and types of groynes is of importance for designing groynes. In order to use groynes as an eco-friendly river structure, the ecological effects should also be considered at the design stage. In Korea, the ecological effects of groynes have rarely been examined or included for the actual design. In this study, a set of experiments were carried out to investigate flow pattern changes depending on different types of groynes. Based on the flow characteristics in the groyne zone, the scales of habitats and shelters by the groyne types were estimated. In addition, to test the applicability of a habitat evaluation model to the ecological design of groynes, River2D was used for a virtual river. For assessment of the groyne’s function of ecological habitat, the suitability index of a habitat for pale chub, one of the popular fishes in Korea, was used and the habitat areas by the groyne types were analyzed. The flow changes depending on the groyne types simulated by River2D show the applicability for the simulation of an ecological habitat to the groyne design.

KL10-1油田明下段窄河道型曲流河沉积特征研究

窄河道型河流相砂体是陆相含油气盆地的重要储层类型,其储层沉积特征研究成果尚不多见。为了揭示明下段储层发育特征及其与含油气的关系,本文在岩心观察基础上,结合不同层段测井特征及三维地震资料,通过开展层序划分、岩相类型与岩相组合分析、高分辨率储层反演以及砂体平面展布分析对其沉积相类型及展布特征进行研究。研究结果表明:明下段沉积时期,该区主要为曲流河沉积特征,沉积微相主要发育末期河道、边滩、决口扇、废弃河道、泛滥平原等,河道在平面上呈枝状分布。沉积微相上边滩及边滩内部侧积层的发育,对油气分布起明显的控制作用。研究可为渤海海域相似地质条件和资料条件的窄河道曲流河储层精细描述及评价提供参考。

Application of Mechanical Grain Harvest of Maize by Combiners in Anhui Province

Eight summer maize varieties were evaluated in Funan County,Anhui Province,for yield and grain quality under mechanical grain harvest conditions in2019 growth season.ZY432,LY35 and JNK728 had higher grain yield potentials than FDC10,LX98,LD575,YD9953 and TT619.Postponed harvest from 28th Sept.to 11 thOct.was positively linked to the grain yield at roughly 1% of daily yield increase.Early harvest gave higher grain water content which was positively related to the percentage of broken grain as y=0.422 x-2.984(R^2=0.445),and to the percentage of foreign substance as y=0.248 x-3.245(R2=0.698).The relationship between grain water content and the rate of grain loss was negative as y=-0.052x+2.450(R^2=0.089).There was about 0.89% of grain water content decrease daily between harvests from 28^th Sept.to 4^th Oct.,and then was a‘slow-down’rate of dehydration.Grain weight was increasing for each variety when the harvest was postponed.JNK728 had the highest hundred-grain weight(HGW) and YD9953 had the lowest HGW.To make the mechanical grain harvest of summer maize feasible and acceptable,farmers need to pay attention to the adoption of proper varieties,following the suitable cultivation procedure and the improvement of mechanical facilities and operation.

沿黄灌区不同种植密度对胡麻产量和植株性状的效应

为探索胡麻产量和植株性状对种植密度的响应规律,筛选适宜白银市灌区胡麻的种植密度。以陇亚13号为供试品种,研究不同种植密度(600万、750万、900万、1050万、1200万粒/hm^(2))对胡麻产量和植株性状的影响。结果表明,随着种植密度的增加,胡麻产量、株高、工艺长度、单株生物量、单株粒重、每果粒数和经济系数呈先增后降的趋势,分茎数、分枝数、分枝长、果层厚度、单株果数和千粒重逐渐降低,主茎贡献率增加,分茎贡献率逐渐降低。在白银市灌区现阶段生产水平下,胡麻种植密度为750万粒/hm^(2)时,产量水平最高,为2299.68kg/hm^(2)。