灌溉水利用系数测定方法研究   总被引：9，自引：0，他引：9  

高峰  赵竞成  许建中  黄修桥  倪文进  李英能  王景雷 《灌溉排水学报》2004,23(1):14-20

通过开展对灌溉水利用系数资料的搜集、整理并对灌区进行实地调研,在了解目前灌区灌溉水利用系数测量中存在问题及原因的基础上,对灌区灌溉水利用系数测量计算方法进行了分析研究,提出了测定灌溉水利用系数的综合测定计算方法。该方法既克服了传统测量方法中工作量大,需要大量人力、物力才能完成的缺点,又弥补了只测量典型渠段而引起较大误差的不足,而且能反映出灌区渠系用水情况、灌溉工程质量及灌溉用水管理水平等。为灌区今后经常性地测量符合实际的灌溉水利用系数及指导灌区节水工程改造等提供了一种切实可行的计算方法。并结合实例进行了应用分析。  相似文献   

Construction of mouse ESC line stably expressing Pdx1 by Tet-On system     

ZHONG Wa  XIA Zhong-sheng  YU Tao  NI Chu-yan  LI Jie-yao  CHEN Qi-kui 《园艺学报》2021,37(1):187-192

AIM To construct the mouse embryonic stem cell （ESC） line with stable pancreatic and duodenal homeobox 1 （Pdx1） expression by Tet-On system, which may lay a foundation for further research on the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells. METHODS The Pdx1-overexpressing lentiviral vector with green fluorescent protein marker and puromycin resistance was constructed by Tet-On system and was used to infect the mouse ESC. The cells were divided into 3 groups： blank control group （ESC group）, empty lentivirus control group （PDX1^- ESC group） and Pdx1 lentivirus transfection group （PDX1⁺ ESC group）. Flow cytometry was used to detect the transfected cells after screening by doxycycline （DOX）. The function of Tet-On system and the expression of Pdx1 gene were detected. The transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were sorted by flow cytometry, and constructed ESC line with stable expression of Pdx1 and negative control ESC line were verified. RESULTS （1） The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were 90.72% and 94.01% after screening by DOX, respectively. The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group was 97.84% and 98.13% after sorting by flow cytometry, respectively. （2） With DOX, green fluorescence was observed in PDX1^- ESC group and PDX1⁺ ESC group. The mRNA and protein expression of Pdx1 was significantly increased in PDX1⁺ ESC group （P<0.05）. Without DOX, no green fluorescence was observed in the cells of the 3 groups, and no significant difference in the mRNA and protein expression of Pdx1 was observed （P>0.05）. （3） After 3 months of cryopreservation, the cell lines still survived in resuscitation culture and were regulated by DOX. CONCLUSION Using Tet-On system, the mouse ESC line with inducible Pdx1 expression were successfully established and could be used as an effective cell model to research the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells.  相似文献   

水果黄瓜新品种'青玉'的选育     

薛其勤  刘永光  杨园园  吕金浮  尼秀媚  李美芹 《北方园艺》2021,(13):177-180,封2

水果黄瓜新品种'青玉'是以自交系HQ6548为母本,自交系GY4237为父本经杂交而成的一代杂种.该品种植株长势强,早熟,叶片中等,节间稳定,茎粗壮,连续结瓜能力强;瓜长15～17 cm,横径约3 cm,瓜条顺直,口感清脆,瓜色浅绿色,刺瘤稀疏,单瓜质量130～170 g,产量高;抗霜霉病、白粉病和黄瓜花叶病毒病.适宜在山东、河北、河南、海南等四季保护地栽培及山东夏季露天栽培.  相似文献   

春大葱接秋萝卜套栽越冬甘蓝三种三收高效栽培技术     

张志轩  王保国  邵广伟  倪德孟 《北方园艺》2021,(18):173-175

介绍了春大葱、秋萝卜套种越冬甘蓝的模式,该模式一年三种三收,年内土地利用时空上基本无缝对接,实现了作物之间的轮作倒茬,有利于土壤改良和合理利用,拉高复种指数.详细阐述了各个茬次的栽培技术要点,生产过程省工、省时,便于机械化作业,人工投入比较少,经济效益和社会效益十分显著.  相似文献   

LAS对土壤微生物生物学指标的影响及降解条件的正交实验分析   总被引：7，自引：0，他引：7  

陈宏伟  朱蕴兰  倪世峰  樊美珍 《农业环境科学学报》2006,25(4):908-912

用正交实验方法研究了徐州地区4种土壤在不同组合条件下土壤微生物数量、酶活性及LAS的降解条件。结果表明,LAS对土壤细菌生长有促进作用,对真菌则有抑制作用,而对放线菌无明显影响。LAS对转氨酶和脱氢酶均有抑制作用。微生物数量波动最大的组合条件为荒土、30℃、LAS浓度50mg·kg-1、时间8d;LAS最大降解的组合条件为河土、25℃、LAS浓度20mg·kg-1、时间8d(降解率为33.2%);土壤酶活性减少最多的组合条件为麦田土、25℃、LAS浓度30mg·kg-1、时间8d(转氨酶活性减少0.0594,脱氢酶抑制率达49.58%)。另外,土壤对LAS污染的环境效应与土壤类型和性质等因素有关。  相似文献   

不同茶树品种原料对青砖茶品质的影响     

殷雨心  陈玉琼  焦远方  郝娟  余志  倪德江 《茶叶科学》2021,41(1):48-57

探究不同茶树品种原料对青砖茶品质的影响.采用13个不同茶类适制性品种的原料制成青砖茶,采用感官审评评价茶叶感官品质,通过化学分析和GC-MS法比较分析主要品质成分及香气成分含量.结果表明,不同茶树品种原料制成的青砖茶主要品质成分差异显著,迎霜、乌龙2号和4号品种原料加工的青砖茶水浸出含量、茶多酚、儿茶素、氨基酸和可溶性...  相似文献   

宿主植物对AM真菌生长发育的影响     

陈宁  王幼珊  杨延杰  林多  仇宏伟  倪小会  张美庆 《华北农学报》2006,21(6):103-106

研究了宿主植物对丛枝菌根(Arbuscular mycorrhizae,AM)真菌(Glomus mosseae)生长发育的影响。结果表明:温室条件下,4种宿主植物都能与丛枝菌根真菌共生,综合比较菌根长度、根外菌丝量及孢子数3项指标,高粱敖杂1号对真菌的生长发育最为有利。宿主植物菌根长度及根中的可溶性糖质量分数与根外孢子数呈显著正相关,而宿主植物中磷质量分数与菌根真菌的生长发育没有显著的相关性。说明不同宿主植物甚至同种宿主植物不同基因型的品种与丛枝菌根真菌的共生状况不同,宿主植物的菌根长度及根中可溶性糖质量分数对菌根真菌的生长发育有显著影响。  相似文献   

木芙蓉上亚利桑那跳小蜂对扶桑绵粉蚧的寄生研究          下载免费PDF全文

陈伟玮  李紫成  王媛  倪美虹  敖艳  王英  蒋明星 《中国生物防治学报》2023,39(1):10-17

扶桑绵粉蚧Phenacoccus solenopsis Tinsley是我国重要观赏和药用植物木芙蓉上的主要害虫之一,但迄今对其被优势天敌亚利桑那跳小蜂Aenasius arizonensis (Girault)（班氏跳小蜂A. bambawalei Hayat）的寄生情况了解甚少。为此,自2017年开始,在浙江兰溪西部的一个木芙蓉种植区开展了为期四年的调查,每年6—9月,分批从木芙蓉植株上采集3龄若虫及未产卵雌成虫,于室内观察寄生情况;并于其中两年观察了不同生境中的寄生情况,探讨了寄生季节变化的动态特征及相关影响因素、杂草促进寄生的途径以及增强该粉蚧自然控制的措施。结果表明,在前期（6—7月）寄生率总体上较低,其中两年最高分别仅有38%和32%,另外两年也很少发现被寄生个体,而且该时期寄生率年份间存在明显波动。而在后期（8—9月）,寄生率相对较高,且具有从8月上旬开始逐步上升这一显著特点。观察期间,最高寄生率均出现于各年份9月下旬,四年中分别为89%、62%、55%和13%,年份间差异十分明显。生境类型可对寄生水平产生较大影响,与木芙蓉地块内和杂草稀疏的田埂相比,杂草丛生的田埂上和路...  相似文献   

Effects of sediment load on the abrasion of soil aggregate and hydraulic parameters in experimental overland flow          下载免费PDF全文

WANG Jun-guang  YU Bing  NI Shi-min  GUO Zhong-lu  CAI Chong-fa 《农业科学学报》2020,19(4):1117-1126

The breakdown of soil aggregates under rainfall and their abrasion in overland flow are important processes in water erosion due to the production of more fine and transportable particles and, the subsequent significant effect on the erosion intensity. Currently, little is known about the effects of sediment load on the soil aggregate abrasion and the relationship of this abrasion with some related hydraulic parameters. Here, the potential effects of sediment load on soil aggregate abrasion and hydraulic parameters in overland flow were investigated through a series of experiments in a 3.8-m-long hydraulic flume at the slope gradients of 8.7 and 26.8%, unit flow discharges from 2×10~(–3) to 6×10~(–3) m~2 s~(-1), and the sediment concentration from 0 to 110 kg m~(–3). All the aggregates from Ultisols developed Quaternary red clay, Central China. The results indicated that discharge had the most significant(P0.01) effect on the aggregates abrasion with the contributions of 58.76 and 60.34%, followed by sediment feed rate, with contributions of 39.66 and 34.12% at the slope gradients of 8.7 and 26.8%, respectively. The abrasion degree of aggregates was found to increase as a power function of the sediment concentration. Meanwhile, the flow depth, friction factor, and shear stress increased as a power function along with the increase of sediment concentration at different slope gradients and discharges. Reynolds number was obviously affected by sediment concentration and it decreased as sediment concentration increased. The ratio of the residual weight to the initial weight of soil aggregates(Wr/Wi) was found to increase as the linear function with an increasing flow depth(P=0.008) or Reynolds number(P=0.002) in the sediment-laden flow. The Wr/Wi values followed a power function decrease with increasing friction factor or shear stress in the sediment-laden flow, indicating that friction factor is the best hydraulic parameter for prediction of soil aggregate abrasion under different sediment load conditions. The information regarding the soil aggregate abrasion under various sediment load conditions can facilitate soil process-based erosion modeling.  相似文献   

Pseudomonas sp. TK35-L enhances tobacco root development and growth by inducing HRGPnt3 expression in plant lateral root formation          下载免费PDF全文

CAO Yuan-yuan  NI Hai-ting  LI Ting  LAY Khien-duc  LIU Dai-song  HE Xiang-yi  OU Kang-miao  TANG Xin-yun  WANG Xiao-bo  Qiu Li-juan 《农业科学学报》2020,19(10):2549-2560

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