oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 104 )

2018 ( 2569 )

2017 ( 2820 )

2016 ( 2978 )

Custom range...

Search Results: 1 - 10 of 126473 matches for " 徐小元 "
All listed articles are free for downloading (OA Articles)
Page 1 /126473
Display every page Item
sars诊断与治疗中有关问题的思考
王广发,
北京大学学报(医学版) , 2003,
Abstract:
北京市再生灌区地下水动态特征及数值模拟研究
Groundwater Dynamic Characteristics and Numerical Simulation for Reclaimed Water Reclaimed Water Irrigation District
 [PDF]

尹世洋, 吴文勇, 刘洪禄, 潘兴瑶,
Journal of Water Resources Research (JWRR) , 2012, DOI: 10.12677/JWRR.2012.16070
Abstract: 本文基于GMS软件建立了北京市再生水灌区地下水数值模型,预测了不同情景下地下水的动态变化趋势及调控方案。研究表明,随着再生水灌区的再生水利用率逐步提高,灌区内的地下水水位逐步抬升,向下游地区的侧向排泄量也呈加大趋势;为了减少下游的侧向排泄量、避免该区域由于地下水位过高而产生土壤次生盐渍化,应控制灌区内的地下水位埋深;再生水利用率达到50%时,每年需开采出3307.2m3置换的浅层地下水资源,再生水利用率达到70%时,每年需开采出4567.0m3置换的浅层地下水资源,再生水利用率达到90%时,每年需开采出6128.3m3置换的浅层地下水资源。研究成果对再生水的安全利用、地下水资源的涵养具有重要意义。
 In order to predict the changing trends of groundwater under different scenarios and make regulation programs, a groundwater numerical model of reclaimed water irrigation district is developed based on GMS software. Research results indicate that with the gradual increase of reclaimed water utilization, irrigation area groundwater level progressive uplift, lateral excretion to the lower reaches also show a trend of increase. In order to avoid the soil salinization, shallow groundwater resources must be mining to control the depth of groundwater according to the different utilization rates of the reclaimed water. 50% of total water consumption is reclaimed water, 33.1 million m3 replacement of shallow
苏云金杆菌与灭幼脲混剂对美国白蛾幼虫 围食膜的破坏研究
,,徐福,
南京林业大学学报(自然科学版) , 2016, DOI: 10.3969/j.issn.1000-2006.2016.03.009
Abstract: 为明确苏云金杆菌(Bt)与灭幼脲混剂对美国白蛾幼虫的毒杀效果,笔者对美国白蛾4龄幼虫围食膜被破坏的状况进行了研究。经超薄切片透射电镜观察发现,美国白蛾4龄幼虫围食膜表面平整光滑,有较明显的多层结构。经Bt+灭幼脲混剂对美国白蛾4龄幼虫处理120 h后, 围食膜上出现较多的白色和黑色斑点状孔洞,并扩大为斑块状孔洞,形成了薄而易脆、易断或溃烂、无弹性的围食膜碎片,并致围食膜被破坏和幼虫死亡。试验证明,Bt+灭幼脲混剂对白蛾4龄幼虫围食膜的破坏最快,Bt和灭幼脲单剂次之。同时,经Bt+灭幼脲混剂及其单剂对美国白蛾4龄幼虫的林间LT50、LT100值和飞防毒杀速率测定发现,Bt+灭幼脲混剂对美国白蛾幼虫的致死率均高于其单剂,毒杀速率快于单剂。因此,Bt+灭幼脲混剂处理可较快地破坏白蛾4龄幼虫围食膜,其毒杀速率明显提高。
The ultrathin section was studied by the observation of electron microscope. The results showed that the peritrophic membrane(PM)presented a more obvious multilayer structure, and the surface was evenness and smooth in the 4th instar larvae of Hyphantria cunea Drury. After treated 120h by using the mixture of Bt and Chlorbenzuron on larvae of H. cunea Drury, many white and black spots were formed on PM. Then the spots expanded to patchy pores. Finally thin and brittle, easily broken or fester, inelastic PM fragments were formed. It lead to destruction of the PM and death of larval. The test proved that the damage effect of the treatment of the mixture of Bt and Chlorbenzuron on the PM of the 4 instar larvae of H. cunea was the fastest, and which of the single agent of Bt and Chlorbenzuron on the PM was the second. At the same time, the tests of the value of LT50, LT100 of the 4th instar larvae of H. cunea and the air-spraying control effect by using the mixture of Bt & Chlorbenzuron and its single dose proved that the mortality rate of the mixture was higher than that of the single dose, and the rate of death toxicity of the mixture was faster than single agent. The results showed that the mixture could quickly destroy the PM of the 4th instar larvae of H. cunea, and the toxic effect of the treatment was significantly enhanced
三氟甲磺酸盐催化甲苯硝化反应的研究有机化学
,杜晓华,
有机化学 , 2006,
Abstract: 利用三氟甲磺酸盐作为新型的Lewis酸催化剂,用于甲苯与等物质的量的硝酸的硝化反应.通过对不同催化剂进行考察发现Zr(OTf)4和Sm(OTf)3的催化性能最好,甲苯转化率分别达77.1%和67.4%.使用98%硝酸能使转化率达100%,而用甲苯作溶剂时转化率达95.4%.对硅胶负载催化剂的考察发现硅胶负载催化剂Sm(OTf)3能使甲苯转化率升至89.9%,且异构体分布有所改变,其o∶m∶p为44.6∶5.7∶49.7.
具有随机丢包的非线性网络化控制系统鲁棒故障检测
,李娜,,关新平
控制与决策 , 2013,
Abstract: 针对具有随机丢包的Lipschitz非线性网络化控制系统,研究了系统存在外部干扰情况下的鲁棒故障检测问题.由于带宽有限,传感器-控制器和控制器-执行器的网络通道中存在随机数据包丢失,鉴于此,设计一种基于观测器的故障检测滤波器,给出存在故障检测滤波器的充分条件,使误差系统均方指数稳定并达到鲁棒??∞干扰抑制水平,同时给出基于观测残差均方值的故障检测策略.通过仿真算例验证了所提出方法的有效性.
优质鲜食红辣椒新品种‘粤红1号’
李颖,王得,王恒明,
园艺学报 , 2009,
Abstract: ‘粤红1号’是鲜食红辣椒早中熟一代杂种,适合在南方地区露地栽培。青熟果绿色,羊角形,无棱沟,果长17.7cm,宽2.0cm,果肉厚0.3cm,单果质量30g。红熟果大红色,鲜艳有光泽,果面光滑,果条直,硬度好,耐贮运,辣味浓,品质佳。
引洮供水工程水资源开发利用探讨
,畅建霞,张洪波,黄强
资源科学 , 2009,
Abstract: 引洮供水工程是以九甸峡水利枢纽为龙头,为改善甘肃省中部地区极度缺水现状而实施的跨流域调水工程。2010年和2020年水平年洮河下游总需水量分别为47.26×108m3和47.74×108m3,引洮需水量分别为2.14×108m3和6.04×108m3。在分析九甸峡梯级水库群特点的基础上,以尽可能满足引洮水量、洮河下游生产生活需水,以及下游生态用水为目标,建立了该系统的模拟调度模型,并确定了系统结构和调度原则。结合引洮工程实际情况,设定了三种方案,分别考虑2010年一期工程、2020年一期工程和2020年二期工程。通过长系列模拟计算,得出了各方案的水资源利用情况,模拟计算表明,不同水平年多年平均引洮水量和洮河下游经济社会、生态环境用水均可保证,但冲沙用水不能满足,三个方案缺水量分别为0.95×108m3、0.98×108m3和2.31×108m3;典型年计算结果表明,只有在来水较丰时,才能同时满足洮河下游需水量和引洮水量的需求,典型枯水年和平水年分别缺水11.51×108m3和3.13×108m3。
二维NMR测定1,3-双烯膦酸酯的构型
王绮文,,耀
化学学报 , 1986,
Abstract: 本文报道用1HNMR二维J谱、二维同核相关谱及NOE技术测定了三个共轭双烯膦酸酯的双键构型,并求得各δ和J值。
Nd:YAIO_3晶体主折射率的测量
,,沈鸿
硅酸盐学报 , 1987,
Abstract:
一株黄色短杆菌基因工程菌株的构建及其l-缬氨酸积累
大庆,谭延振,缪铭,
食品科学 , 2010,
Abstract: ?从谷氨酸棒杆菌模式菌株c.glutamicumatcc13032中克隆出l-缬氨酸合成途径上的限速酶——乙酰羟酸合酶编码基因ilvbn。对ilvbn进行定点突变,获得其抗反馈抑制突变型ilvbnr。以大肠杆菌-黄色短杆菌穿梭表达载体pdxw-10为基础,构建重组质粒pdxw-10-ilvbnr,并转化野生型黄色短杆菌b.flavumatcc14067,获得工程菌株atcc14067/pdxw-10-ilvbnr。3l罐发酵实验结果显示:在野生型菌株发酵液中检测不到l-缬氨酸积累,而工程菌株发酵液中l-缬氨酸积累达5.0g/l。
Page 1 /126473
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.