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Search Results: 1 - 10 of 515272 matches for " <br>张晓晨 "
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Degradation of unsymmetrical dimethylhydrazine by O_3/VUV
真空紫外光臭氧降解偏二甲肼的研究

Wang Xiaochen Zhang Pengyi,<br>王,彭义
环境工程学报 , 2009,
Abstract: The widely used propellant unsymmetrical dimethylhydrazine(UDMH) was treated with three ozone-based advanced oxidation processes(AOPs),i.e.O3,O3/UV and O3/VUV.Among them,the most efficient process was O3/VUV,and its rate constant was 39.8% and 65.6% higher than O3/UV and O3 respectively.Meanwhile,the degradation intermediate i.e.formaldehyde could also be removed fastest in the O3/VUV process and its concentration was lowered to be undetectable within 50 min.The dependence of reaction efficiency on several ...
Research of distributed data stream query reusing algorithm
一种分布式数据流查询重用算法研究*

ZHANG Fu zhi,REN Xiao chen,<br>付志,
计算机应用研究 , 2008,
Abstract: This paper proposed an algorithm of distributed data stream query reusing. Firstly, query trees existing in distributed DSMS matched with the new query tree created by the distributed DSMS and calculated reusing proceeds. Secondly, reused the overlapped query operators between the existing query trees and the new query tree based on the reusing proceeds.
分数阶脉冲微分方程三点边值问题解的存在性和唯一性
Existence and uniqueness of solutions for three point boundary value problems of impulsive fractional differential equations

,贾梅,李燕,<br>ZHANG Sha, JIA Mei, LI Yan, LI Xiao-chen
- , 2017, DOI: 10.6040/j.issn.1671-9352.0.2016.213
Abstract: 摘要: 研究了一类分数阶脉冲微分方程三点边值问题解的存在性和唯一性。 利用Schauder不动点定理及压缩映射原理,获得了该边值问题解的存在性和唯一性定理。
Abstract: The existence and uniqueness of solutions is investigated for a class of three point boundary value problems of fractional differential equations with impulsive. By using the Schauder fixed point theorem and contraction mapping principle, some theorems about the existence and uniqueness of solutions for the boundary value problem are obtained
Research on Performance of Wave-plate Mist Eliminators
折板式汽液分离元件的性能

ZHANG Xiao-chen,ZHANG Ming,RUAN Guo-ling,HU Kong-cheng,<br>,,阮国岭,胡孔诚
过程工程学报 , 2012,
Abstract: The influential factors on the separation property of wave-plate mist eliminator were studied with cold-state simulation experiments by using an air-water medium.The effects of operating conditions such as gas velocity and liquid droplet diameter and structural parameters such as the installation,geometry and spacing of the plate were examined.The gas velocity limit was controlled in 1~6 m/s,and the liquid droplet diameters from 50~80 μm,the plate was installed in horizontal and vertical directions,its geometry had V and W shapes,and the spacing was from 10~50 mm.The experimental results showed that there were some rules on the effects of influential factors such as gas velocity on the separation efficiency,and the spacing of 20 mm was the best arrangement.A reasonable empirical equation obtained by regressing the experimental data could predict experimental data within 10% error.A medium-scale experiment of desalination was also carried out to evaluate the separation property of the eliminator.
Ultrastructure changes of mice liver induced by nodularin
节球藻毒素对小鼠肝脏微结构的影响研究

YE Binhui,ZHOU Mengting,HUANG Liming,CAI Chenchen,SHOU Xiaolu,HAN Li,JIA Xiuying,ZHANG Hangjun,<br>叶斌晖,周梦婷,黄黎明,,寿,韩丽,贾秀英,杭君
环境科学学报 , 2013,
Abstract: 作为新型生物毒素,节球藻毒素(NOD)常见于爆发水华的水体中,是泡沫节球藻分泌的具有高肝毒性的次生代谢产物.由于其毒性高、暴露途径广且不易降解而日趋受到人们的重视.为了阐明NOD的肝毒性机理,本研究以模式生物小鼠为载体,研究亚慢性NOD诱导下小鼠肝脏在形态学、病理学上的微结构变化.结果表明,10 μg·kg-1·d-1 NOD下暴露21 d可诱导小鼠肝脏出现"草莓状表面"的肉眼可见的形态学改变.在H&E染色下,观察到在NOD暴露21 d可诱导小鼠肝脏出现微小结节、细胞嗜酸性病变、炎症细胞浸润、慢性淤胆及脂肪病变等病理学现象.当暴露时间延长到28 d时,嗜酸性病变恶化并出现嗜酸小体.在TEM观察下,小鼠肝细胞在NOD的诱导下出现肝细胞核皱缩、染色质凝集或边集、线粒体嵴横纹加深及分布散乱、内质网肿胀、核糖体脱粒等现象,并且在胞质中多有观察到微泡性脂肪变性及吞噬小泡.上述变化充分说明,在亚慢性暴露条件下,NOD依然具有强烈肝毒性.引起NOD慢性肝中毒的主要原因是肝细胞嗜酸性病变及炎症的诱发,并在暴露时间延长后进一步恶化,肝板结构破坏更加严重.
宽带双泵浦光纤参量放大器的优化设计
,姜淳
自然科学进展 , 2005,
Abstract: 对一种由两段高非线性光纤级联构成的双泵浦光纤参量放大器(FOPA)的数学模型进行了推导及数值分析,并借助遗传算法对相应参数进行了优化.数值模拟结果表明,当输入总功率为0.5W时,由两段高非线性光纤构成的光参量放大器可以在1500—1600nm频带范围内实现均值为10dB,波动幅度在0.4dB以内的增益谱.
Host plant effects on the morphological and biological characteristics of Bemisia tabaci (Gennadius) biotype B
寄主植物对B型烟粉虱形态学和生物学特性的影响

Chen Luo,Xiaojun Guo,Mei Yue,Yuyong Xiang,Zhili Zhang,<br>罗,,岳梅,向玉勇,芝利
生物多样性 , 2006,
Abstract: 为了解B型烟粉虱(Bemisiatabaci)在不同寄主植物上的生物学特性,以制定科学的综合治理措施,作者在271℃的条件下,研究测定了B型烟粉虱在棉花(Gossypiumhirsutum)、一品红(Euphorbiapulcherrima)、甘蓝(Brassicaoleraceavar.capitata)、黄瓜(Cucumissativus)、西葫芦(Cucurbitapepo)、茄子(Solanummelongena)和番茄(Lycopersiconesculentum)上各虫态大小、成活率、发育历期、成虫寿命、平均产卵量等生物学参数。结果表明:取食不同寄主植物的烟粉虱伪蛹在黄瓜和棉花上体型最大,在一品红上最小;烟粉虱从卵到成虫羽化,发育历期以在一品红上最长(22.0d),黄瓜上最短(17.3d);平均单雌产卵量以在番茄上最多(266.5粒/雌),一品红上最少(112.9粒/雌);成虫的寿命在番茄、黄瓜和茄子上显著长于在其他4种寄主植物上。烟粉虱从卵发育到成虫的存活率以在黄瓜上最高(77.8%),西葫芦上最低(55.6%),两者差异显著。综合比较7种寄主植物,黄瓜是烟粉虱种群生长发育和繁殖的最适寄主。
Power generation of microbial fuel cell from aniline and glucose
以苯胺和葡萄糖为燃料的微生物燃料电池的产电特性研究

WU Chen,ZHANG Jiaqi,WANG Xiaoli,CHI Qianglong,HU Ying,<br>武,嘉琪,,池强龙,胡瑛
环境科学学报 , 2011,
Abstract: 通过构建空气阴极型双室微生物燃料电池(Microbial Fuel Cell, MFC),并以苯胺和葡萄糖为燃料,研究了MFC对苯胺的降解特性及MFC的产电性能.结果表明,在1000 Ω电阻下,500mg·L-1葡萄糖为单一燃料时,MFC的最大输出电压为440 mV,最大输出功率密度为215mW·m-2.当苯胺的初始浓度为500mg·L-1,葡萄糖的浓度分别为500、300和100mg·L-1时,MFC的最大输出电压分别为430、402和390 mV,最大输出功率密度分别为205、180和169mW·m-2(按阳极截面积计算).高浓度苯胺对MFC利用葡萄糖进行产电有一定的影响.MFC可以实现对苯胺的降解,104 h内苯胺的降解率达到70%以上,MFC在闭路状态下对苯胺的降解速率比开路厌氧状态下高约14%.当以500mg·L-1苯胺为单一燃料时,MFC最大输出电压为280 mV,最大输出功率密度为87mW·m-2.MFC以苯胺和葡萄糖为混合燃料时,可在降解苯胺的同时实现稳定地向外输出电压,这为难降解的苯胺类有机物的处理提供了一条新的思路.
Effect of nutrients ratio on contamination removal by immobilized algal-bacterial beads and study on kinetics
废水营养比对固定化藻菌去除污染物的影响及动力学研究

Mao Shuduan,Zhang Xiaoping,Lan Yonghui,Wang Xiaochen,Xiao Xiansheng,<br>毛书端,小平,兰永辉,,肖贤声
环境工程学报 , 2012,
Abstract: Ca-Alginate was used for immobilizing the algal and bacteria cells.The immobilized algal-bacterial beads were then coated with chitosan and used for treatment of simulated wastewater.The effect of initial NH+4-N concentrations and C/N ratio on the removal of contamination from wastewater was studied.The results showed that the maximum removal rate of NH+4-N was 74.4% when initial concentrations of NH+4-N was 50 mg/L.The maximum removal rate of COD was 77.7% when C/N ratio was 35∶1.The best N/P ratio and C/N ratio for pollutants removal by immobilized algal-bacterial beads were 5∶1 and 35∶1,respectively.The process of organic biodegradation with immobilized algal-bacterial beads was an irreversible first-order reaction.The degradation rate constant was about 0.099 h-1.
Cloning, expression and characterization of a thermostable chitinase from Thermoascus aurantiacus var. aurantiacus
嗜热子囊菌原变种Thermoascus aurantiacus var. aurantiacus热稳定几丁质酶的克隆表达及活性研究

ZHANG Jie,XIE Chen,GUO Xiao-Hong,LI Duo-Chuan,<br>,,,李多川
菌物学报 , 2010,
Abstract: 研究通过RT-PCR和Tail-PCR技术从嗜热子囊菌原变种Thermoascus aurantiacus var. aurantiacus中克隆了一个几丁质酶同源基因。该基因全长1,253bp,包含一个由1,197个碱基构成的开放阅读框,编码398个氨基酸。序列比对分析表明,该基因编码蛋白属于糖苷水解酶18家族的几丁质酶。利用基因重组的方法构建酵母分泌型表达载体,并转化毕赤酵母。在甲醇的诱导下,重组蛋白得到了高效表达,第6天的表达量最高,达到0.433g/L,酶活力为28.96U/mg,同时对表达的几丁质酶进行了纯化,SDS-PAGE检测该蛋白的分子量为43.9kDa。该几丁质酶的最适反应温度为60℃,最适反应pH值为8.0,70℃处理30min仍有45%的相对酶活,具有较好的热稳定性及工业应用价值。
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