共查询到20条相似文献,搜索用时 156 毫秒
2.
IntroductionSpace timecodingisanewencodingandsignalprocessingtechniqueinmobilecommunicationsystem ,whichtransmitsandreceivesinformationusingmultipletransmitantennasandreceiveantennas[1].Space timeprocessingcan greatlyimproveinformationcapacityandinformationrate[2 ].Space timecodeisdividedintospace timetrelliscodeandspace timeblockcode[3].Space timeblockcodecanachievefulldiversity .Thecodeputforwardin[4]can providemaximum possibletransmissionrateaswellasprovidingfulldiversity .Itisprovedin[4]t… 相似文献
3.
《上海理工大学学报》2004,26(1):93-93
期刊: [序号] 作者(姓前名后). 题名[J]. 刊名(外文刊名可缩写), 出版年, 卷(期): 起止页码. 专著: [序号] 作者(姓前名后). 书名[M]. 版本(第一版不写). 出版地: 出版者, 出版年. 起止页码. 论文集: [序号] 作者(姓前名后). 题名[A]. 编者. 论文集名[C]. 出版地: 出版者, 出版年. 起止页码. 科技报告: [序号] 作者(姓前名后). 题名[R]. 报告题名, 编号. 出版地: 出版者, 出版年. 起止页码. 学位论文: [序号] 作者(姓前名后). 题名[D]. 保存地点: 保存单位, 授予年份. 页码. 国际、国家标准: [序号] 起草责任者. 标准编号, 标准名称[S]. … 相似文献
4.
IntroductionApoptosisisacellularautodestructionprocessfortheactiveeliminationofunwantedcells[1].Apoptosishasbeenobservedinmanyanimaltissuesandwasfoundtoplayavitalroleinnormaldevelopment,maintenanceofhomeostasisandpathologicalprocessesassociatedwithvariousdiseases[2,3].Thereismoreandmoreevidenceshowingthatapoptosisalsooccursinhigherplants[4].However,comparedwiththeresearchinanimals,thestudyofapoptosisinplantsisstillinitsinitialstage.Ourstudyinvestigatestheapoptosis-inducingeffectsofsomeabiotic… 相似文献
5.
Dynamic analysis of QTL for plant height at different developmental stages in maize (Zea mays L.) 总被引:8,自引:2,他引:6
YAN Jianbing TANG Hua HUANG Yiqin SHI Yonggang LI Jiansheng & ZHENG Yonglian . National Key Lab of Crop Genetic Improvement Huanzhong Agri-cultural University Wuhan China . Xiangfan Chia-Tai Agricultural Development Co. LTD. Xiangfan China . National Maize Improvement Center of China China Agricultural University Beijing China Correspondence should be addressed to Zheng Yonglian 《科学通报(英文版)》2003,48(23):2601-2607
Plantheightisoneofimportantagronomictraitsinmaizebreeding.Inthepastfewyears,toincreasetheplantingdensityandpreventplantsfromlodging,studiesonthegeneticmechanismofplantheightweregivengreatattentionto.Sincethe1990s,molecularmarkershaveprovidedapowerfultooltostudythetraitofplantheightatthemolecularlevel[1—3].Butmostofresearchforplantheightonlyfocusedondataatmaturestage.Tillnow,about70genesorQTLshavebeenlocated[4].Moreover,somegeneshavebeenevencloned[5—7].Duringthevege-tativegrowthperiod,plant… 相似文献
6.
《晋中师范高等专科学校学报》2010,(5):33-33
[序号]专利申请者或所有者.专利题名:专利国别,专利号[文献类型标志].公告日期或[公开日期].获取和访问路径.示例:[1]姜锡洲.一种温热外敷药制备方案:中国,88105607,3[P].1989-07-26.[2]西安电子科技大学.光折变自适应光外差探测方法:中国,01128777.2[P/OL].2002-03-06[2002-05-28].http;//211.152.9.47/sipoasp/zljs/hyjs-yx-new.asp?recid=01128777.2&Ieixin=0. 相似文献
7.
LUOKunli ZHANGXinmin CHENChanghe LUYilun 《科学通报(英文版)》2004,49(20):2183-2189
Arsenicisoneofthemostpopularandharmele-mentsintheenvironment[13].ThearsenicpollutionintheatmosphereisveryheavyinFushun,Shenyang,Lanzhou,Guiyang,ChengduandChongqing,etc.IntheSouthwestChinathereare3000eventsofarsenictoxicosisbecauseofhigharseniccoalscombustionandabout10000peopleareeffected[4,5].Therefore,thesourcesofarsenicintheenvironmentanditstreatmentarepaidmoreattentionto.CoalisthebasicpowersourceinChinaandabout1000milliontonsperyearisconsumeddirectlyasfuel[6,7].Steamcoalburntinpowerstat… 相似文献
8.
《中央民族大学学报(自然科学版)》2005,14(1):83-83
a .专著、论文集、学位论文、报告[序号 ]主要责任者 .文献题名 [文献类型标识 ].出版地 :出版者 ,出版年 .起止页码 (任选 ) .[1]刘国钧 ,陈绍业 ,王凤翥 .图书馆目录 [M].北京 :高等教育出版社 ,195 7.15 - 18.[2 ]辛希孟 .信息技术与信息服务国际研讨会论文集 :A集 [C].北京 :中国社会科学出版社 ,1994 .[3]张筑生 .微分半动力系统的不变集 [D].北京 :北京大学数学系数学研究所 ,1983.[4 ]冯西桥 .核反应堆压力管道与压力容器的LBB分析 [R].北京 :清华大学核能技术设计研究院 ,1997.b .期刊文章[序号 ]主要责任者 .文献题名 [J].刊名… 相似文献
9.
《辽宁师范大学学报(自然科学版)》2013,(3):349-349
1专著著录格式主要责任者.题名:其他题名信息[文献类型标志].其他责任者.版本项.出版地:出版者,出版年:引文页码[引用日期].获取和访问路径.示例:[1]余敏.出版集团研究[M].北京:中国书籍出版社,2001:179-193.[2]昂温G,昂温P S.外国出版史[M].陈生铮,译.北京:中国书籍出版社,1988. 相似文献
10.
《辽宁师范大学学报(自然科学版)》2011,(1)
1专著著录格式主要责任者.题名:其他题名信息[文献类型标志].其他责任者.版本项.出版地:出版者,出版年:引文页码[引用日期].获取和访问路径.示例:[1]余敏.出版集团研究[M].北京:中国书籍出版社,2001:179-193.[2]昂温G,昂温P S.外国出版史[M].陈生铮,译.北京:中国书籍出版社,1988.2专著中的析出文献析出文献主要责任者.析出文献题名[文献类型标志].析出文献其他责任者//专著主要责任者.专著题名:其他题名 相似文献
11.
A rapid and sensitive on-line preconcentration method for spectrophotometric determination of chromium (VI) in nature water
is described. Preconcentration and determination are based on (i) the quantitative and fast adsorption of chromium (VI) on
the high surface area nanometer-size TiO2 (anatase) powders, which prepared by a sol-gel method from hydrolysis of TiCl4 and (ii) the quantitative and reproducible elution of Cr (VI) by 2.0 mol·L−1 HCl. A mini-column system for preconcentration is developed, Cr(VI) on the mini-column is eluted and merged with a stream
water and DPCB (1,5-diphenylcarbazide) as the chromogenic reagent. The proposed system permits throughputs of 6 sample h−1 (0.001 μg·mL−1 Cr(VI)) or 20 sample h−1 (0.1 μg·mL−1 Cr(VI)). The preconcentration factor is 55. The detection limit is 0.8 ng · mL−1 Cr(VI). The reproducibility is satisfactory with a relative standard deviation of less than 3.35% (0.01 μg·mL−1 Cr(VI),n=5).
Supported by the National Natural Science Foundation of China
Ma Wanhong: born in 1961, Ph. D. Graduate student, Associate professor 相似文献
12.
QIAN Shahua LIN Han LI Xueqin XIAO Mei DENG Hongbing XIANG Luojing School of Resource Environmental Science Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2007,12(2):349-352
A new absorbent of nanometer-size TiO2 colloid for Cu(Ⅱ) was studied in this work. The adsorption rate could reach above 99% when the pH values were at the range of 5-6. The adsorption balance time, adsorption capacities, and the eluent were investigated. A novel method of trace Cu(Ⅱ) preconcentration and separation with nanometer-size titanium dioxide colloid and determination by flame atomic absorption spectrometry (FAAS) was advanced. The detection limit (3σ) of the method was 1.15 μg· L~(-1) , and the relative standard deviation (R.S.D) was 1.53% (n=6). Environmental sample experiments were also conducted to test the feasibility of the method, and it came out that the recovery rates were between 95.9% and 97.8%. 相似文献
13.
A new method is proposed for the preconcentration of vanadium(V) with crosslinked chitosan (CCTS) and determination by graphite
furnace atomic absorption spectrometry (GFAAS). The adsorption rate of vanadium(V) by CCTS was 97% at pH 4.0, and vanadium(V)
was eluted from crosslinked chitosan with 2 mL 2.0 mol·L−1 chlorhydric acid and determined by GFAAS. The detection limit (3σ,n=7) for vanadium (V) was 4.8×10−12g and the relative standard deviation (R.S.D) at concentration level of 2.6 μg·L−1 is less than 3.6%. The method shows a good selectivity and high sensity, and it was applied to determination of vanadium(V)
in oyster and water samples. The analytic recoveries are (97±5)%.
Biography: Wu Wei (1975-), female, Master candidate, research direction: environmental & analytical chemistry. 相似文献
14.
SHI Bo’an~ ZENG Danyun~ JI Xinghu~ XI Juan~ AI Xinping~ HE Zhike~ . College of Chemistry Molecular Sciences Wuhan University Wuhan Hubei China . Department of Chemistry Chemical Engineering Hubei Institute for Nationalities Enshi Hubei China 《武汉大学学报:自然科学英文版》2006,11(3):672-676
0 IntroductionThbiep ycroidmipnlee)xru ctahteinoinu mof(Ⅱ r)u t(he Rniuu(mbip,y m)3ai2n +ly) atrnids- t(r2is -,(21’ -,10-phenanthroline)ruthenium(Ⅱ) (Ru(phen)32 +) ,is a kindof sensitive analytical reagent for electrogenerated chemilumi-nescence(ECL) and chemiluminescence(CL) ,on which a par-ticular review has been presented[1]. The earliest publicationon the synthesis of Ru(bipy)32 +appeared in 1936[2], andduringthefollowing30 years ,theinvestigations relatedtothissubstance were only in… 相似文献
15.
Applications of crown ether cross-linked chitosan for the analysis of lead and cadmium in environmental water samples 总被引:2,自引:0,他引:2
A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4′-dibromodibenzo-18-crown-6
(Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behaviors for lead and cadmium in environmental
water samples by FAAS were studied. In addition the best analysis conditions were discussed and the adsorption mechanism was
explained. As the enrichment factor is above 100, both recoveries are 94%–106%, the detection limits of lead and cadmium are
0.5μg·L−1 and 0.04 μg·L−1 and the relatively standard deviations of lead and cadmium are 3.1% and 2.8% respectively, this new method was successfully
applied to the determination of environmental water samples. This method is fast and simple and it greatly enhances the determination
ability of FAAS for lead and cadmium.
Foundation item: Supported by the State Education Committee Doctoral Foundation (No. 2000048615)
Biography: Tang Yu-rong(1943-), female, Associate professor, research direction: trace elements analysis. 相似文献
16.
ZHANG YunSong ;WANG RenGuo ;WANG XianXiang ;LEI SanZhong ;TONG DongMei 《科学通报(英文版)》2008,53(9):1365-1372
The anatase nano-TiO2 powder, with crystal size between 40 and 80 nm, was prepared by the liquid phase hydrolysis of TiCI4. At the same time, the nano-TiO2 was utilized with the baker's yeast biomass as a composite adsorbent to adsorb the Cu ions in the artificial aqueous solution. The investigation showed that the composite adsorbent had a fine adsorption efficiency. The TiO2 in the composite adsorbent could cooperate well with baker's yeast to improve the adsorbing capability of Cu^2+ under the following experimental conditions as well: a quantity of composite adsorbent of 5 g·L^-1, pH≥4.0, an adsorption time of 40 min and an initial concentration of Cu ions of 10 mg·L^-1. In addition, the results of measurements, obtained with a scanning electron microscope, an infrared spectrophotometer and a Zeta potential analyzer, revealed that the baker's yeast and nano-TiO2 produced the composite adsorbent through coordination and hydrogen bonds in particular, etc. The stability of the composite adsorbent and the amount of titania loaded were largely dependent on the concentration of hydrogen ion in the solution. 相似文献
17.
An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon
paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of the modified electrode via formation of chemical complexes with calix[6]arene, and reduced
at 1.40 V. During the following anodic potential sweep, reduced lead and cadmium were oxidized, and two well-defined striping
peaks appeared at about −0.60 V and −0.84 V. Compared with a bare carbon paste electrode, the calix[6]arene modified CPE greatly
improves the sensitivity of determining lead and cadmium. The stripping peak currents change linearly with the concentration
of Pb2+ 3.0×10−8–8.0×10−6 mol·L−1 and with that of Cd2+ 6.0×10−8–1.0×10−5 mol ·L−1. The detection limits of Pb2+ and Cd2+ are found to be 8.0×10−9 mol·L−1 and 2.0×10−8 mol·L−1, respectively. The modified carbon paste electrode was applied to determine trace levels of lead and cadmium in water samples.
Comparing with that of atomic absorption spectrometry, the results suggests that the calix[6]arene modified CPE has great
potential for the practical sample analysis.
Foundation item: Supported by the National Natural Science Foundation of China (60171023)
Biography: JI Xiao-bo (1980-), male, Master, research direction: electroanalytical chemistry. 相似文献
18.
A novel material MnO2 nanosheet has been used as the support matrix for the immobilization of horseradish peroxidase (HRP). HRP entrapped in MnO2 nanosheet film exhibits facile direct electron transfer with the electron transfer rate constant of 6.86 s^-1. The HRP/MnO2 nanosheet film gives a reversible redox couple with the apparent formal peak potential (E^0') of -0.315 V (vs. Ag/AgCl) in pH 6.5 phosphate buffer solution (PBS). The formal potential E^0' of HRP shifts linearly with pH with a slope of -53.75 mV.pH^-1, denoting that an electron transfer accompanies single-proton transportation. The immobilized HRP shows an electrocatslytic activity to the reduction of H2O2. The response time of the biosensor for H2O2 is less than 3 s, and the detection limit is 0.21 μmol · L^-1 based on signal/noise = 3. 相似文献
19.
A new method for determination of trace sillicon in high purity lanthanum oxide by using electrothermal vaporization (ETV)-ICP-AES
with polytetrafluoroethylene (PTFE) slurry as a fluorinating reagent has been proposed. Under the optimized experimental conditions,
the fluorination reactions of analyte (Si) and matrix(La) with PTFE in the graphite furnace took place at high temperature,
and the fractional volatilily between Si and La was observed. Based on this principle the matrix interference could be eliminated.
The detection limit of Si was 4.0μg·L−1, and the RSD was 3.4%(C=0.2mg·L−1,n=10). The procedure proposed has been applied successfully to determine trace Si in La2O3 without any chemical pre-treatment.
Supported by the National Natural Science Foundation of China
Qin Yongchao: born in Dec. 1953, ph. D., Assciate Professor 相似文献
20.
CHEN Lihua~ ZHANG Yongkang~ YIN Hong~ LIU Liuzhan~ YANG Zhaoxia~ SHEN Hanxi~ . College of Chemistry Chemical Engineering Jishou University Jishou Hunan China . College of Chemistry Nankai University Tianjin China 《武汉大学学报:自然科学英文版》2006,11(3):704-708
0 IntroductionMaalnadria siusb atr ompajicosr .he aAltrthe pmrisoibnlienmi (n qtihneghtraoopsiucs,QHS,Fig.1) is a sesquiterpene endoperoxide isola-ted fromArtemisia annuaL., an ancient Chineseherbal medicine usedfor treatment of fever and ma-laria.Studies of the structure and activity relation-ship have shownthat endoperoxide groupis essentialfor anti malarial activity of QHS and absence of thismoiety lead to completely loss in activity of thedrug. Many techniques have been developed to de… 相似文献