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41.
In this paper, we study the single neutral top-higgs (h0t) production processes at the CERN Large Hadron Collider (LHC) and the International Linear Collider (ILC). At the LHC, the production rates of processes pp→Z(W)h0t are too small to detect h0t . However, with the reasonable parameter values, the cross sections can reach the level of 102 fb for qq→qqh0t process and 103 fb for top quark associated production process pp→th0t+X, respectively. At the ILC, we study the single top-higgs production processes e-γ→νeW-h0t and γγ→W+W-h0t in e-γ and γγ collisions. It is found that the production cross sections can reach the level of a few fb with reasonable parameter values. Furthermore, such processes with the flavor-changing decay mode h0t→tc might provide typical signatures to detected the top-higgs. Therefore, it is hopeful to find the signal of top-higgs at the LHC and ILC experiments via theses processes and test the TC2 model directly.  相似文献   
42.
Three new sesquiterpenes,namely schensianol A(1),schensianolside A(2) and schensianolside B(3) were isolated from the stems and leaves of Euonymus schensianus Maxim.Their structures were established by chemical methods and spectroscopic techniques including 2D NMR.  相似文献   
43.
Biphenyl units are present in a wide range of compounds both natural and synthetic, and many of them have pharmacological activity1. Xie Jingxi et al. found that dimethyl 4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'-dicarboxylate((-DDB) as an important intermediate for the synthesis of Schizandrin C analogue which is effective in lowering elevated SGPT level2-3. Two isomers dimethyl 6,6'-dimethoxy-4,5,4',5'-dimethylenedioxybiphenyl-2,2'-dicarboxylate ((-DDB) and 6,4,-dimethoxy-4…  相似文献   
44.
<正>Acetonylacetone 1 was treated with thiourea,aniline,glycine and glutamic acid to give pyrrole derivatives 2,3,5,and 9 by Paal-Knorr reaction,respectively.Then 3 was successfully transformed into the related pyrrole derivative 4 by Mannich reaction. Compounds 6,7 and 8 were obtained by reacting 5 with phenethyl alcohol,phenylallylic alcohol and leaf alcohol by esterification reactions,respectively.The structures of all new products were elucidated by IR,NMR and HRMS spectra.  相似文献   
45.
In this article, we consider the eigenvalue problem for the bi-Kohn Laplacian and obtain universal bounds on the (k + 1)-th eigenvalue in terms of the first k eigenvalues independent of the domains.  相似文献   
46.
本文用十六烷基三甲基溴化铵(CTAB)作为试剂,通过软模板法合成介孔二氧化硅,利用在合成过程中,由伪莫尔转动所引起的微粒内部的大量缺陷,通过溶剂抽提,形成了具有空腔结构的介孔二氧化硅纳米微球.采用透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)、N2吸附-脱附等手段对产物的形貌和结构进行了详细的表征.并以溴甲酚绿作为目标物,通过改变压强和温度,调节溴甲酚绿进入空心SiO2微球中的不同部位,对所制备的空腔介孔二氧化硅微球进行染料的装载和释放试验.结果显示该微球腔壁具有可渗透性和缓释性,而且在负压蒸发溶剂的情况下可以得到较高的药物负载量和极大地提高缓释性能.  相似文献   
47.
The concentrations of Cd,Cr,Cu,Ni,Pb and Zn were determined in the water and surface sediments from the Henan reaches of the Yellow River.Twenty-three sampling sites along the Yellow River and its tributaries were selected.Generally,metal concentrations were found to decrease in sequences of Zn>Cu>Pb>Cr>Ni>Cd in water and Zn>Cr>Pb>Ni>Cu>Cd in sediments.High levels of metal concentration were determined at a few stations of the river and its tributaries,such as Yiluo River,Si River and Qin River.The pollutio...  相似文献   
48.
Since nalidixic acid1 was first clinically used as a potent antibacterial agent, many analogues, such as bicyclic ciprofloxacin2, tricyclic ofloxacin3, have become an important class of therapeutical compounds. Recently, novel tetracyclic fluoroquinolones having a thiazolooxazine ring with potent antibacterial activity against both G+ and G- have been reported4. In order to find better antibacterial agents for our urgent research of the multidrug resistant (MDR)5, we herein describe a facil…  相似文献   
49.
The title compound (1) was treated with NaH at room temperature in anhydrous DMF to give a sodium salt (containing nitrogen anion)which could shift the methyl group from oxygen to nitrogen atom to form N-methyl phosphinic acid as the reaction temperature was increased to 120 ℃.Three nitro derivatives containing 5,10-dihydrophenophosphazine ring system were prepared for the investigation on the above reaction mechanism which would be possible regarded as a special inter-molecular substitution.viz.,the nucleophilic nitrogen anion from one molecule of 1 attacked the cabon atom of the O-methyl of another 1.In addition,the chemical structures of seven compounds containing 5,10-dihydrophenophosphazine ring system involved in the experiment were confirmed by IR,^1 H NMR,^31P NMR and mass spectroscopy.  相似文献   
50.
4-Amino-5-(pyridin-3-yl)-4H-l,2,4-triazole-3-thiol 1 were condensed with 2-bromo-l-(substituted phenyl)ethanone to give pyridinyltriazolothiadiazines 2a-c, which were quaternarized with methyl iodide and oxidized with 30 % hydrogen peroxide to afford the corresponding methyl pyridinium salts 3a-c and pyridine- 1 -oxides 4a-c, respectively. The redtiction of compounds 3 and 4 with NaBH4 in methanol produced the target compounds 1-methyl- 1.2.5.6-tetrahydropyridin-3-yl)-6-aryl-s-triazolothiadiazines 5a-c and 3-( l-hydroxyl- 1, 2, 5, 6-tetrahydropyridin -3-yl)-6-aryl-s-triazolothiadiazines 6a-c, respectively. The endothelium vascular relaxing activity of the target compounds was screened.  相似文献   
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