超线性Schr(o)dinger方程的无穷多解

运用喷泉定理来研究超线性Schr(o)dinger方程的无穷多解.非线性项增长速度并不超过∣u∣μ-1对于某个μ＞2.     

两种新的多羟基甾醇化合物分离与结构鉴定

采用现代分离手段,从采自中国南海硇洲岛的软珊瑚Chromonephthea sp.中分离纯化得到两种甾醇化合物,经过MS,IR,1H NMR,13C NMR(DEPT),HSQC,HMBC和NOE等光谱技术鉴定它们的结构为:24-甲基胆甾-5-烯-3β,12β,16β,20-四醇(1)和24-乙基胆甾-5-烯-3β,12β,16β,20-四醇(2),这两个化合物均为新化合物.肿瘤活性实验表明两种甾醇化合物显示微弱的细胞毒性.     

Polymeric architectures of bismuth citrate based on dimeric building blocks

Four bismuth complexes, (H₂En)[Bi₂(cit)₂(H₂O)_4/3]·(H₂O) _x (1), (H₂En)₃[Bi₂(cit)₂Cl₄]·(H₂O) _x (2), (HPy)₂[Bi₂(cit)₂(H₂O)_8/5]·(H₂O) _x (3) and (H₂En)[Bi₂(cit)₂](H₂O) _x (4) [cit = citrate^4?; En = ethylenediamine; Py = pyridine] have been synthesized and crystallized. The crystal structures reveal that the basic building blocks in all of these complexes are bismuth citrate dimeric units which combine to form polymeric architectures. The embedded protonated ethylenediamine and pyridine moieties in the polymeric frameworks have been identified by X-ray crystallography and solid-state cross polarization/magic angle spinning (CP/MAS) ¹³C NMR. Based on the framework of complex 1, a structural model of a clinically used antiulcer drug, ranitidine bismuth citrate (RBC) was generated. The behavior of the protonated amine-bismuth citrate complexes in acidic aqueous solution has been studied by electrospray ionization-mass spectrometry (ESI-MS).     

第14届流动注射分析国际会议(Ⅰ)

本届会议于2007年9月2日至7日在德国柏林市召开,由柏林技术大学、自由大学与日本流动注射分析协会(JAFIA)联合主办.会议参加者计116人,来自30个国家.     

第59届Pittcon会议(Ⅰ)

本届会议于2008年3月2日至7日在美国New Orlearls市召开,收到论文逾二千一百篇.为使代表获得有关分析化学的创新领域及其基础知识举行了涉及近60个专题的百个短期讲座,大会报告的题目为:"系统生物系与系统药物",由LHood博士担任报告人.     

A new approach to the synthesis of diacetals（diketals） pentaerythritol catalyzed by SO3H-functionalized ionic liquids

<正>In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SO_3H-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high catalytic activity and reusability with good to excellent yields of the desired products.Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction.Maximum product yield of 93%was observed on using[PSPy][OTf]as catalyst and it can be reused at least 8 times without obvious activity loss.     

A new derivative of triterpene with anti-melanoma B16 activity from Conyza Canadensis

<正>A new derivative of triterpene named Erigeronol 1 was isolated from the EtOH extract of the aerial part of Conyza canadensis together with 15 known compounds for the first time from this plant.The structure of Erigeronol 1 was elucidated as 3-O-(hydroxyacetyl) -23,28-dihydroxy-β-amyrin by hydrolysis and spectroscopic analysis.Erigeronol 1 showed potent cytotoxic activity with IC_(50) value of 7.77±0.47μg/mL against melanoma B16 determined by the 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide(MTT) method.     

银在光催化分解NO反应中的光催化行为研究

以光催化分解NO反应为探针,研究了负载银催化剂在紫外光激发作用下光催化分解NO反应的催化行为.对银物种的调变会对银的光催化活性产生显著影响,结合XRD(X射线粉末衍射),UV-vis(紫外可见漫反射)等表征手段对反应中起重要作用的活性银物种的表征结果表明,高度分散于分子筛内的银离子及银簇是光催化分解NO的活性中心.     

投资和再保险策略下保险公司的最优合并时刻问题

本文考虑的是允许采用比例再保险策略和投资策略的两个保险公司如何寻找最优合并时刻的问题.两个保险公司的风险过程由漂移布朗运动刻画,目标为最大化它们的生存概率.各个公司的安全负荷系数和波动系数在决定两公司是否要合并时起到了关键作用.决定合并后,公司合并费用,合并前后公司的生存概率状况在决定最优合并时刻时起到了关键作用.我们分两种情况讨论了这个问题并分别给出相应情况下的最优策略和值函数.     

Experimental study on the local similarity scaling of the turbulence spectrum in the turbulent boundary layer

The streamwise fluctuating velocity in the turbulent boundary layer is measured under approximately medium Reynolds Number by hot wire in order to investigate the scaling properties of the overlapped turbulent spectrum among energy-containing area, inertial subrange and dissipation range based on FFT analysis. The experiment indicates that the high Reynolds flow reported before is not indispensable to produce −1 scaling. So far as the measured position is provided with much higher spatial resolution and enough closing to the wall, −1 scaling is determinate to exist when approaching medium Reynolds. The scaling ranges are supposed to begin at inner scale and end in outer scale, which reveals the local similarity of the energy spectrum over the energy-containing eddies near the wall. In the logarithmic area (y ⁺ > 130), −5/3 scaling occurs in the energy spectrum, while moving away from the wall with Reynolds numbers increasing, the inertial subrange extends to the lower wavenumbers. On the condition k ₁ η ≫ 0.1, the curves of the turbulence spectrum in the logarithmic layer are superposed, which expresses the similarity of turbulence energy distributed in Komogorov scaling area and exhibits local isotropy characteristics by virtue of the viscous dissipation. Supported by the National Natural Science Foundation of China (Grant Nos. 10832001 and 10872145), the Program for New Century Excellent Talents in Universities of Education Ministry of China, and the Plan of Tianjin Science and Technology Development (Grant No. 06TXTJJC13800)