Secondary metabolites from fungus Alternaria sp. CIB 108

A new compound,3-butyryl-6-[rel-(1S,2S)-1,2-dihydroxypropyl]-4-hydroxy-2H-pyran-2-one(1),was isolated from the solid fermented rice culture of Alternaria sp.CIB 108,along with three known ones,deoxyradicinin(2),3-epiradicinol(3),and 3- epideoxyradicinol(4).Their structures were elucidated on the basis of spectroscopic data.The single crystal X-ray diffraction was applied to further clarify the structure of 1.Furthermore,compounds 1-4 possessed no cytotoxicity against several cell lines(HeLa, HepG2,and Ros) and showed no antibacterial activity at 40μmol/L.     

Study on the interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate by the resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectra and its analytical application

The interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate was investigated by ultravioletvisible absorption,resonance Rayleigh scattering(RRS),second-order scattering(SOS)and frequency doubling scattering (FDS)spectroscopy.In pH 5.3 Britton-Robinson(BR)buffer medium,chlorpromazine hydrochloride(CPZ)reacted with Pd(II) to form 2:1 cationic chelate,which further reacted with Na2WO4 to form a 1:1 ternary ion-association complex ([Pd(CPZ)2]·WO4).As a result,the signal intensities o...     

苯甲醛丙氨酸金属配合物中性载体水杨酸根离子电极的研究

首次研究了基于苯甲醛丙氨酸合钴(Ⅱ)金属配合物[Co(Ⅱ) BBAA]为中性载体的PVC膜电极。该电极对水杨酸根(Sal-)具有优良的电位响应性能和->选择性并呈现出反Hofmeister选择性行为,其选择性次序为Sal->ClO42->SO42-。在pH5.0的磷酸盐缓->NO2->Br->Cl->SO3SCN->I->NO3冲体系中,电极电位呈现近能斯特响应,线性响应范围为3.2×10-5～1.0×10-1mol L,斜率为-56.4mV dec(20℃),检测下限为9.0×10-6mol L。采用交流阻抗技术和紫外可见光谱技术研究了电极的响应机理,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之间有非常密切的构效关系。电极可用于药品分析。     

规则结构生物膜滴滤塔可视化实验研究

本文通过可视化实验,研究了规则多孔结构生物膜滴滤塔的两相流动阻力特性以及气体流量、液体流量、污染物进口浓度等参数对填料塔净化效率的影响,获得了填料塔内孔隙率沿塔高方向的变化规律。实验结果表明:随着气体流量和液体流量的增加以及废气中甲苯浓度的增加,滴滤塔净化效率降低;滴滤塔内液体分布不匀导致生物膜生长不均匀。     

Solid state cathodoluminescence based on tris-(8-hydroxyquinoline) aluminum and its quenching mechanism

A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternating current(AC) voltage is applied to this device,uniform emissions are observed.When the voltage is 50 V,a longer wavelength emission(522 nm) is obtained,but the shorter wavelength emission(465 nm) is dominant when the voltage is 76 V.The origins of these emissions are discussed.The interface f...     

Measurement of the total reaction cross section for the mirror nuclei ~(12)N and ~(12)B

The mirror nuclei 12N and 12B are separated by the Radioactive Ion Beam Line in Lanzhou(RIBLL) at HIRFL from the breakup of 78.6 MeV/u 14N on a Be target.The total reaction cross-sections of 12N at 34.9 MeV/u and 12B at 54.4 MeV/u on a Si target have been measured by using the transmission method.Assuming 12N consists of a 11C core plus one halo proton,the excitation function of 12N and 12B on a Si target and a C target were calculated with the Glauber model.It can fit the experimental data very well.The ch...     

双波长数据包并行缓存

以半导体光放大器为非线性元件的双环耦合全光缓存器(DLOB)为基础,实现了速率为2.5 Gb/s双波长数据的并行缓存.不同波长光信号合成后的功率随机波动,导致由半导体光放大器交叉相位调制产生的相位差随机波动.在考虑吸收损耗的情况下,对常用的半导体光放大器增益特性曲线进行了修正并与实测值拟合,得到了更为准确的增益特性曲线.在此基础上进行了理论分析,提出了通过调节控制光功率到最佳点以便减小相位差波动的方法.     

高Tc超导体YBCO磁通钉扎的计算机模拟研究

临界电流密度Jc是影响高温超导体在强电领域应用的一个重要参数,在实际应用中,特别在外加磁场下,临界电流密度与超导材料的磁通钉扎性质密切相关.因此,磁通钉扎一直是高温超导体研究中的一个重要领域.由于高温超导体磁通钉扎力密度Fp的标度律存在,本文根据D.Dew-Hughes总结的钉扎力函数,主要存在两种主要作用类型(正常相和△K).我们将D.Dew-HugBes给出的钉扎力密度Fp标度函数改进为一个简化的具有物理意义的函数表达式.结合文献中已有的实验数据,我们对YBcO进行了计算机模拟,确定了它的磁通钉扎类型,模拟的研究结果与实际情况比较吻合.