利用原子力显微镜和分子技术研究海水微生物腐蚀(英文)

生物膜在自然界无处不在,但生物膜造成的腐蚀却基本上被忽视.本文展示了几种化学和微生物学新方法在海水微生物腐蚀研究中的应用.原子力显微镜用来揭示生物最初形成的机理和钢在受污染海水中的腐蚀程度,16SrDNA/RNA技术则用来分析生物膜中的微生物组成.试验结果表明,微生物腐蚀在6d内就已经开始了,腐蚀体积与时间的2.83次方成正比;腐蚀生物膜中的微生物以硫酸还原菌(脱硫弧菌科)为最多,其次是梭状芽孢杆菌.     

［Vmo_3O_4（O_2CEt）_8］_2Na_2的合成与结构

［ＶＭｏ３Ｏ４（Ｏ２ＣＥｔ）８］２Ｎａ２（１），三斜晶系，Ｐ１空间群，ａ＝１２．９７７（７），ｂ＝１４．０７０（６），ｃ＝１２．３３８（８），α＝１０９．８１（４），β＝１１７．２０（４），γ＝９０．５１（５）°，Ｖ＝１８４８．８３，Ｍｒ＝２０２０．６，Ｄｃ＝１．８１ｇ／ｃｍ３，Ｚ＝１，Ｆ（０００），μ＝１２．９ｃｍ１（ＭｏＫα）对３７４２个可观测反射点（Ｉ＞３σ（Ｉ））最终一致性因子为Ｒ＝０．０１８，Ｒω＝０．０５４。单晶结构分析表明，簇阴离子中两个［Ｍｏ３Ｏ４］４＋单元通过两个＂桥＂金属Ｖ原子连接成一个奇特的环状结构，Ｍｏ－Ｍｏ平均键长为２．５１９（１），Ｍｏ…Ｖ间平均距离为３．６５４。簇阴离子通过Ｎａ＋连成一个一维长链，Ｎａ原子与氧原子形成一个少见的五配位三角双锥结构，Ｎａ－Ｏ距离仅为２．３１２，Ｎａ－Ｏ间较强的相互作用以及无限长链的晶体结构很好地解释了簇合物（１）的稳定性和不溶性。     

A double constrained robust capon beamforming based imaging method for early breast cancer detection

Ultra-wideband （UWB） microwave images are proposed for detecting small malignant breast tumors based on the large contrast of electric parameters between a malignant tumor and normal breast tissue. In this study, an antenna array composed of 9 antennas is applied to the detection. The double constrained robust capon beamforming （DCRCB） algorithm is used for reconstructing the breast image due to its better stability and high signal-to-interference-plus-noise ratio （SINR）. The successful detection of a tumor of 2 mm in diameter shown in the reconstruction demonstrates the robustness of the DCRCB beamforming algorithm. This study verifies the feasibility of detecting small breast tumors by using the DCRCB imaging algorithm.     

光电探测器对光谱仪器精度的影响

通过优化光谱探测环节来提高光谱仪器的精度是改进或研制新型光谱仪的重要途径。为此,文章基于对光电成像系统中光学传递函数的研究,建立了光谱图像经探测器积分抽样后重建的数学模型,并在此基础上分析了光电探测器积分抽样特性参数对光谱线频谱的影响,讨论了光谱线半宽度与探测器积分区间宽度、灵敏度及抽样间隔的关系,提出了准确重建光谱线,提高光谱仪器波长精度和光度精度的探测器优化原则。     

Synthesis and Crystal Structure of a New Tetracopper Complex [Cu(H_2O)_3Cu(HCDTA)]_2(ClO_4)_2·H_2O

A new tetracopper complex [Cu(H2O)3Cu(HCDTA)]2(ClO4)2·H2O (CDTA = transcyclohexane-1,2-diamine-N,N,N′,N′-tetraacetate) has been prepared and characterized by singlecrystal X-ray diffraction analysis. The crystal adopts space group C2/c with a = 16.990(10), b = 9.150(5), c = 29.318(17) , β = 104.289(9)°, V = 4417(4) 3, Z = 4, C28H52Cl2Cu4N4O31, Mr = 1265.80, Dc = 1.904 g/cm3, μ = 2.130 mm-1, F(000) = 2584, T = 293(2) K, the final R = 0.0328 and wR = 0.0809 for 4938 observed reflections (I 2σ(I)). The tetracopper units are interconnected by weak covalent bonds into a layered structure.     

一种新颖钒.钨异金属八核簇合物[VW~3~4(O~2CEt)~8]~2Na~2的合成与结构

本文报道了一种钒.钨异金属八核簇合物[VW~3~4(O~2CEt)~8]~2Na~2(1)在恒温液相条件下的合成与结构研究,晶体属三斜晶系,P1空间群,a=1.2973(4),b=1.4063(3),c=1.2396(5)nm,α=1.09.92(2),β=117.32(2),γ=90.53(2)°,V=1.8513nm^3,D~c=2.29g/cm^3,Z=1对5499个可观测反射点[I>3σ(I)] 最终一致性因子为R=0.030.单晶结构分析表明,簇阴离子中两个[W~3O~4]^4^+单元通过两个"桥"金属V原子联接成一个奇特的环状结构,W-W平均键长为0.25328(6)nm,W...V间平均距离为0.3654nm,簇阴离子通过Na^+联成一个一维长链.Na 原子具有少见的五配位,Na-O距离仅为0.2314nm,Na-O间教情的相互作用以及无限长链的晶体结构很好地解释乐簇合物1的稳定性和不溶性.     

Synthesis and Crystal Structure of [K(18-Crown-6)]_3P_(11)·2en

1 INTRODUCTIONSince the first report on the reduction of lead by sodium to a green solution in 1891 by Johannis, polyanionic clusters of post-transition metals known as Zintl ions have attracted much attention in chemistry due to their beautiful molecules, diverse reactivity and potential applications[1, 2]. Polyphos- phide anions represent one of the most important classes of zintl ions. The binary alkali-metal poly- phosphides, such as MI4P6 (M = K, Rb, Cs)[3～5], MI3P7 (M = Li-Cs)…     

Synthesis and Crystal Structure of Bi（Hsal）3（1,10- phenanthroline） （Hsal = O2CC6H4-2-OH）

A new bismuth compound Bi（Hsal）3（1,10-phenanthroline） （Hsal = O2CC6H4-2-OH） has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in the triclinic system, space group P1, with a = 10.243（2）, b = 11.905（3）, c = 12.934（3） A, α= 76.780（6）, β= 68.683（6）,γ= 80.930（7）°, V = 1425.6（5） A^3, Dc = 1.865 g/cm^3, Mr = 800.51, F（000） = 780, μ= 6.247 mm^-1, Z = 2, R = 0.0456 and wR = 0.1131 for 5612 observed reflections （I 〉 2σ（I））. In this compound, three salicylate ligands coordinate to the Bi atom through the carboxylate groups to form a four-membered chelate ring, and phenanthroline ligand chelates the metal through two N atoms. The structure of the title compound manifests a possible coordination mode between bismuth subsalicylate and N atom containing amino acid in the biological system.