间质结构中液态金属的磁声B扫成像研究

磁声B扫成像算法简单,能够实现实时成像,在液态金属标记下的间质结构实时检测中具有潜在的应用价值。由于液态金属与生物组织的声特性及电磁特性差异大,需要额外考虑液态金属与生物组织声阻抗的差异性对声场传播的影响。在液态金属磁声正问题分析的基础上,研究液态金属的磁声B扫成像,分析图像伪影成因,并提出了多向扫描叠加与圆周扫描的方法抑制反射伪影。然后搭建磁声扫描实验平台,对不同分布特点的液态金属样品进行磁声扫描实验并提取B扫图像。结果表明,采用多向扫描叠加及圆周扫描的方法能够有效抑制反射伪影,但由于超声换能器指向性的影响,在圆周扫描中引入了新的指向性伪影。

镁离子转运蛋白CorA间质结构域删除分析

为了研究CorA的镁离子转运机理,对大肠杆菌CorA的间质结构域区进行了删除突变分析,并利用酵母突变体互补技术进行了突变体活性测定。以酿酒酵母质膜镁离子转运系统敲除突变体菌株CM66及其基因型对照菌株CM52为宿主菌,建立了大肠杆菌CorA转运活性测定体系。结果显示:大肠杆菌CorA间质结构域N-端起始的24个残基对于CorA在酵母质膜中的表达或维持其本身正确构象发挥重要作用,CorA M124到D154段的部分残基在CorA介导的镁离子转运过程中起到重要作用。

A New Experimental Method for Investigations on Microstructure of Liquid-Vapor Interface

Many physical,chemical,and biological processes happen in liquid-vapor interface and are profoundly influenced with the local microstructures.In contrast to the liquid bulk,molecular orientation is the remarkable one of asymmetric structural features of the interface.Here we report an experimental method,namely,electron-impact time-delayed mass spectrometry and give a Ion Detector Time-of-Flight Tub*Liquid Microjet Ion Attrac Liq Electron Multiplier Quadrupole Mass Filter Bender j id Beai Electrons Liquid Dump Pulsed Electron Gun brief review about our recent progresses.This brand-new method not only enables us to have more insights into the interfacial structures,as done with small-angle X-ray and neutron scatterings and vibrational sum frequency generation spectroscopy,but also provides opportunity to explore the electron-driven chemical reactions therein.

Research on characters of surrounding rock in complex geology conditions and supporting time

The methods combined by test, field monitoring and theoretical analysis were adopted to do the systemic research on the rock mass from micro-structure to macro-deformation, and rheological model of Jinchuan rock mass was established to discuss the reasonable supporting time. Resuhs show that supporting after suitable stress and displacement release can benefit for the long-term stability of surrounding rock.

Urban Integrated Activity Zone （UIAZ） in Shanghai

Urban integrated activity zone （UIAZ） refers to multi-functional area that can provide various services. Integrated activity zone （IAZ）, which is based on the existing financial district and Central Business District （CBD）, often weakens administrative boundaries and changes the original single functional partition. It emphasizes the mixture of different functions and the vitality of the central area. The construction of IAZ is different from the simple space construction of economy and material production. IAZ emphasizes the participation of city dwellers in urban renewal process. Shanghai IAZs are those vigorous public activity centers in Shanghai. ]ust like those active cells, IAZs in Shanghai are to inspire and improve the comprehensive competitiveness and vitality of the city at macro, intermediate, and micro level, they are the public places in which urban cultural life takes place, develops, and precipitates. This paper provides broad and profound presentation on IAZ structure planning in Shanghai： mix-used function, multi-dimensions scale, people oriented development （POD） transportation, commercial development, and city form vitality. This paper provides not only qualitative analysis, but also makes a serious attempt to quantify the result and statement.

Structural and Thermodynamic Properties of TiAl intermetallics under High Pressure

The structural and thermodynamic properties of TiAI intermetallics under high pressure have been investigated by ab initio plane-wave pseudopotential density functional theory method. It is found that the ratio of lattice parameter c to a keeps almost constant with a value of 1.02 under the pressure from 0 to 20 GPa, which agrees well with the experimental results. With the pressure increasing from 20 to 45 GPa the values of c/a decrease almost linearly from 1.02 to 0.99. These calculated results indicate under low pressure the variation rate for a-axis is almost the same to that for c-axis, but under higher pressure the variation for a-axis is smaller than along e-axis. Through the quasi-harmonic Debye model, the equation of state （EOS） of TiAI intermetallies, as well as the thermal expansion and heat capacity at various pressures and temperatures are also studied.

Landslide Susceptibility Mapping by Using Landslide RatioBased Logistic Regression:A Case Study in the Southern Taiwan

The object of the research is to compare the model performance and explain the error source of original logistic regression landslide susceptibility model(abbreviated as or-LRLSM) and landslide ratio-based logistic regression landslide susceptibility model(abbreviated as lr-LRLSM) in the Chishan watershed with a serious landslide disaster after 2009 Typhoon Morakot. The landslide inventory induced by 2009 Typhoon Morakot in South Taiwan is the main research material, while the Chishan watershed is the research area. Six variables, including elevation, slope, aspect, geological formation, accumulated rainfall, and bank erosion, were included in the two models. The performance of lr-LRLSM is better than that of or-LRLSM. The Cox & Snell R2, Nagelkerke R2 value, and the area under the relative operating characteristic curve(abbreviated as AUC) of lrLRLSM is larger than those of or-LRLSM, and the average correct ratio for the lr-LRLSM to predict landslide or non-landslide is larger than that of orLRLSM by 5.0%. The increase of the average correct ratio(abbreviated as ACR) difference from or-LRLSM to lr-LRLSM shows in slope, revised accumulated rainfall, aspect, geological formation and bank erosion variables, and only light decreases in elevation variable. The error sources of continuous variables in building the or-LRLSM is the dissimilarity between the distribution of landslide ratio and production of coefficient and characteristic values, while those of categorical variables is due to low correlation of landslide ratio and the coefficient value of each parameter. Using the classification of landslide ratio as the database to build logistic regression landslide susceptibility model(abbreviated as LRLSM) can revise the errors. The comparison of or-LRLSM and lr-LRLSM in the Chishan watershed also shows that building the landslide susceptibility model(abbreviated as LSM) by using lr-LRLSM is practical and of better performance than that by using the or-LRLSM.

On Linearly Topological Structure and Orthogonality of Menger Probabilistic Inner Product Spaces

In this paper the linearly topological structure of Menger Probabilistic inner product space is discussed. In virtue of these, some more general convergence theorems, Pythagorean theorem, and the orthogonal projective theorem are established.

Super-aligned films of sub-1 nm Bi_(2)O_(3)-polyoxometalate nanowires as interlayers in lithiumsulfur batteries

Sub-1 nm nanowires(SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed and engineered multicomponent heterostructure SNWs can further enhance their multifunction performance while it is very challenging to achieve such SNWs at sub-nanoscale.Herein, we synthesized Bi_(2)O_(3)-polyoxometalate heterostructure SNWs(PMB SNWs), and fabricated super-aligned PMB SNWs films(S-PMB SNWs films), which can serve as interlayers to efficiently suppress lithium polysulfide(LPS)shuttling, intrinsically promote the redox kinetics of the LPS conversion and substantially protect the Li anode. The lithium-sulfur(Li-S) battery with the S-PMB SNWs film as the interlayer showcases an ultralow capacity decay rate with 0.013% per cycle over 850 cycles. This study demonstrates the potential of heterostructure SNWs to improve the performance of Li-S batteries.

Structural and electronic properties of chiral single-wall copper nanotubes

The structural,energetic and electronic properties of chiral(n,m)(3≤n≤6,n/2≤m≤n)single-wall copper nanotubes(CuNTs)have been investigated by using projector-augmented wave method based on density-functional theory.The(4,3)CuNT is energetically stable and should be observed experimentally in both free-standing and tip-suspended conditions,whereas the(5,5)and(6,4)CuNTs should be observed in free-standing and tip-suspended conditions,respectively.The number of conductance channels in the CuNTs does not always correspond to the number of atomic strands comprising the nanotube.Charge density contours show that there is an enhanced interatomic interaction in CuNTs compared with Cu bulk.Current transporting states display different periods and chirality,the combined effects of which lead to weaker chiral currents on CuNTs.

A Study of the Unsteady Tip Flow Field of a Transonic Compressor

An experimental investigation on the unsteady tip flow field of a transonic compressor rotor has been performed.The casing-mounted high frequency response pressure transducers were arranged along both the blade chord and the blade pitch.The chord-wise ones were used to indicate both the ensemble averaged and time varying flow structure of the tip region of the rotor at different operating points under 95% design speed and 60% design speed.The pitch-wise circumferential transducers were mainly used to analyze the unsteadiness frequency of the tip leakage flow in the rotor frame at the near stall condition.The contours of casing wall pressure show that there were two clear low pressure regions in blade passages,one along the chord direction,caused by the leakage flow and the other along the tangential direction,maybe caused by the forward swept leading edge.Both low pressure regions were originated from the leading edge and formed a scissor-like flow pattern.At 95% design speed condition,the shock wave interacted with the low pressure region and made the flow field unsteady.With the mass flow reduced,the two low pressure regions gradually contracted to the leading edge and then a spike disturbance emerged.