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In this paper the single-use protective clothing for medical use was sterilized by γ-ray irradiation. Compared with the non-irradiated control, the apparent morphology of PP melt-blown fiber and amboss had no fracture. According to the national standard of GB/T 19082-2009, the mechanical properties, resistance to synthetic blood penetration, resistance to water penetration and filtering efficiency were measured. The results showed that the post-irradiation effects did not decrease the resistance to synthetic blood penetration or water penetration. Moreover, the filtering efficiency remained higher than 99.8%. On the other hand, the mechanical properties were reduced significantly due to the degradation of poly chain of PP induced by γ-ray irradiation. It has been assured that the important properties of single-use protective clothing for medical use are still above the quality level after γ-ray irradiation sterilization process. which can supply reference for the produce single-use protection of clothing of medical purpose at high quality.

Metal oxide semiconductors are recognized as an excellent underlying substance for the assembly of gas sensors to detect the volatile organic compounds in industry or healthcare, but are constrained by their low selectivity and high operation temperature. In the present paper, we present a nanostructured p-type delafossite CuCrO2, synthesized by the hydrothermal method, that provides a high selectivity, stability and high dynamic response to triethylamine at a low temperature of 140 ℃. In-situ heating spectrum analysis and systematic gas sensing tests with the assistance of first principles calculations based on the density functional theory demonstrate that this ternary oxide takes a unique synergy mechanism for gas sensing process, rather than the ionosorption effect of ambient oxygen. It starts with the adsorption of gas molecules to the unsaturated coordinative metal sites of Cr, which is then followed by the dehydrogenation on Cu resulting in the formation of oxygen vacancies. This gas sensing mechanism successfully explains the extraordinary properties of CuCrO2 nanoparticles as a triethylamine sensor. This work delivers an exploratory approach to the assigned interaction of gas molecules and the sensitive layer at atomic scale, which provides ways to design and develop more advanced gas sensors for other material systems. The authors are grateful to the National Natural Science Foundation of China 61504079, 11847053, 11904100, and the Science and Technology Commission of Shanghai Municipality Program 19DZ2281000.

Spectral computed tomography (CT) is a perfect combination of diamond probe and strong computer processing technology and a technological revolution of traditional CT. This article reviews the application of spectral CT in the diagnosis of liver and gallbladder diseases. It summarizes the application value of monochromatic spectral CT imaging, spectral curve, material separation and quantitation, and effective atomic number in the diagnosis and differentiation of liver and gallbladder diseases and analyze the advantages of energy spectrum in identification of small lesions, low dose, and judgment of homology. It is pointed out that the application of spectral CT can be further explored in the aspects of early identification, differentiation, and prognosis of tumors.

The hot deformation behavior of an Al–5.7 wt.%Mg alloy with erbium was studied by compressive deformation tests in the strain rate range of 0.001–10 s −1 and temperature range of 300–500 °C. The constitutive equations were presented considering the values of A and β as a function of strain in the exponential function form. The error of predicted and measured data was less than 9%. Dynamic recrystallization was restrained by precipitate with Er and dynamic recovery dominated in the hot deformation. The mechanism of dynamic recovery was dislocation movement and the development of microstructure during deformation can be characterized by the Z parameter, and then the relationship between subgrains and deformation parameters have been also established.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a naturally sourced polymer with good biocompatibility and potential applications in biomedical field after sterilization. Radiation sterilization technology has been extensively applied on medical products. However, for polymer-based biomedical materials, gamma irradiation can cause random chain scission on the polymer backbone. In this paper, we studied the effect of gamma irradiation on the mechanical and thermal properties of PHBHHx. The tensile strength and fracture strain of PHBHHx decreased after irradiation, while the brittleness increased after irradiation. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results showed that the melting temperatures of irradiated PHBHHx are lower than the non-irradiated films, but the irradiated specimen shows a higher decomposition temperature than non-irradiated PHBHHx.

This paper proposes a novel online real-time assessment method based on equilibrium solution region of branch power flow. This method demonstrates the use of line stability index in order to determine the voltage stability limits in a power system. Line voltage stability indices presented in the literatures are reviewed and discussed. The shortcomings of these methods are pointed out in the face of special operation mode. A new index is deduced based on the feasible solution region of branch equations. The equations of active power and reactive power via node voltage of the branch are listed to form the equilibrium solution region. The similarities and differences between the flow direction of active power and reactive power are analyzed to determine the incidence of them to equilibrium solution. The examples show that the new index has the advantage of low computation burden, and can supply an effective analysis tool for real time on-line assessment of voltage stability in power systems.

A general and procedural algorithm for Z-matrix building is proposed in this paper. This algorithm can be accomplished by an improved search technique to choose the tree branch set (TS) and link branch set (LS) and is easily implemented for a network containing the controlled sources. The look-up table saved during the search process of TS is fully utilized to reduce the computational amount when formulating the transitional matrix MIB. During the construction of another transitional matrix MBV, the applications of different kinds of controlled sources are discussed thoroughly considering the characteristics of the current-controlled sources and voltage- controlled sources, respectively. With these two matrices, the relationships between the bus current injections, branch currents and bus voltages can easily be found. Numerical example shows that the proposed method is very effective and suitable to be used for the analysis of large-scale power systems.