Magnetized strange quark matter in the equivparticle model with both confinement and perturbative interactions

We investigated the properties of strange quark matter in an external strong magnetic field with both confinement and leading-order perturbative interactions considered. It was found that the leading-order perturbative interaction can stiffen the equation of state of magnetized quark matter, while the magnetic field lowers the minimum energy per baryon. By solving the Tolman–Oppenheimer–Volkoff equations, we obtain the internal structure of strange stars. The maximum mass of strange stars can be as large as 2 times the solar mass.     

Investigation of Dissipation,Adsorption, Degradation,and Leaching of Triazophos Pesticide in Various Soils

This study concerns the investigation of dissipation, adsorption, and degradation of triazophos in different soils from Pakistan. These processes help in the disappearance of pesticide from the environment. Gas chromatography was used for dissipation and adsorption analysis while for degradation study mass spectrometer was used in addition of gas chromatography (GC-MS). The dissipation rate of triazophos in three different soils was 90% over 30 days with average half-life of 9.059 days. From dissipation study it was inferred that rate is variable in each soil due to climatic changes, soil nature and soil-pesticide interactions. Adsorption experiment has revealed that the adsorption of this pesticide to soil follows the pseudo first order kinetic model with rate constant value of 0.479/h and Freundlich isotherm with adsorption capacity of 1.832 mol/g. Degradation study has displayed two major metabolites, one is phosphorothioic acid, S-[2-[(1-cyano-1-methylethyl) amino]-2-oxoethyl] O,O-diethyl ester at retention time of 9.136 and the other is sulfotep at 14.304 min. The leaching potential of triazophos was also calculated from its half-life and organic carbon content present in soil which was 1.688 representing it as non leacher pesticide.     

浅埋偏压软弱围岩大断面隧道综合处治措施

针对某隧道开挖断面大、地质条件差、Ⅳ级、Ⅴ级围岩所占比例大等特点,施工过程中发生过塌方、地表沉降、溶洞、特大溶洞、软弱围岩收敛变形超限,分别采用针对性的综合处治措施,顺利通过了出口长大浅埋偏压地段,取得了十分满意的效果。     

某连续刚构桥大体积0号块简易托架法施工技术

山区连续刚构桥大体积0号块由于受自身高墩、大跨度及地形、地势条件的限制,现场采用简易托架给施工带来了很大的方便。主要介绍了牛腿托架施工方案,并介绍了托架安装技术。牛腿托架安装完成后进行了预压,并通过Midas civil计算软件进行托架受力验算。在预压过程中对梁段变形进行了监测,监测结果表明托架满足施工要求。     

Experiments on mechanical properties of salt rocks under cyclic loading

The primary purpose of underground gas storages is to provide gas for seasonal consumptions or strategic reserve.The periodical operations of gas injection and extraction lead to cyclic loading on the walls and surrounding rocks of gas storages.To investigate the mechanical behaviors of different host rocks in bedded salt deposit,laboratory experiments were conducted on the samples of rock salt,thenardite,glauberite and gypsum.The mechanical properties of rock samples under monotonic and cyclic loadings were studied.Testing results show that,under monotonic loading,the uniaxial compressive stress(UCS) of glauberite is the largest(17.3 MPa),while that of rock salt is the smallest(14.0 MPa).The UCSs of thenardite and gypsum are 16.3 and 14.6 MPa,respectively.The maximum strain at the peak strength of rock salt(halite) is much greater than those of the other three rocks.The elastic moduli of halite,thenardite,glauberite and gypsum are 3.0,4.2,5.1 and 6.8 GPa,respectively.Under cyclic loading,the peak strengths of the rock specimens are deteriorated except for rock salt.The peak strengths of thenardite,glauberite and gypsum decrease by 33.7%,19.1% and 35.5%,respectively;and the strains of the three rocks at the peak strengths are almost the same.However,the strain of rock salt at the peak strength increases by 1.98%,twice more than that under monotonic loading.Under monotonic loading,deformation of the tested rock salt,thenardite and glauberite shows in an elastoplastic style.However,it changes to a ductile style under cyclic loading.Brittle deformation and failure are only observed for gypsum.The results should be helpful for engineering design and operation of gas storage in bedded salt deposit.     

岩石冻融循环试验建议性方案探讨

岩石冻融循环试验是低温岩石力学基础性试验,其主要涉及冻融循环温度、冻融时长、循环次数等3个指标。但目前关于指标的选取,国内外的试验规程或相关学者研究成果,均未给出明确参考依据,对岩石冻融循环试验方案的确定造成较大困扰。本研究旨在明确各指标的确定办法,提出建议性岩石冻融循环试验方案。首先,展开国内外冻融循环试验方案的全面综述,指出目前冻融循环试验方案确定时所存在问题,并藉此明确冻融循环试验方案思路;接着,针对以上三大影响指标,通过设计室内岩石冻融循环试验,详细探讨冻融循环温度、冻融时长、循环次数对岩石物理、力学参数的影响,最终根据试验结果,明确出针对不同岩性、孔隙率所对应的建议性试验方案。本研究将为后期冻融循环指标选取及标准化试验方案建立提供技术借鉴。     

Design and Analysis of MEMS Comb Drive Capacitive Accelerometer for SHM and Seismic Applications

This work presents the design of a MEMS accelerometer that is specifically intended for Structural Health Monitoring (SHM) applications where sensing low frequency low amplitude accelerations with high resolution is essential. The surface micromachined comb drive capacitance accelerometer structure has been considered in this design. The simulation experiments conducted on these devices using IntelliSuite MEMS design tool show that it has excellent displacement sensitivity of 21.39 μm/g, a capacitive sensitivity of 1.22 pF/g and voltage sensitivity of 1783 mV/g/V when it is designed to measure 0–0.1 g. Further, it is seen that it has a very low noise floor of 1.32 μg/√Hz and therefore high resolution. Since the accelerations can be as low as 0.04 g in SHM applications, excellent resolution is the primary goal in this design. Further, one more sensor specifically meant for strong motion seismic application has also been reported. This device has a bandwidth of 0–250 Hz and a noise floor of 5.612 μg/√Hz in addition to a sensor level voltage sensitivity of 97.9 mV/g/V. Finally, the comparison of these results with other similar devices reported in the past clearly illustrates the comparable performance of the present devices. Further, these devices, unlike the commercial low frequency accelerometers and other similar devices reported in the past can be fabricated by surface micromachining and CMOS compatible processes.     

六盘山隧道软弱围岩快速施工工艺

结合六盘山隧道Ⅴ级围岩的工程特点,着重介绍软弱围岩隧道快速施工方案及技术要求,通过工程实践,详细地介绍了三台阶七步开挖法施工的技术特点、工艺原理、施工工艺等,对类似隧道施工有一定的参考价值。     

A Mathematical Model for Vacuum Far-Infrared Drying of Potato Slices

A mathematical model of mass and heat transfer for vacuum far-infrared drying of potato slices is introduced in this study on the basis of energy and diffusion equations. The finite difference method is used to mathematically simulate the sample temperature and moisture content in different drying conditions. Calculated results are compared with the experimental findings at varying conditions of heater temperature (120°C, 140°C, and 160°C), chamber pressure (1500, 8000, and 15000 Pa), sample thickness (0.004, 0.006, and 0.008 m), and radiation distance (0.08, 0.12, and 0.16 m). Comparison results show that the model fits well the changes in sample temperature and moisture content at different times of drying, with the values of the coefficient of determination close to 1.0 and the relative error values less than 10%.     

Measurement of the natural ^36Cl and ^236U in uranium mineral with accelerator mass spectrometry

The concentration of the natural ultra-trace radionuclides CI and U in the uranium depended on the neutron flux.In this article,a method for measuring ³⁶C1 and ²³⁶U in the same uranium mineral with accelerator mass spectrometry was developed in China Institute of Atomic Energy,providing a protocol of the potential application of ²³⁶U in uranium mining,environmental,and geological research.The two samples were from Guangxi and Shanxi province,China,and their ratios ³⁶Cl/C1 and ²³⁶U/²³⁸U were measured.More experimental data conduced to understand the natural nuclides in the uranium mineral.We plan to conduct more efforts on the research.