Laboratory tests and numerical simulations of brittle marble and squeezing schist at Jinping II hydropower station, China

AbstractFour 16.7 km-long tunnels with diameters ranging from 12.4 to 14.6 m are now under construction at Jinping II hydropower station along the Yalong River. The tunnels pass through Triassic rocks below Jinping Mountain. The tunnels are characterized with high overburden, long alignment and complex geological conditions. Brittle failure in marble and squeezing in schist are the primary problems in tunnelling. This paper introduces the studies of laboratory tests on Jinping II marble as well as numerical prediction of excavation damaged zone (EDZ) of tunnel section in brittle marble and determination of reinforced concrete lining thickness for restraining time-dependent deformation in the schist tunnel section. Laboratory tests indicate that Jinping II marble presents a complex brittle-ductile-plastic transition behavior of post-peak response with increasing confining pressure. Such behavior can be described numerically with the Hoek-Brown model. The EDZ was calibrated and predicted using both fast Lagrangian analysis of continua (FLAC) and particle flow code (PFC). The predicted result of EDZ in sections with different qualities of rock mass under various overburden pressures is quite helpful in understanding EDZ characterization and support design. A power-law creep model was used to support the lining design, especially in determining the lining thickness. Field convergence measurement data over 19 months were used to calibrate the creep model properties, followed by a sensibility analysis of reinforced concrete lining thickness that was launched to present the maximum lining compressive stress

Optical loss compensation in a bulk left-handed metamaterial by the gain in quantum dots

A bulk left-handed metamaterial with fishnet structure is investigated to show the optical loss compensation via surface plasmon amplification, with the assistance of a Gaussian gain in PbS quantum dots. The optical resonance enhancement around 200 THz is confirmed by the retrieval method. By exploring the dependence of propagation loss on the gain coefficient and metamaterial thickness, we verify numerically that the left-handed response can endure a large propagation thickness with ultralow and stable loss under a certain gain coefficient.Comment: 6 pages with 4 figure

Invasion and Metastasis Significance of Serum MMP-9 in Lung Cancer Patients

目的 研究基质金属蛋白酶-9(matrix metalloproteinase 9，MMP-9)在肺癌患者侵袭和转移的意义。方法 收集肺癌患者血清70例，健康体检者血清60例，通过酶联免疫吸附法(ELISA)检测鳞癌、腺癌、小细胞肺癌患者和不同年龄健康者血清样本中MMP-9的表达水平，进行统计学分析。结果 MMP-9在肺癌患者血清中的含量明显高于健康人群；且伴有淋巴结转移组血清MMP-9水平显著高于无淋巴结转移组；在鳞癌组、腺癌、小细胞肺癌组组间差异无统计学意义；在不同年龄的健康组中差异无统计学意义。结论 MMP-9可以作为临床判断肺癌侵袭和转移的生物学指标。Objective To investigate the expression of metastasis value of matrix metalloproteinases-9 (MMP-9) and its’ relationship with invasion and metastasis in lung cancer. Methods The levels of MMP-9 in serum were tested by ELISA in 70 patients with lung cancer and 60 healthy people. Results The serum levels of MMP-9 were higher than that in healthy control group significantly (р<0.05). The level of MMP- 9 significantly increased with lymphnode metastasis. The level of MMP-9 were not related with age and pathological type (р>0.05).Conclusion MMP-9 is a good marker in prediction of lung cancer invasion and metastas stages

Light neutralino dark matter in U(1)XU(1)_XSSM

The $U(1)_X$ extension of the minimal supersymmetric standard model(MSSM) is called as $U(1)_X$SSM with the local gauge group $SU(3)_C\times SU(2)_L \times U(1)_Y \times U(1)_X$. $U(1)_X$SSM has three singlet Higgs superfields beyond MSSM. In $U(1)_X$SSM, the mass matrix of neutralino is $8\times8$, whose lightest mass eigenstate possesses cold dark matter characteristic. Supposing the lightest neutralino as dark matter candidate, we study the relic density. For dark matter scattering off nucleus, the cross sections including spin-independent and spin-dependent are both researched. In our numerical results, some parameter space can satisfy the constraints from the relic density and the experiments of dark matter direct detection.Comment: 23 pages, 9 figure

Miniature bioinspired artificial compound eyes: microfabrication technologies, photodetection and applications

As an outstanding visual system for insects and crustaceans to cope with the challenges of survival, compound eye has many unique advantages, such as wide field of view, rapid response, infinite depth of field, low aberration and fast motion capture. However, the complex composition of their optical systems also presents significant challenges for manufacturing. With the continuous development of advanced materials, complex 3D manufacturing technologies and flexible electronic detectors, various ingenious and sophisticated compound eye imaging systems have been developed. This paper provides a comprehensive review on the microfabrication technologies, photoelectric detection and functional applications of miniature artificial compound eyes. Firstly, a brief introduction to the types and structural composition of compound eyes in the natural world is provided. Secondly, the 3D forming manufacturing techniques for miniature compound eyes are discussed. Subsequently, some photodetection technologies for miniature curved compound eye imaging are introduced. Lastly, with reference to the existing prototypes of functional applications for miniature compound eyes, the future development of compound eyes is prospected

1D SbSeI, SbSI, and SbSBr With High Stability and Novel Properties for Microelectronic, Optoelectronic, and Thermoelectric Applications

Mechanical exfoliation of 2D materials has triggered an explosive interest in low dimensional material research. We extend this idea to 1D van der‐Waals materials. Three 1D semiconductors (SbSeI, SbSI, and SbSBr) with high stability and novel electronic properties are discovered using first principles calculations. Both the dynamical and the thermal stability of these 1D materials are examined. We demonstrate that their nanowire thinner than 7 Å can be easily obtained by mechanical exfoliation, hydrothermal method, or sonochemical method. The bulk‐to‐1D transition results in dramatic changes in band gap, effective mass, and static dielectric constant due to quantum confinement, making 1D SbSeI a highly promising channel material for transistors with gate length shorter than 1 nm. Under small uniaxial strain, these materials are transformed from indirect into direct band gap semiconductors, paving the way for optoelectronic devices and mechanical sensors. Moreover, the thermoelectric performance of these materials is significantly improved over their bulk counterparts. These highly desirable properties render SbSeI, SbSI, and SbSBr promising 1D materials for applications in future microelectronics, optoelectronics, mechanical sensors, and thermoelectrics

Local Consolidative Radiation Prolongs Disease Control of Patients with Oligometastatic NSCLC Harboring EGFR Activating Mutation Treated with First-Line EGFR-TKIs

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Enhanced sensing performance by the plasmonic analogue of electromagnetically induced transparency in active metamaterials

The gain-assisted plasmonic analogue of electromagnetically induced transparency (EIT) in a metallic metamaterial is investigated for the purpose to enhance the sensing performance of the EIT-like plasmonic structure. The structure is composed of three bars in one unit, two of which are parallel to each other (dark quadrupolar element) but perpendicular to the third bar (bright dipolar element), The results show that, in addition to the high sensitivity to the refractive-index fluctuation of the surrounding medium, the figure of merit for such active EIT-like metamaterials can be greatly enhanced, which is attributed to the amplified narrow transparency peak