A displacement solution for circular openings in an elastic-brittle-plastic rock

Huang, Houxu,Li, Jie,Rong, Xiaoli,Hao, Yiqing,Dong, Xin Techno-Press 2017 Geomechanics & engineering Vol.13 No.3

The localized shear and the slip lines are easily observed in elastic-brittle-plastic rock. After yielding, the strength of the brittle rock suddenly drops from the peak value to the residual value, and there are slip lines which divide the macro rock into numbers of elements. There are slippages of elements along the slip lines and the displacement field in the plastic region is discontinuous. With some restraints, the discontinuities can be described by the combination of two smooth functions, one is for the meaning of averaging the original function, and the other is for characterizing the breaks of the original function. The slip lines around the circular opening in the plastic region of an isotropic H-B rock which subjected to a hydrostatic in situ stress can be described by the logarithmic spirals. After failure, the deformation mechanism of the plastic region is mainly attributed to the slippage, and a slippage parameter is introduced. A new analytical solution is presented for the plane strain analysis of displacements around circular openings. The displacements obtained by using the new solution are found to be well coincide with the exact solutions from the published sources.

Theoretical explanation of rock splitting based on the micromechanical method

Huang, Houxu,Li, Jie,Hao, Yiqing,Dong, Xin Techno-Press 2018 Geomechanics & engineering Vol.14 No.3

In this paper, in order to explain the splitting of cylindrical rock specimen under uniaxial loading, cracks in cylindrical rock specimen are divided into two kinds, the longitudinal crack and the slanting crack. Mechanical behavior of the rock is described by elastic-brittle-plastic model and splitting is assumed to suddenly occur when the uniaxial compressive strength is reached. Expression of the stresses induced by the longitudinal crack in direction perpendicular to the major axis of the crack is deduced by using the Maxwell model. Results show that the induced stress is tensile and can be greater than the tensile strength even before the uniaxial compressive strength is reached. By using the Inglis's formula and simplifying the cracks as slender ellipse, the above conclusions that drawn by using the Maxwell model are confirmed. Compared to shearing fracture, energy consumption of splitting seems to be less, and splitting is most likely to occur when the uniaxial loading is great and quick. Besides, explaining the rock core disking occurred under the fast axial unloading by using the Maxwell model may be helpful for understanding that rock core disking is fundamentally a tensile failure phenomenon.

Incorporating CsPbBr3 Nanocrystals into Porous AlO(OH) Matrices to Improve their Stability in Backlit Displays

Jiangcong Zhou,Yiqing Lai,Na Lin,Xiaotian Huang,Yu Chen,Yao Yao,Bo Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01

Currently, the poor stability of inorganic perovskite CsPbX3 (X = Cl, Br, I) nanocrystals restricts their practical application in optoelectronic devices. Therefore, improving the stability of this material remains an urgent task for most researchers. In this study, incorporation of CsPbBr3 nanocrystals into porous AlO(OH) matrices through simple in situ synthesis was demonstrated to be an efficient approach for improving the nanocrystal stability. X-ray diffraction (XRD) revealed that the as-obtained product was composed of cubic CsPbBr3 nanocrystals and orthorhombic AlO(OH) compounds. In addition, transmission electron microscopy (TEM) revealed that the CsPbBr3 nanocrystals were successfully encapsulated by AlO(OH) matrices. The Brunauer–Emmett–Teller (BET) specific surface area was 234.96 m2 g -1 for AlO(OH) and 60.08 m2 g -1 for the CsPbBr3@AlO(OH) composites. The decrease in surface area could be attributed to the filling of the AlO(OH) pores by the CsPbBr3 nanocrystals. Further, the as-prepared composites showed red-shifted emission at 522 nm and a larger full width at half-maximum (FWHM) as 26 nm, compared with those of the CsPbBr3 nanocrystals with the emission at 517 nm and FWHM as 17 nm. More importantly, the emission intensity preserved 67% of the original value after a storage time of 120 h, but bare CsPbBr3 nanocrystals rapidly degraded within only 1 h in the polar ethanol solution. Finally, a light-emitting diode (LED) device was fabricated by coating the CsPbBr3@AlO(OH) composites and red commercial K2SiF6:Mn4+ phosphors on the surface of a blue InGaN chip, covering 96% of National Television Standards Committee. The results indicate that the obtained composites could be promising luminescent materials for backlit displays.

Bit-Usage Analysis Based Frame Layer QP Adjustment for H.264/AVC Rate Control at Low Bit-Rate

Shuijiong WU,Yiqing HUANG,Qin LIU,Takeshi IKENAGA 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7

To regulate the output video streaming, rate control is introduced into practical video codec. It allocates the bit budget, dynamically adjusts quantization parameter (QP) to achieve target bit-rate while keeping the coding quality. This paper presents a bit analysis based frame layer QP adjustment for H.264/AVC rate control at low bit-rate. The bit generation of previous coded frames, bit estimation of current frame and the remaining bit resources are utilized to get estimation for current coding status. Backward and forward bit usage measurements are combined to make a global judgment based on the whole sequence. Then the QP computed for current frame is further adjusted by the bit usage judgment. Simulation results verify the performance of proposed algorithm. Compared with the recommended rate control in H.264/AVC reference software JM13.2, a gain up to 0.3 ㏈ on peak-signal-noise-ratio (PSNR) is observed. And the rate mismatch is reduced about 84 % for tested sequences.

Intra Mode Decision for Reducing Block Types and Prediction Modes Based on Edge Information in H.264/AVC

Zhewen ZHENG,Yiqing HUANG,Qin LIU,Takeshi IKENAGA 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7

H.264/AVC performs rate-distortion optimization (RDO) in order to select the best coding modes with best coding efficiency. However, computation complexity is also increased. In this paper, a fast intra mode decision algorithm is proposed. With both the magnitude and the orientation of the local edge information, most proper block mode is selected from 4×4, 8×8 and 16×16 block modes. Then by the edge information obtained from previous step, candidate prediction modes are decided for the chosen block modes. The number of modes investigated in RDO can be reduced to 36 or 48 in common case instead of 736 in full search. Simulation results show that the proposed algorithm saves about 75% coding time with negligible PSNR loss and bit-rate increase compared with full search.

A resource preserved MAC protocol for QoS provided UWB ad hoc networks

Jiachen Zhou,Yiqing Huang,Takeshi Ikenaga 대한전자공학회 2008 ITC-CSCC :International Technical Conference on Ci Vol.2008 No.7

This paper proposes a resource preserved medium access control (MAC) protocol which provides Quality of Service (QoS) support for multimedia applications in ultra-wideband (UWB) ad hoc network. The proposed protocol accounts for the UWB unique characteristics while considering the QoS requirements. The evaluation results in throughputs, end to end delay, power consumption and power utilization show that, the proposed algorithms achieve a balance work between the throughputs and power consumption.

Molecular and Cellular Microbiology / Biomedical Sciences : Alteration of the Metabolome Profile in Endothelial Cells by Overexpression of miR-143/145

( Wenshuo Wang ),( Ye Yang ),( Yiqing Wang ),( Liewen Pang ),( Jiechun Huang ),( Hongyue Tao ),( Xiaotian Sun ),( Chen Liu ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.3

Communication between endothelial cells (ECs) and smooth muscle cells (SMCs) via miR-143/145 clusters is vital to vascular stability. Previous research demonstrates that miR-143/145 released from ECs can regulate SMC proliferation and migration. In addition, a recent study has found that SMCs also have the capability of manipulating EC function via miR-143/145. In the present study, we artificially increased the expression of miR-143/145 in ECs, to mimic a similar change caused by miR-143/145 released by SMCs, and applied untargeted metabolomics analysis, aimed at investigating the consequential effect of miR-143/145 overexpression. Our results showed that miR-143/145 overexpression alters the levels of metabolites involved in energy production, DNA methylation, and oxidative stress. These changed metabolites indicate that metabolic pathways, such as the SAM cycle and TCA cycle, exhibit significant differences from the norm with miR-143/145 overexpression.

Role of span length in the adaptation of implant-supported cobalt chromium frameworks fabricated by three techniques

Zhou Ying,Li Yong,Ma Xiao,Huang Yiqing,Wang Jiawei 대한치과보철학회 2017 The Journal of Advanced Prosthodontics Vol.9 No.2

PURPOSE. This study evaluated the effect of span length on the adaptation of implant-supported cobalt chromium frameworks fabricated by three techniques. MATERIALS AND METHODS. Models with two solid abutment analogs at different inter-abutment distances were digitized using a laboratory scanner. Frameworks of two-, three-, and four-unit fixed prostheses were designed by a computer. Six dots with a diameter of 0.2 mm were preset on the surface of each framework. A total of 54 implant-supported cobalt chromium frameworks were fabricated by milling, selective laser melting (SLM), and cast techniques. The frameworks were scanned and exported as Stereolithography files. Distances between two dots in X, Y, and Z coordinates were measured in both the designed and fabricated frameworks. Marginal gaps between the framework and the abutments were also evaluated by impression replica method. RESULTS. In terms of distance measurement, significant differences were found between three- and four-unit frameworks, as well as between two- and four-unit frameworks prepared by milling technique (P<.05). Significant differences were also noted between two- and three-unit frameworks, as well as between two- and four-unit frameworks prepared by cast technique (P<.05). The milling technique presented smaller differences than the SLM technique, and the SLM technique showed smaller differences than the cast technique at any unit prostheses (P<.05). Evaluation with the impression replica method indicated significant differences among the span lengths for any fabrication method (P<.05), as well as among the fabrication methods at any unit prostheses (P<.05). CONCLUSION. The adaptation of implant-supported cobalt chromium frameworks was affected by the span length and fabrication method.

Risk of Death in Colorectal Cancer Patients with Multi-morbidities of Metabolic Syndrome: A Retrospective Multicohort Analysis

Qingting Feng,Lingkai Xu,Lin Li,Junlan Qiu,Ziwei Huang,Yiqing Jiang,Tao Wen,Shun Lu,Fang Meng,Xiaochen Shu 대한암학회 2021 Cancer Research and Treatment Vol.53 No.3

Purpose The prevalence of multi-morbidities with colorectal cancer (CRC) is known to be increasing. Particularly prognosis of CRC patients co-diagnosed with metabolic syndrome (MetSyn) was largely unknown. We aimed to examine the death risk of CRC patients according to the multiple MetSyn morbidities.Materials and Methods We identified CRC patients with MetSyn from the electronic medical records (EMR) systems in five independent hospitals during 2006-2011. Information on deaths was jointly retrieved from EMR, cause of death registry and chronic disease surveillance as well as study-specific questionnaire. Cox proportional hazards regression was used to calculate the overall and CRC-specific hazards ratios (HR) comparing MetSyn CRC cohort with reference CRC cohort.Results A total of 682 CRC patients in MetSyn CRC cohort were identified from 24 months before CRC diagnosis to 1 month after. During a median follow-up of 92 months, we totally observed 584 deaths from CRC, 245 being in MetSyn cohort and 339 in reference cohort. Overall, MetSyn CRC cohort had an elevated risk of CRC-specific mortality (HR, 1.49; 95% confidence interval [CI], 1.07 to 1.90) and overall mortality (HR, 1.43; 95% CI, 1.09 to 1.84) compared to reference cohort after multiple adjustment. Stratified analyses showed higher mortality risk among women (HR, 1.87; 95% CI, 1.04 to 2.27) and specific components of MetSyn. Notably, the number of MetSyn components was observed to be significantly related to CRC prognosis.Conclusion Our findings supported that multi-morbidities of MetSyn associated with elevated death risk after CRC. MetSyn should be considered as an integrated medical condition more than its components in CRC prognostic management.