Studies of Micromechanical Deformation Processes in Particle-Filled Glassy Polymer

The deformation behavior of rubber-toughened polymer, which was prepared by incorporating soft, core-shell rubbery particles into a glassy polymer such as poly (methyl methacrylate) (PMMA), has been investigated by means of mechanical tests, optical monitoring (OM), and scanning electron microscopy (SEM). By mechanical testing, the neat PMMA reveals a 2% strain with high yield stress. After inclusion of 17.5 and 35 vol%rubber particles, the softened-PMMA samples exhibit corresponding strain of 20% and 38%, showing an increase of strain along with the relative decrease of yield stress, resulting in a toughening behavior of PMMA. Clear shear bands and stress whitening develop in the rubber-toughened PMMA after deformation, as observed by OM. Investigation by SEM shows crazes/cracks in the stretched, rubber-softened PMMA samples in which the core-shell particles are found to be cavitated. The mechanism of this deformation has been explained based on the void formation in the rubbery shell as well as the initiation and propagation of crazing.     

Posttraumatic stress disorder and retrospectively reported stressor exposure: A longitudinal prediction model.

There has been recent concern about the degree to which posttraumatic stress disorder (PTSD) symptomatology influences reports of prior exposure to highly stressful life events. In this longitudinal study of 2,942 male and female Gulf War veterans, the authors documented change in stressor reporting across 2 occasions and the association between change and PTSD symptom severity. A regression-based cross-lagged analysis was used to examine the relationship between PTSD symptom severity and later reported stressor exposure. Shifts in reporting over time were modestly associated with PTSD symptom severity. The cross-lagged analysis revealed a marginal association between Time 1 PTSD symptom severity and Time 2 reported stressor exposure for men and suggested that later reports of stressor exposure are primarily accounted for by earlier reports and less so by earlier PTSD symptomatology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of an Enantiocomplementary Catalyst of β‐Isocupreidine (β‐ICD) from Quinine

Compound 20 , a pseudoenantiomer of β‐isocupreidine (β‐ICD), was synthesized from quinine employing a Barton reaction of nitrosyl ester 13 and acid‐catalyzed cyclization of carbinol 18 as key steps. The Baylis–Hillman reaction of benzaldehyde, p‐nitrobenzaldehyde, and hydrocinnamaldehyde with 1,1,1,3,3,3‐hexafluoroisopropyl acrylate (HFIPA) using 20 as a chiral amine catalyst was found to give the corresponding S‐enriched adducts in high optical purity (>91% ee) in contrast to the β‐ICD‐catalyzed reaction which affords R‐enriched adducts. This result suggests that compound 20 can serve as an enantiocomplementary catalyst of β‐ICD in the asymmetric Baylis–Hillman reaction of aldehydes with HFIPA.     

高精度数控挤齿机及其自动对齿系统

分析了同步器齿套结构特点及倒锥加工工艺,在此基础上研制开发了一种具有基于倒锥齿加工的自动对齿装置的新型数控挤齿机,给出了该机床关键结构的设计方案,介绍了机床工件相位测量,工件齿套正、反面的识别和自动对齿的工作原理.该机床已用于实际生产中,解决了倒锥齿加工的自动化问题,大大提高了加工效率.     

The Protective Effect of Zebularine,an Inhibitor of DNA Methyltransferase,on Renal Tubulointerstitial Inflammation and Fibrosis

Renal fibrosis, the final pathway of chronic kidney disease, is caused by genetic and epigenetic mechanisms. Although DNA methylation has drawn attention as a developing mechanism of renal fibrosis, its contribution to renal fibrosis has not been clarified. To address this issue, the effect of zebularine, a DNA methyltransferase inhibitor, on renal inflammation and fibrosis in the murine unilateral ureteral obstruction (UUO) model was analyzed. Zebularine significantly attenuated renal tubulointerstitial fibrosis and inflammation. Zebularine decreased trichrome, α-smooth muscle actin, collagen IV, and transforming growth factor-β1 staining by 56.2%. 21.3%, 30.3%, and 29.9%, respectively, at 3 days, and by 54.6%, 41.9%, 45.9%, and 61.7%, respectively, at 7 days after UUO. Zebularine downregulated mRNA expression levels of matrix metalloproteinase (MMP)-2, MMP-9, fibronectin, and Snail1 by 48.6%. 71.4%, 31.8%, and 42.4%, respectively, at 7 days after UUO. Zebularine also suppressed the activation of nuclear factor-κB (NF-κB) and the expression of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, by 69.8%, 74.9%, and 69.6%, respectively, in obstructed kidneys. Furthermore, inhibiting DNA methyltransferase buttressed the nuclear expression of nuclear factor (erythroid-derived 2)-like factor 2, which upregulated downstream effectors such as catalase (1.838-fold increase at 7 days, p < 0.01), superoxide dismutase 1 (1.494-fold increase at 7 days, p < 0.05), and NAD(P)H: quinone oxidoreduate-1 (1.376-fold increase at 7 days, p < 0.05) in obstructed kidneys. Collectively, these findings suggest that inhibiting DNA methylation restores the disrupted balance between pro-inflammatory and anti-inflammatory pathways to alleviate renal inflammation and fibrosis. Therefore, these results highlight the possibility of DNA methyltransferases as therapeutic targets for treating renal inflammation and fibrosis.     

Lie group method for solving viscous barotropic vorticity equation in ocean climate models

In studying the problem of the nonlinear viscous barotropic non-divergent vorticity equation on $f$- and $\beta$- planes, the method of Lie group has been applied. The method reduces the number of independent variables by one, and consequently, for the case of three independent variables we applied the method successively twice and the nonlinear partial differential equation reduces to ordinary differential equation. Investigation of exact solutions of the viscous barotropic non-divergent vorticity equation on $f$- and $\beta$- planes, via the application of Lie group, provides large classes of new exact solutions which include both Rossby and Rossby–Haurwitz waves as special cases. Also, The Lie symmetries of the viscous barotropic non-divergent vorticity equation with two parameters $F$ and $\beta$, are determined. The possible reductions of the viscous barotropic vorticity equation with two parameters $F$ and $\beta$ have been investigated by means of one- dimensional Lie subalgebras.     

在线液面连续监测在油水井动态分析中的应用

塔河油田主力油藏为碳酸盐岩缝洞型油藏,辖区油井分布广且井间距离大,前期主要是依靠人工井口测试获取液面数据;受到人员及监测仪器设备数量及运行情况的影响,测试工作量大、监测数据存在滞后,人工监测不能实时全面反映油井能量变化、机采井异常等情况。针对油田生产中动液面无法连续测量的问题,开展了液面远程在线监测,实现液面的连续监测和远程采集。通过液面远程在线连续监测,为油水井动态分析提供完整液面数据,可及时判断油井生产状况、调整优化机采工作制度,保证油井处于高效、安全的生产状态,达到节能降耗和油井效益最大化的目的。     

塔河油田碳酸盐岩油藏定量化注水提高水驱效率现场应用与研究

塔河油田碳酸盐岩油藏具有埋藏深、非均质性强的特点,主要储集空间以溶孔、溶洞和裂缝为主,裂缝为主要渗流通道。随着油田能量的递减,注水做为补充能量最经济有效的方式得到大力推广。根据物质平衡原理,依托酸压曲线、注水指示曲线、能量指示曲线,对注水进行定量化计算,精细注水,明确注采关系,优化注采参数,推动油田提高水驱效率和采收率。     

Assessing Adaptability of Cyclic and Non-Cyclic Approach to Conjunctive use of Groundwater and Surface water for Sustainable Management Plans under Climate Change

Groundwater overdraft in many regions throughout the world has been threatening the sustainability of this valuable resource. It has been argued that climate change may contribute to the severity of the issue; hence “impact assessment” is being replaced by “adaptation,” which explores more adapting scenarios and approaches. This study explores the adaptability of the proposed cyclic and non-cyclic conjunctive use of groundwater and surface water resources in increasing groundwater sustainability while increasing the sustainability of water allocation to the agricultural sector under possible climate change scenarios. To simulate climate change in the study area, precipitation and temperature variables are extracted from the results of three global atmospheric circulation models (Ensemble, CMCC-CMS, MRI-CGCM3) under RCP2.6 and RCP8.5 greenhouse gas emission scenarios in the period of 2021–2031. Spatial downscaling is performed using the M5 decision tree algorithm. The Wavelet-M5 hybrid model is used to predict runoff values as a rainfall-runoff model. Also, the Kharrufa method is applied to calculate evaporation in the future seasons. The system's adaptability to climate change is examined using the multi-objective cyclic and non-cyclic conjunctive use of surface and groundwater models. The study reveals that cyclic operation strategy improves the conjunctive use system adaptability compared to the optimal operation strategy that employs the non-cyclic approach. In this study's case study, the improvement in groundwater sustainability index exceeds 27 percent over the non-cyclic conjunctive use strategy.

     

Spectral analysis of GFDM modulated signal under nonlinear behavior of power amplifier

Wireless Networks - Generalized frequency division multiplexing (GFDM) is a flexible non-orthogonal waveform candidate for 5G which can offer some advantages such as low out-of-band emission and...