多分量力组合加载校准装置主机结构的技术实现

主要介绍了可实现六个分量力和力矩独立或组合加载的校准装置主机结构的设计思路和具体组成。针对该装置量程宽、空间大、准确度高等特点,文章分析了装置研制过程中涉及的技术难点;围绕多分量力组合加载的实现问题,说明了多分量力组合加载的方法原理设计及加载装置主机的机械结构设计等技术问题;最后说明了校准装置实现的技术性能和试验验证情况。     

Pleiotropic Effects of Sodium-Glucose Cotransporter-2 Inhibitors: Renoprotective Mechanisms beyond Glycemic Control

Diabetes mellitus is a major cause of chronic kidney disease and end-stage renal disease. However, the management of chronic kidney disease, particularly diabetes, requires vast improvements. Recently, sodium-glucose cotransporter-2 (SGLT2) inhibitors, originally developed for the treatment of diabetes, have been shown to protect against kidney injury via glycemic control, as well as various other mechanisms, including blood pressure and hemodynamic regulation, protection from lipotoxicity, and uric acid control. As such, regulation of these mechanisms is recommended as an effective multidisciplinary approach for the treatment of diabetic patients with kidney disease. Thus, SGLT2 inhibitors are expected to become key drugs for treating diabetic kidney disease. This review summarizes the recent clinical evidence pertaining to SGLT2 inhibitors as well as the mechanisms underlying their renoprotective effects. Hence, the information contained herein will advance the current understanding regarding the pleiotropic effects of SGLT2 inhibitors, while promoting future research in the field.     

Application of thermophilic temperatures,low hydraulic retention times and high recycling of de-gassed effluent for higher biohydrogen production

This study investigated the external operational factors that would reduce the thermodynamic constrains preventing the simultaneous achievement of high hydrogen productivities (HPs) and hydrogen yields (HYs) in the bioreactor. At hydraulic retention time (HRT) of 1, the maximum HPs and HYs achieved was 35 L H₂/h and 3.91 mol H₂/mol glucose, respectively. At this stage, the bacterial granules occupied approximately 75% of the bioreactor and consisted of the settled biomass density of 40.6 g/L (settled granule bed height = 13.8 cm). The formation of bacterial granules improved the bioreactor performance and resulted in higher substrate conversion efficiency (95%), nutrient influent (7.5 L/h) and de-gassed effluent recycle rates (3.5 L/min). In conclusion, this study demonstrated that high nutrient influent and high de-gassed effluent recycle rates reduced the thermodynamic constrains preventing the achievement of higher H₂ productivities in the bioreactor system.     

Indoor solid fuel use for heating and cooking with blood pressure and hypertension: A cross-sectional study among middle-aged and older adults in China

A cross-sectional study was conducted to investigate the impact of solid fuel use for heating and cooking on blood pressure (BP) and hypertension, using data from the China Health and Retirement Longitudinal Study (CHARLS). The primary fuels used for indoor heating and cooking were collected by questionnaires, respectively. Hypertension was defined based on self-report of physician's diagnosis, and/or measured BP, and/or anti-hypertensive medication use. Multivariate logistic regression models were constructed to assess the associations. Among 10 450 eligible participants, 68.2% and 57.2% used indoor solid fuel for heating and cooking, respectively. Compared with none/clean fuel users, solid fuel for heating was associated with elevated BP (adjusted β: 2.02, 95% CI: 1.04–3.01 for systolic BP; adjusted β: 1.36, 95% CI: 0.78–1.94 for diastolic BP) and increased risk of hypertension (adjusted odds ratio: 1.15, 95% CI: 1.03–1.29). The impact of indoor solid fuel for heating on BP was more evident in rural and north residents, and hypertensive patients. We did not detect any significant associations between solid fuel use for cooking and BP/hypertension. Indoor solid fuel use is prevalent in China, especially in the rural areas. Its negative impact on BP suggested that modernization of household fuel use may help to reduce the burden of hypertension in China.     

Influence of the gasket materials on the clamping pressure distribution in a PEM water electrolyzer: Bolt torques and operation mode in pre-conditioning

To keep optimally connected, all electrolysis cell elements is one of the most important design criteria. The optimal distribution of the clamping points is crucial to increasing cell performance. In this work, the compression pressure distribution inside of a 25 cm² PEM electrolysis cell was evaluated, using different materials: Teflon®, Viton®, ethylene propylene diene monomer rubber (EPDM), and nitrile rubber. Sealing material evaluation was performed taking as performance indicators: total compressed area (%) and compression pressure, for different torques applied. Pressure distribution was obtained by using pressure-sensitive films, analyzing the distribution of pressure points from three-dimensional plots (3D), and quantifying intensities of the images obtained. Results showed that pressure points distribution depends on the stiffness and thickness of the gasket materials. For a tightening torque of 3.70 N m, a pressure of 2.23 MPa is obtained with 85% of the membrane area compressed using nitrile rubber-EPDM gaskets.     

Materials aspects associated with the addition of up to 20 mol% hydrogen into an existing natural gas distribution network

The introduction of hydrogen into the UK natural gas main has been reviewed in terms of how materials within the gas distribution network may be affected by contact with up to 80% Natural Gas (NG)/20 mol% hydrogen blend at up to 2 barg. A range of metallic, polymeric and elastomeric materials in the gas distribution network (GDN) were assessed via a combination of literature review and targeted practical test programmes.The work considered:? The effect of hydrogen on metallic materials identified in the network.? The effect of hydrogen on polymeric materials identified in the network.? The effect of hydrogen exposure on polyethylene pipeline joining and repair techniques (squeeze-off, and socket and saddle electrofusion joints)The experimental work involved soaking materials, under pressure conditions representative of the network, in 100% hydrogen, 20% hydrogen in methane, and 100% methane. For the metal samples, the test programme involved the assessment of hydrogen uptake on the tensile properties. For the polyethylene samples, the test programme looked at the assessment of possible hydrogen absorption/desorption and its effect on electrofusion jointing.The trials concluded that the majority of metallic materials showed no significant deterioration in mechanical (tensile) properties when stored in hydrogen environments compared to those stored in analogous methane or blended gas atmospheres up to 2 barg. Polymeric materials showed no deterioration to efficiency of squeeze-off or collar electrofusion in socket or shoulder orientations following soaking in hydrogen, methane or hydrogen blends.     

拍式浮体闸门充压水封仿真计算研究

为了得到充压伸缩框型水封在不同线荷载下运行时水封背腔所需的充压值及相应的水封变形断面和封头接触属性,首先通过一种非线性近似方法得到各工况下框形水封各段的线压力,将三维问题转化为平面问题;然后通过仿真计算求得各充压值下的水封线压力和变形属性,反过来便是所求结果。计算结果表明,拍门充压水封较传统挤压水封在中低水头(一般水头)下具有更好的封水性能,又因其利于拍门缓冲和人为控制,因此具备较好的应用前景。     

不同降雨入渗条件下预应力锚索加固边坡稳定性分析

为了研究不同降雨条件下边坡安全系数及预应力锚索轴力变化规律,以省道S303沿线某边坡为研究对象,考虑土体饱和-非饱和渗流与非饱和强度理论,基于有限元分析,对不同降雨工况下的孔隙水压分布、锚索轴力及采用强度折减法计算的边坡安全系数变化规律进行了研究。结果表明: 降雨量一定时,降雨入渗范围随雨强增大而减小,暂态饱和区域随雨强增加而增大; 边坡在加固前后的安全系数均随降雨量增加而不断减小,采用预应力锚索加固能有效提高边坡安全系数,并减小降雨对边坡稳定性的影响; 随着降雨量增加,各锚索轴力均增大,当降雨量一定时,雨强越小,对应的锚索轴力提升幅度越大,靠近底部的锚索轴力对降雨最为敏感。     

采煤工作面煤层注水参数试验研究

通过在6198采煤工作面现场施工煤层注水钻孔采取煤样,实验室试验注水钻孔水压力分布、煤样含水率变化,得到了工作面煤层注水影响半径等技术参数,为采煤工作面煤层注水提供了一定的参考依据。