安徽省公路工程超声回弹综合法测强曲线的建立初步研究

无损检测是工程界追求目标,要提高混凝土超声回弹综合法测强精度,必须建立适应本地区的测强曲线.本次超声回弹综合法测强曲线建立研究,在结合国内外研究成果的基础上,综合分析了混凝土强度等级、原材料、成型工艺、养护方式、龄期、含水率及测试面等影响因素,依据相关标准规范,制作并采集大量的试块数据,初步建立了安徽省公路工程超声回弹测强模型,并开发相应的试用软件.     

混凝土结构实体强度现场检测技术探讨

通过混凝土结构实体强度不同检测方法—回弹法、超声回弹综合法、钻芯法,对同条件养护28d、600℃.d、60d、90d四个龄期的混凝土试块的检测结果进行比较,得出了混凝土结构实体强度不同检验方法检测结果的差异,提出了针对不同情况检测方式的选择方法。     

导流槽检测鉴定及仿真数值分析

扼要阐述了某发射场既有导流槽检测鉴定的意义、方法、内容和结论。利用ANSYS/Mechanics有限元软件,按新工艺条件并依据检测结果对导流槽进行了四种工况下的数值仿真分析,分析结果为导流槽的继续使用提供了理论依据。     

复杂环境下的烟囱拆除爆破

介绍了复杂环境条件下的烟囱定向爆破实例及其保证烟囱定向倾倒，控制倒塌着地时反弹飞石的措施。     

龄期对回弹法检测混凝土强度的影响

在分析了龄期对碳化深度、回弹值以及混凝土强度影响的基础上,进一步分析了龄期对回弹测强曲线使用的影响。     

超声回弹综合法检测再生混凝土抗压强度试验研究

为了在实际工程中推广应用再生混凝土,需要加强其质量控制的研究,因此有必要开展再生混凝土无损检测技术的研究.针对 C20～C40 再生混凝土,进行了系统的超声回弹综合法检测其抗压强度试验研究.试验结果表明,与相同强度等级的普通混凝土相比,再生混凝土的超声声速和回弹值均降低;再生混凝土的抗压强度和超声声速以及回弹值之间存在一定的相关关系,但是,普通混凝土抗压强度与超声声速和回弹值的关系不适用于再生混凝土.基于本研究获得的再生混凝土的超声声速和回弹值试验结果,分别建议了再生混凝土抗压强度与超声声速的关系、抗压强度与回弹值的关系、以及抗压强度与超声声速和回弹值三者之间和的综合关系(即再生混凝土的测强曲线).     

兰青线某简支∏梁动载试验检测研究

通过对兰青线某简支∏梁桥动荷载试验,研究了桥梁结构的强度及刚度特性,测试了桥梁结构的自振频率和阻尼、跨中截面的最大竖向位移、正应力和支座截面的剪应力以及梁体在列车荷载作用下的横向、竖向振动特性等,以判定该桥的承载能力是否达到规范要求,验证桥梁的安全度和可靠性。     

构造抬升区泥页岩脆性破裂泄压特征及对页岩油富集的影响——以延安地区延长组长73亚段为例

为深入认识大幅度构造抬升引起的泥页岩脆性破裂泄压特征及对页岩油富集的影响,以鄂尔多斯盆地延安地区延长组长7₃亚段为研究对象,运用改进的超压判识图版和数值模拟技术,综合考虑构造抬升过程中温度降低、孔隙回弹、超压泥页岩脆性破裂泄压等作用,定量分析了研究区目的层不同岩性地层由异常高压转变为异常低压或近常压的演化过程,进一步总结了其对页岩油富集的影响规律。研究区长7₃亚段早白垩世末期超压成因主要为生烃作用和欠压实作用,砂岩层超压主要来源于邻近烃源岩的超压传递;晚白垩世以来构造抬升引起的孔隙回弹和温度降低主导了研究区长7₃亚段砂岩异常低压的形成,脆性破裂泄压和温度降低使得长7₃亚段泥页岩形成弱超压或近常压。研究区长7₃亚段顶底两套富有机质泥页岩脆性破裂泄压时间不同步,使得顶、底2套富有机质泥页岩与其夹持的砂岩间具有较大的油气运移动力(源储过剩压力差),其大小为16~22 MPa;同时,油气保存过程中裂缝已闭合的顶部泥页岩封盖层仍与其下覆砂岩保持着约1.42~6.80 MPa的过剩压力差,一定程度上加强了页岩层系油气的封闭能力,不同源储配置下地层压力的差异演化对页岩油的富集起到了重要控制作用。     

On the role of the macroscopic deformation in liquid film drainage between bubbles

The collision of bubbles in multiphase reactors is critical to bubble size distribution. However, the theoretical models that can reasonably predict collision outcomes and the experimental data that can be used to directly verify the models are still very lacking. We studied the collision of two bubbles in clean water through experiments and theoretical modeling, revealing the mechanism that the collision result shifts from coalescence to rebound with increasing collision velocity. The macroscopic deformation (MacrD) of bubbles is associated with the film drainage via a segmented linear equation as a function of the film radius and initial Weber number. Thus, the current model can reflect the effect of MacrD in a self-consistent way. The coalescence times and critical coalescence velocities predicted by the model were in good agreement with the experiments. This work provides novel insights into bubble coalescence modeling and serves to improve the accuracy of reactor simulations.     

Can industrial robots reduce carbon emissions? Based on the perspective of energy rebound effect and labor factor flow in China

China is a major robot-use and carbon-emitting country, and it is imperative to explore industrial robots' impact on carbon emissions to achieve the nation's planned low-carbon transition. Previous studies have neglected to consider the energy rebound stimulating effect of adopting industrial robots. To address this gap, we explored the relationships between industrial robots, carbon emissions, and the energy rebound effect by applying a fixed-effects model that considers cross-sectional dependence, using data from 2008 to 2019. We also analyze the moderating effect of labor factor mobility on industrial robots and regional differences in conjunction with the labor substitution effect of industrial robots. Three relevant conclusions are obtained. First, although using industrial robots reduces carbon emissions, it also leads to an energy rebound effect, partially offsetting industrial robots' carbon reduction performance. Second, the resulting emissions reduction and energy rebound effects in the western region are greater than those in eastern and central regions. This suggests that the use of industrial robots in less industrialized regions could yield better emissions reduction effects but requires awareness and mitigation of potential increased energy consumption. Third, labor factor flow negatively moderates the impact of industrial robots on carbon emissions, indicating that labor flow between cities reinforces the emissions reduction effect of industrial robots. The negative moderating effect of labor factor flow is greatest in the western region compared to eastern and central regions. Thus, we need adequate awareness of the energy rebound effect in the use of industrial robots. Meanwhile, removing barriers to labor flow between cities could further stimulate the carbon reduction effect.