管卡改进在核电厂仪表管振动治理中的运用研究

针对核电厂仪表管振动过大及疲劳断裂的问题,提出运用管卡改进方式进行振动治理.先是对比分析核电厂中常用的U型管卡和门式管卡的减振性能,得出门式管卡的减震性能较好;之后对门式管卡进行改进优化,以提升改进后门式管卡的运用效果,防止管卡及管道磨损断裂的情况发生.     

油气生产企业重大安全突发事件社会影响扩散模型

油气生产企业发生安全突发事件的频率较高,一般性安全突发事件极易借助一定的条件和动力扩散成为重大安全突发事件,进而造成巨大的经济损失甚至带来更为严重的社会负面影响。为了有效控制突发事件的发生、扩散和衍变,通过分析重大安全突发事件属性及强度、承灾对象脆弱性、应对体系脆弱性这3个扩散影响因素,借助系统分析思想和系统动力学方法构建了社会影响扩散模型来有效控制事件扩散升级;结合油气生产常见突发事件对3个扩散因素进行控制管理分析,建立了影响因素脆弱性指标评价体系,并提出借助层次分析法进行对象脆弱性的定量分析。最后指出:油气生产企业应加强日常管理和监督,降低重大安全突发事件发生的可能性;寻找控制承灾对象和社会应对体系脆弱性的关键因素并进行有效管理,降低事件扩散的速度和可能性。该成果可为安全突发事件的控制、预警机制的构建提供参考。     

Scale-Spanning Strong Adhesion Using Cellulose-Based Microgels

Adhesive gels derived from biobased sustainable materials have extremely broad application prospects, such as in flexible smart materials and biomedicine fields. Combining high toughness and strong, persisting repeatable adhesion has always been a daunting challenge for adhesive gels. However, bulk gels based on polysaccharides as the most abundant bio-based compounds usually possess a high toughness but weak interfacial adhesion due to the strong hydration potential. Herein, a novel kind of highly tough microgel membranes with rough surfaces is fabricated using loosely chemically cross-linked dihydroxypropyl cellulose (cDHPC) microgels (average size = 1.25 ± 0.03 µm). Such microgel membranes exhibit strong, instant, and persisting adhesion to various substrates with different surface roughness. Slight chemical cross-linking and multiple physical interactions within microgels and resulting microgel membranes lead to high tensile strength and toughness of 0.23 ± 0.03 MPa and 73.8 ± 9.3 KJ m⁻³, respectively. The maximum adhesive strength and debonding work exceed 320 ± 0.50 KPa and 160.97 ± 0.20 J m⁻², respectively. After five cycles (re-lap after detaching), the adhesive strength still remains above 200 KPa. Their adhesive properties outperform most bio-based adhesive gels and even petroleum-based gels, which are based on synergistic molecular and microscaled topological interactions.     

知母多糖复合酶提取工艺优化及其免疫活性

本文对知母多糖的提取工艺及体外免疫活性进行研究,为知母多糖的开发利用提供理论依据。试验以复合酶提取知母粗多糖,在正交试验确定复合酶比例的基础上,通过单因素实验和响应面优化试验,确定知母多糖的最佳提取工艺;采用DEAE-52纤维素层析柱进行分离得到4种多糖组分APSE-0、APSE-1、APSE-2和APSE-3。以RAW264.7巨噬细胞为研究模型,采用MTT法、Griess法测定知母多糖各组分对细胞增殖能力和一氧化氮（NO）释放量的影响。结果表明,最佳复合酶比例为:木瓜蛋白酶16000 U/g,纤维素酶1200 U/g,果胶酶1600 U/g。最优提取工艺为酶解时间2 h,液料比15:1（mL/g）,酶解温度52 ℃,在此条件下得率为（10.58%±0.03%）。体外免疫活性实验结果证明,四种知母多糖组分均能明显促进RAW246.7巨噬细胞的增殖,APSE-0、APSE-2和APSE-3均可极显著诱导NO的释放,其中,APSE-2的免疫活性最强,可作为潜在的功能性食品或作为免疫力低下人群的膳食补充剂。剂。     

不同粒径橡胶集料混凝土工程特性试验

用橡胶颗粒取代砂子,对橡胶集料混凝土进行工作性测定及单轴抗压试验、抗水渗试验、抗氯离子渗透试验、冻融循环试验。结果表明:存在最不利橡胶颗粒粒径0.63～1.25 mm,使混凝土流动性最差;混凝土抗压强度随橡胶颗粒粒径减小而下降,但掺入小粒径橡胶颗粒有助于保证混凝土完整性;存在最优取代粒径0.165～0.315 mm,使混凝土电通量、渗水高度、质量损失率、相对动弹性模量损失率分别为普通混凝土的53.15%、52.35%、16.35%、51.79%;利用耐久性最优配合比制备的橡胶集料钢筋混凝土简支梁起裂荷载高于普通钢筋混凝土简支梁,但极限荷载有所降低,降幅约为6.10%。     

基于多目标的小流域污染控制方案及效果——以苏州胥江小流域为例

在太湖流域大网模型基础上,根据设计水文条件、边界水质以及控制断面水质与其上游概化排污口污染源的响应关系,建立胥江小流域污染物限排总量3级串级模型。计算基于多个控制断面在不同水质目标下的流域污染物限排总量。根据流域污染现状及污染物限排总量,提出包括总量控制措施及末端河道微污染水治理措施在内的污染综合控制方案,对综合控制方案水质改善效果进行评估。结果表明：①现状 COD 排放量超出限排总量153％、NH3－N 超出73％、TP 超出236％;②胥江小流域污染综合控制方案实施后,各控制断面水质均能达到目标要求。     

两室气体互通对光合微生物燃料电池性能的影响

以斜生栅藻生长产生氧为电子受体的光合微生物燃料电池(PMFC)和外加CO2光合微生物燃料电池(AC-PMFC)联合构建成微生物碳捕获电池(MCC).研究MCC在不同运行条件下的产电性能及影响因素.测量MCC,PMFC和AC-PMFC三种系统中的电压、溶解氧和pH.结果表明,产电压趋势与所有系统中的藻类阴极的氧浓度相关,...     

Three‐dimensional Printing for Catalytic Applications: Current Status and Perspectives

Three‐dimensional (3D) printing, also known as additive manufacturing, is a fabrication method that has recently received worldwide attention. It provides a convenient and economical way to prepare 3D structures in designable ways. As the technology has developed and the operational costs have decreased, the applications of 3D printing have greatly expanded. Catalyst fabrication is a promising area for 3D printing. Printing processes result in better control of catalyst structures and catalyst distribution. In this perspective, a general overview of the commonly available 3D printing methods that are feasible for the preparation of heterogeneous catalysts is given. Additionally, recent works on printing strategies and new materials for catalysts are discussed. Future development is also addressed.