遗传算法及其在注塑加工中的应用

阐述了遗传算法的基本原理,同时引用实践应用案例,探讨了遗传算法在注塑加工中的应用.     

线型双酚A酚醛树脂的合成

对线型双酚A酚醛树脂的合成工艺及催化剂浓度、种类、反应时间、醛酚比等影响因素进行了研究。结果表明,随着反应物醛酚比的增大,产物中残留的BPA量呈下降趋势,软化点先上升后下降,在1.2左右出现峰值;随反应时间延长,产物的软化点升高,分子质量增大,残留BPA量减少,分子质量分散性增加;催化剂用量增大,分子质量增大,软化点增高,残留BPA含量降低。合理的催化剂用量为m(BPA)∶m(催化剂)=100∶20。以合成的BPAN代替双氰胺(D ICY)作环氧树脂EB454A80的固化剂,在相同的固化工艺条件下,固化物的Tg提高近12℃。     

Muscle Wasting in Chronic Kidney Disease: Mechanism and Clinical Implications—A Narrative Review

Muscle wasting, known to develop in patients with chronic kidney disease (CKD), is a deleterious consequence of numerous complications associated with deteriorated renal function. Muscle wasting in CKD mainly involves dysregulated muscle protein metabolism and impaired muscle cell regeneration. In this narrative review, we discuss the cardinal role of the insulin-like growth factor 1 and myostatin signaling pathways, which have been extensively investigated using animal and human studies, as well as the emerging concepts in microRNA- and gut microbiota-mediated regulation of muscle mass and myogenesis. To ameliorate muscle loss, therapeutic strategies, including nutritional support, exercise programs, pharmacological interventions, and physical modalities, are being increasingly developed based on advances in understanding its underlying pathophysiology.     

Structural and Molecular Kinetic Features of Activities of DNA Polymerases

DNA polymerases catalyze DNA synthesis during the replication, repair, and recombination of DNA. Based on phylogenetic analysis and primary protein sequences, DNA polymerases have been categorized into seven families: A, B, C, D, X, Y, and RT. This review presents generalized data on the catalytic mechanism of action of DNA polymerases. The structural features of different DNA polymerase families are described in detail. The discussion highlights the kinetics and conformational dynamics of DNA polymerases from all known polymerase families during DNA synthesis.     

Customized Utilization Strategies of Industrial Lignin to Produce Adsorbents and Flocculants Based on Fractionation and Adequate Structural Interpretation

Lignin, a by-product of pulping and biorefinery, has great potential to replace petrochemical resources for wastewater purification. However, the defects of lignin, such as severe heterogeneity, inferior reactivity and poor solubility, characterize the production process of lignin-based products by high energy consumption and serious pollution. In this study, several lignin fractions with relatively homogeneous structure were first obtained by organic solvent fractionation, and their structures were fully deciphered by various characterization techniques. Subsequently, each lignin component was custom-valued for wastewater purification based on their structural characteristics. Benefiting from the high reactivity and reaction accessibility, the lignin fraction (lignin-1) refined by dissolving in ethanol and n-butanol could been used as a raw material to produce cationic lignin-based flocculant (LBF) in a copolymerization system using green, cheap and recyclable ethanol as solvent. The lignin fraction (lignin-2) extracted by methanol and dioxane showed low reactivity and high carbon content, which was used to produce lignin-based activated carbon (LAC) with phosphoric acid as activator. Moreover, the influences of synthetic factors on the purification capacity were discussed, and the LBF and LAC produced under the optimal conditions showed distinguished purification effect on kaolin suspension and heavy metal wastewater, respectively. Furthermore, the corresponding purification mechanism and external factors were also elaborated. It is believed that this cleaner production strategy is helpful for the valorization of lignin in wastewater resources.     

浅谈外墙外保温外饰面砖施工技术

结合工程实例从粘结机理、保温层受力情况、安全系数等方面进行了讨论,初步分析了墙体外墙外保温外饰面贴砖的安全性,提出了在施工中应采取的质量控制措施。     

Study on support mechanism of pre-stressed truss cable and its application

The truss cable support technology was put forward to control the large mining height and composite mudstone strata roadway. This technique makes the steady rock in roadway slantwise top be anchor points, makes the truss cable be steady support structure through special implement, and supplied rock in anchor area with horizontal and vertical pressure which strengthens the surrounding rock＇s anti-strain capability, so it can solve the support problem in roadway with the large cross section and large mining height with mudstone strata. The support mechanism of truss cable about how to make the soft strata stabilize is analyzed by use of the mechanical method. Based on the mechanism and numerical simulation method, the truss cable support project was designed and used to the large mining setting room in eleventh mining area of Bailong Mine successfully.     

邻苯二甲酸二烯丙基酯树脂固化特性的研究

运用示差扫描量热(DSC)法研究了邻苯二甲酸二烯丙基酯(DAP)树脂的固化反应历程。讨论了引发剂对DAP固化特性的影响,并由DSC曲线得到了DAP树脂的固化工艺和动力学参数。通过固化度、FT-IR的测试对DAP树脂在中温条件下的固化情况进行了研究。结果表明:在过氧化二异丙苯(DCP)固化体系中引入BPO可以使DAP树脂在更低温度下引发固化;在BPO、DCP用量均为2%的条件下,确定了体系的凝胶温度、固化温度、后处理温度分别为:100.5℃,124.3℃,137.8℃,表观活化能为129.3 kJ/mol,反应级数为0.950。固化度、FTIR的测试结果表明:DAP树脂在中温条件下可以固化得较完全。     

基于改进YOLOv7的钢材表面缺陷检测

钢材表面缺陷对于钢材行业来说是一个巨大的挑战。针对传统的钢材缺陷检测方法存在着效率低、检测精度不高等问题,基于YOLOv7设计了一种AFSD-YOLOv7模型进行实时的钢材表面缺陷检测。首先,在YOLOv7模型中使用一种轻量化卷积结构替换标准卷积结构,,以加速模型的推理过程;然后采用快速空间金字塔池化结构替换原始空间金字塔池化结构,以加速网络的特征提取过程;最后添加改进的ECA-Net注意力机制,以提升模型检测精度。实验结果表明,AFSD-YOLOv7能够对钢材缺陷进行有效识别,相比YOLOv7模型,计算量减少了54.8%,mAP提高了3.2%,对于钢材表面缺陷检测具有实际应用价值。     

新时代背景下劳模文化引导高校开展劳动教育的 实践路径探析

劳模文化是以劳模为代表的先进劳动者的精神风貌和工作方式的集中体现, 作为中华民族精神和时代精神的重要组成部分, 体现了爱国主义和改革创新的核心价值。加强大学生的劳动教育是高校贯彻落实立德树人根本任务之所需, 更是推动大学生全面发展之所应, 而劳模文化为高校劳动教育的开展提供了鲜活案例和丰富教学资源。将探索新时代劳模文化引导高校开展劳动教育的实践路径, 以此树立大学生正确的劳动观, 助力培育具有高尚品德和职业素养的时代新人。