构筑可持续生物炭修饰钨酸铋复合光催化剂实现基于增强电荷转移效应的高效水净化

近年来,全球环境问题日趋严峻,水体中的农药污染愈发严重,亟待解决.光催化作为一种绿色高效的技术,在环境修复领域具有较高的应用价值.然而,光生载流子的快速复合和电荷利用效率低是制约光催化效率的关键问题.生物炭(BC)是一种新兴的碳质材料,来源于可持续利用的生物质废物,因其出色的吸附能力在污染物去除方面备受关注.因此,设计并开发功能化改性的BC基复合光催化剂,有望快速修复农药污染,推动高效、可持续的光催化污水净化技术的发展.本文首先以木屑生物质为原料,在厌氧条件下热解制备了不同氮含量掺杂的BC(Nx-BC,x代表尿素与BC的质量比).然后,以乙二醇为溶剂,将Nx-BC与Bi2WO6前驱体溶液混合,通过溶剂热反应制备一系列Bi2WO6/氮掺杂BC复合材料(BWO/Nx-BC),并用于可见光照射下光催化降解毒死蜱(CPs)农药.X射线衍射、扫描电镜、透射电镜和傅里叶红外光谱等结果表明,成功制备了BWO/Nx-BC复合材料.紫外-可见漫反射光谱结果表明,BWO/Nx-BC能有效吸收可见光,结合X射线光电子能谱分析,确定了其导带和价带位置.特别是,氮掺杂后的BWO/N3-BC在电子导电性提高的同时,还保持了良好的吸附性能,有效避免了光生载流子的重组.通过光致发光光谱、时间分辨光致发光光谱、光电流强度曲线和电化学阻抗曲线研究了光催化剂的载流子分离和重组行为.结果表明,BWO/N3-BC表现出较好的光催化降解效率,仅需0.5 h即可降解99.0%的CPs,其降解速率分别是纯BWO和纯N3-BC的2.91倍和12.13倍.BWO/N3-BC复合材料在8次循环使用后仍保持稳定.同时,考虑到真实水体环境的复杂性,本文还系统地探讨了不同操作参数对光催化降解活性的影响.自由基清除实验和电子顺磁共振结果表明,该反应的关键活性物质有•O_(2)^(-)、•OH和h^(+),其中•O_(2)^(-)是最主要的活性物质,并结合实验结果推测了BWO/N3-BC吸附-光降解的协同增效机制.利用高效液相色谱-质谱技术研究了CPs的降解中间体,提出了三种可能的降解途径,并对每种途径进行了详细分析.最后,通过生态毒性试验(大肠杆菌的培养)和毒性评估软件工具对CPs及其中间体的潜在生态毒性进行了系统评估.综上所述,本文通过直接煅烧辅助溶剂热法成功制备了BC基光催化剂,并揭示了其促进CPs光降解的机理,这为环境可持续的光催化循环经济提供了参考,也为光催化技术与废弃生物质高值利用相结合,实现环境修复开辟了新思路.

有机化学实验课教学质量提升的探索与实践

本文介绍了有机化学实验教学过程中存在的一些问题,并从强化学生预习效果、加强教师技能培训、重视集体备课、强化实验过程的教师指导、增加课后的评价反思等方面介绍了我校提高有机化学实验教学质量的探索和实践。

基于格氏反应的镁离子电解液的合成与性质

随着“双碳”战略的实施,新能源产业的发展已经成为必然趋势,因而对先进储能技术的需求也日益增加。其中,电化学储能技术发展较为迅速,是当前学术界和产业界的研究热点。与锂离子电池相比,镁电池具有能量密度高、成本低、环境资源友好等优势,是下一代电池技术发展的重要方向之一。在传统非水电解液中,金属镁负极易形成低离子导电性的钝化层,阻碍镁离子的电化学沉积/溶出,极大限制了镁电池的发展。因此,探索有效的镁离子电解液体系是提升镁电池性能的关键要素。本工作以经典有机化学实验“格氏反应”为切入点,聚焦于镁离子非水导体的制备及其在镁电池体系的应用探索,将有机化学基础理论知识与前沿电化学储能技术相结合,帮助学生拓展科学视野,激发学习兴趣,同时提高能源安全意识和科学素养。

Mechanistic investigation on Ag-Cu_(2)O in electrocatalytic CO_(2) to CH_(4) by in situ/operando spectroscopic and theoretical analysis

Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,we construct chemically bonded Ag-Cu_(2)O boundaries,in which the complete reduction of Cu_(2)O to Cu has been strongly impeded owing to the presence of surface Ag shell.The interfacial confinement effect helps to maintain Cu^(+)sites at the Ag-Cu_(2)O boundaries.Using in situ/operando spectroscopy and theoretical simulations,it is revealed that CO_(2) is enriched at the Ag-Cu_(2)O boundaries due to the enhanced physisorption and chemisorption to CO_(2),activating CO_(2) to form the stable intermediate^(*)CO.The boundaries between Ag shell and the Cu_(2)O mediate local^(*)CO coverage and promote^(*)CHO intermediate formation,consequently facilitating CO_(2)-to-CH_(4) conversion.This work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO_(2) reduction.

Phase engineering of Ni-Mn binary layered oxide cathodes for sodiumion batteries

Nickel-manganese binary layered oxides with high working potential and low cost are potential candidates for sodium-ion batteries,but their electrochemical properties are highly related to compositional diversity.Diverse composite materials with various phase structures of P3,P2/P3,P2,P2/O3,and P2/P3/O3 were synthesized by manipulating the sodium content and calcination conditions,leading to the construction of a synthetic phase diagram for Na_(x)Ni_(0.25)Mn_(0.75)O_(2)(0.45≤x≤1.1).Then,we compared the electrochemical characteristics and structural evolution during the desodiation/sodiation process of P2,P2/P3,P2/03,and P2/P3/O3-Na_(x)Ni_(0.25)Mn_(0.75)O_(2).Among them,P2/P3-Na0.75Ni0.25Mn0.75O2exhibits the best rate capability of 90.9 mA h g^(-1)at 5 C,with an initial discharge capacity of 142.62 mA h g^(-1)at 0.1 C and a capacity retention rate of 78.25%after 100 cycles at 1 C in the voltage range of 2-4.3 V.The observed superior sodium storage performance of P2/P3 hybrids compared to other composite phases can be attributed to the enhanced Na^(+)transfer dynamic,reduction of the Jahn-teller effect,and improved reaction reversibility induced by the synergistic effect of P2 and P3 phases.The systematic research and exploration of phases in Na_(x)Ni_(0.25)Mn_(0.75)O_(2)provide new sights into high-performance nickel-manganese binary layered oxide for sodium-ion batteries.

Calculation of Mass Concrete Temperature Containing Cooling Water Pipe Based on Substructure and Iteration Algorithm

Mathematical physics equations are often utilized to describe physical phenomena in various fields of science and engineering.One such equation is the Fourier equation,which is a commonly used and effective method for evaluating the effectiveness of temperature control measures for mass concrete.One important measure for temperature control in mass concrete is the use of cooling water pipes.However,the mismatch of grids between large-scale concrete models and small-scale cooling pipe models can result in a significant waste of calculation time when using the finite element method.Moreover,the temperature of the water in the cooling pipe needs to be iteratively calculated during the thermal transfer process.The substructure method can effectively solve this problem,and it has been validated by scholars.The Abaqus/Python secondary development technology provides engineers with enough flexibility to combine the substructure method with an iteration algorithm,which enables the creation of a parametric modeling calculation for cooling water pipes.This paper proposes such a method,which involves iterating the water pipe boundary and establishing the water pipe unit substructure to numerically simulate the concrete temperature field that contains a cooling water pipe.To verify the feasibility and accuracy of the proposed method,two classic numerical examples were analyzed.The results showed that this method has good applicability in cooling pipe calculations.When the value of the iteration parameterαis 0.4,the boundary temperature of the cooling water pipes can meet the accuracy requirements after 4∼5 iterations,effectively improving the computational efficiency.Overall,this approach provides a useful tool for engineers to analyze the temperature control measures accurately and efficiently for mass concrete,such as cooling water pipes,using Abaqus/Python secondary development.

Differences between two methods to derive a nonlinear Schrödinger equation and their application scopes

The present paper chooses a dusty plasma as an example to numerically and analytically study the differences between two different methods of obtaining nonlinear Schrödinger equation(NLSE).The first method is to derive a Korteweg–de Vries(KdV)-type equation and then derive the NLSE from the KdV-type equation,while the second one is to directly derive the NLSE from the original equation.It is found that the envelope waves from the two methods have different dispersion relations,different group velocities.The results indicate that two envelope wave solutions from two different methods are completely different.The results also show that the application scope of the envelope wave obtained from the second method is wider than that of the first one,though both methods are valuable in the range of their corresponding application scopes.It is suggested that,for other systems,both methods to derive NLSE may be correct,but their nonlinear wave solutions are different and their application scopes are also different.

Identification and validation of novel prognostic fatty acid metabolic gene signatures in colon adenocarcinoma through systematic approaches

Colorectal cancer(CRC)belongs to the class of significantly malignant tumors found in humans.Recently,dysregulated fatty acid metabolism(FAM)has been a topic of attention due to its modulation in cancer,specifically CRC.However,the regulatory FAM pathways in CRC require comprehensive elucidation.Methods:The clinical and gene expression data of 175 fatty acid metabolic genes(FAMGs)linked with colon adenocarcinoma(COAD)and normal cornerstone genes were gathered through The Cancer Genome Atlas(TCGA)-COAD corroborating with the Molecular Signature Database v7.2(MSigDB).Initially,crucial prognostic genes were selected by uni-and multi-variate Cox proportional regression analyses;then,depending upon these identified signature genes and clinical variables,a nomogram was generated.Lastly,to assess tumor immune characteristics,concomitant evaluation of tumor immune evasion/risk scoring were elucidated.Results:A 8-gene signature,including ACBD4,ACOX1,CD36,CPT2,ELOVL3,ELOVL6,ENO3,and SUCLG2,was generated,and depending upon this,CRC patients were categorized within high-risk(H-R)and low-risk(L-R)cohorts.Furthermore,risk and age-based nomograms indicated moderate discrimination and good calibration.The data confirmed that the 8-gene model efficiently predicted CRC patients’prognosis.Moreover,according to the conjoint analysis of tumor immune evasion and the risk scorings,the H-R cohort had an immunosuppressive tumor microenvironment,which caused a substandard prognosis.Conclusion:This investigation established a FAMGs-based prognostic model with substantially high predictive value,providing the possibility for improved individualized treatment for CRC individuals.

Short-Term Household Load Forecasting Based on Attention Mechanism and CNN-ICPSO-LSTM

Accurate load forecasting forms a crucial foundation for implementing household demand response plans andoptimizing load scheduling. When dealing with short-term load data characterized by substantial fluctuations,a single prediction model is hard to capture temporal features effectively, resulting in diminished predictionaccuracy. In this study, a hybrid deep learning framework that integrates attention mechanism, convolution neuralnetwork (CNN), improved chaotic particle swarm optimization (ICPSO), and long short-term memory (LSTM), isproposed for short-term household load forecasting. Firstly, the CNN model is employed to extract features fromthe original data, enhancing the quality of data features. Subsequently, the moving average method is used for datapreprocessing, followed by the application of the LSTM network to predict the processed data. Moreover, the ICPSOalgorithm is introduced to optimize the parameters of LSTM, aimed at boosting the model’s running speed andaccuracy. Finally, the attention mechanism is employed to optimize the output value of LSTM, effectively addressinginformation loss in LSTM induced by lengthy sequences and further elevating prediction accuracy. According tothe numerical analysis, the accuracy and effectiveness of the proposed hybrid model have been verified. It canexplore data features adeptly, achieving superior prediction accuracy compared to other forecasting methods forthe household load exhibiting significant fluctuations across different seasons.

Tennis ball cord combined with endoscopy for giant gastric phytobezoar:A case report

BACKGROUND Due to the specificity of Chinese food types,gastric phytobezoars are relatively common in China.Most gastric phytobezoars can be removed by chemical enzyme lysis and endoscopic fragmentation,but the treatment for large phytobezoars is limited,and surgical procedures are often required for this difficult problem.CASE SUMMARY For giant gastric phytobezoars that cannot be dissolved and fragmented by conventional treatment,we have invented a new lithotripsy technique(tennis ball cord combined with endoscopy)for these phytobezoars.This non-interventional treatment was successful in a patient whose abdominal pain was immediately relieved,and the gastroscope-induced ulcer healed well 3 d after lithotripsy.The patient was followed-up for 8 wk postoperatively and showed no discomfort such as abdominal pain.CONCLUSION The combination of tennis ball cord and endoscopy for the treatment of giant gastric phytobezoars is feasible and showed high safety and effectiveness,and can be widely applied in hospitals of all sizes.

Analysis of the Current Situation of Stigma Among Elderly Hemodialysis Patients and its Influencing Factors

Objective:To understand the current situation of stigma among elderly hemodialysis patients and to analyze its influencing factors.Methods:Convenience sampling was used to select 242 elderly patients undergoing hemodialysis in one of the two tertiary hospitals in Mianyang City.The survey was carried out from December 2022 to March 2023,with the Basic Information Questionnaire,the Social Influence Scale,and the Collaborative Social Support Scale.All influencing factors were analyzed by correlation analysis,univariate analysis,and multiple linear regression.Results:The average stigma score among elderly hemodialysis patients was 72.94±9.58,and the influencing factors of stigma among elderly hemodialysis patients were determined to be social support and economic status(P<0.05).Conclusion:The occurrence of stigma among elderly hemodialysis patients was at a moderate to high level,and the influencing factors were mainly economic status and social support.To reduce the occurrence of stigma in elderly hemodialysis patients,appropriate economic support from families and social support from medical personnel are needed.

分子及团簇的分子动力学模拟——介绍一个计算化学实验

分子动力学方法在化学及相关学科研究中的重要地位日趋凸显,但在本科化学实验中鲜有涉及,现有计算化学实验多侧重量子化学方法对分子性质的计算。为普及分子动力学模拟这一有力工具,同时帮助学生理解分子的动态行为,本文以丙氨酸二肽模型分子为例设计了一个简单的分子动力学模拟实验。通过本实验学生能初步掌握分子动力学模拟的基本原理、流程和分析方法,同时加深对物理化学中势能面等抽象概念的理解。本实验即可作为单独设课的计算化学实验的内容,亦可在物理化学实验中作为拓展实验开设。

格氏试剂的合成实验改进

采用二异丁基氢化铝(DIBAH)替代分子碘,对格氏试剂的合成实验进行了改进,系统研究了DIBAH引发对反应体系安全性的影响,以及不同结构卤代烃底物在DIBAH引发下对格氏反应速率的影响。结果表明,添加2%(摩尔分数,以卤代烃的摩尔量为基础)的DIBAH,可以在温和(20℃)条件下,高效合成苯基溴化镁、正丁基溴化镁等两种典型的格氏试剂,并能获得比分子碘引发体系更高产率的格氏反应产物。本工作通过提高格氏试剂合成反应的安全性,加强学生对实验安全的重视,引导学生关注化工产业实践中的实际问题。通过对反应体系的优化和结构解析,引导学生将基础知识活学活用、融会贯通。

“考古”陶片中酒类残留的分析检测

通过对陶器中酒类残留的检测分析,介绍了化学技术手段在考古工作中的应用。在实验中,学生通过萃取、抽滤、离心、旋转蒸发等实验步骤提取酒的标志物——有机酸,并对其进行高效液相色谱(HPLC)检测,最后结合陶片的考古背景分析陶片的可能用途。该实验依托于考古化学这一新兴交叉学科,面向化学、考古学等专业的学生开设,有助于学生了解并掌握分析化学中样品分离和制备、液相色谱分析等基本概念与操作,并对考古学的研究内容形成一定认识。

新文科背景下理论与实践相结合的考古化学教学模式探索

在新文科建设背景下,我们将化学和考古学融合构建了理论实践相结合的通识核心课程考古化学,打破了文、理学科壁垒,对学生进行理论知识和实验技能紧密结合的跨学科培养。同时结合开放创新实验、毕业设计,根据学生兴趣和职业发展规划量身打造个性化研究课题,引导学生在应用化学理论知识和实验技能解决考古实际问题的过程中建立化学、考古学紧密结合的综合创新思维,提升学生的科研创新能力,为新型文理复合型人才的培养提供了思路。

《分子模拟》教材建设的探索与实践

教材建设是课程建设的重要一环,本文重点对山东大学分子模拟实验国家一流课程的教材建设情况进行了介绍。从历史与传承、发展与创新、总结与展望三个方面对山东大学化学学科的教材编写历史、国内外分子模拟相关教材的建设情况、《分子模拟》教材的主要内容和特色之处,以及下一步的修订计划进行了详细介绍,以期对相关教材的编写与修订提供启发与借鉴。

仿生高取向结构聚乳酸/聚乙二醇/十二烷基硫酸钠熔喷非织造材料的原位牵伸制备及定向导液特性

为增强聚乳酸(PLA)超细纤维非织造材料的液体定向传输能力,选用聚乙二醇(PEG)和十二烷基硫酸钠(SDS)改善PLA的亲水性,并通过原位牵伸辅助的熔喷成型工艺制备了仿生高取向结构PLA/PEG/SDS超细纤维非织造材料,研究了不同牵伸倍率对材料结构与性能的影响。结果表明,PLA/PEG/SDS共混聚合物的玻璃化转变温度为50℃左右,适合进行牵伸;随着牵伸倍率从1.0增加至2.0,高取向度纤维(取向角度≤20°)数量从10%增大至67%,纵向拉伸断裂强力提升151.5%,液体爬升高度从20 mm增大至62 mm。仿生高取向结构PLA/PEG/SDS熔喷非织造材料定向导液特性得到增强,因此满足其在加湿器、雾化器和3D打印机等微流体传输领域的应用。

捕碳记

二氧化碳等温室气体的过度排放加剧了全球气候不稳定性,导致极端天气频发。本文以一场代号为“捕碳”行动的故事,简要介绍了目前主要的CO_(2)捕集技术及其优缺点,有助于读者了解CO_(2)捕集技术的发展现状。

腹腔热灌注化疗治疗胃癌腹膜转移患者的预后分析及安全性评价

目的:探讨腹腔热灌注化疗(hyperthermic intraperitoneal chemotherapy,HIPEC)对胃癌腹膜转移[腹膜癌指数(peritoneal cancer index,PCI≤7)]患者预后及术后并发症的影响。方法:回顾性分析2019年1月至2021年1月就诊于山西医科大学第五临床医学院的124例胃癌腹膜转移(PCI≤7)患者的临床资料,根据是否行HIPEC将患者分为干预组和对照组,并对患者进行随访。采用Cox分析方法探究HIPEC与患者术后生存率的关系;Kaplan-Meier方法绘制生存曲线,采用Log-rank检验法进行组间生存率对比;χ2检验分析HIPEC对患者生活质量及术后并发症发生情况的影响。结果:干预组1年、2年累积生存率分别为92.1%、81.2%;对照组分别为75%、63.3%。干预组1年(P=0.011)、2年(P=0.024)总体生存率明显高于对照组,差异有统计学意义。Cox多因素分析结果提示HIPEC可以降低胃癌腹膜转移患者的死亡风险(P=0.004),2年死亡风险降低为对照组的0.341倍。两组之间生活质量卡氏评分(KPS)提高水平无显著差异(P=0.602)。HIPEC降低了发热并发症出现的概率(P<0.05),其他并发症无显著差异。结论:HIPEC在不影响患者生活质量的前提下明显提高胃癌腹膜转移(PCI≤7)患者的1年、2年生存率,且不增加术后并发症的发生风险。

“乙酰水杨酸的制备和分析表征”教学实验的优化和改进

以水杨酸和乙酸酐为原料,硅胶为催化剂,利用微波技术优化改进“乙酰水杨酸的制备和分析表征”大学有机化学教学实验,通过实验探究,分析了微波功率、反应时间、原料配比等因素对最终产率的影响,得到了最佳实验条件:硅胶目数为100–200目,用量为0.25 g,反应时间60 s,反应温度70°C,微波功率500 W,乙酸酐与水杨酸的物质的量之比为2:1,平均产率约为68.0%。与常规加热情况下乙酰水杨酸的制备相比,微波辅助合成法具有操作简便、反应时间短、产品的产率高、杂质少、对环境友好等优势。将该微波实验引入大学本科生有机化学实验教学,能开阔学生视野、丰富实验教学内容,进一步提高教学水平。