面向德才兼备拔尖创新人才培养的分析化学(2)教学思考与实践

在科学和技术日益精进的年代,探索如何培养德才兼备的拔尖创新人才是分析化学(2)教学实践的一项重要任务。基于对现有分析化学(2)经典教学内容中中国元素显示度不明显、理论知识与实践结合不够紧密、教学内容缺乏时代性和前沿性的思考等问题,我们不断完善教学内容和教学方法,在教学内容中融入思政案例、社会热点案例、科学前沿进展,推进分析化学(2)科学育人和思政育人双重育人功能的有机融合,对培养德才兼备拔尖创新人才进行了教学探究和实践。

部省际联席会议的运行机制及其制度化逻辑——基于昆山深化两岸产业合作试验区的案例分析

随着改革开放的持续推进,联席会议逐渐成为政府推进重大战略或综合性项目的重要工作机制。作为联席会议的重要类型,部省际联席会议一般呈现出怎样的运行机制,其实现制度化运作需要哪些必要的推动因素?论文以制度性集体行动理论为基础,构建昆山深化两岸产业合作试验区部省际联席会议机制的分析框架,并以部省际联席会议作为研究案例,综合运用重点访谈、社会网络分析、政策文本计量分析等研究方法,分析部省际联席会议的运行机制及其实现制度化运作的基本逻辑。研究表明:第一,在部省际联席会议的府际合作模式中,其运行机制由“自下而上”政策诉求机制和“自上而下”政策制定与执行机制组成。第二,部省际联席会议各参与部门的权力关系呈现多重性;第三,部省际联席会议负有政策制定和执行的双重职责;第四,地方发展经济的动机与国家重大方针政策的长期契合,是部省际联席会议持续制度化的基本逻辑;第五,部省际联席会议机制为地方政府有限度地突破行政级别壁垒,获取超出自身行政权限的政策资源提供了结构化的机会。

Microstructure and corrosion behavior of Mg-Zn-Y-Al alloys with long-period stacking ordered structures

Mg97−xZn1Y2Alx alloys with long-period stacking ordered(LPSO)structures were prepared by conventional casting method.The optical microscopy(OM),X-ray diffraction(XRD)and the scanning electron microscope(SEM)equipped with energy dispersive X-ray spectroscopy(EDS)were used to analyze the microstructure of the alloys with different compositions.Immersion test and electrochemical measurement were used to evaluate the corrosion behavior of the alloys at room temperature,and the corrosive medium is 3.5%NaCl aqueous solution.The results showed that,with the increasing aluminum(Al)addition,exceptα-Mg and LPSO phases,new phases also emerged on the grain boundaries.At the same time,the zigzag part of LPSO phases disappeared,and the boundaries between LPSO phases andα-Mg became smooth.Furthermore,the addition of Al to Mg-Zn-Y alloys could hinder the activity of cathodic hydrogen evolution reaction and improve the uniformity and compactness of the protective surface film,thus,enhanced the corrosion resistance of Mg-Zn-Y alloys.

Determining the microstructure and properties of magnesium aluminum composite panels by hot rolling and annealing

The researchers made magnesium aluminum composite panels by asymmetric metal packaging and studied rolling temperature,holding time,and high temperature heat treatment,such as short time and low temperatures over long periods of time parameters under the new preparation method.We tested the new magnesium aluminum composite panels’tensing properties and bending performance by using scanning electric mirror and EDS.It is concluded that the new magnesium aluminum composite panels’elongation is 24%under the tensile strength of 260 MPa.Regarding performance when compared with other methods,traditional magnesium aluminum composite panels’elongation is 10%,which shows its advanced nature.At the same time,bending performance test showed that the combination of the composite board has higher performance,offering the reference value for the preparation of magnesium–aluminum composite plate.

Effect of the Al–Si eutectic on the microstructure and corrosion behavior of the single-phase Mg alloy Mg–4Li

The influence of alloying with Al–Si eutectic on the microstructure and corrosion resistance of single-phase Mg–4Li was studied in this paper.The microstructure was characterized using an electron microscopy.The corrosion properties were measured by immersion tests and electrochemical impedance spectrum(EIS)measurements.Alloying with Al–Si eutectic caused the formation of Mg_(2)Si and Mg–Al phase.The grain orientation of Mg–4Li was mainly composed of(0001)while the grain orientation of Mg–4Li–6(Al–Si)was mainly consisted of(10–10)and(11–20).Mg–4Li–6(Al–Si)shows worse corrosion resistance than Mg–4Li owing to the galvanic corrosion from the precipitates and texture change.

Decomplexation of Cu-1-hydroxyethylidene-1,1-diphosphonic acid by a three-dimensional electrolysis system with activated biochar as particle electrodes

The feasibility of decomplexation removal of typical contaminants in electroplating wastewater,complexed Cu(Ⅱ)with 1-hydroxyethylidene-1,1-diphosphonic acid(Cu-HEDP),was first performed by a three-dimensional electrode reactor with activated biochar as particle electrodes.For the case of 50 mg/L Cu-HEDP,Cu(Ⅱ)removal(90.7%)and PO_(4)^(3−)conversion(34.9%)were achieved under the conditions of electric current 40 mA,initial pH 7,acid-treated almond shell biochar(AASB)addition 20 g/L,and reaction time 180 min,with second-order rate constants of 1.10×10^(−3) and 1.94×10^(−5) min^(−1) respectively.The growing chelating effect between Cu(II)and HEDP and the comprehensive actions of adsorptive accumulation,direct and indirect oxidation given by particle electrodes accounted for the enhanced removal of Cu-HEDP,even though the mineralization of HEDP was mainly dependent on anode oxidation.The performance attenuation of AASB particle electrodes was ascribed to the excessive consumption of oxygen-containing functionalities during the reaction,especially acidic carboxylic groups and quinones on particle electrodes,which decreased from 446.74 to 291.48μmol/g,and 377.55 to 247.71μmol/g,respectively.Based on the determination of adsorption behavior and indirect electrochemical oxidation mediated by in situ electrogenerated H_(2)O_(2) and reactive oxygen species(e.g.,•OH),a possible removal mechanism of Cu-HEDP by three-dimensional electrolysis was further proposed.

An integrated micromachined flexible ultrasonicinductive sensor for pipe contaminant multiparameter detection

Pipe contaminant detection holds considerable importance within various industries,such as the aviation,maritime,medicine,and other pertinent fields.This capability is beneficial for forecasting equipment potential failures,ascertaining operational situations,timely maintenance,and lifespan prediction.However,the majority of existing methods operate offline,and the detectable parameters online are relatively singular.This constraint hampers real-time on-site detection and comprehensive assessments of equipment status.To address these challenges,this paper proposes a sensing method that integrates an ultrasonic unit and an electromagnetic inductive unit for the real-time detection of diverse contaminants and flow rates within a pipeline.The ultrasonic unit comprises a flexible transducer patch fabricated through micromachining technology,which can not only make installation easier but also focus the sound field.Moreover,the sensing unit incorporates three symmetrical solenoid coils.Through a comprehensive analysis of ultrasonic and induction signals,the proposed method can be used to effectively discriminate magnetic metal particles(e.g.,iron),nonmagnetic metal particles(e.g.,copper),nonmetallic particles(e.g.,ceramics),and bubbles.This inclusive categorization encompasses nearly all types of contaminants that may be present in a pipeline.Furthermore,the fluid velocity can be determined through the ultrasonic Doppler frequency shift.The efficacy of the proposed detection principle has been validated by mathematical models and finite element simulations.Various contaminants with diverse velocities were systematically tested within a 14mm diameter pipe.The experimental results demonstrate that the proposed sensor can effectively detect contaminants within the 0.5−3mm range,accurately distinguish contaminant types,and measure flow velocity.

Gold nanorod-photosensitizer conjugate with extracellular pH-driven tumor targeting ability for photothermal/photodynamic therapy

Chlorin e6-pHLIPss-AuNRs, a gold nanorod-photosensitizer conjugate containing a pH （low） insertion peptide （pHLIP） with a disulfide bond which imparts extracellular pH （pHe）-driven tumor targeting ability, has been successfully developed for bimodal photodynamic and photothermal therapy. In this bimodal therapy, chlorin e6 （Ce6）, a second-generation photosensitizer （PS）, is used for photodynamic therapy （PDT）. Gold nanorods （AuNRs） are used as a hyperthermia agent for photothermal therapy （PTT） and also as a nanocarrier and quencher of Ce6. pHLIPss is designed as a pile-driven targeting probe to enhance accumulation of Ce6 and AuNRs in cancer cells at low pH. In Ce6- pHLIPss-AuNRs, Ce6 is close to and quenched by AuNRs, causing little PDT effect. When exposed to normal physiological pH 7.4, Ce6-pHLIPs^-AuNRs loosely associate with the cell membrane. However, once exposed to acidic pH 6.2, pHLIP actively inserts into the cell membrane, and the conjugates are translocated into cells. When this occurs, Ce6 separates from the AuNRs as a result of disulfide bond cleavage caused by intracellular glutathione （GSH）, and singlet oxygen is produced for PDT upon light irradiation. In addition, as individual PTT agent, AuNRs can enhance the accumulation of PSs in the tumor by the enhanced permeation and retention （EPR） effect. Therefore, as indicated by our data, when exposed to acidic pH, Ce6-pHLIPss-AuNRs can achieve synergistic PTT/PDT bimodality for cancer treatment.

Cellular microparticles and pathophysiolog, of traumatic brain injury

Traumatic brain injury （TBI） is a leading cause of death and disability worldwide. The finding that cellular microparticles （MPs） generated by injured cells profoundly impact on pathological courses of TBI has paved the way for new diagnostic and therapeutic strategies. MPs are subcellular fragments or organelles that serve as carriers of lipids, adhesive receptors, cytokines, nucleic acids, and tissue-degrading enzymes that are unique to the parental cells. Their sub-micron sizes allow MPs to travel to areas that parental cells are unable to reach to exercise diverse biological functions. In this review, we summarize recent developments in identifying a casual role of MPs in the pathologies of TBI and suggest that MPs serve as a new class of therapeutic targets for the prevention and treatment of TBI and associated systemic complications.

Effect of addition of Al-Si eutectic alloy on microstructure and mechanical properties of Mg-12wt%Li alloy

Mg-12 Li, Mg-12 Li-3（Al-Si）, Mg-12 Li-7（Al-Si） and Mg-12 Li-9（Al-Si） alloys（all in wt%） were fabricated by high frequency vacuum induction melting in a water cooled copper crucible. After subsequently hotrolling and annealing, their microstructure and mechanical properties were investigated. Experimental results show that mechanical properties of Mg-12 Li alloy were significantly improved by the addition of Al-Si eutectic alloy. Mg-12 Li-7（Al-Si） alloy shows the highest strength of 196 MPa of the investigated alloys, which is about 1.8 times of the strength of Mg-12 Li alloy, and maintains high elongation of 27%.The improved mechanical property with addition of Al and Si in the eutectic proportion into Mg-12 Li alloy was attributed to the solution strengthening effect of A1 and precipitation hardening effect from AlLi and Mg_2 Si precipitates.

Synergistic Effects of Chiral Morphology and Reconfiguration in Cattail Leaves

Cattail, a type of herbaceous emergent aquatic macrophyte, has upright-standing leaves with a large slenderness ratio and a ehiral morphology. With the aim of understanding the effect of chiral morphology on their mechanical behavior, we investi- gated, both experimentally and theoretically, the twisting chiral morphologies and wind-adaptive reconfigurations of cattail leaves. Their multiscale structures were observed by using optical microscope and scanning electron microscopy. Their me- chanical properties were measured by uniaxial tension and three-point bending tests. By modeling a chiral leaf as a pre-twisted cantilever-free beam, fluid dynamics simulations were performed to elucidate the synergistic effects of the leaf＇s chiral mor- phology and reconfiguration in wind. It was observed that the leaves have evolved multiscale structures and superior mechanical properties, both of which feature functionally gradient variations in the height direction, to improve their ability to resist lodging failure by reducing the maximal stress. The synergistic effect ofchiral morphology and reconfiguration can greatly improve the survivability of cattail plants in wind.

New Insights from Chemical Biology:Molecular Basis of Transmission,Diagnosis,and Therapy of SARS-CoV-2

Coronavirus disease 2019(COVID-19)is caused by a novel strain of coronavirus,designated as severe acute respiratory syndrome coronavirus 2(SARSCoV-2).It has caused a global pandemic rapidly sweeping across all countries,bringing social and economic hardship to millions.Most countries have implemented early warning measures to detect,isolate,and treat patients infected with SARS-CoV-2.This minireview summarizes some of those steps,in particular,testing methods and drug development in the context of chemical biology,and discusses the molecular basis of COVID-19’s virulent transmissibility.

Carbamazepine degradation by visible-light-driven photocatalyst Ag_(3)PO_(4)/GO:Mechanism and pathway

Carbamazepine(CBZ),as one of the most frequently detected pharmaceuticals,is of great concern due to its potential impact on the ecosystem and human health.This study provides an effective approach to remove CBZ by using photocatalyst silver phosphate combined with graphene oxide(Ag_(3)PO_(4)/GO)under visible irradiation.The morphology,composition,and optical properties of Ag_(3)PO_(4)/GO were characterized employing SEM,XRD,and DRS.Graphene oxide could improve the visible-light utilization and promote electron's charge to enhance the photocatalytic performance of Ag_(3)PO_(4)/GO.With the optimal reaction condition of 5.86 mW/cm_(2)light intensity,15-25℃ temperature,5-7 pH,and 0.5 mg/L catalytic dosages,5 mg/L CBZ could be completely degraded in 30 min,and the apparent rate constant could reach 0.12 min^(-1).Additionally,the radical trapping experiments indicated·OH and O_(2)^(-)· were the main reactive oxygen species employed to eliminate CBZ.The decay pathways of CBZ had been proposed accordingly,and the main product was the low-molecular products.

Nanocarrier based on the assembly of protein and antisense oligonucleotide to combat multidrug resistance in tumor cells

Chemotherapy-induced multi-drug resistance(MDR) in tumors poses a huge challenge for clinical treatment of tumors. The downregulation of the multi-drug resistance relative protein, represented by P-glycoprotein(P-gp), can reverse MDR of cancer cells. In this study, we developed doxorubicin-loading nanocarrier based on the assembly of protein and antisense oligonucleotide(ASO) to combat MDR of cancer cells. The data demonstrate that the nanocarrier can efficiently deliver ASO to cytoplasm and downregulate the P-glycoprotein expression, subsequently improving the therapeutic effects of Dox in doxorubicin-resistant MCF-7/ADR cancer cells. The preparation is simple and effective, providing a powerful tool for gene delivery. Therefore, our nanocarrier shows high promise in cancer treatment.

Framework nucleic acid-based confined enzyme cascade for efficient synergistic cancer therapy in vivo

Artificial enzyme cascade systems with confinement effect are highly important in synthetic biology and biomedicine.Herein,a framework nucleic acid-based confined enzyme cascade(FNA-CEC)for synergistic cancer therapy in vivo was developed.The FNA-CEC consisted of glucose oxidase and horseradish peroxidase precisely assembled on an addressable DNA tetrahedron scaffold within few nanometers.Glucose oxidase(GOx)can trigger efficient glucose depletion for tumor starvation therapy,and increase the local concentration of H_(2)O_(2) in situ for enhanced downstream horseradish peroxidase(HRP)-activated prodrug therapy.Due to the spatial-confinement on DNA tetrahedron scaffold,the efficiency of intermediate metabolites transportation between the enzyme cascades was improved.Moreover,FNA-CEC was applied for efficient synergistic cancer therapy in vitro and in vivo.As a simple and efficient approach,the FNA-CEC is expected to expand the toolbox of technologies in synthetic biology and biomedicine.