化学“101计划”结构化学课程与教材的建设与改革——面向拔尖创新人才培养的深度探索

在全球科技竞争加剧的背景下,教育在培养创新人才中发挥关键作用。结构化学作为化学专业的核心基础课程,其课程定位为以量子力学和群论为科学语言,更深层次理解化学原理与现象。本文总结了化学“101计划”结构化学课程与教材的改革情况,探讨了在一流课程标准下的改革路径。通过重构课程知识模块、构建知识框架与脉络以及多元化教学资源的引入,推动了高等教育质量提升和化学学科的发展。

Biomass Homogeneity Reinforced Carbon Aerogels Derived Functional Phase-Change Materials for Solar–Thermal Energy Conversion and Storage

We deviseda functional form stable compositephase-change materials(PCMs)toachieve a three-dimensional(3D)interconnectedporous carbon aerogel structure for encapsulating polyethyleneglycol(PEG).Anovelhomogeneity reinforced carbonaerogel witha well-interconnected porous structure was constructed bycombining a flexible carbonresource from biomass guar gum with hard-brittle carbonfrom polyimide,to overcome severeshrinkage andpoor mechanical performance of traditionalcarbon aerogel.Thesupportingcarbon aerogel-encapsulated PEG produced thenovel composite PCMswithgood structure stability andcomprehensive energy storage performance.Theresults showed thatthecomposite PCMsdisplayed awell-defined 3Dinterconnected structure,and theirenergy storage capacities were 171.5 and169.5 J/g,which changed onlyslightlyafter 100 thermalcycles,andthe compositescould maintainthe equilibrium temperature at50.0−58.1℃ for about 760.3 s.The thermal conductivityofthe compositescould reach0.62 W m^(−1) K^(−1),which effectively enhanced the thermalresponse rate.And thecomposite PCMs exhibited good leakage-proof performance andexcellent light–thermal conversion.The compressive strengthof thecomposite PCMscan improveupto 1.602 MPa.Results indicatethatthisstrategy canbe efficiently usedtodevelop novel composite PCMswithimproved comprehensive thermalperformance and high light–thermal conversion.

Fabrication of taxifolin loaded zein-caseinate nanoparticles and its bioavailability in rats

Taxifolin loaded zein-caseinate nanoparticles(TZP)were fabricated by the anti-solvent method and were used as an oral delivery vehicle to improve their bioavailability in the rat.The formulations of TZP were optimized.With mass ratio of 1:1:2 between taxifolin,zein and sodium caseinate,the particle size andζpotential of TZP were(168.74±0.35)nm and−(57.67±0.25)mV,while the encapsulation and loading efficiency of taxifolin were(85.83±0.89)%and(17.11±0.88)%,respectively.After freeze-drying,TZP exhibited excellent redispersibility in water without aggregation.Physicochemical characterization showed that taxifolin existed in amorphous form in TZP and its interaction with the protein was observed.After encapsulating in TZP,the excellent dispersion of taxifolin in water signifi cantly improve its diffusion velocity through a semipermeable membrane.After oral administration,taxifolin and its 5 metabolites were identifi ed in rat plasma by ultra high performance liquid chromatography(UPLC)with quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS).The dynamic variation of taxifolin and its metabolites in plasma were then quantifi ed by UPLC with a triple-quadrupole typemass spectroscopy(UPLC-QqQ-MS/MS).A pharmacokinetic study showed that the bioavailability of taxifolin increased from 0.35%to 0.52%through TZP fabrication.The plasma concentration of taxifolin glucuronide and methylated taxifolin glucuronide was much higher than taxifolin.Glucuronidation was the dominating metabolism pathway of taxifolin in vivo.

Dry/wet climate zoning and delimitation of arid areas of Northwest China based on a data-driven fashion

The division of arid areas is important in water and land resources management, planning and for a long-term agricultural, economic and social planning. Northwest China （NW） dominates the main arid areas in China. There is thus a need to adopt adequate concepts relative to the scope of arid areas of NW China and identify its climate types and characteristics. In this study, we analyzed climatic data over the last 30 years （1981-2010） from 191 stations in three provinces and three autonomous regions of NW China. The factor-cluster analysis technique （FC）, an objective and automated method was employed to classify the dry/wet climate zones. The traditional methods with predefined thresholds were adopted for providing a comparison with FC. The results showed that the wet/dry climate zones by FC were mainly distributed along mountains, rivers and desert borders. Climate-division boundaries relied heavily on the major terrain features surrounding the grouped stations. It also showed that the climate was dry in the plain sandy areas but relatively wet in the high mountain areas. FC method can reflect the climate characteristics more fully in NW China with varied and complicated topography, and outperform the tradi- tional climate classifications. Arid areas of NW China were defined as four climate types, including five resultant classes in FC classifications. The Qinling and Da Hinggan Mountains were two important boundaries, besides main administrative boundaries. The results also indicated that there are some differences between two traditional clas- sifications. The precipitation moved and fluctuated to an extent, which confirmed that climate change played an important role in the dry/wet climate zoning, and the boundaries of dry/wet climate zones might change and migrate with time. This paper is expected to provide a more in-depth understanding on the climate characteristics in arid areas of NW China, and then contribute to formulate reasonable water and land management planning and agri- cultural production programs.

A better carbon-water flux simulation in multiple vegetation types by data assimilation

Background:The accurate estimation of carbon-water flux is critical for understanding the carbon and water cycles of terrestrial ecosystems and further mitigating climate change.Model simulations and observations have been widely used to research water and carbon cycles of terrestrial ecosystems.Given the advantages and limitations of each method,combining simulations and observations through a data assimilation technique has been proven to be highly promising for improving carbon-water flux simulation.However,to the best of our knowledge,few studies have accomplished both parameter optimization and the updating of model state variables through data assimilation for carbon-water flux simulation in multiple vegetation types.And little is known about the variation of the performance of data assimilation for carbon-water flux simulation in different vegetation types.Methods:In this study,we assimilated leaf area index(LAI)time-series observations into a biogeochemical model(Biome-BGC)using different assimilation algorithms(ensemble Kalman filter algorithm(EnKF)and unscented Kalman filter(UKF))in different vegetation types(deciduous broad-leaved forest(DBF),evergreen broad-leaved forest(EBF)and grassland(GL))to simulate carbon-water flux.Results:The validation of the results against the eddy covariance measurements indicated that,overall,compared with the original simulation,assimilating the LAI into the Biome-BGC model improved the carbon-water flux simulations(R^(2)increased by 35%,root mean square error decreased by 10%;the sum of the absolute error decreased by 8%)but more significantly,improved the water flux simulations(R^(2)increased by 31%,root mean square error decreased by 18%;the sum of the absolute error decreased by 16%).Among the different forest types,the data assimilation techniques(both EnKF and UKF)achieved the best performance towards carbon-water flux in EBF(R^(2)increased by 44%,root mean square error decreased by 24%;the sum of the absolute error decreased by 28%),and the performances of EnKF and UKF showed slightly different when simulating carbon fluxes.Conclusion:We suggest that to reduce the uncertainty in global carbon-water flux quantification,forthcoming data assimilation treatment should consider the vegetation types where the data assimilation experiments are carried out,the simulated objectives and the assimilation algorithms.

High-quality draft genome sequence of Streptomyces agglomeratus 5-1-8 with strong anti-MRSA ability, isolated from the frozen soil of Tibet in China

Streptomyces agglomeratus 5-1-8 with strong anti methicillin-resistant Staphylococcus aureus(MRSA)ability,isolated from the frozen soil of Tibet in China,has a strong ability to kill the multi-drugs-resistant MRSA.To identify the second-ary metabolism ability of this strain,we describe here the phenotypic characteristics of this strain,along with its high-quality draft genome sequence,its annotation,and analysis.The 7.1M draft genome encodes 6,284 putative open reading frames(ORFs),of which 4,416 ORFs were assigned with clusters of orthologous genes(COG)categories.Also,65 t RNA genes and 24 r RNA operons were identified.The genome contains 12 gene clusters involved in antibiotics production and 1 gene cluster involved in anticancer-compounds production;4 gene clusters belong to polyketides and nonribosomal peptides,1gene cluster belong to the butyrolactone,4 gene clusters belong to the bacteriocin or lantipeptide,and 3 gene clusters belong to the others.This genome-sequence data will facilitate efforts to probe the potential of new antibiotics to kill multidrugs-resistant MRSA.

Effect of Slope Gradient on Erosion Evolution Process at Microtopographic Tillage Soil Surfaces

Slope gradient is one of the critically important factors which drive the erosional response of microtopographic surfaces. This study investigates the effect of slope gradient on the evolution of erosion under accumulative rainfall in laboratory experiments and calculates critical slope values that help evaluate land suitability for farming and similar purposes. Dynamics of accumulative runoff, accumulated sediment and their rates in each erosion stage are studied when the slope gradient varies. The critical slope value for the microtopographic surface was calculated according to the relationship between the sediment yield and slope gradient. The amount of eroded soil downhill in each erosion stage was calculated using DEM data of point cloud. Results show that 1) a steeper slope would increase cumulative runoff;2) cumulative sediment increases rapidly initially and then stabilizes with the increase of slope;3) the critical slope value for the whole erosion is determined as 10°. The findings of the dynamics of interrill erosion and sediment characteristics are useful information for future research of erosion prediction and conservation of soil and water in the Chinese Loess Plateau.

Research on Information Security Technology of Online Insurance System Based on WEB

With the continuous development and advancement of science and technology,WEB-based online insurance system has become an inevitable choice to adapt to the development trend of the times.On the basis of establishing a system,it is necessary to manage the safe operation structure,thus effectively establishing complete supervision and maintenance.The system ensures that the management level of insured information security technology can be optimized.This paper briefly analyzes the framework of the WEB-based online insurance system and discusses the security mode and system implementation.

硅基毫米波集成电路设计发展现状与挑战

毫米波相控阵系统因其大带宽、高速率和多波束的优点,在移动通信和雷达感知系统中得到了广泛的应用.硅基毫米波集成电路设计是其中的关键核心技术.本文基于国家自然科学基金委员会第347期“双清论坛(青年)”的研讨成果,根据毫米波集成电路与集成系统研究方面的重大需求,针对硅基毫米波集成电路设计的关键挑战和科学问题,按照相控阵架构、关键电路和器件模型3个层级,总结梳理了国内外硅基毫米波集成电路设计领域近年来所取得的主要进展和成就,凝炼了该领域未来5~10年的重大关键科学问题,探讨了前沿研究方向和科学基金资助战略.

Rational Design of Plasmonic Nanoparticle-Molecule Complexes for Chirality Sensing

Comprehensive Summary,Sensing the chirality of molecules is of great importance to fields such as enantioselective synthesis,pharmaceutical industry,and biomedicine.Plasmonic nanoparticles are ideal candidates for molecular sensing due to their inherent plasmonic properties that significantly enhance their sensitivity to surrounding molecules.Developing plasmonic nanoparticle-molecule complexes for chirality sensing has drawn enormous attention in recent years due to their intriguing properties and potential applications.Thus,in this review,we believe it is timely to circumnavigate the rational design of plasmonic nanoparticle-molecule complexes and widen the scope of their emerging applications in chirality sensing.First,we present different fundamental mechanisms for plasmon-based chirality that are built on the system of plasmonic nanoparticle-molecule complexes.Second,we review the typical applications of plasmonic nanoparticle-molecule complexes in chirality sensing.Third,we discuss the emerging biomedical applications that the plasmon-based chirality has attracted enormous interest.Finally,we provide an outlook on the challenges and opportunities in the field of plasmonic approaches for chirality sensing.

铁电体热释电循环的能量转换机理

环境中的废热可以被铁电体在变温和变电场的热释电循环中转换为电能.然而,铁电体的极化强度随外界条件的变化一直是待解的难题.本文根据电场作用下铁电体中偶极子在三维空间转动的唯象理论,引入偶极子的耦合效应解决了极化强度在一定初始条件下随温度和电场的变化规律,推导出了奥尔森热释电循环中温度和电场对极化强度和热释电转换效率的影响规律.通过数值模拟得到如下结论:热释电循环的等高温线与电滞回线的上曲线重合;等低温线在电滞回线的中线与上线之间,由所加最大电场决定;热释电循环时,低温端的温度越接近居里点,以及高温端的温度略高于居里点,会有较高且较为稳定的热释电转换效率.上述结论与实验结果基本相符.

Bone-inspired(GNEC/HAPAAm)hydrogel with fatigue-resistance for use in underwater robots and highly piezoresistive sensors

A novel bone-inspired fatigue-resistant hydrogel with excellent mechanical and piezoresistive properties was developed,and it exhibited great potential as a load and strain sensor for underwater robotics and daily monitoring.The hydrogel was created by using the high edge density and aspect ratio of graphene nanosheet-embedded carbon(GNEC)nanomaterials to form a three-dimensional conductive network and prevent the expansion of microcracks in the hydrogel system.Multiscale progressive enhancement of the organic hydrogels(micrometer scale)was realized with inorganic graphene nanosheets(nanometer scale).The graphene nanocrystals inside the GNEC film exhibited good electron transport properties,and the increased distances between the graphene nanocrystals inside the GNEC film caused by external forces increased the resistance,so the hydrogel was highly sensitive and suitable for connection to a loop for sensing applications.The hydrogels obtained in this work exhibited excellent mechanical properties,such as tensile properties(strain up to 1685%)and strengths(stresses up to 171 kPa),that make them suitable for use as elastic retraction devices in robotics and provide high sensitivities(150 ms)for daily human monitoring.

Chiral AuCu heterostructures with site-specific geometric control and tailored plasmonic chirality

Rational design and construction of chiral-achiral hybrid structures are of great importance to realize the multifunctional complex chiral structures toward emerging technological applications. However, significant challenges remain due to the lack of fine control over the heterostructure. Here, we have developed a general bottom-up synthetic strategy for the site-selective growth of Cu nanodomains on intrinsically chiral Au nanocrystals. Chiral AuCu heterostructures with three distinct architectures were achieved by controlling the overgrowth of Cu nanodomains in a site-specific manner. The geometry-dependent plasmonic chirality of the heterostructures was demonstrated experimentally by circular dichroism spectroscopy and theoretically through finite-difference time-domain simulations. The site-specific geometric control of chiral AuCu heterostructures was also extended to employ anisotropic chiral Au nanoplates and nanorods as the building blocks. By virtue of the galvanic replacement reactions between metal ions and Cu atoms, chiral heterostructures with increasing architectural complexity and compositional diversity can be further achieved. The current work not only opens up a promising strategy to synthesize complex chiral hybrid nanostructures but also provides an important knowledge framework that guides the rational design of multifunctional chiral hybrid nanostructures toward chiroptical applications.

Recent status and advanced progress of tip effect induced by micro-nanostructure

The unique structural features represented by micro-nanoneedle tip structure reflect wonderful physical and chemical properties.The tip effect includes the concentration of energy such as electrons,photons and magnetism in the tip region,which has promising applications in the fields of energy conversion,water capture,environmental restoration and so on.In this review,a comprehensive and systematic summary of the latest advances in the application of the tip effect in different fields is provided.Utilizing advanced Finite Difference Time Domain simulation,we further propose our understanding of the fundamental mechanism of the tip effect induced by micro-nanostructure.However,we need to forge the present study to further reveal the essential law of the tip effect from the perspective of theoretical calculations.This review would provide a solid foundation for further development and application of the tip effect.

iHypoxia:An Integrative Database of Protein Expression Dynamics in Response to Hypoxia in Animals

Mammals have evolved mechanisms to sense hypoxia and induce hypoxic responses.Recently,high-throughput techniques have greatly promoted global studies of protein expression changes during hypoxia and the identification of candidate genes associated with hypoxiaadaptive evolution,which have contributed to the understanding of the complex regulatory networks of hypoxia.In this study,we developed an integrated resource for the expression dynamics of proteins in response to hypoxia(iHypoxia),and this database contains 2589 expression events of 1944 proteins identified by low-throughput experiments(LTEs)and 422,553 quantitative expression events of 33,559 proteins identified by high-throughput experiments from five mammals that exhibit a response to hypoxia.Various experimental details,such as the hypoxic experimental conditions,expression patterns,and sample types,were carefully collected and integrated.Furthermore,8788 candidate genes from diverse species inhabiting low-oxygen environments were also integrated.In addition,we conducted an orthologous search and computationally identified 394,141 proteins that may respond to hypoxia among 48 animals.An enrichment analysis of human proteins identified from LTEs shows that these proteins are enriched in certain drug targets and cancer genes.Annotation of known posttranslational modification(PTM)sites in the proteins identified by LTEs reveals that these proteins undergo extensive PTMs,particularly phosphorylation,ubiquitination,and acetylation.iHypoxia provides a convenient and user-friendly method for users to obtain hypoxia-related information of interest.

Realizing simultaneously excellent energy storage and discharge properties in AgNbO_(3)based antiferroelectric ceramics via La^(3t)and Ta^(5+)co-substitution strategy

AgNbO_(3)based antiferroelectric(AFE)ceramics have large maximum polarization and low remanent polarization,and thus are important candidates for fabricating dielectric capacitors.However,their energy storage performances have been still large difference with those of lead-based AFEs because of their room-temperature ferrielectric(FIE)behavior.In this study,novel La^(3+)and Ta^(5+)co-substituted AgNbO_(3)ceramics are designed and developed.The introduction of La^(3+)and Ta^(5+)decreases the tolerance factor,reduces the polarizability of B-site cations and increases local structure heterogeneity of AgNbO_(3),which enhance AFE phase stability and refine polarization-electric field(PeE)loops.Besides,adding La^(3+)and Ta^(5+)into AgNbO_(3)ceramics causes the decrease of the grain sizes and the increase of the band gap,which contribute to increased Eb.As a consequence,a high recoverable energy density of 6.79 J/cm3 and large efficiency of 82.1%,which exceed those of many recently reported AgNbO_(3)based ceramics in terms of overall energy storage properties,are obtained in(Ag0.88La0.04)(Nb0.96Ta0.04)O_(3)ceramics.Furthermore,the discharge properties of the ceramic with discharge time of 16 ns and power density of 145.03 MW/cm3 outperform those of many lead-free dielectric ceramics.

Osiers-sprout-like heteroatom-doped carbon nanofibers as ultrastable anodes for lithium/sodium ion storage

We report an in situ carbothermic reduction process to prepare osiers-sprout-like heteroatom-doped carbon nanofibers. The dosage of copper salts and a unique annealing process have a crucial effect on the development of this unique carbon structure. A systematic analysis is performed to elucidate the possible mechanism of synthesis of the carbon nanofibers decorated with carbon bubbles. As anodes for rechargeable lithium/sodium ion batteries, the heteroatom-doped nanofibers exhibit high reversible capacities and satisfactory long-term cycling stabilities. The osiers-sprout-like heteroatom-doped carbon nanofiber electrodes deliver an ultrastable cycling performance with reversible capacities of 480 and 160 mAh·g^-1 for lithium-ion and sodium-ion batteries after 900 cycles at a current density of 800 mA·g^-1, respectively.

Tuning ferroelectricity of polymer blends for flexible electrical energy storage applications

Ferroelectric polymers are the mainstay of advanced flexible electronic devices.How to tailor the ferroelectric polymer films for various applications via simple processing approaches is challenging.Here we demonstrate the tuning of ferroelectric responses can be achieved in polymer blends of poly(vinylidene fluoride-trifluoroethylene)(P(VDF-TrFE))and polymethyl methacrylate(PMMA)prepared via a simple two-step process.The proposed two-step process endows the polymer blends with a random distribution of P(VDF-TrFE)crystalline phase,hence decoupling the coherent ferroelectric domain interactions between continuous ordered crystalline phases that ubiquitously existed in common P(VDF-TrFE)film.The incorporation of the miscible non-crystalline PMMA chains with low-polarity results in reversal dipoles and a transition from ferroelectric to antiferroelectric-like behavior,overcoming the trade-off between the polarization and depolarization fields.In particular,resultant excellent mechanical and electrical properties of the polymer blend films give rise to remarkably improved breakdown strength and energy storage performance,surpassing P(VDF-TrFE)and commercial biaxial-oriented polypropylene films.This work provides a simple and effective strategy to tailor the ferroelectric response of polymeric materials with great potential for flexible electrical energy storage applications.

Phenylboronic acid-modified hollow silica nanoparticles for dual-responsive delivery of doxorubicin for targeted tumor therapy

This work reports a multifunctional nanocarrier based on hollow mesoporous silica nanoparticles(HMSNs)for targeting tumor therapy.Doxorubicin(DOX)was loaded into HMSNs and blocked with cytochrome C conjugated lactobionic acid(CytC–LA)via redox-cleavable disulfide bonds and pH-disassociation boronate ester bonds as intermediate linkers.The CytC–LA was used both as sealing agent and targeting motif.A series of characterizations demonstrated the successful construction of the drug delivery system.The system demonstrated pH and redox dual-responsive drug release behavior in vitro.The DOX loading HMSNs system displayed a good biocompatibility,which could be specifically endocytosed by HepG2 cells and led to high cytotoxicity against tumor cells by inducing cell apoptosis.In vivo data(tumor volume,tumor weight,terminal deoxynucleotidyl transferase dUTP nick end labeling and hematoxylin and eosin staining)proved that the system could deliver DOX to tumor site with high efficiency and inhibit tumor growth with minimal toxic side effect.