摘要：全球变暖对人类的生产生活造成了严重的威胁,已成为当今世界面临的重大挑战之一.碳中和这一重要举措能够有效缓解全球变暖的进程,在这一背景下光催化CO_(2)还原可有效减少碳排放且促进碳循环.g-C_(3)N_(4)因其制备工艺简单、稳定性高、能带位置适宜以及优异的光催化性能而备受关注.因此,提高g-C_(3)N_(4)光催化CO_(2)还原效率是当前研究的热点问题.本文重点探究了碳中和对于全球生态平衡和环境可持续发展的重要性以及在碳中和背景下g-C_(3)N_(4)光催化CO_(2)还原的重要作用和发展前景;综述了目前解决限制g-C_(3)N_(4)光催化CO_(2)还原瓶颈问题的方法和技术手段.对g-C_(3)N_(4)在光催化CO_(2)还原领域存在的问题进行讨论,提出了未来的研究方向,并进行展望.本综述旨在为碳中和背景下基于g-C_(3)N_(4)催化剂光催化CO_(2)还原的应用提供理论支持,为基于g-C_(3)N_(4)高效CO_(2)还原光催化剂的设计提供思路.

摘要：单原子位点催化剂(SSCs)由于能够产生丰富的活性物质来清除类芬顿体系中的污染物,而显示出广阔的潜力.然而,在高级氧化工艺中,实现金属原子100%的利用率和减少金属浸出以满足环境安全标准是困难的.在此基础上,利用强极化力获得了Co原子含量极低(~0.17%)的催化剂,提高了金属原子利用率,降低了抗生素消除过程中金属浸出的风险.正如预期,该催化剂具有有限的Co位点,伴随着丰富的缺陷和大量从大孔到中孔再到微孔分布的骨架,实现了快速的四环素降解(0.07133 min^(−1))和优异的归一化速率常数(k per-site,2.4726×10^(5) min^(−1) M^(−1)).实验和理论结果均表明,充分暴露具有丰富C-N缺陷的Co位点,可以提高Co活性位点的电子密度,降低过硫酸盐(PDS)的吸附能,从而优化Co原子对PDS活化的利用.该研究为设计高性能、环境友好的水修复用SSCs提供了有价值的见解.

摘要：由可见光驱动的将CO_(2)转化为高附加值燃料是一种清洁可再生的技术,有助于控制全球变暖和应对能源短缺.近年来,二维的金属偶氮盐框架(2D MAFs)因其特定的电子传输路径、高度暴露的表面活性位点及可调节的吸光能力,在CO_(2)光还原研究中备受关注.然而,对其在该领域的研究仍处于初级阶段.本文设计了一种新型二维MAFs(compound 1),通过四-(4-四唑基苯基)乙烯(H;4;TTPE)与钴的自组装实现了对CO_(2)的光还原.作为对比,通过类似的合成过程构建了具有三维结构的compound 2.非均相光催化实验结果显示,2D compound 1的光还原性能明显优于3D compound 2,在相同条件下,其CO产率高达11.56 mmol g^(-1)h^(-1),是compound 2(1.94 mmol g^(-1)h^(-1))的6倍.这一性能优势源于compound 1独特的二维结构,其不仅具有有利于CO_(2)还原的能级,还能在整个CO_(2)光还原过程中促进电子-空穴高效分离.本工作为设计适用于高效CO_(2)光还原的2D MAFs光催化剂指引了方向.

摘要：Si C nanowires are excellent high-temperature electromagnetic wave (EMW) absorbing materials. However, their polymer matrix composites are difficult to work at temperatures above 300℃, while their ceramic matrix composites must be prepared above 1000℃ in an inert atmosphere. Thus, for addressing the abovementioned problems, SiC/low-melting-point glass composites were well designed and prepared at 580℃ in an air atmosphere. Based on the X-ray diffraction results, SiC nanowires were not oxidized during air atmosphere sintering because of the low sintering temperature. Additionally, SiC nanowires were uniformly distributed in the glass matrix material. The composites exhibited good mechanical and EMW absorption properties. As the filling ratio of SiC nanowires increased from 5wt%to 20wt%, the Vickers hardness and flexural strength of the composite reached HV 564 and 213 MPa, which were improved by 27.7%and 72.8%, respectively, compared with the low-melting-point glass. Meanwhile, the dielectric loss and EMW absorption ability of SiC nanowires at 8.2–12.4 GHz were also gradually improved. The dielectric loss ability of low-melting-point glass was close to 0. However, when the filling ratio of SiC nanowires was 20wt%, the composite showed a minimum reflection loss (RL) of-20.2 dB and an effective absorption (RL≤-10 dB) bandwidth of2.3 GHz at an absorber layer thickness of 2.3 mm. The synergistic effect of polarization loss and conductivity loss in SiC nanowires was responsible for this improvement.

摘要：Pressurized irrigation systems are economically justifiable for medium-to large-scale farms,while fewer choices are available for *** current research work provides additional options for small plots,as the only income source for low-income farmers in poorer countries,which produce a considerable portion of the agricultural products in some regions of the *** this research,two novel layouts of a semipermanent sprinkler irrigation system,namely,clock hand(CH)and corner pivot(CP)lateral designs,were designed for a lighter irrigation system to lower the cost *** new techniques were based on a quadrant/full circle movement pattern of manually pivoting laterals,with no/shorter main pipe requirements,which causes a higher system *** retrofitted layouts were examined in different farms with areas of 0.20 hm^(2),0.81 hm^(2),1.62 hm^(2),and 3.24 hm^(2) in Guangxi,*** study introduced,analyzed,and compared the layouts with the widespread traditional split lateral method on technical planning,components,implementation,operation details,size optimization,performance evaluation,and economic *** comparison with the traditional system,CH and CP were found to be more user-friendly and cost-effective but slightly complicated in design with higher required manual *** results revealed a distribution uniformity(LQDU)of 81.0%to 84.0%via the catch can method,lower capital costs(35.0%-45.0%),and lower annual expenses(6.5%-9.8%)for CP and CH,respectively,compared to the split lateral *** 0.81 hm^(2) and 1.62 hm^(2) farms were found to be the optimum farm sizes for implementation of the new methods for a 25-year project time *** outcomes of this experimental work can encourage small farm owners with limited capital to apply pressurized systems for efficient irrigation and water resource sustainability.

摘要：合理设计铂纳米颗粒尺寸是制备高效氧还原电催化剂的关键.本工作中,我们借助静电纺丝和ZIF-8的双重限域作用合成了超细铂纳米颗粒锚定在多孔碳纳米纤维上的催化材料.低Pt负载(4.2 wt%)的Pt@PCNFs在碱性和酸性电解质中均表现出优异的氧还原反应活性,其质量活性分别为41和51 A gPt^(-1),分别是商业Pt/C催化剂相应值的8倍和10倍.在不同温度的碱性和酸性环境的计时安培试验和加速稳定性实验中, Pt@PCNFs的稳定性均优于Pt/C基准.该催化剂的优异性能可归因于小尺寸的Pt纳米颗粒、丰富多孔的纤维结构、Pt纳米颗粒与N掺杂碳纳米纤维之间的强金属载体相互作用以及碳壳层的保护作用.

摘要：Functionalized hydrogels stimulate the migration and morphogenesis of endothelial cells(ECs)and are useful substrates for wound *** present study investigates the feasibility of covalent conjugation of taurine(Tau)on a gelatin-based *** hydrogel is expected to maintain positive charged growth factors such as basic fibroblast growth factor(bFGF)and vascular endothelial growth factors(VEGFs)near ECs within the hydrogel *** gelatin was conjugated with hydroxyl phenol(Ph)and Tau moieties,and in following that Ph residues were crosslinked through a horseradish peroxidase-catalyzed *** migration characteristics of ECs were analyzed by scratch migration assay and microparticle-based cell migration *** morphology and amounts of angiopoietin 1(Ang 1),bFGF,and VEGF proteins were evaluated for encapsulated *** potential of synthesized hydrogels in wound healing was assessed by the percentage of reduction from the original wound size and histopathological analyses of rat *** incorporated Tau molecules within the hydrogel remained stable through covalent bonds during *** extended incubation,the gelatin-based hydrogel conjugated with Tau improved the migration distance and number of existing migrated *** Tau within the gelatin-based hydrogel induced high motility of ECs,accompanied by robust cytoskeleton extension and a cell subpopulation that expressed CD44 and CD31 receptors as well as enhancement of Ang 1,bFGF,and *** found that injectable Gel-Ph-Tau effectively improves wound-healing parameters.

摘要：Since the start of the Precision Medicine Initiative by the United States of America in 2015,interest in personalized medicine has grown *** short,personalized medicine is a term that describes medical treatment that is tuned to the *** possible way to realize personalized medicine is 3D *** using materials that can be tuned upon stimulation,4D printing is *** recent years,many studies have been exploring a new field that combines 3D and 4D printing with *** has resulted in many concepts of pharmaceutical devices and formulations that can be printed and,possibly,tailored to an ***,the first 3D printed drug,Spritam®,has already found its way to the *** review gives an overview of various 3D and 4D printing techniques and their applications in the pharmaceutical field as drug delivery systems and personalized medicine.

摘要：当前,高渗透性反渗透膜材料的研究引起了广泛的关注,然而高渗透导致的浓差极化与膜污染加剧等瓶颈问题限制了高性能膜材料的应用发展.本工作采用机器学习结合超级计算提出了针对先进反渗透膜材料的组件进水隔网(亚毫米级)与系统(米级)的多尺度优化设计新方法.在进料含盐度35,000 ppm,回收率50%典型工况下,对标目前国际先进海水反渗透淡化工艺,本文提出的优化方案能使淡水制备比能耗(1.66 k Wh/m^(3))降低27.5%,所需膜面积减少约37.2%,系统最大浓差极化因子控制在工程允许范围以内(<1.20),可有效缓解高渗透膜系统中膜污染问题,为高性能膜材料精准设计提供理论依据、计算工具和大数据支撑,有重要的应用潜力.本文提出的机器学习结合超算的多尺度设计新研究范式,突破了基于“试错法”的传统单一尺度组件设计限制,高通量并行计算规模可扩展至93,120核以上,较串行算法计算效率提升3000倍以上,可大幅度缩短高性能膜组件的设计周期.

摘要：Hydrogels are a class of special materials that contain a large amount of water and behave like *** materials have found broad applications in tissue engineering,cell culturing,regenerative medicine ***,the exploration of peptide-based supramolecular hydrogels has greatly expanded the repertoire of hydrogels suitable for biomedical ***,the mechanical properties of peptide-based hydrogels are intrinsically ***,it is crucial to develop methods that can improve the mechanical stability of such peptide-based *** this review,we explore the factors that determine or influence the mechanical stability of peptide-based hydrogels and summarize several key elements that may guide scientists to achieve mechanically improved *** addition,we exemplified several methods that have been successfully developed to prepare hydrogels with enhanced mechanical *** mechanically strong peptide-based hydrogels may find broad applications as novel *** is still challenging to engineer hydrogels in order to mimic the mechanical properties of biological *** hydrogel materials with optimal mechanical properties suitable for various types of biological applications will be available in the near future.