Advances in CIGS thin film solar cells with emphasis on the alkali element post-deposition treatment

In the past tens of years,the power conversion efficiency of Cu(In,Ga)Se2(CIGS)has continuously improved and been one of the fastest growing photovoltaic technologies that can also help us achieve the goal of carbon emissions reduction.Among several key advances,the alkali element post-deposition treatment(AlK PDT)is regarded as the most important finding in the last 10 years,which has led to the improvement of CIGS solar cell efficiency from 20.4%to 23.35%.A profound understanding of the influence of alkali element on the chemical and electrical properties of the CIGS absorber along with the underlying mechanisms is of great importance.In this review,we summarize the strategies of the alkali element doping in CIGS solar cell,the problems to be noted in the PDT process,the effects on the CdS buffer layer,the effects of different alkali elements on the structure and morphology of the CIGS absorber layer,and retrospect the progress in the CIGS solar cell with emphasis on the alkali element post deposition treatment.

Exogenous Inoculation of Microorganisms Effect on Root Exudates and Rhizosphere Microorganism of Tobaccos

Studying the relationship between rhizosphere microorganisms and root exudates is of great significance for the interaction between rhizosphere microorganisms and plants, and the prevention and control of soil-borne diseases. This article analyzed the effects of different microorganisms on tobacco root exudates and rhizosphere microorganisms. It was found that the bacterial wilt pathogen can greatly increase acids and amines, while the probiotic B. amyloliquefaciens ZM9 can eliminate some acids and amines. The results of the study show that the root exudates of pathogenic bacteria may contain a variety of allelochemicals that cause soil-borne diseases.

Polyimide separators for rechargeable batteries

Separators are indispensable components of modern electrochemical energy storage devices such as lithium-ion batteries(LIBs).They perform the critical function of physically separating the electrodes to prevent short-circuits while permitting the ions to pass through.While conventional separators using polypropylene(PP) and polyethylene(PE) are prone to shrinkage and melting at relatively high temperatures(150℃ or above) causing short circuits and thermal runaway,separators made of thermally stable polyimides(PIs) are electrochemically stable and resistant to high temperatures,and possess good mechanical strength-making them a promising solution to the safety concerns of LIBs.In this review,the research progress on PI separators for use in LIBs is summarized with a special focus on molecular design and microstructural control.In view of the significant progress in advanced chemistries beyond LIBs,recent advances in PI-based membranes for applications in lithium-sulfur,lithium-metal,and solid-state batteries are also reviewed.Finally,practical issues are also discussed along with their prospects.

Comparative study on wheel-rail dynamic interactions of side-frame cross-bracing bogie and sub-frame radial bogie

Improving freight axle load is the most effective method to improve railway freight capability; based on the imported technologies of railway freight bogie, the 27 t axle load side-frame cross-bracing bogie and sub-frame radial bogie are developed in China. In order to analyze and compare dynamic interactions of the two newly developed heavy-haul freight bogies, we establish a vehi- cle-track coupling dynamic model and use numerical calculation methods for computer simulation. The dynamic performances of the two bogies are simulated separately at various conditions. The results show that at the dipped joint and straight line running conditions, the wheel-rail dynamic interactions of both bogies are basically the same, but at the curve negotiation condition, the wear and the lateral force of the side-frame cross-bracing bogie are much higher than that of the sub-frame radial bogie, and the advantages become more obvious when the curve radius is smaller. The results also indicate that the sub- frame radial bogie has better low-wheel-rail interaction characteristics.

Construction of Lactuca sativa Plastid Transformation Vector and High-level Expression of gfp Gene in Escherichia coli

Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragments of exogenous gene were integrated to construct lettuce plastid expression vector p Brpo AGFP,which harbored the expression cassette Prrn-gfp-aad A-Tpsb A. The results showed that the amplified flanking fragments were 1.2 and 1.1 kb in size. After sequencing,restriction digestion,ligation and transformation,lettuce plastid expression vector containing expression cassette Prrn-gfp-aad A-Tpsb A was constructed and confirmed by SDS-PAGE electrophoresis. The results of SDS-PAGE electrophoresis indicated that gfp gene was efficiently expressed under the regulation of plasmid specific promoter Prrn and terminator Tpsb A. GFP accounted for 45. 6% of total soluble proteins; inclusion bodies accounted for 47.5 % of bacterial proteins,which reached relatively high expression levels. The construction of lettuce plastid expression vector p Brpo A-GFP laid a solid foundation for establishment of subsequent lettuce plastid transformation system and genetic improvement of lettuce using various functional genes.

Cloning and Sequence Analysis of Polygalacturonase(PG) Promoter in Tomato

In this study, 1 500 bp PG gene promoter was amplified from leaves of tomato cultivar ＇ Zhongshu No. 4＇. The bioinformatic analysis of PG promoter sequences was conducted. PG promoter elements were predicted and analyzed by PLANTCARE and PLACE. The results showed that tomato PG promoter contained multiple c/s-acting regulatory elements such as typical basic elements TATA-Box and CAAT-Box, light responsive elements 3-AF1 binding site, ATl-motif, ATCT- motif, Box 4, Box I, GA-motif, GTl-motif, Spl and MRE, heat stress-responsive element HSE, ethylene-responsive element ERE, meristem-specifie regulatory element CCGTCC-box, endosperm expression-related regulatory elements GCN4_motif and Skn-l_motif, defense and stress responsiveness element TC-rich repeats, and circadian control-related element circadian, indicating that the expression of tomato PG gene is related to light, temperature, hormone, stress and other factors. This study laid the foundation for subsequent research about regulation of PG gene expression in plants.

Speed-up Multi-modal Near Duplicate Image Detection

Near-duplicate image detection is a necessary operation to refine image search results for efficient user exploration. The existences of large amounts of near duplicates require fast and accurate automatic near-duplicate detection methods. We have designed a coarse-to-fine near duplicate detection framework to speed-up the process and a multi-modal integra-tion scheme for accurate detection. The duplicate pairs are detected with both global feature (partition based color his-togram) and local feature (CPAM and SIFT Bag-of-Word model). The experiment results on large scale data set proved the effectiveness of the proposed design.

Influence of Curve Geometric Parameters on Curving Performance of Sub-frame Radial Bogie

Based on the theory of vehicle-track coupling dynamics,the coupling dynamic model of the freight car mounted with the sub-frame bogies and the numerical model of curved track were established,utilizing the fast numerical integration method,the curving performance of the vehicle was simulated to study the influence of the curve geometric parameters such as curve radius,transition curve length and superelevation of outer rail on the wheel-rail dynamic interaction.The simulation results indicate that:(1)Increasing the curve radius can decrease the wheel-rail wear,but the effect will weaken while the curve radius is greater than 800m.(2)If the transition curve length is less than 30m,vibrations will appear at the transition-circle connecting point,and the smaller the transition length,the bigger the vibrations,the worse the wheel-rail wear,but when the length is bigger than 50m,its further variation has very little effect on wheel-rail wear.(3)The superelevation of outer rail can affect the distribution and difference of the inner and outer wheel-rail forces,and too large deficient or excessive superelevation will worsen the wheel-rail wear either.However,an appropriate deficient superelevation of outer rail(e.g.<20mm)is helpful to reduce the wheel-rail wear,which is consistent with the engineering practice of settling a certain deficient superelevation value.

Effects of long-term blood pressure variability on renal function in community population

High blood pressure is a significant contributor to premature mortality,resulting in nearly 10 million deaths and over 200 million disabilities worldwide.1 In recent years,hypertension treatment has shifted focus not only to average blood pressure but also to blood pressure variability(BPV),categorized into very short-term,short-term,and long-term BPV based on the time period of occurrence.2,3 Long-term BPV has emerged as clinically significant,with studies demonstrating its superiority in predicting long-term cardiovascular events,stroke,and mortality compared to short-term variability.Given its association with pre-renal function decline,reducing blood pressure fluctuations is imperative.

4.3%铜锌锡硫硒太阳能电池组件

铜锌锡硫硒半导体材料组成元素储量丰富、绿色环保、稳定性高,由其制备的薄膜太阳能电池效率已接近15%的商业化基准线.然而,目前铜锌锡硫硒太阳能电池的研究主要集中于有效面积小于1 cm~2的单节电池,面向商业化应用的组件还未见报道.本文报道面积10.5 cm~2的铜锌锡硫硒太阳能电池组件,该组件基于二甲亚砜前体溶液法制备,效率达到4.25%.与单节电池相比,效率损失率为56.8%.扫描电子显微镜形貌及元素组成分析结果表明:通过激光(P1,P2)和机械(P3)划线成功实现了模块化和串联集成;溶液制备工艺在P1凹槽沉积了更厚的吸收层,有利于降低横向电荷传输电阻;在皮秒激光划线下未观察到吸收层材料的金属化.组件的成功制备将铜锌锡硫硒薄膜太阳能电池向实际应用推进了一步.

Electrochemical scanning probe microscopies for artificial photosynthesis

The rational design of efficient artificial photosynthetic components requires thorough understandings towards(photo)electrochemical properties and kinetic processes at the solid/liquid interface.Electrochemical scanning probe microscopy(EC-SPM),which enables the high-spatial resolution imaging in an electrolyte environment,becomes an indispensable experimental technique for operando studies of(photo)electrochemistry.This review summarizes the latest results of relevant ECSPM techniques to study the interfacial properties of electrocatalysts and photoelectrodes.Covered methods include atomic force microscopy,Kelvin probe force microscopy,conductive atomic force microscopy,scanning tunneling microscopy,scanning electrochemical microscopy,and other advanced SPM-based operando techniques.Finally,we offer some perspectives on the future outlook in this fascinating research area.

Pyrolysis of single carbon sources in SBA-15: A recyclable solid phase synthesis to obtain uniform carbon dots with tunable luminescence

Most of carbon dots(CDs) are synthesized in solutions, but the extensive use of solvents produces too much waste, needs complex purification and results in low yield. Particularly for the popular hydrothermal/solvothermal syntheses, safety issues hinder the large-scale production of CDs. Solid phase synthesis in air seems perfect to solve the above problems once for all, but nanoparticle growth in solid phase is always difficult to control. Here we suggest a new method to synthesize CDs in SBA-15 template, just by heating single carbon sources in air. Employing single carbon sources is important, which ensures both homogeneity of the nucleation and uniformity of the nanoparticle growth. The pores confinement of SBA-15 guarantees the uniform sizes of CDs, while the catalytic effect of SBA-15 accelerates the carbonization process of precursors. The products are easily extracted from the template by ethanol, and then the template can be recycled for the next synthesis after calcination. Various CDs are synthesized in this way by using different carbon sources and SBA-15 templates with different pore diameters, respectively. The results show that, the fluorescence properties of these CDs are determined by their composition and surface states, but not the particle sizes. This work opens a new avenue to synthesize uniform CDs in solid phase with high yield, low cost and tunable luminescence.

Rumen microbiota-host transcriptome interaction mediates the protective effects of trans-10,cis-12 CLA on facilitating weaning transition of lambs

Developing alternatives to antibiotics for prevention of gastrointestinal dysbiosis in early-weaning farmed animals is urgently needed.This study was to explore the potential effects of trans-10,cis-12 conjugated linoleic acid(CLA)on maintaining ruminal homeostasis of young ruminants during the weaning transition period.Thirty neonatal lambs were selected(6 lambs per group)and euthanized for rumen microbial and epithelial analysis.The lambs were weaned at 28 d and experienced the following 5 treatments:euthanized on d 28 as the pre-weaning control(CON0),fed starter feed for 5(CON5)or 21(CON21)d,fed starter feed with 1%of CLA supplemented for 5(CLA5)or 21(CLA21)d.Results showed that the average daily weight gain and dry matter intake were significantly higher in CLA5 than CON5 group.As compared with the CON5 and CON21 group,the relative abundances of volatile fatty acid(VFA)producing bacteria including Bacteroides,Treponema,Parabacteroides and Anaerovibrio,as well as the concentrations of acetate,butyrate and total VFA were significantly increased in CLA5 and CLA21 group,respectively.Integrating microbial profiling and epithelial transcriptome results showed that 7 downregulated inflammatory signaling-related host genes IL2RA,CXCL9,CD4,CCR4,LTB,SPP1,and BCL2A1 with CLA supplementation were significantly negatively correlated with both VFA concentration and VFA producing bacteria,while 3(GPX2,SLC27A2 and ALDH3A1)and 2(GSTM3 and GSTA1)upregulated metabolism-related genes,significantly positively correlated with either VFA concentration or VFA producing bacteria,respectively.To confirm the effects of CLA on epithelial signal transduction,in vitro experiment was further conducted by treating rumen epithelial cells without or with IL-17A+TNF-αfor 12 h after pretreatment of 100μM CLA or not(6 replicates per treatment).The results demonstrated the anti-inflammatory effect of CLA via suppressing the protein expression of NF-кB p-p65/p65 with the activation of peroxisome proliferator-activated receptor gamma(PPARγ).In conclusion,CLA supplementation enhanced the ruminal microbiota-driven transcriptional regulation in healthy rumen epithelial development via rumen VFA production,and CLA may therefore serve as an alternative way to alleviate early-weaning stress and improve physiological and metabolic conditions of young ruminants.

Correction to“Multifunctional Flexible Vanadium Dioxide Films”

The author affiliation of the author Ying Zhu should be changed to“State Key Laboratory of High-Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China”.Miss Zhu received her M.S.in Materials Engineering from Shanghai Institute of Ceramics,Chinese Academy of Sciences,in 2020.Then she became a joint Ph.D.student of The University of British Columbia,Canada and Southern University of Science and Technology,China.

Multifunctional Flexible Vanadium Dioxide Films

CONSPECTUS:As a typical phase transition material,vanadium dioxide(VO_(2))has attracted much attention due to its amazing metal−insulator transition(MIT)at the critical temperature of 68°C,which could be driven by multiple stimuli,including electricity,thermal irradiation,THz waves,strain,etc.In the MIT process,VO_(2)exhibits significant changes in its structure from monoclinic structure at low temperature to rutile structure at high temperature,accompanied by significant modulation of physical properties,such as the infrared transmittance from high to low and a resistivity drop over 5 magnitudes.Based on these features,VO_(2)has functioned as thermochromic coatings,sensors,switches,electronic devices,actuators,etc.However,the vanadium element possesses multiple valent states and can produce complicated thermodynamics of vanadium oxides.The fabrication of tetravalence VO_(2)with desirable phase-transition features usually requires rigorous fabrication conditions with a precisely controlled atmosphere for stoichiometric components and high temperatures for good crystallinity.Under these circumstances,it is difficult to directly fabricate crystalline VO_(2)films on flexible polymer substrates because most of them could not stand such high temperatures(usually>400°C),which will lead to the loss of the substrate functionality.However,the featured phase transition of VO_(2)makes it a promising candidate for future flexible devices,while VO_(2)owns great potential as flexible optical coatings,flexible sensors,flexible electronics,etc.Hence,research on flexible VO_(2)films is necessary and could largely pave the way to the application field of VO_(2)material.In this Account,we start with a brief introduction to phase transition properties of VO_(2)to reveal the intrinsic advantages as key materials in flexible devices.Next,multifunctional devices based on flexible VO_(2)films with different forms and characteristics are presented,including(1)flexible VO_(2)-film-based thermochromic smart windows for energy-saving function depending on the change of environmental temperatures,(2)flexible VO_(2)films optical devices based on the changing emissivity of VO_(2),(3)flexible VO_(2)films with compatibility as multifunctional sensors,(4)next-generation flexible electronics based on VO_(2)films,and(5)flexible VO_(2)actuators with significant mechanical motions under external stimuli.Meanwhile,various fabrication technologies of flexible VO_(2)films have been introduced and discussed.Finally,we end the Account with an overview of the remaining challenges and new opportunities that have been opened up for vanadium dioxide in new forms of flexible optical and electronic devices.We hope this Account will inspire new innovative designs,fabrication approaches,and more possible functions of flexible VO_(2)films in future work.