Multifunctional phase change film with high recyclability, adjustable thermal responsiveness, and intrinsic self-healing ability for thermal energy storage

Phase change materials(PCMs) present promising potential for guaranteeing safety in thermal management systems.However,most reported PCMs have a single application in energy storage for thermal management systems,which does not meet the growing demand for multi-functional materials.In this paper,the flexible material and hydrogen-bonding function are innovatively combined to design and prepare a novel multi-functional flexible phase change film(PPL).The 0.2PPL-2 film exhibits solid-solid phase change behavior with energy storage density of 131.8 J/g at the transition temperature of42.1℃,thermal cycling stability(500 cycles),wide-temperature range flexibility(0-60℃) and selfhealing property.Notably,the PPL film can be recycled up to 98.5% by intrinsic remodeling.Moreover,the PPL film can be tailored to the desired colors and configurations and can be cleverly assembled on several thermal management systems at ambient temperature through its flexibility combined with shape-memory properties.More interestingly,the transmittance of PPL will be altered when the ambient temperature changes(60℃),conveying a clear thermal signal.Finally,the thermal energy storage performance of the PPL film is successfully tested by human thermotherapy and electronic device temperature control experiments.The proposed functional integration strategy provides innovative ideas to design PCMs for multifunctionality,and makes significant contributions in green chemistry,highefficiency thermal management,and energy sustainability.

Study on the Effect of Behavioral Interventions Based on the Theory of“Knowledge,Attitude,Practice”on Tuberculosis Cognitive Level of Close Contacts

Objective:Based on the theory of“Knowledge,Attitude,Practice,”health education was carried out for close contact with tuberculosis(TB)at a university in Beijing,and its impact on the students’awareness of TB was studied.This study could provide a reference for effective health education interventions among close contacts of TB in undergraduates.Methods:102 undergraduates who had close contact with one confirmed case of pulmonary TB in April 2021 at a university were randomly divided into a control group and an intervention group.The intervention group was given the“Knowledge,Attitude,Practice”health education intervention by professionally trained doctors,and were asked to complete a self-designed TB-related questionnaire before and after the intervention.Both groups performed the Tuberculin Skin Test(TST)and chest X-ray(CR)examination.Results:The rate of the TST test was 18.6%,and CR examination showed 0 cases of pulmonary TB.The survey results showed that the TB awareness rate(96.1%,49/51)in the intervention group was significantly higher than that of the control group(51.0%,26/51),and the differences in awareness rate between the two groups were statistically significant(P<0.05).Regarding the attitude/skills toward TB,the prevalence rate of tuberculosis-related attitude/behavior in the intervention group(94.1%,47/51)was significantly higher than that of the control group(60.8%,31/51),and the differences between the two groups were statistically significant(P<0.05).Conclusion:Both self-controlled and parallel-controlled studies showed that the health education intervention of“Knowledge,Attitude,Practice”improved the awareness of TB among close contacts of TB in undergraduates.

钙钛矿同质结太阳电池研究进展

钙钛矿太阳电池制备工艺简单,效率提升迅速,被认为是最具应用潜力的新一代光伏技术之一。近年来,大量研究表明,钙钛矿光电材料可以通过自掺杂或外源掺杂的方式实现薄膜导电类型(p型或n型)的定向调控;而具有双层薄膜结构的钙钛矿p-n同质结可以通过薄膜双沉积技术制备,这为钙钛矿同质结太阳电池的设计与制备提供了技术基础。新型钙钛矿同质结太阳电池摒弃传统的电子传输层和空穴传输层,可简化电池结构,不仅有利于提升电池工作稳定性,降低成本,更能进一步释放钙钛矿太阳电池在柔性和半透明应用中的潜力,推动钙钛矿电池的实用化进程。本文围绕钙钛矿同质结太阳电池,综述了钙钛矿光电材料p/n特性掺杂和钙钛矿同质结的研究进展,讨论了钙钛矿同质结太阳电池的基本结构和工作原理,并对其当前存在的技术问题和应用前景进行了总结与展望。

Comparison of total splenic artery embolization and partial splenic embolization for hypersplenism

AIM:To evaluate whether total splenic artery embolization(TSAE) for patients with hypersplenism delivers better long-term outcomes than partial splenic embolization(PSE).METHODS:Sixty-one patients with hypersplenism eligible for TSAE(n = 27,group A) or PSE(n = 34,group B) were enrolled into the trial,which included clinical and computed tomography follow-up.Data on technical success,length of hospital stay,white blood cell(WBC) and platelet(PLT) counts,splenic volume and complications were collected at 2 wk,6 mo,and 1,2,3,4 years postoperatively.RESULTS:Both TSAE and PSE were technically successful in all patients.Complications were significantly fewer(P = 0.001),and hospital stay significantly shorter(P = 0.007),in group A than in group B.Postprocedure WBC and PLT counts in group A were significantly higher than those in group B from 6 mo to 4 years(P = 0.001),and post-procedure residual splenic volume in group A was significantly less than that observed in group B at 1,2,3 and 4 years post-procedure(P = 0.001).No significant differences were observed in red blood cell counts and liver function parameters between the two groups following the procedure.CONCLUSION:Our results indicate that TSAE for patients with hypersplenism not only delivers a better longterm outcome,but is also associated with lower complication rates and a shorter hospital stay than PSE.

Astragalus polysaccharide enhances immunity and inhibits H9N2 avian influenza virus in vitro and in vivo

This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on H9N2 infection was evaluated by an Mqq- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MFIC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV wet enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on HgN2 infection was evaluated by an M]q- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to PIgN2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces HgN2 AIV replication and promotes early humoral immune responses in young chickens.

Functional markers developed from TaGS3, a negative regulator of grain weight and size, for marker-assisted selection in wheat

The TaGS3 homoeologous genes(homoeologs)located on chromosomes 7 A,4 A,and7 D in hexaploid wheat were cloned.Relative expression analysis of the three Ta GS3 homoeologs revealed that the expression levels of TaGS3-4 A and TaGS3-7 D in developing grains were higher than that of TaGS3-7 A.Genetic evidence showed that Ta GS3 was a negative regulator of grain weight and grain size.Fifteen polymorphic sites and five haplotypes were detected in TaGS3-4 A.Two molecular markers were developed to distinguish the five haplotypes.Association analysis using 260 accessions from Chinese wheat mini-core collection(MCC)indicated that TaGS3-4 A affected thousand grain weight(TGW)and grain length(GL).HAP-4 A-1 and HAP-4 A-2 were favorable haplotypes that increased TGW and GL and had undergone strong selection during domestication of wheat.In addition,interaction of the TaGS3-4 A and TaGS3-7 D homoeologs had significant additive effects on the grain traits.Hap-4 A-1/Hap-7 D-2 was the best haplotype combination in increasing TGW and GL.The frequencies and geographic distributions of favorable TaGS3 haplotypes among 1388 wheat accessions from worldwide sources provided clues for selection of yield-related traits.Our findings demonstrated that TaGS3-4 A had significant effects on TGW and GL.Marker-assisted selection of HAP-4 A-1/2 combined with HAP-7 D-2 has potential to increase wheat yields.

Fine mapping and validation of a stable QTL for thousand-kernel weight in wheat(Triticum aestivum L.)

Thousand-kernel weight(TKW)is a measure of grain weight,a target of wheat breeding.The object of this study was to fine-map a stable quantitative trait loci(QTL)for TKW and identify its candidate gene in a recombinant inbred line(RIL)population derived from the cross of Kenong 9204(KN9204)and Jing411(J411).On a high-density genetic linkage map,24,26 and 25 QTL were associated with TKW,kernel length(KL),and kernel width(KW),respectively.A major and stable QTL,QTkw-2D,was mapped to an8.3 cM interval on chromosome arm 2DL.By saturation of polymorphic markers in its target region,QTkw-2D was confined to a 9.13 Mb physical interval using a secondary mapping population derived from a residually heterozygous line(F6:7).This interval was further narrowed to 2.52 Mb using QTkw-2D near-isogenic lines(NILs).NILs~(KN9204)had higher fresh and dry weights than NILsJ411at various grain-filling stages.The TKW and KW of NILs~(KN9204)were much higher than those of NILsJ411in field trials.By comparison of both DNA sequence and expression between KN9204 and J411,TraesCS2D02G460300.1(TraesKN2D01HG49350)was assigned as a candidate gene for QTkw-2D.This was confirmed by RNA sequencing(RNA-seq)of QTkw-2D NILs.These results provide the basis of map-based cloning of QTkw-2D,and DNA markers linked to the candidate gene may be used in marker-assisted selection.

Computational Study of Ternary Devices: Stable, Low-Cost,and Efficient Planar Perovskite Solar Cells

Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In this work, the perovskite configuration of MAPbX(MA = CH_3 NH_3,X = I_3, Br_3, or I_2Br) integrated with stable and low-cost Cu:Ni Oxhole-transporting material, ZnO electron-transporting material, and Al counter electrode was modeled as a planar PSC and studied theoretically. A solar cell simulation program(wx AMPS), which served as an update of the popular solar cell simulation tool(AMPS: Analysis of Microelectronic and Photonic Structures), was used. The study yielded a detailed understanding of the role of each component in the solar celland its effect on the photovoltaic parameters as a whole. The bandgap of active materials and operating temperature of the modeled solar cell were shown to influence the solar cell performance in a significant way. Further, the simulation results reveal a strong dependence of photovoltaic parameters on the thickness and defect density of the light-absorbing layers. Under moderate simulation conditions, the MAPb Br_3 and MAPbI _2 Br cells recorded the highest PCEs of 20.58 and 19.08%, respectively, while MAPbI_3 cell gave a value of 16.14%.

Computing the Moore-Penrose Inverse of a Matrix Through Symmetric Rank-One Updates

This paper presents a recursive procedure to compute the Moore-Penrose inverse of a matrix A. The method is based on the expression for the Moore-Penrose inverse of rank-one modified matrix. The computational complexity of the method is analyzed and a numerical example is included. A variant of the algorithm with lower computational complexity is also proposed. Both algorithms are tested on randomly generated matrices. Numerical performance confirms our theoretic results.

Study on Multi-effect Time Parameters of Ergonomic Validity Index in Low-carbon Residential Kitchen

In the study on functional low-carbon ergonomic validity in buildings,ergonomic validity is different from resource validity which is easy for quantitative analysis. To eliminate the complexity and uncertainty impacts of human factors on quantitative study,it proposes a method of building a parameter of ergonomic validity—multi-effect time by using cardiotachometer to record heart rate change,being used to evaluate the functional low-carbon ergonomic validity targeting at the ontological characteristics of kitchen. This method is used to determine the physical consumption intensity( multi-effect) through heart rate incremental relation based on the principles of physiology and ergonomics,and to confirm the ergonomic validity of environmental factors by the time to complete standard work as well as multi-effect quantitative analysis. The test results show that,under the kitchen operating conditions,the multi-effect( ME) can properly reflect the real-time status of the operator and is easily operated; the parameters obtained are not significantly related to the physiological status of the operator,and multi-effect time( MT) is sensitive to the physical consumption brought about to the operator due to kitchen environmental factors; thus,it can be taken as an objective index,which is simple and easy to operate in residential kitchen functional low-carbon evaluation.

Investigation,Analysis,and Countermeasures of College Teachers'Psychological Pressure

Objective:This paper aims to explore the investigation,analysis,and countermeasures of the psychological pressure of college teachers.Method:From March 2023 to May 2023,3266 college teachers in our city were selected as the research objects,and the sources of their psychological stress were analyzed through a questionnaire survey.Results:In this paper,there were 500 cases of education and teaching pressure accounting for 15.31%,600 cases of research pressure accounting for 18.37%,1000 cases of professional title evaluation pressure accounting for 30.62%,and 1266 cases of life pressure accounting for 35.70%.Conclusion:The psychological pressure on teachers in colleges and universities in our city is relatively high,and this paper puts forward targeted countermeasures for this problem.

建筑碳中和的关键前沿基础科学问题

我国建筑全过程碳排放已占我国碳排放总量的50%以上,持续稳定的降低建筑碳排放将是我国实现碳中和目标的重要支撑。本文基于国家自然科学基金委员会第326期双清论坛总结了面向碳中和的建筑学科领域的研究现状、发展趋势及面对的挑战,凝练出未来5~10年建筑碳中和涉及的关键科学问题与技术前沿。

Effect of pH, milling time, and Isobam content on porous silicon nitride ceramics prepared by gel casting

As a non-toxic copolymer of isobutylene and maleic anhydride,Isobam is successfully used as a dispersant and a gelling agent for fabricating porous Si_(3)N_(4) ceramics by gel casting.The dispersity and rheological properties of the Si_(3)N_(4) slurry are influenced by the pH,milling time,and Isobam content which varies from 0.1 wt.%to 0.6 wt.%,and these factors are investigated.The slurry with 40 vol.%solid content and milled for 4 h has a high zeta potential at pH 12(adjusted by Tetramethyl ammonium hydroxide(TMAH)),which means that the particles are well dispersed.The mechanisms of TMAH are electrostatic repulsion and steric hindrance.The viscosity of the slurry increases with the increase of Isobam content.After pressureless sintering at 1700℃ for 2 h,a uniform unique interlocking microstructure of rod-like β-Si_(3)N_(4) grains is observed,which may improve the flexural strength of the ceramics by intergranular fracture and particle pullout of β-Si_(3)N_(4) grains.The density and porosity of the samples fluctuate negligibly with the increase of Isobam content,and the Si_(3)N_(4) ceramic with 0.1 wt.% Isobam exhibits the highest bending strength of 251.6 MPa among all samples.

土木工程智能防灾减灾研究进展

本文基于国家自然科学基金创新研究群体项目“城市工程结构抗灾韧性与智能防灾减灾”(编号:51921006)和重大研究计划集成项目“高雷诺数湍流数据库的构建及湍流机器学习集成研究”(编号:92152301)的研究,从土木工程防灾减灾学科背景和现状、灾害控制方程物理机器学习求解理论、智能风工程、智能地震工程和防灾减灾智能设计等方面介绍国内外土木工程智能防灾减灾理论体系的研究进展,并对其未来学术发展方向做了探讨和展望。

Comparative genomic and transcriptomic analyses uncover the molecular basis of high nitrogen-use efficiency in the wheat cultivar Kenong 9204

Studying the regulatory mechanisms that drive nitrogen-use efficiency(NUE)in crops is important for sustainable agriculture and environmental protection.In this study,we generated a high-quality genome assembly for the high-NUE wheat cultivar Kenong 9204 and systematically analyzed genes related to nitrogen uptake and metabolism.By comparative analyses,we found that the high-affinity nitrate transporter gene family had expanded in Triticeae.Further studies showed that subsequent functional differentiation endowed the expanded family members with saline inducibility,providing a genetic basis for improving the adaptability of wheat to nitrogen deficiency in various habitats.To explore the genetic and molecular mechanisms of high NUE,we compared genomic and transcriptomic data from the high-NUE cultivar Kenong 9204(KN9204)and the low-NUE cultivar Jing 411 and quantified their nitrogen accumulation under high-and low-nitrogen conditions.Compared with Jing 411,KN9204 absorbed significantly more nitrogen at the reproductive stage after shooting and accumulated it in the shoots and seeds.Transcriptome data analysis revealed that nitrogen deficiency clearly suppressed the expression of genes related to cell division in the young spike of Jing 411,whereas this suppression of gene expression was much lower in KN9204.In addition,KN9204 maintained relatively high expression of NPF genes for a longer time than Jing 411 during seed maturity.Physiological and transcriptome data revealed that KN9204 was more tolerant of nitrogen deficiency than Jing 411,especially at the reproductive stage.The high NUE of KN9204 is an integrated effect controlled at different levels.Taken together,our data provide new insights into the molecular mechanisms of NUE and important gene resources for improving wheat cultivars with a higher NUE trait.

Weighted Moore-Penrose inverses and fundamental theorem of even-order tensors with Einstein product

We treat even-order tensors with Einstein product as linear operators from tensor space to tensor space, define the mill spaces and the ranges of tensors, and study their relationship. We extend the fundamental theorem of linear algebra for matrix spaces to tensor spaces. Using the new relationship, we characterize the least-squares （M） solutions to a multilineax system and establish the relationship between the minimum-norm （N） leastsquares （M）solution of a multilinear system and the weighted Moore-Penrose inverse of its coefficient tensor. We also investigate a class of even-order tensors induced by matrices and obtain some interesting properties.

Acupuncture for migraine without aura:a systematic review and metaanalysis

Background： Migraine without aura （MWoA）, the most common type of migraine, has great impacts on quality of life for migraineurs. Acupuncture is used in the treatment and prevention of migraine for its analgesic effects. Objective： The aim of this systematic review and meta-analysis is to systematically assess the therapeutic and preventive effect of acupuncture treatment and its safety for MWoA,Search strategy： Nine electronic databases （PubMed, MEDLINE, Cochrane Library, Lilacs, Embase, China National Knowledge Infrastructure （CNKI）, Chongqing VIP （CQV1P）, Wanfang Data and Chinese Clinical Trial Registry （ChiCTR）） were systematically searched from their beginning through June 2017 using MeSH terms such as ＂acupuncture, acupuncture therapy, electro-acupuncture, ear acupuncture, acupuncture points, acupuncture analgesia,＂ and ＂migraine disorders, cluster headache.＂ Manual searching included other conference abstracts and reference lists. Inclusion criteria： Randomized controlled trials （RCTs） with a clinical diagnosis of MWoA, which were treated with acupuncture versus oral medication or sham acupuncture treatment. Data extraction and analysis： Two evaluators screened and collected literature independently; they extracted information on participants, study design, interventions, follow-up, withdrawal and adverse events and assessed risk of bias and quality of the acupuncture intervention. The primary outcomes were frequency of migraine （FM） and number of migraine days （NM）. Secondary outcomes included the visual analogue scale （VAS） score, effective rate （ER） and adverse events. Pooled estimates were calculated as mean difference （MD） with 95% confidence interval （CI） for continuous data and relative risk （RR） with 95% CI for dichotomous data. Results： Overall, 14 RCTs including 1155 participants were identified. The analysis found that acupunc- ture had a significant advantage over medication in reducing FM （MD）=-1.50; 95% CI： -2.32 to -0.68; P〈 0.001） and VAS score （MD =0.97; 95% CI： 0.63-1.31; P〈 0.00001） and had a higher ER （RR = 1.30; 95Z Cl： 1.16-1.45; P 〈 0.00001）. Acupuncture also had a significant advantage over sham acupuncture in the decrease of FM （MD = -1.05; 95% CI： -1.75 to -0.34; P=0.004） and VAS score （MD = -1.19; 95g CI： -1.75 to -0.63; P〈 0.0001）. Meanwhile, acupuncture was more tolerated than medication because of less side effect reports （RR= 0.29; 95% CI： 0.17-0.51; P〈 0.0001）. However, the quality of evidence in the included studies was mainly low （to very low）, making confidence in the FM and VAS score results low. Conclusion： Our meta-analysis shows that the effectiveness of acupuncture is still uncertain, but it might be relatively safer than medication therapy in the treatment and prophylaxis of MWoA. Further proof is needed.

Systematic Review and Meta-Analysis of Acupuncture for Pain Caused by Liver Cancer

Objective:The objective of this study is to systematically review and analyze the efficacy of acupuncture for pain caused by primary liver cancer(PLC).Materials and Methods:We searched databases,including PubMed,Medline,Embase,Cochrane Library,Web of Science,China National Knowledge Infrastructure,Chinese Science and Technology Periodicals Database(VIP),Wanfang,and SinoMed/Chinese Biomedical Database(CBM),and retrieved randomized controlled trials(RCTs)that used acupuncture as the primary intervention to treat pain caused by PLC.Two investigators then screened the articles,extracted and pooled data,and evaluated the risk of bias of the included articles according to the Cochrane Handbook.RevMan5.3 was used for the meta-analysis of eligible RCTs.Results:A total of 145 articles were retrieved;after screening,8 RCTs involving 496 patients were eventually included in this meta-analysis.The results showed that acupuncture effectively improved cancer pain and was superior to Western medicine.Moreover,acupuncture was fast-acting for pain relief,prolonged the relief,and prevented relapse.Its adverse reaction rate was also significantly lower than that of Western medicine.No significant difference was observed in Visual Analog Scale score between acupuncture and Western medicine.Conclusion:Acupuncture relieves pain caused by liver cancer and can be used as an adjunct and alternative therapy for drug treatment.The existing research evidence is not yet objective or comprehensive,and more rigorous clinical trials are needed to validate the results.

The Core-EP, Weighted Core-EP Inverse of Matrices and Constrained Systems of Linear Equations

We study the constrained systemof linear equations Ax=b,x∈R(A^(k))for A∈C^(n×n)and b∈Cn,k=Ind(A).When the system is consistent,it is well known that it has a unique A^(D)b.If the system is inconsistent,then we seek for the least squares solution of the problem and consider min_(x∈R(A^(k)))||b−Ax||2,where||·||2 is the 2-norm.For the inconsistent system with a matrix A of index one,it was proved recently that the solution is A^(■)b using the core inverse A^(■)of A.For matrices of an arbitrary index and an arbitrary b,we show that the solution of the constrained system can be expressed as A^(■)b where A^(■)is the core-EP inverse of A.We establish two Cramer’s rules for the inconsistent constrained least squares solution and develop several explicit expressions for the core-EP inverse of matrices of an arbitrary index.Using these expressions,two Cramer’s rules and one Gaussian elimination method for computing the core-EP inverse of matrices of an arbitrary index are proposed in this paper.We also consider the W-weighted core-EP inverse of a rectangular matrix and apply the weighted core-EP inverse to a more general constrained system of linear equations.

Formation mechanisms of Ti_(3)(Si,Al)C_(2)/Al_(2)O_(3) composites from Ti_(3)AlC_(2) and SiO via low-temperature sintering

Ti_(3)SiC_(2)/Al_(2)O_(3) composites have attracted attention due to their excellent mechanical and electromagnetic properties,but the high temperatures(≥1400℃)required for the densification of aluminum oxide(Al_(2)O_(3))leads to the decomposition of Ti_(3)SiC_(2).To address this issue,Ti_(3)(Si_(x)Al_(1−x))C2/Al_(2)O_(3)(x represents the Si content)composites were synthesized for the first time via hot-pressing(HP)sintering and current-assisted sintering(CAS)of mixed Ti_(3)AlC_(2) and silicon monoxide(SiO)powders at 1300 and 1200℃,respectively.Both approaches produced composites with x values greater than 0.9,indicating that the compositions of the prepared composites were similar to those of Ti_(3)SiC_(2)/Al_(2)O_(3) composites.The synthetic mechanism involved substitution and continuous interdiffusion of Al and Si atoms.The composite prepared by CAS at 1200℃ was compacted,whereas the composite prepared by HP had a low density.The low-temperature densification mechanism is attributed to the combined effects of amorphous SiO,liquid Al,and the high heating rates for CAS.The flexural strength and hardness of the composite prepared by CAS were also comparable to those of compacted Ti_(3)SiC_(2)/Al_(2)O_(3) composites.