Distinct behavior of electronic structure under uniaxial strain in BaFe_(2)As_(2)

We report a study of the electronic structure of BaFe_(2)As_(2) under uniaxial strains using angle-resolved photoemission spectroscopy and transport measurements. Two electron bands at the MY point, with an energy splitting of 50 meV in the strain-free sample, shift downward and merge into each other under a large uniaxial strain, while three hole bands at theГ point shift downward together. However, we also observed an enhancement of the resistance anisotropy under uniaxial strains by electrical transport measurements, implying that the applied strains strengthen the electronic nematic order in BaFe_(2)As_(2). These observations suggest that the splitting of these two electron bands at the MY point is not caused by the nematic order in BaFe_(2)As_(2).

大语言模型在电催化领域中的应用

大语言模型作为现代科技的杰出代表,已经在社会的各个领域产生了深远影响.这些模型由数十亿个神经元相互连接构建而成,集成了人类至今为止的丰富知识,具备与全球各地人们进行流畅、精确对话的卓越能力.其类人智能特性不仅使其能够应对现代社会的各种挑战,更在多个科学领域中展现出巨大的应用前景.然而,目前大语言模型广泛应用的潜力尚未被完全挖掘.本文旨在深入探讨现代大语言模型在电催化领域的潜在应用,以期阐明这些人工智能驱动的模型如何助力科研人员深化对催化学科的理解,并推动催化剂的智能设计.通过对大语言模型在电催化领域应用的系统研究,我们期望能够为未来的科研工作提供新的思路和方法.本文首先分析了传统的实验法和多尺度模拟方法在催化研究中的局限性,包括资源消耗大、实验周期长、研究进展缓慢以及受人类自身能力限制等问题.随后,着重探讨了大语言模型在电催化研究中的显著优势,如突破人类认知界限、理论上具备无限知识累积能力等.尽管大语言模型展现出巨大的潜力,但仍面临泛化能力与领域专业性之间的权衡、文本限制等挑战.为应对这些挑战,本文进一步介绍了多模态大语言模型的发展及其在电催化研究中的具体应用,包括与实验者的直接互动、基于实验反馈的持续优化、预训练模型的微调以及结合视觉编码器实现多模态数据融合等.最后,强调了多模态大语言模型在光谱分析、实验路径设计、过渡状态搜索、分子结构设计、催化剂优化和问题诊断等方面的巨大潜力.总之,多模态方法在催化领域具有广泛的应用前景,能够整合多种数据源,为催化剂设计、反应机理研究和反应条件优化提供强大的工具和技术支持.最后,本文展望了大语言模型在科学研究中的作用和未来发展趋势.大语言模型在知识积累和效率提升方面展现出了出色的能力,但在创造全新知识方面,或许还无法与科学先驱相提并论.展望未来,大语言模型应当与实验和模拟方法深度融合,以增强其预测能力和多模态学习能力.通过这样的结合,大语言模型将能够更全面地辅助科学研究者,进而推动科学研究更迅速地发展.这一发展趋势不仅有助于提升科学研究的效率和准确性,还将为科学领域带来更多的创新和突破.

Automatic Sensing and Detection for Subway Tunnel Pathologies

Subway tunnels often suffer from surface pathologies such as cracks,corrosion,fractures,peeling,water and sand infiltration,and sudden hazards caused by foreign object intrusions.Installing a mobile visual pathology sensing system at the front end of operating trains is a critical measure to ensure subway safety.Taking leakage as the typical pathology,a tunnel pathology automatic visual detection method based on Deeplabv3+(ASTPDS)was proposed to achieve automatic and high-precision detection and pixel-level morphology extraction of pathologies.Compared with similar methods,this approach showed significant advantages and achieved a detection accuracy of 93.12%,surpassing FCN and U-Net.Moreover,it also exceeded the recall rates for detecting leaks of FCN and U-Net by 8.33%and 8.19%,respectively.

Bexarotene improves motor function after spinal cord injury in mice

Spinal cord injury is a challenge in orthopedics because it causes irreversible damage to the central nervous system.Therefore,early treatment to prevent lesion expansion is crucial for the management of patients with spinal cord injury.Bexarotene,a type of retinoid,exerts therapeutic effects on patients with cutaneous T-cell lymphoma and Parkinson's disease.Bexarotene has been proven to promote autophagy,but it has not been used in the treatment of spinal cord injury.To investigate the effects of bexarotene on spinal cord injury,we established a mouse model of T11–T12 spinal cord contusion and performed daily intraperitoneal injection of bexarotene for 5 consecutive days.We found that bexarotene effectively reduced the deposition of collagen and the number of pathological neurons in the injured spinal cord,increased the number of synapses of nerve cells,reduced oxidative stress,inhibited pyroptosis,promoted the recovery of motor function,and reduced death.Inhibition of autophagy with 3-methyladenine reversed the effects of bexarotene on spinal cord injury.Bexarotene enhanced the nuclear translocation of transcription factor E3,which further activated AMP-activated protein kinase-S-phase kinase-associated protein 2-coactivator-associated arginine methyltransferase 1 and AMP-activated protein kinase-mammalian target of rapamycin signaling pathways.Intravenous injection of transcription factor E3 sh RNA or intraperitoneal injection of compound C,an AMP-activated protein kinase blocker,inhibited the effects of bexarotene.These findings suggest that bexarotene regulates nuclear translocation of transcription factor E3 through the AMP-activated protein kinase-Sphase kinase-associated protein 2-coactivator-associated arginine methyltransferase 1 and AMP-activated protein kinase-mammalian target of rapamycin signal pathways,promotes autophagy,decreases reactive oxygen species level,inhibits pyroptosis,and improves motor function after spinal cord injury.

Focused-ion-beam assisted technique for achieving high pressure by uniaxial-pressure devices

Uniaxial pressure or strain can introduce a symmetry-breaking distortion on the lattice and may alter the ground states of a material. Compared to hydrostatic pressure, a unique feature of the uniaxial-pressure measurements is that a tensile force can be applied and thus a “negative” pressure can be achieved. In doing so, both ends of the sample are usually glued on the frame of the uniaxial-pressure device. The maximum force that can be applied onto the sample is sometimes limited by the shear strength of the glue, the quality of the interface between the sample and the glue, etc. Here we use focused ion beam to reduce the width of the middle part of the sample, which can significantly increase the effective pressure applied on the sample. By applying this technique to a home-made piezobender-based uniaxial-pressure device, we can easily increase the effective pressure by one or two orders of magnitude as shown by the change of the superconducting transition temperature of an iron-based superconductor. Our method thus provides a possible way to increase the upper limit of the pressure for the uniaxial-pressure devices.

Challenges and Trends for Multifunctional Materials

1.Background Materials science is the study of materials,their properties and their applications.As the rapid de­velopment of material science,materials tend to ap­proach multifunctionality.Multifunctional materials are designed to perform multiple responsibilities through prudent combinations of different functional capabilities.

经皮椎间孔镜技术在腰椎病变中的应用和进展

经皮椎间孔镜技术属于微创技术,具有创伤小、出血少、术后恢复快、术后并发症少、对脊柱稳定性影响小等优点。最初用来治疗的疾病为腰椎间盘突出症(Lumbar Disc Herniation, LDH),即经皮椎间孔镜腰椎间盘切除术(Percutaneous Endoscopic Lumbar Discectomy, PELD)。腰椎间盘突出症是骨伤科的常见病、多发病,大部分通过保守治疗可以达到临床治愈,但保守治疗无效者需要手术治疗。传统手术治疗该病创伤大、出血多、术后恢复慢,随着微创技术的发展,经皮椎间孔镜椎间盘切除术越来越受到脊柱外科医生的青睐。此技术的应用范围也从腰椎间盘突出症扩展到腰椎不稳、椎间盘源性腰痛、腰椎管狭窄等疾病。本文将就此技术的发展概况、麻醉方法、运用范围与临床疗效作一综述。

Supplementation of amylase combined with glucoamylase or protease changes intestinal microbiota diversity and benefits for broilers fed a diet of newly harvested corn

Background: The effect of amylases combined with exogenous carbohydrase and protease in a newly harvested corn diet on starch digestibility, intestine health and cecal microbiota was investigated in broiler chickens.Methods: Two hunderd and eighty-eight 5-day-old female chickens were randomly divided into six treatments: a newly harvested corn-soybean meal diet(control); control supplemented with 1,500 U/g α-amylase(Enzyme A);Enzyme A + 300 U/g amylopectase + 20,000 U/g glucoamylase(Enzyme B); Enzyme B + protease 10,000 U/g(Enzyme C); Enzyme C + xylanase 15,000 U/g(Enzyme D); and Enzyme D + cellulase 200 U/g + pectinase 1,000 U/g(Enzyme E). Growth performance, starch digestibility, digestive organ morphology, and intestinal microbiota were evaluated in the birds at 16 and 23 d of age.Results: Compared with the control diet, supplementation with Enzyme A significantly decreased ileum lesion scoring at 16 d of age(P < 0.05); supplementation with Enzyme B or Enzyme C showed positive effects on ileal amylopectin and total starch digestibility(P < 0.05); Broilers fed with a diet supplemented with Enzyme D had a tendency to decrease body weight gain at 23 d. Enzyme E supplementation improved lesion scoring of jejunum and ileum at 16 d(P < 0.05), and increased ileal amylopectin or total starch digestibility at 23 d(P < 0.05).Supplementation of enzymes changed cecal microbiota diversity. High numbers of Campylobacter, Helicobacter and Butyricicoccus, Anaerostipes and Bifidobacterium, Sutterella and Odoribacter were the main genera detected in supplementations with Enzymes B, C, D, and E respectively.Conclusions: Supplementation with amylase combined with glucoamylase or protease showed a beneficial effect on starch digestibility and intestinal microbiota diversity, and increased growth of broilers fed with newly harvested corn.

In-Plane Anisotropic Response to Uniaxial Pressure in the Hidden Order State of URu_(2)Si_(2)

We investigate the uniaxial-pressure dependence of resistivity for URu_(2−x)Fe_(x)Si_(2)samples with x=0 and 0.2,which host a hidden order(HO)and a large-moment antiferromagnetic(LMAFM)phase,respectively.For both samples,the elastoresistivityζshows a seemingly divergent behavior above the transition temperature T_(0)and a quick decrease below it.We find that the temperature dependence ofζfor both samples can be well described by assuming the uniaxial pressure effect on the gap or certain energy scale except forζ(110)of the x=0 sample,which exhibits a nonzero residual value at 0 K.We show that this provides a qualitative difference between the HO and LMAFM phases.Our results suggest that there is an in-plane anisotropic response to the uniaxial pressure that only exists in the hidden order state without necessarily breaking the rotational lattice symmetry.

Numerical simulation of frost jacking response of a single pile considering hydro-thermo-mechanical coupling

Permafrost is widely distributed in China and around the world.In permafrost regions,soil frost heave and thawing are severe and frequent,and can destabilize pile foundations.To this end,a finite element model of a single pile in frozen soil is established to investigate the frost heave and frost jacking response to ensure its safety in the Qinghai-Tibet Plateau.Firstly,a hydro-thermal coupling model of a single pile in frozen soil is established based on coupling parameters and initial and boundary conditions.Then the temperature and moisture distributions are analyzed through the established coupling model.A hydro-thermo-mechanical coupling model is developed by importing the ice content and temperature results.Simulation results indicate that the amount of frost heave is greater at locations closer to the ground surface,and the displacement is smaller for frozen soil that is closer to the side of the pile.The results on frost jacking behavior of piles from this study can serve as a reference for the design,construction and maintenance of foundations.

Design of Real-Time Document Control Based on Zigbee and Surface Electromyography (sEMG)

The human-computer interaction (HCI) is now playing a great role in computer technology. This study introduces an automatic document control technique which is based on the human hand waving movements. The recognition of hand movement is realized according to the surface electromyography (sEMG). A collector is set on the forearm. The sEMG signal is recorded and conveyed to a PC terminal by using wireless Zigbee. An automatic algorithm is developed in order to extract the characteristics of sEMG, recognize the waving movements, and transmit to document control command. The developed human-computer interaction technique can be used as a new gallery for teaching, as well as an assistant tool for disabled person.

基于数据分析与数据挖掘的社交类Web App开发

随着经济的发展、人们生活水平的提高,外出旅行成为了人们放松娱乐的重要方式。为了让人们在陌生的城市有更好的旅行体验,本论文旨在实现一款基于数据爬取、分析的关于便捷旅行以及社交分享的应用系统,系统包含web端以及手机应用端。

Corrosion behaviors and kinetics of nanoscale zero-valent iron in water:A review

Knowledge on corrosion behaviors and kinetics of nanoscale zero-valent iron(nZVI)in aquatic environment is particularly significant for understanding the reactivity,longevity and stability of nZVI,as well as providing theoretical guidance for developing a cost-effective nZVI-based technology and designing large-scale applications.Herein,this review gives a holistic overview on the corrosion behaviors and kinetics of nZVI in water.Firstly,Eh-pH diagram is introduced to predict the thermodynamics trend of iron corrosion.The morphological,structural,and compositional evolution of(modified-)nZVI under different environmental conditions,assisted with microscopic and spectroscopic evidence,is then summarized.Afterwards,common analytical methods and characterization technologies are categorized to establish time-resolved corrosion kinetics of nZVI in water.Specifically,stable models for calculating the corrosion rate constant of nZVI as well as electrochemical methods for monitoring the redox reaction are discussed,emphasizing their capabilities in studying the dynamic iron corrosion processes.Finally,in the future,more efforts are encouraged to study the corrosion behaviors of nZVI in long-term practical application and further build nanoparticles with precisely tailored properties.We expect that our work can deepen the understanding of the nZVI chemistry in aquatic environment.

Attractive egg color?Red eggs facilitate egg acceptance in a cavity-nesting host

Hosts evolve defensive strategies to minimize the reproductive costs of brood parasitism,in turn,the hosts'defense promote the optimization of cuckoo parasitism strategies(Soler 2017).Recognizing foreign eggs and selectively removing them from the nest can minimize the fitness costs associated with rearing parasitic fledglings(Soler 2017).Since Rothstein(1971)first experimented with the addition of a model egg to a host nest in the early incubation period to study host egg recognition,the use of model eggs has become one of the most important methods for testing the egg recognition abilities of hosts(Hauber et al.2019).Some studies have looked at various egg colors and their effect on host egg rejection and found differential responses to egg colors(for more details,see Supplementary Materials),highlighting that more work needs to examine the effect of model egg color on host egg rejection behavior.

具有NIR-Ⅱ吸收的碳包覆磁铁矿纳米团簇用于成像引导的光热-化学动力学协同治疗

化学动力学疗法(CDT)是基于磁铁矿纳米酶治疗癌症的新兴治疗方式.但是,它的低催化能力和单模治疗限制了其治疗功效.本工作中,我们开发了一种在第二近红外(NIR-Ⅱ)窗口中具有高吸光度的碳涂覆的磁铁矿纳米团簇(CCMNCs),用于NIR-Ⅱ光热增强的化学动力抗癌疗法.这种尺寸约58 nm的CCMNCs通过使用二茂铁作为单一前体的一步溶剂热法合成.CCMNCs不仅用作肿瘤靶向磁共振成像的造影剂,而且还吸收并将NIR-Ⅱ辐射转化为局部热量,用于高温杀死癌细胞.CCMNCs在酸溶液中产生的亚铁离子和铁离子催化Fenton反应生成CDT的羟基自由基(·OH),并减少作为自由基清除剂的细胞内谷胱甘肽.本文报道的CCMNCs通过组合的化学动力学光热处理的协同效应显示出优异的治疗功效.

Fast UV-vis-NIR photoresponse of self-oriented F_(16)CuPc nanoribbons

Controlling the vapor-deposited nanoribbons to grow along a consistent orientation will enable the desired in situ integration of functional devices,representing a major technological advance compared to post-growth processing strategies.In this work,ntype F_(16)CuPc molecules are self-assembled into horizontally-oriented nanoribbons with a consistent growth axis after creating periodic hydrophobic nanogrooves on a sapphire surface.Consequently,electrodes are deposited directly on the growth substrate to enable in situ fabrication of photodetectors.Depending on the deposited electrodes,these horizontally-oriented nanoribbons are connected to form a monolithic photodetector with a large sensing area or an on-chip array of photodetectors with multiple detector units.This in situ integration strategy avoids potential structural damage and contamination from impurities associated with post-growth processing steps.Therefore,the vapor-deposited nanoribbons can retain their high quality during the device manufacturing process,which contributes to performance improvement.As a result,the in-situ integrated F_(16)CuPc photodetectors exhibit a sensitive response in the ultraviolet-visible-near-infrared(UV-vis-NIR)region.The response time is on the order of tens of milliseconds,the fastest record ever for the F_(16)CuPc-based photodetectors.Furthermore,statistics from an array of 6×6 photodetectors show little variation in their sensitivity and response time,and hence this in situ fabrication scheme will contribute to the implementation of on-chip integrated photodetectors with consistent performance based on bottom-up nanoribbons.Overall,this self-oriented growth provides a versatile option to achieve desired in-situ integrated functional devices based on bottom-up nanoribbons.

MoLrp1-mediated signaling induces nuclear accumulation of MoMsn2 to facilitate fatty acid oxidation for infectious growth of the rice blast fungus

Fatty acid b-oxidation is critical for fatty acid degradation and cellular development.In the rice blast fungus Magnaporthe oryzae,fatty acid b-oxidation is reported to be important mainly for turgor generation in the appressorium.However,the role of fatty acid b-oxidation during invasive hyphal growth is rarely documented.We demonstrated that blocking peroxisomal fatty acid b-oxidation impaired lipid droplet(LD)degradation and infectious growth of M.oryzae.We found that the key regulator of pathogenesis,MoMsn2,which we identified previously,is involved in fatty acid b-oxidation by targeting MoDCI1(encoding dienoyl-coenzyme A[CoA]isomerase),which is also important for LD degradation and infectious growth.Cytological observations revealed that MoMsn2 accumulated from the cytosol to the nucleus during early infection or upon treatment with oleate.We determined that the low-density lipoprotein receptor-related protein MoLrp1,which is also involved in fatty acid b-oxidation and infectious growth,plays a critical role in the accumulation of MoMsn2 from the cytosol to the nucleus by activating the cyclic AMP signaling pathway.Our results provide new insights into the importance of fatty acid oxidation during invasive hyphal growth,which is modulated by MoMsn2 and its related signaling pathways in M.oryzae.

黄芪当归贴膏对维持性血液透析患者自体动静脉内瘘的保护作用

目的探讨黄芪当归贴膏联合个体化处理对维持性血液透析(MHD)患者自体动静脉内瘘(AVF)的影响。方法选取2019年3月至2021年5月我院收治的行AVF的MHD患者,随机分为观察组87例和对照组89例。对照组给予个体化处理,观察组在对照组基础上外敷黄芪当归贴膏,治疗2周。比较两组患者干预前后血管直径、吻合口血流量和AVF管路通畅率,以及血清低氧诱导因子-1α(HIF-1α)、血小板衍生生长因子(PDGF)和血管内皮生长因子(VEGF)水平及AVF并发症。结果治疗后,两组血管直径和吻合口血流量均增大,且观察组更为明显(P<0.05),观察组的AVF管路通畅率高于对照组(P<0.05),观察组的HIF-1α、VEGF和PDGF亦明显升高(P<0.05)。观察组的AVF并发症发生率(6.90%)显著低于对照组(25.84%)(P<0.05)。结论黄芪当归贴膏对MHD患者可能具有改善AVF血流、减少AVF并发症的作用。

Integrating deep learning to achieve phase compensation for free-space orbital-angular-momentum-encoded quantum key distribution under atmospheric turbulence

A high-dimensional quantum key distribution(QKD), which adopts degrees of freedom of the orbital angular momentum(OAM) states, is beneficial to realize secure and high-speed QKD. However, the helical phase of a vortex beam that carries OAM is sensitive to the atmospheric turbulence and easily distorted. In this paper, an adaptive compensation method using deep learning technology is developed to improve the performance of OAM-encoded QKD schemes. A convolutional neural network model is first trained to learn the mapping relationship of intensity profiles of inputs and the turbulent phase, and such mapping is used as feedback to control a spatial light modulator to generate a phase screen to correct the distorted vortex beam. Then an OAM-encoded QKD scheme with the capability of real-time phase correction is designed, in which the compensation module only needs to extract the intensity distributions of the Gaussian probe beam and thus ensures that the information encoded on OAM states would not be eavesdropped. The results show that our method can efficiently improve the mode purity of the encoded OAM states and extend the secure distance for the involved QKD protocols in the free-space channel, which is not limited to any specific QKD protocol.

Long-Term Existence of SARS-CoV-2 in COVID-19 Patients:Host Immunity,Viral Virulence,and Transmissibility

COVID-19 patients can recover with a median SARS-CoV-2 clearance of 20 days post initial symptoms(PIS).However,we observed some COVID-19 patients with existing SARS-CoV-2 for more than 50 days PIS.This study aimed to investigate the cause of viral clearance delay and the infectivity in these patients.Demographic data and clinical characteristics of 22 long-term COVID-19 patients were collected.The median age of the studied cohort was59.83±12.94 years.All patients were clinically cured after long-term SARS-CoV-2 infection ranging from 53 to112 days PIS.Peripheral lymphocytes counts were normal.The ratios of interferon gamma(IFN-c)-secreting cells to total CD4^(+)and CD8^(+)cells were normal as 24.68%±9.60%and 66.41%±14.87%respectively.However,the number of IFNc-secreting NK cells diminished(58.03%±11.78%).All patients presented detectable IgG,which positively correlated with mild neutralizing activity(Mean value neutralisation antibodies titers=157.2,P=0.05).No SARS-CoV-2 virus was isolated in Vero E6 cells inoculated with nasopharyngeal swab samples from all patients 50 days PIS,and the cytopathic effect was lacking.But one sample was positive for SARS-CoV-2 nucleic acid test in cell supernatants after two passages.Genome sequencing revealed that only three synonymous variants were identified in spike protein coding regions.In conclusion,decreased IFN-c production by NK cells and low neutralizing antibodies might favor SARS-CoV-2 long-term existence.Further,low viral load and weak viral pathogenicity were observed in COVID-19 patients with long-term SARSCoV-2 infection.