两相钛合金热加工中初生带状α相形态演变（英文）

为实现钛合金初生带状α相的球化,以具有这种组织的TA15钛合金为对象,研究其在热加工中的组织演变。结果表明:带状α相形态演变的机理与片层组织球化机理相同。由于带状α相尺寸较大,界面分离和末端物质迁移机制较粗化更为重要。带状α相在退火中较为稳定,主要原因是:内部晶界的几何取向不利于球化、带状组织的宽度较大和α粒子几何稳定性高。预变形和低速变形通过以下方式加速球化:直接改变α相的几何形状、通过增加大角度晶界以及相界的面积促进界面分离和末端物质迁移、通过形成位错结构促进粗化。采用大预变形结合高温退火是球化带状α相的有效途径。

在β锻TA15两相钛合金中的变形带（英文）

为了研究在β锻TA15两相钛合金中的变形带,在Gleeble 3500热模拟实验机上进行热模拟压缩试验,同时通过光学显微镜(OM)和电子背散射衍射(EBSD)对显微组织进行研究。研究发现:在TA15钛合金β变形中,变形带在温度高达0.7T_m(T_m为熔点)时仍是重要的组织细化机制。变形带的边界可以是尖锐或者连续变化的。尖锐的变形带界面能够阻碍不连续动态再结晶形核,从而抑制再结晶的发生,而连续变化的界面是连续动态再结晶产生之处。变形带在高应变速率和初始粗晶组织中更加明显。分裂后的晶粒宽度对应变速率敏感,但受温度和初始晶粒尺寸影响较小。多向锻造产生交织的变形带可用于细化小型锻件的组织。

Geochronology and geochemistry of Late Carboniferous dykes in the Aqishan-Yamansu belt,eastern Tianshan:Evidence for a post-collisional slab breakoff

With aim of providing constraints on the Late Paleozoic tectonic evolution of the southern Central Asian Orogenic Belt(CAOB),an integrated study was conducted on the geochronological and geochemical data for dioritic,granitic and diabase dykes from the Aqishan-Yamansu belt in the eastern Tianshan,NW China.Zircon U-Pb dating indicates that the dioritic and granitic dykes were both emplaced in the Late Carboniferous(~311 Ma and^315 Ma).The dioritic dykes show adakitic characteristics and have high Na2 O and positiveεHf(t)values(+12 to+17),which suggest an origin from partial melts of a subducted oceanic slab.The granitic dykes have high SiO2 and K2 O contents and are characterized by en riched light rare earth elements(LREE)and slightly flat heavy rare earth elements(HREE),with negative Eu and Nb-Ta-Ti anomalies.These dykes are alkali-calcic and show geochemical features of highly fractionated Itype granites.Their positiveεHf(t)values(+16 to+17)suggest that they were derived from a juvenile accreted oceanic crustal sou rce.The coeval diabase dykes have low SiO2 and K2 O contents but high TiO2,MgO and Mg#(54-59).They are enriched in LREE and show characteristics of enriched mid-ocean ridge basalts(E-MORB).The relatively high Ba/Th,slightly low Th/Ta ratios,and negative Nb-Ta anomalies imply a mantle source metasomatised by slab-derived fluids.Thus,these basic dykes were generated likely by partial melting of the upwelling asthenosphere mantle with a slight influence of slab-derived fluids.Therefore,we suggest that the formation of these Late Carboniferous dykes were triggered by a post-collisional slab breakoff and the Aqishan-Yamansu belt was a continental arc formed by southdipping subduction of the Kangguer oceanic plate.

Occurrence Regularity and Sexual Pheromone Trapping Effect of Spodoptera litura in Field in Central Guizhou

The Spodoptera litura occurrence quantity in Tianlong Town,Pingba County,Anshun City was dynamically monitored by an insect sex pheromone electronic measurement and forecast system in 2015 and 2016 and the trapped effect of S. litura was studied by the home-made S. litura sex pheromone traps in Baishiyan Town,Ziyun County and Tianlong Town,Pingba County in 2016 to accurately grasp the occurrence regularity of S. litura and apply insect sex pheromone for controlling S. litura in Central Guizhou tobacco-growing region. There are 5 generations of S. litura in a year in Central Guizhou region. The first generation of S.litura occurs from late April to middle May,the second from middle-to-late July to middle-to-late August,the third from early-to-middle August to the end of September,the fourth is in the end of October and the fifth in the end of November. S. litura emigrates or enters into the overwintering stage in December. S. litura is almost in active in the daytime during the peak occurrence period of S. litura adults. The first mating time of S. litura is at 17: 30 and its peak mating time is about 22: 00. The second mating time of S. litura is at 1: 00-5: 00 and its peak mating time is about 2: 30. The trapped S. litura quantity presents an obvious layer-belt distribution that the number in the outer ring is significantly higher than that in the middle ring,and the number in the middle ring is significantly higher than that in the inner ring. The number of trapped S. litura is higher around the outer ring of the testing field and at the draught position than in the low-lying land and inner flat ground.

Effect of Trap Space Layout on Trapped Number of Spodoptera litura in Tobacco Field

[Objectives] This study was to find out the effect of trap space layout on the trapped number of Spodoptera litura in tobacco field. [Methods]From2015 to 2017,investigations were made using different hanging heights,distances( densities) and equidistant plane layout in the tobacco planting area in central Guizhou Province. [Results] The trapped number of S. litura was different at different hanging heights of the trap,and some had the difference reached the5% significant level in the trapped number. The optimum hanging height was 1. 5-2. 0 m. The trapping effect was the best at the field layout distance of20. 0-30. 0 m( density of 5-8 traps/hm^2). Under the conditions of even distribution at the equal distance between traps of 40.0 m in the field,the accumulated trapped number of S. litura from April to August was in the order of outer ring > central ring > inner ring,presenting the zonal distribution. The difference in the trapped numbers was significant among different rings,reaching the 5% significant level. [Conclusions]This study provided theoretical bases for the physiochemical control of S. litura in tobacco field.

企业诚信文化能抑制财务报告重述吗?

文章以2012—2016年中国A股上市公司为样本,通过对企业诚信文化的文本分析及综合评分,实证检验企业诚信文化与财务报告重述的关系。研究发现,企业诚信文化与财务报告重述显著负相关,企业诚信文化在一定程度上能够约束企业行为。进一步研究发现,作为一种正式制度,法制发展与企业诚信文化存在一定的替代效应,即法制环境较差时,企业诚信文化与财务报告重述的负相关性更显著;作为应对代理问题的一种股权激励机制,管理层持股与企业诚信文化对财务报告重述具有一定的互补效应,即企业诚信文化与管理层持股的共存对财务报告重述的约束作用更显著;内部控制是企业诚信文化影响财务报告重述的路径之一。

Crystal orientation and morphology of a lamellae in wrought titanium alloys: On the role of microstructure evolution in b processing

To obtain high-quality aviation forgings of titanium alloys, b forging is an essential processing step which must be considered throughout a production process. In this work, the effect of b forging on the crystal orientation and morphology of lamellar a was experimentally investigated in a two-phase titanium alloy. Strong dynamic recovery during b working resulted in the formation of low-angle grain boundary(LAGBb) inside b grains. The lamellar a can penetrate through the LAGBb, leading to similar intra a LAGBs on subgrain boundaries. Deformation banding occurs at high strain rates, and both diffusive and sharp boundaries of deformation bands can be observed.A continuous change of the b orientation in diffusive boundaries results in the formation of fine and disordered a lamellae without intra-lamellar boundary to hold the Burgers orientation relationship(OR). On sharp boundaries, it is prone to producing continuous grain boundary a(aGB) with a highly similar orientation along the boundaries. Meanwhile, there may exist several lower-angle boundaries within the grain boundary a for a smoother orientation change on the b grain boundary.

Injectable cartilage matrix hydrogel loaded with cartilage endplate stem cells engineered to release exosomes for non-invasive treatment of intervertebral disc degeneration

Low back pain,mainly caused by intervertebral disc degeneration(IVDD),is a common health problem;however,current surgical treatments are less than satisfactory.Thus,it is essential to develop novel non-invasive surgical methods for IVDD treatment.Here,we describe a therapeutic strategy to inhibit IVDD by injecting hydrogels modified with the extracellular matrix of costal cartilage(ECM-Gels)that are loaded with cartilage endplate stem cells(CESCs).After loaded with CESCs overexpressing Sphk2(Lenti-Sphk2-CESCs)and injected near the cartilage endplate(CEP)of rats in vivo,ECM-Gels produced Sphk2-engineered exosomes(Lenti-Sphk2-Exos).These exosomes penetrated the annulus fibrosus(AF)and transported Sphk2 into the nucleus pulposus cells(NPCs).Sphk2 activated the phosphatidylinositol 3-kinase(PI3K)/p-AKT pathway as well as the intracellular autophagy of NPCs,ultimately ameliorating IVDD.This study provides a novel and efficient non-invasive combinational strategy for IVDD treatment using injectable ECM-Gels loaded with CESCs that express Sphk2 with sustained release of functional exosomes.

哺乳动物单细胞研究技术的现状与未来

近年来,生命科学和医学的基础研究已深入到单细胞阶段。单细胞研究为揭示生命活动的基本规律、探索细胞异质性、提高对疾病发病机制的认识等提供了重要的线索和依据,同时,单细胞技术已被应用于日常实践中,如法医学和临床生殖医学。单细胞研究中使用的技术也在不断变化,并越来越复杂。文中主要介绍单细胞分离技术,包括手工挑取、激光捕获显微切割和微流控技术,以及单细胞中DNA、RNA和蛋白质分析方法的各种技术。此外,文中总结了近年来生命科学和医学领域的主要单细胞研究成果,讨论了单细胞相关技术和研究的不足,并介绍了其未来的发展方向。

Visible-Light Photocatalytic and Photo-bactericidal Activity of Ni-CuWO_(4)/OTiO_(2) Composite

A series of nickel-doped copper tungstate/oxygen-rich TiO_(2) heterojunction-constructed composites of xNi-CuWO_(4)/OTiO_(2) were successfully prepared to demonstrate the enhancement of the visible-light photoactivity through promoting the photogenerated charge carrier separation efficiency.Of all these composites,0.2Ni-CuWO_(4)/OTiO_(2) exhibits excellent and stable visible light photoactivity for the photooxidative coupling of benzylamine to the corresponding N-benzyl-1-phenymethanimine(BPMI)in air atmosphere.The conversion of benzylamine and the selectivity to BPMI reach 97%and 99%,respectively.The catalyst shows good cyclability with the conversion of benzylamine decreasing just by 22%after being repeated six times with the well-maintained selectivity of BPMI.The composite also exhibits excellent photo-bactericidal ability,which greatly inhibits the reproducing of both the Gram-positive bacteria(e.g.,S.epidermidis)and Gram-negative bacteria(e.g.,E.coli).

Regulation of the Macrophage Phenotype on Titanium Metal by Surface Modification

The regulation of macrophage phenotype(M1/M2)is very important for tissue repair.The macrophage phenotypes could be affected by the physical and chemical parameters of implant surface.The aim of this study was to investigate the effects of surface modifications of titanium metals on macrophage phenotype.The medical pure titanium metals(PT-Ti)subjected to Anodic Oxidation(AO-Ti),Sand Blasting/acid etching(SLA-Ti)and Plasma-sprayed HA coating(HA coating-Ti)were used for regulating the phenotype of macrophage.The results showed that the Raw264.7 cells of AO-Ti groups had no obvious pseudopodia and could spread evenly in all directions.The levels of IL-1βand TNF-α,which belong to pro-inflammatory genes,expressed by the cells on AO-Ti groups were the lowest among all of the modified titanium groups.But,the levels of IL-10 and TGF-β,which belong to anti-inflammatory genes,expressed on AO-Ti groups were much higher than those on the other groups.Furthermore,the AO-Ti could regulate the expression of SOCS-1 and SOCS-3 to affect the active of NF-κB signaling.The gene expression results of macrophages showed that the AO-Ti was more conductive to inhibit the expression of M1-related genes and promote the expression of M2-related genes in an inflammatory environment.The AO-Ti was more beneficial to tissue repair than other modified titanium metals.The results showed that the anodic oxidation is an effective method to regulate the phenotype of macrophages.

Deep Learning in Predicting Preterm Birth:A Comparative Study of Machine Learning Algorithms

Objective:To determine whether deep learning algorithms are suitable for predicting preterm birth.Methods:A retrospective study was conducted at Peking University Third Hospital from January 2018 to June 2023.Birth data were divided into two parts based on the date of delivery:the first part was used for model training and validation,while real world viability was evaluated using the second part.Four machine learning algorithms(logistic regression,random forest,support vector machine,and transformer)were employed to predict preterm birth.Receiver operating characteristic curves were plotted,and the area under the curve(AUC),sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and accuracy were calculated.Results:This research included data on 30,965 births,where 24,770 comprised the first part,and included 3164(12.77%)in the preterm birth group,with 6195 in the second part,including 795(12.83%)in the preterm birth group.Significant differences in various factors were observed between the preterm and full-term birth groups.The transformer model(AUC=79.20%,sensitivity=73.67%,specificity=72.48%,PPV=28.21%,NPV=94.95%,and accuracy=72.61%in the test dataset)demonstrated superior performance relative to logistic regression(AUC=77.96%in the test dataset),support vectormachine(AUC=71.70%in the test dataset),and random forest(AUC=75.09%in the test dataset)approaches.Conclusion:This study highlights the promise of deep learning algorithms,specifically the transformer algorithm,for predicting pretermbirth.