Cr涂层对Zr-4合金蠕变行为的影响

报道化学气相沉积Cr涂层对Zr-4合金蠕变性能的影响以及Cr涂层在服役温度下的热稳定性。利用扫描电镜、电子探针显微分析和电子背散射衍射研究样品的显微组织。结果表明:样品Zr-4基体中晶粒呈等轴状,存在明显的<0001>//ND织构。蠕变后涂层样品的Zr-4合金基体中亚晶界数量明显低于无涂层样品Zr-4合金基体中亚晶界数量,表明Cr涂层显著降低了Zr-4合金基体在蠕变过程中承载的应力,提高了合金的抗蠕变性能。Cr涂层在长时间扩散实验中保持高稳定性。涂层在高蠕变应力下(350℃时不小于157 MPa,400℃时不小于137 MPa)出现裂纹。系统总结蠕变断裂的数据,得到了关于稳态蠕变速率与蠕变断裂时间的Monkman-Grant关系式。

Residual alkali-evoked cross-linked polymer layer for anti-air-sensitivity LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)cathode

High-energy density lithium-ion batteries(LIBs)with layered high-nickel oxide cathodes(LiNi_(x)Co_(y)Mn_(1-x-y)O_(2),x≥0.8)show great promise in consumer electronics and vehicular applications.However,LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)faces challenges related to capacity decay caused by residual alkalis owing to high sensitivity to air.To address this issue,we propose a hazardous substances upcycling method that fundamentally mitigates alkali content and concurrently induces the emergence of an anti-air-sensitive layer on the cathode surface.Through the neutralization of polyacrylic acid(PAA)with residual alkalis and then coupling it with 3-aminopropyl triethoxysilane(KH550),a stable and ion-conductive cross-linked polymer layer is in situ integrated into the LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)(NCM)cathode.Our characterization and measurements demonstrate its effectiveness.The NCM material exhibits impressive cycling performance,retaining 88.4%of its capacity after 200 cycles at 5 C and achieving an extraordinary specific capacity of 170.0 mA h g^(-1) at 10 C.Importantly,this layer on the NCM efficiently suppresses unfavorable phase transitions,severe electrolyte degradation,and CO_(2)gas evolution,while maintaining commendable resistance to air exposure.This surface modification strategy shows widespread potential for creating air-stable LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)cathodes,thereby advancing high-performance LIBs.

Metastable face-centered cubic ruthenium-based binary alloy for efficient alkaline hydrogen oxidation electrocatalysis

Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocatalysts have been widely investigated toward hydrogen oxidation reaction(HOR)under alkaline electrolytes,these studies are mostly limited to conventional hexagonal-close-packed(hcp)phase,mainly arising from the lack of sufficient synthesis strategies.In this study,we report the precise synthesis of metastable binary RuW alloy with face-centered-cubic(fcc)phase.We find that the introduction of W can serve as fcc phase seeds and reduce the formation energy of metastable fcc-RuW alloy.Impressively,fcc-RuW exhibits remarkable alkaline HOR performance and stability with the activity of 0.67 mA cm_(Ru)^(-2)which is almost five and three times higher than that of hcp-Ru and commercial Pt/C,respectively,which is attributed to the optimized binding strength of adsorbed hydroxide intermediate derived from tailored electronic structure through W doping and phase engineering.Moreover,this strategy can also be applied to synthesize other metastable fcc-RuCr and fcc-RuMo alloys with enhanced HOR performances.

Icariin ameliorates viral myocarditis by inhibiting TLR4-mediated ferroptosis

Objective:To explore the mechanism by which icariin alleviates viral myocarditis.Methods:CVB3-induced cardiomyocytes were used as an in vitro model of viral myocarditis to assess the effects of icariin treatment on cell viability,inflammation,and apoptosis.Moreover,the effects of icariin on ferroptosis and TLR4 signaling were assessed.After AC16 cells were transfected with TLR4 overexpression plasmids,the role of TLR4 in mediating the regulatory effect of icariin in viral myocarditis was investigated.Results:Icariin significantly elevated cell viability and reduced inflammatory factors TNF-α,IL-1β,IL-6,and IL-18.Flow cytometry revealed that icariin decreased apoptosis rate,and the protein expression of Bax and cleaved caspase 3 and 9 in CVB3-induced cardiomyocytes.Additionally,it suppressed ferroptosis including lipid peroxidation and ferrous ion,as well as the TLR4 signaling.However,TLR4 overexpression abrogated the modulatory effects of icariin.Conclusions:Icariin mitigates CVB3-induced myocardial injury by inhibiting TLR4-mediated ferroptosis.Further animal study is needed to verify its efficacy.

Identification of loci and candidate genes controlling kernel weight in barley based on a population for which whole genome assemblies are available for both parents

Kernel weight(KW), together with kernel number per unit area, determines yield of cereal crops. Here,two barley recombinant inbred lines(RILs) populations with a shared parent were used to identify loci controlling KW. One is Baudin/AWCS276(BA) for which a linkage map was available. Several largeeffect QTL controlling KW were detected in this population. Another is Morex/AWCS276(MA). A linkage map with 5273 makers formed 1454 clusters, was constructed by the genotyping by sequence(GBS) data of 201 RILs from this population. A single marker was selected to represent each of the clusters and the linkage map constructed with these markers covers a total length of 1022.4 c M with an average interval of approximately 0.7 cM between loci. Three of the large-effect loci controlling KW(located on 2 HL, 6 HL,and 7 HL, respectively) identified from the BA population were also detected in the MA population under different environments. The locus on 6 HL was detected in each of the experiments conducted for both populations thus was selected for developing near isogenic lines(NILs). Apart from KW, the two isolines for each pair of the putative NILs obtained showed no significant difference for any of the morphological characteristics assessed. The average difference in KW between the isolines for all the NILs obtained was about 15% based on assessments under both glasshouse and field conditions. Taken advantage that high quality genome assemblies for both Morex and AWCS276 are available, we identified candidate genes underlying two of the three loci based on an orthologous analysis. The NILs developed and the candidate genes identified in this study should facilitate the cloning and functional analysis of genes regulating KW in barley.

Growth, Mortality and Stock Assessment of Squaliobarbus curriculus (Actinopterygii: Cypriniformes: Xenocyprididae) from Lanxi Section of Qiantang River, China

Population dynamics parameters and stock status of Squaliobarbus curriculus (Richardson, 1846) were analyzed from May to September 2021 in the Lanxi section of Qiantang River. FiSAT II software program was used. The growth coefficient K = 0.21 year–1, asymptomatic length L∞ = 39.48 cm, and age at theoretical zero-length t0 = –0.74 years were estimated. The von Bertalanffy growth function was calculated as Lt = 39.48[1 – e–0.21(t + 0.74)]. The growth curve for weight had an inflection at 5.86 years, corresponding to 29.61 cm in standard length and 372.29 g in weight. The natural mortality rate (M), the fishing mortality rate (F), and the total mortality rate (Z) were calculated as 0.51, 0.61, and 1.12 year–1, respectively. The exploitation ratio (E) was 0.54, which is greater than the value of 0.5 suggested by Gull (1971), indicating a probable state of overdevelopment. The annual average stock number and biomass of S. curriculus in the Lanxi section of Qiantang River were 31.86 × 106 individuals and 3656.82 t, respectively.

Swarming Responsive Photonic Nanorobots for Motile-Targeting Microenvironmental Mapping and Mapping-Guided Photothermal Treatment

Micro/nanorobots can propel and navigate in many hard-to-reach biological environments,and thus may bring revolutionary changes to biomedical research and applications.However,current MNRs lack the capability to collectively perceive and report physicochemical changes in unknown microenvironments.Here we propose to develop swarming responsive photonic nanorobots that can map local physicochemical conditions on the fly and further guide localized photothermal treatment.The RPNRs consist of a photonic nanochain of periodically-assembled magnetic Fe_(3)O_(4)nanoparticles encapsulated in a responsive hydrogel shell,and show multiple integrated functions,including energetic magnetically-driven swarming motions,bright stimuli-responsive structural colors,and photothermal conversion.Thus,they can actively navigate in complex environments utilizing their controllable swarming motions,then visualize unknown targets(e.g.,tumor lesion)by collectively mapping out local abnormal physicochemical conditions(e.g.,pH,temperature,or glucose concentra-tion)via their responsive structural colors,and further guide external light irradiation to initiate localized photothermal treatment.This work facilitates the development of intelligent motile nanosensors and versatile multifunctional nanotheranostics for cancer and inflam-matory diseases.

光照条件下AuPd合金纳米颗粒上原位形成缺电子Pd位点促进高效的光催化Heck反应

光催化技术通过直接利用太阳光来驱动一系列化学反应,被认为是合成精细化学品的有效手段.光催化反应条件简单温和,避免了传统热催化有机反应所需要的苛刻条件,且有效减少副反应的发生,提高催化反应选择性.传统的半导体光催化剂在光吸收能力和活化有机反应底物等方面均存在一些劣势.近年来,基于贵金属纳米颗粒局域表面等离激元共振效应的新型光催化剂被认为是一种理想的可见光光催化材料,并已受到了广泛关注.通常单一组分的贵金属等离激元纳米颗粒在光催化有机反应中依然表现出一定的局限性.近年来,科研人员发展了一些双金属组分等离激元光催化剂体系,将等离激元组分(如Au)作为光能收集器,与具有催化活性的金属组分(如Pd)耦合形成合金或异质结构,可以实现较好的光催化性能.然而,对双金属组分等离激元光催化的催化微观机制理解仍然存在很大挑战,尤其是光照激发之后如何在等离激元组分和催化活性组分之间实现能量转移,催化剂表面物理化学性质的改变如何促进化学反应的发生等问题值得进一步深入研究.本文以负载型金钯(AuPd)合金纳米颗粒光催化剂为研究对象,利用光照条件下原位X射线光电子能谱研究催化剂表面电荷态,发现在可见光照射下,AuPd合金纳米颗粒上原位形成了缺电子态的Pd位点(Pd^(δ+)),这在双金属组分AuPd合金纳米颗粒光催化中起着决定性作用.AuPd合金纳米颗粒光催化剂对可见光驱动的Heck交叉偶联反应表现出较好的转化率和选择性.光照条件下催化剂表面原位形成的Pd^(δ+)为Heck反应提供了理想的反应平台,在温和条件(40℃)下的催化效率与传统热催化条件(>100℃)下的催化反应相当.催化反应动力学研究结果表明,光催化过程可显著降低反应活化能.反应物分子吸附行为研究结果表明,碘苯分子是在AuPd合金纳米颗粒的Pd位点活化的.此外,机理实验和理论计算结果表明,光催化Heck反应是通过AuPd合金上基于自由基的单电子转移过程进行的,原位形成的Pd^(δ+)提供了有效的催化位点有利于反应物分子的活化.综上,本文揭示了双金属组分等离激元光催化材料用于有机催化反应的新机制.

中国流动人口卫生健康与计划生育动态调查数据:2009-2018年多波大规模全国性横断面调查

这篇数据论文介绍了2009~2018年中国流动人口动态调查(Chinese Migrants Dynamic Survey,CMDS)的数据。CMDS是原国家卫生和计划生育委员会组织开展的全国流动人口的多年度大规模全国性横断面调查。调查对象为15岁以上的国内流动人口,样本取自中国流动人口信息系统,采用多阶段分层抽样方法和概率比例-大小(probability proportional-to-size,PPS)聚类抽样策略进行抽样。2009年至2018年,共有来自23个省、5个自治区和4个直辖市的1,527,650名流动人口参与了该调查。调查工具是由原国家卫生和计划生育委员会组织设计的一系列具有高度继承性和一致性的调查问卷,问卷内容主要包括被调查者及其家庭成员的基本情况、流动状况、医疗保健或健康行为、公共卫生服务利用情况、社会保险情况、社会融合情况、计划生育情况等。该数据集是目前使用最广泛的关于中国流动人口的调查数据,提供了有关流动人口的流动模式、医疗卫生和健康行为、公共卫生服务、社会保障、社会融合和计划生育的信息,对医疗卫生规划、卫生决策和卫生公平研究具有重要价值。

不同剂量利伐沙班对非瓣膜性房颤患者预防血栓形成的药物经济学评价

目的 对比新型口服抗凝药利伐沙班每日1次15 mg或20 mg用于预防非瓣膜性房颤患者血栓形成的成本和效用,为临床合理用药提供参考。方法 采用Markov模型,模拟在30年内两个剂量组的生存状态,分别计算成本和健康产出,获得增量成本-效用比(ICUR)。以3倍的2020年我国人均国内生产总值(GDP)为意愿支付阈值(WTP),判断其经济性。结果 在模拟期限内,20 mg剂量组较15 mg剂量组累计效用改善0.97个质量调整生命年(QALY),ICUR为119 855元/QALY,GDP更高,WTP较低,具有一定的经济性。单因素敏感性分析显示,两种剂量的药品价格和贴现率是影响ICUR的主要因素,由概率敏感性分析可知,在以3倍的人均GDP为WTP时,20 mg剂量有更大的可接受性(65.2%),20 mg的标准剂量具有更大的成本-效用优势。结论对于非瓣膜性房颤患者长期服用利伐沙班预防血栓形成的剂量选择,选择20 mg每日1次的方案相较于15 mg每日1次的方案更具有成本-效用优势。

Pressure control method and device innovative design for deep oil in-situ exploration and coring

Deep oil exploration coring technology cannot accurately maintain the in-situ pressure and temperature of samples, which leads to a distortion of deep oil and gas resource reserve evaluations based on conventional cores and cannot guide the development of deep oil and gas resources on Earth. The fundamental reason is the lack of temperature and pressure control in in-situ coring environments. In this paper, a pressure control method of a coring device is studied. The theory and method of deep intelligent temperature-pressure coupling control are innovatively proposed, and a multifield coupling dynamic sealing model is established. The optimal cardinality three term PID (Proportional-Integral-Differential) intelligent control algorithm of pressure system is developed. The temperature-pressure characteristic of the gas-liquid two-phase cavity is analyzed, and the pressure intelligent control is carried out based on three term PID control algorithms. An in-situ condition-preserved coring (ICP-Coring) device is developed, and an intelligent control system for the temperature and pressure of the coring device is designed and verified by experiments. The results show that the temperature-pressure coupling control system can effectively realize stable sealing under temperature-pressure fields of 140 MPa and 150 °C. The temperature-pressure coupling control method can accurately realize a constant pressure inside the coring device. The maximum working pressure is 140 MPa, and the effective pressure compensation range is 20 MPa. The numerical simulation experiment of pressure system control algorithm is carried out, and the optimal cardinality and three term coefficients are obtained. The pressure steady-state error is less than 0.01%. The method of temperature-pressure coupling control has guiding significance for coring device research, and is also the basis for temperature-pressure decoupling control in ICP-Coring.

Atomic Cu Sites Engineering Enables Efficient CO_(2)Electroreduction to Methane with High CH_(4)/C_(2)H_(4)Ratio

Electrochemical reduction of CO_(2)into high-value hydrocarbons and alcohols by using Cu-based catalysts is a promising and attractive technology for CO_(2)capture and utilization,resulting from their high catalytic activity and selectivity.The mobility and accessibility of active sites in Cubased catalysts significantly hinder the development of efficient Cu-based catalysts for CO_(2)electrochemical reduction reaction(CO_(2)RR).Herein,a facile and effective strategy is developed to engineer accessible and structural stable Cu sites by incorporating single atomic Cu into the nitrogen cavities of the host graphitic carbon nitride(g-C_(3)N_(4))as the active sites for CO_(2)-to-CH_(4)conversion in CO_(2)RR.By regulating the coordination and density of Cu sites in g-C_(3)N_(4),an optimal catalyst corresponding to a one Cu atom in one nitrogen cavity reaches the highest CH_(4)Faraday efficiency of 49.04%and produces the products with a high CH_(4)/C_(2)H_(4)ratio over 9.This work provides the first experimental study on g-C_(3)N_(4)-supported single Cu atom catalyst for efficient CH_(4)production from CO_(2)RR and suggests a principle in designing highly stable and selective high-efficiency Cu-based catalysts for CO_(2)RR by engineering Cu active sites in 2D materials with porous crystal structures.

LOCAL BIFURCATION OF STEADY ALMOST PERIODIC WATER WAVES WITH CONSTANT VORTICITY

In this paper we investigate the traveling wave solution of the two dimensional Euler equations with gravity at the free surface over a flat bed.We assume that the free surface is almost periodic in the horizontal direction.Using conformal mappings,one can change the free boundary problem into a fixed boundary problem for some unknown functions with the boundary condition.By virtue of the Hilbert transform,the problem is equivalent to a quasilinear pseudodifferential equation for an almost periodic function of one variable.The bifurcation theory ensures that we can obtain an existence result.Our existence result generalizes and covers the recent result in[15].Moreover,our result implies a non-uniqueness result at the same bifurcation point.

A Dynamic Plunger Lift Model for Shale Gas Wells

At present,the optimization of the plunger mechanism is shale gas wells is mostly based on empirical methods,which lack a relevant rationale and often are not able to deal with the quick variations experienced by the production parameters of shale gas wells in comparison to conventional gas wells.In order to mitigate this issue,in the present work,a model is proposed to loosely couple the dynamics of gas inflow into shale gas wells with the dynamics of the liquid inflow.Starting from the flow law that accounts for the four stages of movement of the plunger,a dynamic model of the plunger lift based on the real wellbore trajectory is introduced.The model is then tested against 5 example wells,and it is shown that the accuracy level is higher than 90%.The well‘switch’,optimized on the basis of simulations based on such a model,is tested through on-site experiments.It is shown that,compared with the original switch configuration,the average production of the sample well can be increased by about 15%.

Successful multidisciplinary therapy for a patient with liver metastasis from ascending colon adenocarcinoma:A case report and review of literature

BACKGROUND Liver metastasis is the most common form of distant metastasis in colorectal cancer,and the only possible curative treatment for patients with colorectal liver metastases(CRLM)is hepatectomy.However,approximately 25%of patients with CRLM have indications for liver resection at the initial diagnosis.Strategies aimed at downstaging large or multifocal tumors to enable curative resection are appealing.CASE SUMMARY A 42-year-old man was diagnosed with ascending colon cancer and liver metastases.Due to the huge lesion size and compression of the right portal vein,the liver metastases were initially diagnosed as unresectable lesions.The patient was treated with preoperative transcatheter arterial chemoembolization(TACE)consisting of 5-fluorouracil/Leucovorin/oxaliplatin/Endostar®.After four courses,radical right-sided colectomy and ileum transverse colon anastomosis were performed.Postoperatively,the pathological analysis revealed moderately differentiated adenocarcinoma with necrosis and negative margins.Thereafter,S7/S8 partial hepatectomy was performed after two courses of neoadjuvant chemotherapy.Pathological examination of the resected specimen revealed a pathologically complete response(pCR).Intrahepatic recurrence was detected more than two months after the operation,and the patient was then treated with TACE consisting of irinotecan/Leucovorin/fluorouracil therapy plus Endostar®.Subsequently,the patient was treated with aγ-knife to enhance local control.Notably,a pCR was reached,and the patient's overall survival time was>9 years.CONCLUSION Multidisciplinary treatment can promote the conversion of initially unresectable colorectal liver metastasis and facilitate complete pathological remission of liver lesions.

铜纳米颗粒修饰柔性石墨构建无酶葡萄糖传感器

柔性石墨片(FGS)具备优良的导电性与柔韧性,可作为葡萄糖传感器的自支撑载体,解决由于使用黏结剂降低传感器性能的问题。本文采用水热法,使用抗坏血酸还原硫酸铜,在FGS上复合铜纳米颗粒构建Cu/FGS自支撑无酶葡萄糖传感器,在线性范围0.1~3.4 mmol/L内具有较高的灵敏度7254.1μA·mM-1·cm-2(R2=0.9961),较低的检测限1.05μmol/L;在线性范围3.4~5.6 mmol/L灵敏度为3804.5μA·mM-1·cm-2(R2=0.9995)。此外,该电极还有较好的抗干扰性、重复性及稳定性。

无机化学教学中基础知识与前沿研究的协同作用

通过分析两篇前沿研究论文中的基础知识点,阐明了无机化学教学中基础知识与前沿研究的协同作用。

浅谈元素化学教学内容的组织——以Se和Au元素为例

以Se和Au元素为例,展示了元素化学教学内容的组织过程:从单质到化合物,从教材内容到前沿研究,以期让元素化学的授课内容和教授方式更加有趣多样。

Community Characteristics Analysis of Eukaryotic Microplankton via ITS Gene Metabarcoding Based on Environmental DNA in Lower Reaches of Qiantang River, China

Eukaryotic microplankton plays an important role in water biotic community and in maintaining the stability of water ecosystems. Environmental DNA metabarcoding provides the opportunity to integrate traditional and emerging approaches to discover more new species, and develop molecular biotic indices that can be more rapidly, frequently, and robustly used in water quality assessments. In order to examine assemblages of eukaryotic microplankton in lower reaches of Qiantang River, ITS gene metabarcoding technology based on environmental DNA was carried out. As a result, various species of phytoplankton, fungi and zooplankton were annotated on. More phylum, classes and specieses of eukaryotic phytoplankton and zooplankton were found after compared communities taxa based on metabarcoding with that obtained from morphological examination. Nevertheless, Chlorophyceae was the most common assemblage both identified by using these two methods, also Mesocyclops leuckarti and Acanthocyclops bicuspidatus were both found to be the dominant species of Cyclopoida in the river. Additionally, the reads proportions of phytoplankton and zooplankton at the three freshwater sampling sites (Tonglu, Fuyang and Wenyan) decreased as temperature drop. Meanwhile, twenty classes of fungi were annotated on, of which the community characteristic was first researched in the river. There were significant spatial differences in values of Chao1 index for eukaryotic microplankton. Cluster analysis and Non-metric multidimensional scaling ordination further confirmed that the community composition of eukaryotic microplankton at class level for Jiashao-September sample had the most dissimilarity with the others.

高压下的原子和分子行为

近些年,高压化学的研究取得了非常多的成果。本文从基础化学原理出发,讨论高压对原子轨道能量和化学键的影响。高压下,原子轨道能量会发生改变,从而导致核外电子在轨道间的重新排布,影响到元素的化学性质。于分子而言,高压下分子晶体会发生相变,不饱和化合物会发生自聚,饱和化合物则有可能金属化。