Exploring Sulfur Chemistry in TMC-1 with NSRT

There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense clouds.Most of these studies used a C/O ratio of 0.7 or lower.We present NSRT(NanShan 26m Radio Telescope)observations of TMC-1 alongside results from time-dependent chemical simulations using an updated chemical network.Our findings highlight the impact of the C/O ratio on the gas-phase evolution of C2S and C3S.The simulation results show that the C/O ratio is an important parameter,playing a fundamental role in determining the gas-phase abundances of sulfur species in dense cores.

^(40)Ar/^(39)Ar ages of seamount trachytes from the South China Sea and implications for the evolution of the northwestern sub-basin

A chronological study of seamount rocks in the South China Sea basin provides a great opportunity to understand the expansion and evolution history of the sea basin. In this paper, we analyzed the ^40Ar/^39Ar age of trachytic samples collected from the Shuangfeng seamounts in the northwestern sub-basin of the South China Sea. The two samples yielded plateau ages of 23.80 ± 0.18 and 23.29 ± 0.22 Ma, respectively, which indicate magmatic activity in late Oligocene which helpful constraints the expansion time of the northwest sub-basin. Previous studies suggested that the northwestern sub-basin and southwestern sub-basin have experienced a relatively consistent expansion in the NW-SE direction followed by a late expansion of the eastern sub-basin. We concluded that the expansion of the northwestern sub-basin began prior to ca. 24 Ma, which also implicated magmatic events of a late or stop expansion of the northwestern sub-basin combined with our results of^40Ar/^39Ar age data and previous geophysical data.

Petrogenesis and tectonic implication of lavas from the Yap Trench,western Pacific

We present major and trace element data of lava recovered from the northern Yap Trench in the western Pacific and discuss their petrogenesis and tectonic implications within the framework of interactions between the Caroline Ridge and Yap Trench.Rocks were collected from both landward and seaward trench slopes and exhibited geochemical characteristics similar to backarc basin basalt(BABB)and mid-ocean ridge basalt(MORB),including high Fe content,tholeiitic affinity,high TiO_(2) value at a given FeO_(T)/MgO ratio,Ti/V ratio between 20 and50,low Ba/Nb ratio and Th/Nb ratio,and trace element patterns commonly displayed by BABB and MORB,which are distinct from arc lava.These rocks seem to have been generated during mantle upwelling and decompression melting at a spreading center.However,compared with typical forearc lava produced by seafloor spreading in the Mariana forearc region,such as the early Eocene forearc basalts and late Neogene forearc lava in the southernmost Mariana Trench,the Yap Trench lava is derived from a more fertile mantle and feature a more minor subduction component;thus,they cannot be the products of forearc mantle decompression melting.We suggest that the landward slope lava represents backarc basin crust that was overthrust onto the forearc lithosphere during the collision of the Caroline Ridge with the Yap Trench(20–25 Ma),which played a key role in the evolution of the Yap subduction system.Moreover,the seaward slope lava represents the subduction plate crust that accreted onto the deep trench during the collision.This collision event resulted in the cessation of Yap Arc magmatism;thus,the Yap Trench volcanic rocks(<25 Ma)previously suggested to be arc magma products may actually represent the nascent island arc lava with a lower subduction component than in the mature Mariana Arc lava.

Chemical composition and petrogenesis of plagioclases in plagioclase-phyric basalts from the Southwest Indian Ridge(51°E)

Electron microprobe analysis was conducted on plagioclase from the plagioclase ultraphyric basalts(PUBs)erupted on the Southwest Indian Ridge(SWIR)(51°E)to investigate the geochemical changes in order to better understand the magmatic processes occurring under ultraslow spreading ridges and to provide insights into the thermal and dynamic regimes of the magmatic reservoirs and conduit systems.The phenocryst cores are generally calcic(An74–82)and are depleted in FeO and MgO.Whereas the phenocryst rims(An67–71)and the plagioclase in the groundmass(An58–63)are more sodic and have higher FeO and MgO contents than the phenocryst cores.The crystallization temperatures of the phenocryst cores and the calculation of the equilibrium between the phenocrysts and the matrix suggest that the plagioclase cores are unlikely to have crystallized from the host basaltic melt,but are likely to have crystallized from a more calcic melt.The enrichment in incompatible elements(FeO and MgO),as well as the higher FeO/MgO ratios of the outermost phenocryst rims and the groundmass,are the result of plagioclase-melt disequilibrium diffusion during the short residence time in which the plagioclase crystallized.Our results indicate that an evolved melt replenishing under the SWIR(51°E)drives the eruption over a short period of time.

Role of solute in stress development of nanocrystalline films during heating:An in situ synchrotron X-ray diffraction study

The effect of the solute(Mo)on the stress development of nanocrystalline Ni and Ni-Mo films upon heat-ing has been investigated in real time using in situ synchrotron X-ray diffraction.The complex and distinct relationship between the film stress and grain boundaries(GBs)has been examined by the evolution of real-time intrinsic stress in combination with the in situ grain growth and thermal characterizations.The different intrinsic stress evolutions in the Ni and Ni-Mo films during the heating process result from the modification of GBs by Mo alloying,including GB amorphization,GB relaxation,and GB segregation.It has been found that GBs play a vital role in the stress development of nanocrystalline films.The addition of a solute can not only inhibit grain growth but also influence the stress evolution in the film by changing the atomic diffusivity at the GBs.This work provides valuable and unique insights into the effect of solutes on stress development in nanocrystalline films during annealing,permitting control of the film stress through solute addition and heat treatment,which is critical for improving the design,processing,and lifetime of advanced nanocrystalline film devices at high temperatures.

不同内翻负荷对大鼠胫股关节生物力学影响的研究

目的:研究不同内翻负荷下大鼠胫股关节生物力学特性,探讨胫股关节生物力学的改变诱导膝骨性关节炎的发病机制。方法:采集10例SD大鼠下肢Micro-CT影像,利用Mimics和ANSYS等软件构建大鼠膝关节有限元模型,施加0%,50%和100%内翻负荷下,分析大鼠站立时胫股关节的内外侧腔室最大接触压强和接触面积。利用生物力学测试平台设计相应的膝内翻实验验证与有限元分析结果的一致性,统计学方法采用独立样本t检验。结果:有限元分析和实验结果表明:不同内翻负荷下胫股关节最大接触压强和接触面积变化趋势基本一致。与施加0%体重力内翻负荷相比,施加50%体重力内翻负荷和100%体重力内翻负荷的胫股关节内侧腔室最大接触压强和接触面积随着负荷增大而增大,最大增加了0.53 MPa和1.07 mm2。而外侧腔室最大接触压强和接触面积随着负荷增大而减小,最大减小了0.41 MPa和1.84 mm2。研究结果独立样本t检验表明,内、外腔室最大接触压强P>0.05,接触面积P>0.05,在胫股关节生物力学特性上不具有统计学差异。结论:本研究的大鼠胫股关节模型受到内翻负荷时内侧腔室最大接触压强变化与人类KOA发展过程中的胫股关节最大接触压强变化(0.54 MPa)相似,并随着内翻负荷的增大,软骨磨损概率增加,膝骨性关节炎发病风险也随之增大。研究结果可为胫股关节生物力学诱导膝骨性关节炎的发病机制、临床预防和治疗提供依据。

AGING PROPERTIES OF THE LIFETIME IN SIMPLE ADDITIVE DEGRADATION MODELS

这份报纸与单个随机的效果应付简单添加剂降级模特儿。作者进一步学习在暗示一生和随机的变化的变老的性质之间的连接。它两个都被发现那随机的变化和吝啬的降级路径影响的分析行为的变老的性质暗示一生的变老的行为。

A new dynamic bacterial foraging optimization and its application on model reduction

Inspired by the foraging behavior of E.coli bacteria,bacterial foraging optimization(BFO)has emerged as a powerful technique for solving optimization problems.However,BFO shows poor performance on complex and high-dimensional optimization problems.In order to improve the performance of BFO,a new dynamic bacterial foraging optimization based on clonal selection(DBFO-CS)is proposed.Instead of fixed step size in the chemotaxis operator,a new piecewise strategy adjusts the step size dynamically by regulatory factor in order to balance between exploration and exploitation during optimization process,which can improve convergence speed.Furthermore,reproduction operator based on clonal selection can add excellent genes to bacterial populations in order to improve bacterial natural selection and help good individuals to be protected,which can enhance convergence precision.Then,a set of benchmark functions have been used to test the proposed algorithm.The results show that DBFO-CS offers significant improvements than BFO on convergence,accuracy and robustness.A complex optimization problem of model reduction on stable and unstable linear systems based on DBFO-CS is presented.Results show that the proposed algorithm can efficiently approximate the systems.

Investigating Sulfur Chemistry in the HD163296 Disk

Sulfur chemistry in the formation process of low-mass stars and planets remains poorly understood.The protoplanetary disks are the birthplace of planets and its distinctive environment provides an intriguing platform for investigating models of sulfur chemistry.We analyzed the Atacama Large Millimeter/submillimeter Array observations of CS 7-6 transitions in the HD 163296 disk and performed astrochemical modeling to explore its sulfur chemistry.We simulated the distribution of sulfur-containing molecules and compared it with observationally deduced fractional column densities.We have found that the simulated column density of CS is consistent with the observationally deduced fractional column densities,while the simulated column density of C_(2)S is lower than the observationally deduced upper limits on column densities.This results indicate that we have a good understanding of the chemical properties of CS and C_(2)S in the disk.We also investigated the influence of the C/O ratio on sulfur-containing molecules and found that the column densities of SO,SO_(2),and H_2S near the centra star are dependent on the C/O ratio.Additionally,we found that the N[CS]/N[SO]ratio can serve as a promising indicator of the disk’s C/O ratio in HD 163296.Overall,the disk of HD 163296 provides a favorable environmen for the detection of sulfur-containing molecules.

Supermodulus effect by grain-boundary wetting in nanostructured multilayers

The effect of thermal treatments on mechanical properties was systematically investigated in Ni/Mo multilayers with a constant modulation period(160 nm)prepared by magnetron sputtering deposition.A supermodulus effect was found in the annealed multilayers as compared to the as-deposited state.A large tensile stress development was observed in the multilayers.The evolution of grain-boundary(GB)wetting was observed at the interfaces of the multilayers,which results in an enhanced modulus based on the mechanism of GB-wetting-induced interfacial stress/strain.The GB wetting phenomenon was further supported by a thermodynamic calculation.The results not only bring clear evidence of the important role of interfacial structures in governing the elastic behavior of metallic multilayers,but also allow designing the multilayers with special properties through atomic diffusion and wetting at the interfaces based on the thermodynamic calculation.

改革开放以来参政党的履职路径及在新时代的探索——以中国民主同盟为中心的考察

改革开放四十年来,各民主党派立足于实践需要和自身优势,不断探索履行职能的形式和内容,履职活动逐步程序化、制度化、规范化。梳理改革开放以来民主党派的履职路径及在不同时期呈现的不同特点,可以对新时代中国特色社会主义参政党的履职路径创新有所助益。中国特色社会主义新时代,各民主党派要进一步发展完善履行职能的新路径,不断探索参政议政的新领域,完善人才智力资源配置的新机制,丰富参政议政的新载体,切实履行好参政党职能。

生产性服务业集聚、空间溢出效应与区域房价分化

在集聚经济理论和新经济地理理论的基础上探讨生产性服务业集聚对房价分化的作用机制。基于2005~2019年我国生产性服务业和房价的省际面板数据,运用空间面板杜宾模型,实证检验生产性服务业专业化集聚和多样化集聚对区域房价分化的影响。从区域层面来看,东部地区的生产性服务业专业化集聚提升了本省份的房价分化水平,生产性服务业专业化集聚和多样化集聚有助于抑制周边省份的房价分化水平;中部地区的生产性服务业多样化集聚提升了周边省份的房价分化水平,生产性服务业专业化集聚影响有限;西部地区的生产性服务业专业化集聚提升了本省份的房价分化水平,生产性服务业多样化集聚影响有限。分时段来看,在经济刺激计划实施后,生产性服务业集聚对区域房价分化的直接影响和间接影响均有显著提升。本文从多样化集聚和专业化集聚两个方面对生产性服务业聚集对区域房价分化的直接效应、间接效应和总效应进行了较为全面的经验识别。

A NOTE ON THE RIGHT SPREAD ORDER ASSOCIATED WITH EXPONENTIAL DISTRIBUTIONS

这被显示出一个平行系统与的全部的生活独立、相同(i.i.d ) 指数的部件比有象系统的一样的平均数的指数的生活在正确传播顺序是更小的。作为应用，为平均数和有 i.i.d NBUE 部件的一个平行系统的生活长度的变化的简单上面的界限被建立，以及 NBUE 和指数的随机的变量的卷绕旋转的保藏性质。