深冷处理对Cr14Mn2V2高铬铸铁组织转变和磨损性能的影响

分别采用X射线衍射(XRD)、电子透射电镜(TEM)和磨损测量(WT)等方法研究了深冷处理对高铬铸铁显微组织和磨损行为的影响。深冷处理能有效地降低高铬铸铁中的残余奥氏体含量,促进细微碳化物的析出,但不能完全将奥氏体转化为马氏体。大量马氏体的形成和微小二次碳化物的析出,显著提高了高铬铸铁的耐磨性。当残余奥氏体含量约为15%时,材料的耐磨性能达到最好,残余奥氏体量较多或较少都不利于耐磨性的提高。结果表明,亚临界加深冷处理试样的磨损性能较未深冷的试样有较大的提高。     

Study of TiC+TiN Multiple Films On Type of 316L Stainless Steel

RECENTLY there has been great progress on theresearch of chemical vapor deposition(CVD)techniques for making various films on type of316Lstainless steel substrates11'2].The coated stainless steelis a kind of osmosis hydrogen(H2),deuterium(H2)andtritium(H3)resistance material'31.We have successfullyprepared multiple TiC(Titanium carbide)+TiN(Titanium nitride)membranes on type of316L stainlesssteel by HTCVD process.In this paper,we will studydifferent CVD processes in preparing TiC+…     

氢对Zr-4合金在400℃时的低周疲劳性能的影响

用TEM分析了氢在Zr-4合金中存在的形式，用MTS809A／T拉扭试验机（25kN）研究了氢对Zr-4合金在400℃低周疲劳性能的影响。实验中采用对称拉压循环（Rε=εmin／εmax=-1），三角波加载：应变速率为2×10^-3s^-1。研究结果表明：在室温下，氢以艿氢化物的形式存在于Zr-4合金中，艿氢化锆基本与轧面平行；氢含量为240μg／g的Zr-4合金的低周疲劳性能优于无氢Zr-4合金。采用氢致软化机制讨论了氢提高Zr-4合金低周疲劳性能的原因。     

预涂CuO的二氧化钛薄膜光催化性能与结构研究

载波片上浸涂一层CuO的TiO2薄膜会诱导金红石相生成，并有效提高其光催化活性，其中预涂一层含量1．0％（质量分数，下同）Cu（CH3COO）2水溶液其光催化活性增幅最大（提高53％）。结果表明：TiO2薄膜晶格畸变越大，金红石型TiO2含量越高，薄膜光催化性能就越好。扫描电镜显示预涂一层CuO的TiO2薄膜颗粒粒径较纯TiO2薄膜小。X射线光电子能谱研究表明，预涂一层CuO的TiO2薄膜中Ti^3＋含量较纯TiO2薄膜高。     

DEGRADATION BEHAVIORS OF NEW TYPE TiV-BASED HYDROGEN STORAGE ELECTRODE ALLOYS

The degradation behaviors of the TiV-based multiphase hydrogen storage alloy Ti0.8,Zr0.2V3.2Mn0.64 Cr0.96Ni1.2 during electrochemical cycling in alkaline electrolyte have been studied by XRD, SEM, EIS and AES measurements. XRD analysis indicates that the alloy consists of a C14-type Laves phase and a V-based solid solution. The lattice parameters of both phases are increased after discharged with cycling, which indicates that more irreversible hydrogen remains not discharged in the alloy. It should be responsible for the decrease of discharge capacity. SEM micrographs show that after 10 electrochemical cycles, a large number of cracks can be observed in the alloy, existing mainly in the V-based solid solution phase. Moreover, after 30 cycles, the alloy particles are obviously pulverized due to the larger expansion and shrinkage of cell volumes during hydrogen absorption and desorption, which induces the fast degradation of the TiV-based hydrogen storage alloys. EIS and AES measurements indicate that some passive oxide film has been formed on the surface of alloy electrode, which has higher charge-transfer resistance, lower hydrogen diffusivity, and less electro-catalytic activity. Therefore it can be concluded that the pulverization and oxidation of the alloy are the main factors responsible for the fast degradation of the TiV-based hydrogen storage alloys.     

Shape Transformable Strategies for Drug Delivery

In tumor therapy, nanodrug delivery systems have gained momentum in the last decade. However, its efficacy remains insufficient for clinical applications. The physical properties of nanoparticles, including size, shape, and surface characteristics, can strongly affect the delivery efficacy. Ironically, research on shape function is relatively scarce, although the nanoparticle shape greatly impacts their performance; for example, nanorods with a high aspect ratio (AR) achieve greater accumulation, but their penetration is relatively weak. Hence, rather than selecting a suitable AR to balance them, the strategy of a transformable AR (i.e., transformation) is ideal in this case. Nanoparticle transformation can be achieved by either internal stimuli (such as pH and enzymes) or external stimuli (such as light) spatially and temporally with precision, thereby dramatically enhancing the efficiency of drug delivery. Thus, nanoparticle transformation is becoming a promising prospect for improving cancer treatment. In this review, first, the effect of shape on drug delivery is summarized, then, the recently transformable drug delivery systems are reviewed, and finally, the future direction of shape-transformable nanoparticles in tumor therapy is discussed.     

一款高速、低功耗的Sigma-Delta模数转换器

提出了一种高速、低功耗、高分辨率的新型Sigma-Delta模数转换器(ADC)结构。该结构选择过采样率(OSR)为32的4阶调制器设计以缓解输出速率和通带宽度的压力,采用级联和双量化的方法进行优化,并利用SIMSIDES工具(基于Simulink的Sigma-Delta仿真器)进行仿真。数字抽取滤波器部分由级联积分梳状(CIC)滤波器、有限长单位冲激响应(FIR)滤波器和半带(HB)滤波器组成,并且三级滤波器都采用了多相分解结构,以降低动态功耗。使用0.18μm的标准CMOS工艺实现数字抽取滤波器版图。仿真结果表明,在250 kHz带宽下,有效位宽(ENOB)为19 bit。     

Multi-focus images fusion via residual generative adversarial network

Multimedia Tools and Applications - Recently, most existing learning-based fusion methods are not fully end-to-end, which still predict the decision map and recover the fused image by the refined...     

Global existence of three-dimensional incompressible magneto-micropolar system with mixed partial dissipation,magnetic diffusion and angular viscosity

The magneto-micropolar fluid flows describe the motion of electrically conducting micropolar fluids in the presence of a magnetic field. The issue of whether the strong solution of magneto-micropolar equations in three-dimensional can exist globally in time with large initial data is still unknown. In this paper, we deal with the Cauchy problem of the three-dimensional magneto-micropolar system with mixed partial dissipation, magnetic diffusion and angular viscosity. More precisely, the global existence of smooth solutions to the three-dimensional incompressible magneto-micropolar fluid equations with mixed partial dissipation, magnetic diffusion and angular viscosity are obtained by energy method under the assumption that $H^1$-norm of the initial data $(u_0,b_0,w_0)$ sufficiently small, namely $6u_0,b_0,{\omega }_0{6}_{H^1\left({\mathbb{R}}^3\right)}^2\le \frac{\epsilon }{2}$, where $\epsilon$ is a sufficiently small positive number. This work follows the techniques in the paper of Cao and Wu (2011).     

Fractional Wishart processes and ε-fractional Wishart processes with applications

In this paper, we introduce two new matrix stochastic processes: fractional Wishart processes and $\epsilon$-fractional Wishart processes with integer indices which are based on the fractional Brownian motions and then extend $\epsilon$-fractional Wishart processes to the case with non-integer indices. Both processes include classic Wishart processes (if the Hurst index $H$ equals $\frac{1}{2}$) and present serial correlation of stochastic processes. Applying $\epsilon$-fractional Wishart processes to financial volatility theory, the financial models account for the stochastic volatilities of the assets and for the stochastic correlations not only between the underlying assets’ returns but also between their volatilities and for stochastic serial correlation of the relevant assets.