Determination of Some Herbicides by Ring-Oven Technique

Abstract

A Weisz ring-oven technique is described for estimation of some herbicides, using a combination of NaNO₂ and N-1-naphthyl-ethylenediamine dihydrochloride as a spraying reagent for amiben and methanolic NaOH for diquat and paraquat.     

稻壳SiO2/钒催化剂上苯乙酮液相氧化（英文）

Rice husk silica catalyst loaded with 10 wt% vanadium was synthesized from agricultural biomass via a sol-gel synthetic route at pH = 9. The catalyst was characterized by different physico-chemical methods. The FTIR spectra showed the formation of Si–O–V and V=O stretching bands. The presence of vanadium was confirmed by EDX elemental analysis. RH-10V possessed a high specific surface area of 276 m2/g and pore volume of 0.83 ml/g. The prepared catalyst possessed a narrow pore size distribution centered around 7.9 nm. The catalytic performance of RH-10V was tested in the oxidation of acetophenone at 70 ℃. RH-10V was found to be an active catalyst in the oxidation of acetophenone, producing 36.28% conversion efficiency. The products identified were benzoic acid, 2-hydroxyacetophenone, phenol, acetic acid, and 3-hydroxyacetophenone.     

具有分布偏差变元的二阶中立型方程的振动准则(英文)

利用Riccati变换及积分平均技巧,建立一类具有非线性中立项及分布偏差变元的二阶中立型方程的振动准则,我们的结果推广并改进了一些已有的结果.     

Optical nonlinearity measurement of 4-（N-methyl,N-hydroxyethl）amino,4＇-nitroazobenzene using a transmittance technique with a phase object（T-PO） with top-hat beams at 600-nm wavelength

The transmittance technique with a phase object（T-PO）,for measuring optical nonlinear coefficients is proposed with a top-hat beam.The sensitivity of the T-PO with a top-hat beam is a factor of 4 greater than that with a Gaussian beam.The validity of this method is verified by measuring the nonlinearity of a well-characterized liquid,CS 2 at 532-nm wavelength.The ease of use of this method has been proved by measuring a new compound 4-（N-methyl,N-hydroxyethyl）amino,4＇-nitroazobenzene（ANAB） at 600-nm wavelength,indicating that this method can be extended to the measurement of optical nonlinearities in a wide-band spectrum.     

基于代表性频率的介电谱解析形式

基于电介质复折射率的实验数据,采用晟小二乘法结合选取的代表频率拟合得到了电介质的介电谱解析表达式,可以得到电介质在全频段的光频常数和介电常数．研究了三个典型液态电介质,水、乙醇和甲苯的介电谱．在实验数据可以获取的频率范围内,采用解析表达式得到的光频常数与采用Kramers—Kronig转换得到的折射率实部和实验得到的折射率虚部吻合得很好．基于介电谱解析表达式可以预测目前实验无法测量的区域的介电谱．     

Symmetric and skew-symmetric weight functions in 2D perturbation models for semi-infinite interfacial cracks

In this paper we address the vector problem of a 2D half-plane interfacial crack loaded by a general asymmetric distribution of forces acting on its faces. It is shown that the general integral formula for the evaluation of stress intensity factors, as well as high-order terms, requires both symmetric and skew-symmetric weight function matrices. The symmetric weight function matrix is obtained via the solution of a Wiener–Hopf functional equation, whereas the derivation of the skew-symmetric weight function matrix requires the construction of the corresponding full field singular solution.The weight function matrices are then used in the perturbation analysis of a crack advancing quasi-statically along the interface between two dissimilar media. A general and rigorous asymptotic procedure is developed to compute the perturbations of stress intensity factors as well as high-order terms.     

System of set-valued mixed quasi-variational-like inclusionsinvolving H-η-monotone operators in Banach spaces

A new system of the set-valued mixed quasi-variational-like inclusions （SSMQVLI） involving H-η-monotone operators is studied in general Banach spaces without uniform smoothness. By using the resolvent operator technique of H-η-monotone operators, a new iterative algorithm for finding approximate solutions to SSMQVLI is proposed. It is shown that the iterative sequences generated by the algorithm converge strongly to the exact solution of SSMQVLI under appropriate assumptions. These obtained new results have extended and improved previous results.     

Euler solution using adaptive Cartesian grid with a gridless boundary treatment

A quadtree-based adaptive Cartesian grid generator and flow solver were developed. The grid adaptation based on pressure or density gradient was performed and a gridless method based on the least-square fashion was used to treat the wall surface boundary condition, which is generally difficult to be handled for the common Cartesian grid. First, to validate the technique of grid adaptation, the benchmarks over a forward-facing step and double Mach reflection were computed. Second, the flows over the NACA 0012 airfoil and a two-element airfoil were calculated to validate the developed gridless method. The computational results indi- cate the developed method is reasonable for complex flows.     

光纤位移干涉仪在爆轰加载飞片速度测量中的应用

利用光学多普勒效应和外差方法搭建了一台光纤位移干涉仪。装置采用光通信行业中已经发展成熟的器件,主要由带尾纤的半导体激光器、三端口环形器、光纤探头、宽带探测器以及宽带高采样率示波器等构成。整个装置结构简单,价格便宜,采用了信号光和参考光同轴结构,实现了任意反射面的速度测量,克服了偏振模式色散的影响,能够实现长量程测量,量程达到20 mm。利用该装置进行了爆轰加载下飞片速度测量,测量最高速度达到1 300 m/s,工作距离达到20 mm,同时利用VISAR对飞片速度进行了对比测量,结果表明用两种不同方法所测得的速度曲线吻合很好。     

应用数字散斑相关技术研究缺口根部高温疲劳变形

应用数字散斑相关技术研究了耐热合金试件在450°环境中缺口根部的弹塑性变形及其与疲劳循环次数的相关性。疲劳试验在单边带缺口的拉伸板状试件上进行。试件由耐热合金GH4169材料制成,试件表面预先通过离子溅射法制作了离散的金粒散斑图。试验采用逐级循环加载和疲劳循环加载交替的方式进行。首先进行逐级循环加载,将最大载荷Pmax平均分成8级,由0逐级加载至最大载荷,再由最大载荷逐级卸载至0;同时由图像系统半自动地、连续同步地采集系列散斑图。然后按0→Pmax→0加载方式,连续进行250次疲劳循环加载。逐级循环加载和疲劳循环加载不断交替,直至疲劳断裂。利用数字散斑相关技术计算出缺口根部的弹塑性应变,进而求出缺口根部应变、名义迟滞回线面积及斜率与疲劳循环次擞的相关性。试验结果对于耐热合金材料的疲劳寿命研究很有意义。