New Energetic Complexes as Catalysts for Ammonium Perchlorate Thermal Decomposition

Main observation and conclusion In this study,four new energetic complexes (1) [Cu(vimi)4]DCA2,(2) [Co(vimi)4]DCA2,(3) [Ni(vimi)4]DCA2,and (4) [Cu(vimi)4]CBH2 (...     

Theoretical Perspectives on Natural and Artificial Micro-swimmers

The observations of microorganisms revealed how they swim.As inspired by them,studies on artificial micro-robots with various actuation mechanisms have been thr...     

Characterization of Remaining Oil After Polymer Flooding by Laser Scanning Confocal Fluorescence Microscopy

In the mid- to late period of oil field development, it is important to consider the microscopic distribution of remaining oil of the reservoir in time, for it is the foundation of enhanced oil recovery. Focusing on the present insufficient research status of microscopic distribution of remaining oil after polymer flooding, this article first put forward and developed a set of fluorescence microscope technology of frozen core analysis of remaining oil, and used this technology combined with laser confocal microscopic detection technology to study microscopic distribution rules of remaining oil before and after polymer flooding. Through comparison and analysis on the difference of microscopic distribution form of remaining oil, the experimental results show that polymer flooding has different effects on different types of remaining oil. Using this technology, analysis of many different distribution forms of remaining oil involving the same mode of occurrence in different layers, different parts of the same layer, and different types of the same layer can be more clearly distinguished. Using polymer flooding pertinently according to the different distribution form of remaining oil will make the use of polymer more efficiently and the recovery higher.     

电感耦合等离子体质谱法测定高纯金中痕量杂质

建立了高纯金中40余种痕量杂质的电感耦合等离子体质谱测定方法。方法检出限为0．0006～0．21μg/L。考察了基体Au的谱干扰及基体效应,采用Cs内标补偿基体对待测信号的抑制作用。方法简单、快速、灵敏、准确。     

用ICP—MS测定高纯氧化镝中痕量稀土元素

考察了源于基体镝的多原子离子干扰。研究了基体对待测稀土杂质信号的影响，采用Ｔｌ内标能基本上补偿基体影响。建立了直接测定高纯氧化镝中痕量稀土杂质的电感耦合等离子体－质谱法。检测限为００１３～００８８μｇ／Ｌ，平均回收率为９２３％～１０１４％，相对标准偏差为２７％～９２％。方法简便、快速、灵敏。     

When is every linear transformation a sum of two commuting invertible ones?

A well-known result of Wolfson [7] and Zelinsky [8] says that every linear transformation of a vector space V over a division ring D   is a sum of two invertible linear transformations except when dim(V)=1$\dim (V)=1$ and D=_F2$D={\mathbb{F}}_2$. Indeed, many of these linear transformations satisfy a stronger property that they are sums of two commuting invertible linear transformations. The goal of this note is to prove that every linear transformation of a vector space V over a division ring D   is a sum of two commuting invertible ones if and only if |D|?3$|D|?3$ and dim(V)<∞$\dim (V)<\infty$. As a consequence, a sufficient and necessary condition is obtained for a semisimple module to have the property that every endomorphism is a sum of two commuting automorphisms.     

Feebly Baer Rings and Modules

A right module M over a ring R is called feebly Baer if, whenever xa = 0 with x ∈ M and a ∈ R, there exists e² = e ∈ R such that xe = 0 and ea = a. The ring R is called feebly Baer if R_R is a feebly Baer module. These notions are motivated by the commutative analog discussed in a recent paper by Knox, Levy, McGovern, and Shapiro [6 Knox , M. L. , Levy , R. , McGovern , W. Wm. , Shapiro , J. ( 2009 ) Generalizations of complemented rings with applications to rings of functions. . J. Alg. Appl. 8 ( 1 ): 17 – 40 .[Crossref] , [Google Scholar]]. Basic properties of feebly Baer rings and modules are proved, and their connections with von Neumann regular rings are addressed.     

电感耦合等离子体质谱法测定高纯氧化钆中痕量稀土杂质

考察了起因于钆基体的多原子离子干扰，当基体浓度为１ｇ／Ｌ时，基体质谱对相邻低质量同位素产生严重的峰前沿干扰，基体的多原子离子也会对待测稀土杂质同位素产生严重的谱干扰。研究了Ｇａ，Ｉｎ，Ｉ，Ｃｓ和Ｔｌ内标对基体抑制效应的补偿作用，加入内标元素Ｔｌ后，基本上克服了基体效应。     

用电感耦合等离子体质谱法测定高纯稀土中稀土杂质时的基体影响

考察了基体对待测稀土杂质元素信号的影响，研究了内标对基体效应的补偿作用。对于不同的基体元素最佳的内标元素是不一致的，Ｇａ、Ｉｎ、Ｉ、Ｃｓ和Ｔｌ是稀土纯度分析中合适的内标元素。内标法简便易行，效果好，其测定方法的精度和回收率令人满意。     

Nonlinear structural dynamics of a new sliding-mode triboelectric energy harvester with multistability

A new sliding-mode triboelectric energy harvester in the form of a cantilever beam with a tip mass that is acted upon by both magnetic and friction forces is modelled and simulated. A numerical scheme based on the trapezoidal rule with the second-order backward difference formula (TR-BDF2) method is introduced to solve the combined non-smooth mechanical and stiff electrical system. This is the first study of the structural dynamics of the sliding-mode triboelectric energy harvesting; additionally, a magnetic field that induces multistability is present. A comparison between the coupled and uncoupled electromechanical models suggests that the electrostatic force between the electrodes can be ignored, which makes the uncoupled model preferable in the dynamical analysis. The influence of the non-conservative force (the friction force) on the multistability of the system is investigated. It is found that the distribution of the multistability on the parametric plane changes even when a small amount of friction is involved, and the areas of bistability and tristability shrink while that of the monostability expands. A comparison among these three types of stability reveals the superiority of invoking bistability as it facilitates broadband energy harvesting. The excitation level plays an important role in inducing the snap-through motion (the interwell oscillation) by enabling the crossing of the energy barriers between wells. The increase in the friction shrinks the frequency band of interwell oscillations from high frequencies down to low frequencies on the discrete frequency sweep. An analysis of the basins of attraction finds that at low frequencies the bistable system can undergo only interwell oscillations, while the tristable system can merely experience intrawell oscillations. The basins can intermingle with each other in both bistable and tristable systems. Finally, an increase in the excitation level can break the basins into discrete pieces and/or points.