Abstract:
Fully epitaxial magnetic tunnel junctions (MTJs) with off-stoichiometric Co2-based Heusler alloy shows a intense dependency of the tunnel magnetoresistance (TMR) on the Mn composition, demonstrating giant TMR ratios of up to 1995% at 4.2 K for 1. This work reports on the electronic structure of non-stoichiometric CoxMnyGez thin films with a fixed Co/Ge ratio of x : z = 2 : 0.38. The electronic structure was investigated by high energy, hard X-ray photoelectron spectroscopy combined with first-principles calculations. The high-resolution measurements of the valence band of the non-stoichiometric CoxMnyGez films close to the Fermi energy indicate a shift of the spectral weight compared to bulk Co2MnGe. This is in agreement with the changes in the density of states predicted by the calculations. Furthermore it is shown that the co-sputtering of Co2MnGe together with additional Mn is an appropriate technique to adjust the stoichiometry of the CoxMnyGez film composition. The resulting changes of the electronic structure within the valence band will allow to tune the magnetoresistive characteristics of CoxMnyGez based tunnel junctions as verified by the calculations and photoemission experiments.

Abstract:
DC and ac magnetization, resistivity, specific heat, and neutron diffraction data reveal that stoichiometric LaOFeP is metallic and non-superconducting above T = 0.35 K, with gamma = 12.5 mJ/mol*K. Neutron diffraction data at room temperature and T = 10 K are well described by the stoichiometric, tetragonal ZrCuSiAs structure and show no signs of structural distortions or long range magnetic ordering, to an estimated detectability limit of 0.07 uB/Fe. We propose a model, based on the shape of the iron-pnictide tetrahedron, that explains the differences between LaOFeP and LaOFeAs, the parent compound of the recently discovered high-Tc oxyarsenides, which, in contrast, shows both structural and spin density wave (SDW) transitions.

Abstract:
Alkynylphosphines or their borane complexes are available either through C–P bond forming reactions or through modification of the phosphorus or the alkynyl function of various alkynyl phosphorus derivatives. The latter strategy, and in particular the one involving phosphoryl reduction by alanes or silanes, is the method of choice for preparing primary and secondary alkynylphosphines, while the former strategy is usually employed for the synthesis of tertiary alkynylphosphines or their borane complexes. The classical C–P bond forming methods rely on the reaction between halophosphines or their borane complexes with terminal acetylenes in the presence of a stoichiometric amount of organometallic bases, which precludes the access to alkynylphosphines bearing sensitive functional groups. In less than a decade, efficient catalytic procedures, mostly involving copper complexes and either an electrophilic or a nucleophilic phosphorus reagent, have emerged. By proceeding under mild conditions, these new methods have allowed a significant broadening of the substituent scope and structure complexity.

Abstract:
为了深入探究Z轴离焦量对激光熔覆成形的影响，综合考虑Z轴离焦量导致的熔池粉末利用率、激光能量密度等因素对熔覆成形的影响，通过改变激光功率、扫描速度、气流量、离焦量4个因素进行L16（44）正交试验，以及Z轴离焦量变化的单因素试验，揭示激光功率、扫描速度、气流量、离焦量4个因素对熔覆成形的耦合作用规律.正交试验结果表明，离焦量、激光功率、扫描速度、气流量在激光熔覆成形中都扮演着重要角色，对熔覆效率的因素影响主次为：激光功率>气流量>离焦量>扫描速度.Z轴离焦量单因素试验结果表明:激光熔覆过程需要一定的离焦量才能获得最佳熔覆质量；当离焦量为5mm时，熔覆层的高度最高；当离焦量小于或大于5mm时，熔覆层高度降低；当Z轴离焦量逐渐增加时，粉末利用率先逐渐增加再逐渐减少. Abstract：The variation of distance between laser head and substrate (named defocus distance) has a considerable effect on powder utilization efficiency and energy density, therefore affecting the laser cladding forming (LCF) process. Orthogonal experiments L16 (44) of the four parameters: laser power, scanning speed, gas flow rate and defocusing distance and single factor experiment of the defocusing distance along Z axis were conducted to investigate the coupling effects of these parameters on LCF process. The result of orthogonal experiment suggests that all four parameters play important roles in LCF, and the order of factors which affect the cladding efficiency is: laser power>gas flow rate>defocusing distance>scanning speed. The result of the single factor experiment indicates that the optimal cladding quality occurs when the defocusing distance reaches a certain level. The maximum cladding layer height can be achieved when the defocusing distance is 5mm. The cladding layer height is reduced when the defocusing distance is less or larger than 5mm. It is proved that the powder utilization efficiency gradually increases and then decreases when the defocusing distance keeps increasing.

Abstract:
The problem of calculating stoichiometric coefficients in a chemical equation can be solved by standard methods and the method of multidimensional vector space, but good knowledge of vector algebra is required. In this paper, the authors proposed a matrix method and other treatment of the problem was given as the authors' own interpretation. A matrix was formed in the form of base using all the elements which take place in a chemical reaction, after which the matrixes of all the chemical compounds were determined based on numerical indexes and element symbols. This approach enables the setting of a principal matrix equation based on a mathematical approach. The solutions of this matrix equation are the desired stoichiometric coefficients that form a balanced equation. A new approach to tabular solving is presented. This method, compared to existing standard methods, is faster, simpler, and more effective, especially for complex chemical equations. The method was tasted on examples from inorganic chemistry and metallurgy.