A New Approach to Solving Nonlinear Programming

1　 IntroductionConsider a class of nonlinear programming problems as follows:max F( x1 ,x2 ,… ,xn)s.t.ai1 x1 ai2 x2 … ainxn=bi,i =1 ,2 ,… ,pai1 x1 ai2 x2 … ainxn bi,i =p 1 ,… ,mSuch nonlinear programming problems are wildly applied to the areas of engineering,economic management and even policy decision of the government,e.g.over-bounderyanalysis ofthe economy.Unfortunately,so far there is nota systemetic method to solvingsuch nonlinear programming problems.Only for some pro…     

"大通牦牛"新品种及培育技术

"大通牦牛"是中国农科院兰州畜牧与兽药研究所和青海省大通种牛场在青藏高原自然生态条件下,以野牦牛为父本,当地家牦牛为母本,应用低代牛横交和控制近交方式、有计划地采用建立横交固定育种核心群、闭锁繁育、选育提高等主要阶段,获得了生产性能高,特别是产肉性能、繁殖性能,抗逆性能远高于家牦牛,体型外貌、毛色高度一致、遗传性能稳定的含1/2野牦牛基因的第一个肉用型牦牛新品种.     

A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization

Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis'. For this reason, it is important to understand the response of pelagic biota to increased iron supply. Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest. Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days. This drawdown was mostly due to the proliferation of diatom stocks. But downward export of biogenic carbon was not increased. Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters. Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.     

Studies of the first lithiation of graphite materials by electrochemical impedance spectroscopy

Recently, lithium-ion batteries have attracted inten- sive research interests, especially with respect to the complex interfacial reactions between electrolyte and electrode. Carbonaceous materials are most widely em- ployed as negative materials for lith…     

Application of support vector machine in the prediction of mechanical property of steel materials

The investigation of the influences of important parameters including steel chemical composition and hot rolling parameters on the mechanical properties of steel is a key for the systems that are used to predict mechanical properties. To improve the prediction accuracy, support vector machine was used to predict the mechanical properties of hot-rolled plain carbon steel Q235B. Support vector machine is a novel machine learning method, which is a powerful tool used to solve the problem characterized by small sample, nonlinearity, and high dimension with a good generalization performance. On the basis of the data collected from the supervisor of hot-rolling process, the support vector regression algorithm was used to build prediction models, and the off-line simulation indicates that predicted and measured results are in good agreement.     

Processing and characterization of B4C/Cu graded composite as plasma facing component for fusion reactors

A new approach for fabricating B₄C/Cu graded composite by rapid self-resistance sintering under ultra-high pressure was presented, by which a near dense B₄C/Cu graded composite with a compositional spectrum of 0-100% was successfully fabricated. Plasma relevant performances of sintered B₄C/Cu composite were preliminarily characterized, it is found that its chemical sputtering yield is 70% lower than that of SMF800 nuclear graphite under 2.7keV D+ irradiation, and almost no damages after 66 shots of in situ plasma discharge in HL-1 Tokamak facility, which indicates B₄C/Cu plasma facing component has a good physical and chemical sputtering resistance performance compared with nuclear graphite.     

Ultra-fine ferrite grains obtained in the TSDR process

By careful design of rolling schedule,ultra-fine (~2μm) ferrite grains in a low carbon high niobium (0.09wt%Nb) microalloying steel with average austenite grain sizes above 800 μm can be achieved in the simulated thin slab direct rolling process. The 5-pass deformation was divided into two stages: the refinement of austenite through complete recrystallization and the refinement of ferrite through dynamic strain-induced transformation. The effects of Nb in solution and strain-induced NbCN precipitates on the ferrite transformation were also extensively discussed.     

Electrochemical determination of Gibbs free energy of formation of magnesium ferrite

The standard Gibbs free energy of formation of magnesium ferrite was determined by means of two types of solid state electrochemical cells: one using MgZr₄(PO₄)₆ (MZP) as the solid electrolyte and the other using CaF₂ as the solid electrolyte. The first cell was operated in the range of 950 to 1100 K. The second cell was operated in the range of 1125 to 1200 K. The reversibility of the cell EMFs was confirmed by microcoulometric titration. The Gibbs energy changes of magnesium ferrite relative to component oxides were calculated based on EMF measurements and are given by following expressions, respectively: △$G_Ⅰ^{{\rm{\rlap{-} o}}}$ = -3579-15 T (J/mol) and △$G_Ⅱ^{{\rm{\rlap{-} o}}}$ =6258-24.3 T (J/mol). The results obtained from two different cells are consistent with each other. The results also are in agreement with Rao's and Tretjakov's data in the measured temperature range. When the Gibbs free energies of formation of MgO and Fe₂0₃ were substituted in the reaction, the Gibbs free energies of formation of MgFe₂0₄ was obtained in two temperature ranges and the for mations are shown as follows: △$G_{Ⅰ\;{\rm{Formation}}}^{{\rm{\rlap{-} o}}}$ =-1427394+360.5 T (J/mol) and △$G_{Ⅱ\;{\rm{Formation}}}^{{\rm{\rlap{-} o}}}$ =-1417557+351.2 T (J/mol).     

Tuning Li3PO4 modification on the electrochemical performance of nickel-rich LiNi0.6Co0.2Mn0.2O2

Surface deterioration occurs more easily in nickel-rich cathode materials with the increase of nickel content. To simultaneously pre-vent deterioration of active cathode materials and improve the electrochemical performance of the nickel-rich cathode material, the surface of nickel-rich LiNi0.6Co0.2Mn0.2O2 cathode material is decorated with the stable structure and conductive Li3PO4 by a facile method. The LiNi0.6Co0.2Mn0.2O2–1wt％, 2wt％, 3wt％Li 3PO4 samples deliver a high-capacity retention of more than 85％ after 100 cycles at 1 C under a high voltage of 4.5 V. The effect of different coating amounts (0–5wt％) for the LiNi0.6Co0.2Mn0.2O2 cathode is analyzed in detail. Results show that 2wt％ coating of Li3PO4 gives better performance compared to other coating concentrations. Detailed analysis of the structure of the samples during the charge?discharge process is performed by in-situ X-ray diffraction. It is indicated that the modification for LiNi0.6Co0.2Mn0.2O2 cathode could protect the well-layered structure under high voltages. In consequence, the electrochemical performance of modified samples is greatly improved.     

Efficient spread space-time block coding scheme in multiple antenna systems

1 .INTRODUCTIONRecently ,an intense interest has focused on wire-less systems that can provide good quality and highdata rate .Space-ti me coding is an i mportant tech-nique that can i mprove system performance at fa-ding environments by obtaining diversity gains andcoding gains in multiple antenna systems .To make multiple antenna system practical ,methods that can obtain diversity gains with mod-erate complexity and provide acceptable bit errorrate ( BER) performance are investigated i…