产学研合作创新方式下政府补贴策略选择

创新补贴策略是政府鼓励企业创新的一种常见政策,考虑到企业内在的吸收能力与外部不同政府补贴策略方式的存在,本文以产学研合作创新方式为基础,通过建立三阶段博弈模型,利用模型解析与仿真分析讨论吸收能力与创新投入分配比例系数对政府补贴策略选择的影响。研究结果表明:无论政府采取哪一种补贴方式,均可以有效激励企业加大创新投入规模,并且企业的吸收能力与R&D投入、产量及社会福利均呈正相关关系;但是,吸收能力对利润及政府补贴的影响受限于补贴方式和企业的创新投入分配比例系数;此外,在创新产品补贴下,创新难度系数对政府补贴额度的影响并不明显,而创新产品补贴总体优于创新投入补贴。     

On the Debye temperature and Grüneisen parameters for hexagonal close-packed crystals consisting of p-H2 and o-D2 molecules

The expressions for the Debye temperature Θ as well as for the first (γ = ?[?ln(Θ)/?ln(V)] _T ) and second (q = [?ln(γ)/?ln(V)] _T ) Grüneisen parameters are derived based on the Mie-Lennard-Jones pair atomic interaction potential. The conditions imposed on the Θ(V/V ₀), γ(V/V ₀), and q(V/V ₀) dependences for V/V ₀ → 0 and for V/V ₀ → ∞ are analyzed. Here, V/V ₀ is the ratio of the molar volumes for pressure P at temperature T and for P = 0 at T = 0 K. Calculations are performed for crystals of parahydrogen and orthodeuterium at T = 0 K for V/V ₀ ranging from 1.30 to 0.01. Good agreement is reached between the calculated dependences and experimental data. The behavior of dependences Θ(V/V ₀), γ(V/V ₀), and q(V/V ₀) upon a variation of the isotopic composition of the crystal is analyzed.     

Structural and Kinetic Features of Formation of Elastic,Relaxation, Dissipative,and Mechanical Properties of Carbon-Fiber-Reinforced Epoxy-Phenolic Plastic Materials Based on Binary Prepregs

The static bending strength and dynamic elastic, relaxation, and dissipative properties of two types of unidirectional carbon-fiber-reinforced plastic materials based on blend and binary prepregs were studied by the bending resonance vibration method in various directions in the course of curing (pressing).     

Preparation of Anion Exchange Membrane Based on Imidazolium Functionalized Poly(arylene ether ketone)

The authors presented a novel synthetic route for the imidazolium functionalized poly(arylene ether ketone)s, derived from an engineering plastics polymer, a poly(arylene ether ketone) with 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl moiety(PAEK-TM). The preparation of anion exchange membranes comprised converting benzylic methyl groups to bromomethyl groups by a radical reaction, followed by the functionalization of bromomethylated PAEK with alkyl imidazoles, i.e., methyl, butyl or vinyl imidazole. The structure of imidazolium functionalized PAEK was proved by ¹H NMR spectra. A class of flexible and tough membranes was then achieved by subsequent film-forming and anion exchange processes. The water uptake and hydroxide conductivities of membranes are comparable or superior to those of quaternary ammonium(QA) anion exchange membranes. This work demonstrated a new route for non-QA anion exchange membrane design, avoiding the chloromethylation reagent and precisely controlling the degree and location of imidazolium groups.     

OMS-2/Al2O3/堇青石整体式催化剂的制备及其催化性能研究

以Al₂O₃/堇青石蜂窝陶瓷为载体,氧化锰八面体分子筛(OMS-2)为活性组分,采用涂覆法制备了系列整体式催化剂。考察了黏合剂种类和活性组分涂覆次数对二甲醚(DME)催化燃烧性能的影响,并对催化剂进行XRD、BET、SEM、H₂-TPR、O₂-TPD等表征。结果表明,以甲氧基聚乙二醇为黏合剂经一次涂覆制备的整体式催化剂的性能最佳,活性组分OMS-2以相互交织的簇体均匀分布在载体上,并与Al₂O₃之间存在较强的相互作用。涂层的添加有效增加了催化剂的比表面积,提高了催化剂的性能,最佳催化活性t₉₀为257 ℃。     

碳化铁催化剂的制备及其对CO加氢的催化活性

 以Fe2O3为原料,采用两种预处理方法制备了碳化铁催化剂. 结果表明,直接在CO气氛下进行碳化处理,或者以H2预还原后再用CO进行碳化处理均可以制备出碳化铁催化剂. 碳化温度是制备过程中的关键因素. 对于Fe2O3样品,较适宜的碳化温度是350 ℃,而对于添加了K助剂的样品,只有经H2预还原处理后再于350 ℃用CO碳化处理4 h才能将样品完全转化为Fe5C2. 在CO加氢的评价实验中,碳化铁催化剂表现出很高的催化活性,生成的烃类产物中主要是饱和烷 烃,未检测到乙烯的生成. 而在K改性的催化剂上反应产物中烯烃的含量明显提高.     

C_(18)膜萃取/液相色谱-质谱联用法测定极地水体中有机磷酸酯

建立了C_(18)膜萃取/液相色谱-质谱联用技术测定极地水体中10种有机磷酸酯(OPEs)的方法。根据优化后的样品前处理及仪器方法,利用C_(18)膜富集4 L水体中的10种OPEs,经二氯甲烷超声提取,在电喷雾正离子模式下,采用选择反应监测(SRM)模式进行分析,线性相关系数为0.994 4~0.999 9。10种OPEs的加标回收率为64.1%~115%,方法检出限为0.08~0.55 ng/L。该方法适用于极地水体中10种OPEs的分析,利用该方法对北极水体样品中的10种OPEs进行检测,测得冰川融水中∑OPEs的质量浓度为0.64~6.64 ng/L,海水中∑OPEs的质量浓度为0.09~2.03 ng/L。     

Angular distributions of muon pairs produced by 194 GeV/c negative pions

We present the angular distributions of muon pairs obtained in a high-statistics experiment using a 194-GeV/c π^- impinging on a tungsten target. Our results are based on the analysis of 145,000 events with positive Feynmanx and mass above 4.07 GeV/c², excluding the ? region. Simple first-order QCD relations allow us to determine the ratio of annihilation with hard-gluon emission to the sum of annihilation with hard-gluon emission and hard-gluon Compton scattering, which is found to be about 58% to 75%. We determine the parton square intrinsic transverse momenta to be of the order of 0.6 (GeV/c)², and about 30% larger in the pion than in the nucleon. At largex ₁, our data agree with the higher-twist hypothesis, and support the interpretation of the relevant scale parameter as the dimuon square transverse momentum.     

Dependence of the surface energy on the size and shape of a nanocrystal

An expression is derived for the surface energy σ as a function of the size and shape of a nanocrystal. It is shown that the wider the deviation of the shape parameter f from unity, the more pronounced the decrease in the surface energy σ with a decrease in the number N of atoms in the nanocrystal. The dependences of the average coordination number, the surface energy, and the melting temperature on the number N exhibit an oscillatory behavior with maxima at points corresponding to numbers of atoms forming a defect-free cube. The surface energy decreases with an increase in the temperature T. It is found that the smaller the nanocrystal size or the greater the deviation of the nanocrystal shape from the thermodynamically most stable shape (a cube), the larger the quantity-(dσ/dT). It is established that the nanocrystal undergoes melting when the surface energy decreases to a value at which it becomes independent of the nanocrystal size and shape. The conditions providing fragmentation and dendritization of the crystal are discussed. It is demonstrated that, at N>1000, the dependence σ(N) coincides, to a high accuracy, with the dependence of the surface tension of the nanocrystal on N. The inference is made that bimorphism is characteristic of nanocrystals. This implies that nanocrystals can have platelike and rodlike shapes with equal probability.