Branches of positive solutions of quasilinear elliptic equations on non-smooth domains

We prove existence of an unbounded global branch (i.e. connected set) of weak solutions of a second order quasilinear equation depending on a real parameter λ$\lambda$ on an arbitrary (possibly non-smooth) bounded domain in R^N${\mathbb{R}}^N$, with a Leray–Lions operator as the leading part. Here, we can allow lower order nonlinearities which depend on first derivatives, satisfying appropriate growth conditions including the critical case. Furthermore, we give sufficient conditions for the existence of a branch consisting entirely of nonnegative solutions for positive λ$\lambda$. Our approach also yields a new existence result in the case of critical growth in derivatives of lower order.     

右半平面上解析的Laplace-Stieltjes变换对数级

本文研究了零级Laplace-Stieltjes变换的增长性问题.利用对数级和对数下级的定义,获得了这类变换具有对数级的特征,即变换的对数级和对数下级与其系数之间的关系,推广了Dirichlet级数的相关结果.     

低真空管道列车表面压力变化规律研究

既有高速铁路进一步提速受限,构建低真空管道运行超高速列车的发展趋势日益明显.运用滑移网格技术,建立动车组列车和低真空管道的三维耦合模型,考虑管道气体的瞬态压缩效应,分析低真空管道横截面积、动车组列车运行速度、管道环境温度和环境压力对车体表面压力的影响.研究表明,低真空管道横截面积、动车组列车运行速度、管道环境温度和环境...     

Growth and thermal studies on pure ADP,KDP and mixed K1‐x(NH4)xH2PO4 crystals

The investigations on the formation of mixed crystals of ammonium dihydrogen orthophosphate (ADP) and potassium dihydrogen orthophosphate (KDP) i.e. potassium ammonium dihydrogen phosphate, K_1‐x(NH₄)_xH₂PO₄ have been presented in this paper. Pure and mixed crystals of ADP and KDP have been grown by slow evaporation technique from the supersaturated solution at an ambient temperature 26±1 °C for ammonium concentration x in the range 0.0 ≤ x ≤ 1.0 in the case of mixed crystals. Crystal compositions were determined by flame atomic absorption spectroscopy and chemical analysis. The results of the X‐ray analysis of the grown crystals are also reported. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study the kinetic process of dehydration and the high temperature phase behaviour. DTA showed the distinct thermal events attributed to dehydration of ADP, KDP and K_1‐x(NH₄)_xH₂PO₄. The results of thermal analysis and chemical analysis are consistent with each other. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Effect of temperature programmes on protein crystallisation

Varying the temperature has been proven to be beneficial for improving the screening efficiency of protein crystallisation, and thus a crystallisation screening strategy based on this phenomenon can be developed. Such a temperature varying strategy can be applied in practical crystallisation screening, however, there are no guidelines for determining what temperature programme should be utilised. It is therefore necessary to investigate how the temperature programme affects the crystallisation process, so as to help people design a suitable temperature programme. For this purpose, we investigated the effect of temperature programmes on the protein crystallisation (lysozyme, proteinase K, and concanavalin A) that are characterised by different solubility behaviours with respect to temperature. Judging from the reproducibility studies of protein crystallisation with different temperature programmes, we recommend using linear temperature programmes for a moderate time period (24 to 48 h) and a large temperature range according to the properties of the proteins. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis of highly‐ordered hierarchical ZnO nanostructures and their application in dye‐sensitized solar cells

In order to improve the performance of ZnO‐based solar cells, highly‐ordered hierarchical ZnO nanostructures were design and fabricated. The hierarchical nanostructures were grown on FTO (fluorine doped tin oxide, SnO₂:F) glass substrates via a facile, low‐temperature, and low‐cost chemical route. The morphology and structure of the obtained products has been confirmed by field‐emission scanning electron microscopy and X‐ray diffraction measurements. The performance investigation of the prepared dye‐sensitized solar cells (DSSCs) demonstrates that the hierarchical ZnO nanostructure‐based solar cell shows a higher short‐circuit current density compared with the ZnO nanowire counterpart. The enhanced current density may be due to the fact that the surface area of the hierarchical nanostructures is increased. These results indicate that hierarchical ZnO nanostructures are more suitable for the application as photoelectrode of DSSCs. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The spirit of capitalism,non-expected utility and asset pricing

0Intr0ducti0nAferEpsteinandZin(1989,199l)andWeil(1990),n0n-expectedutilitypreferences0ftenaPpwinassetpricingthe0ryinsteadofc0nventi0naltime-allitive,expectedutilityAnattrec-tivefeature0fthisgeneralisedspecificationisthatintertemp0ralsubStitutinnandriskaversioucanbepartiallydisentangled,incontr8ttothec0nventi0nalcaseofanadditiveandhomthgeneousVonNeumann-MorgellsternintertemPoralutilityfuncti0n,inwhichtheelasticityofsub8titutionandthec0efficielltofrelativeriskaversionarec0nstrainedtoberecipr0…     

低压蒸汽滴状冷凝传热性能的实验研究

实验研究了不同水蒸气压力条件下的滴状冷凝传热特性。10 kPa、40 kPa和70 kPa时的传热系数分别是常压下的56%,68%和81%。随着水蒸气压力的下降,液滴脱落直径变大,液滴生长周期延长,冷凝传热系数下降。通过液滴的动力学特性分析和基于界面效应的滴状冷凝传热模型,分析了低压对水蒸气冷凝传热的主要影响因素,压力变化主要影响了分子扩散率和气-液相际传热热阻,导致总冷凝传热系数随压力下降。     

FePt L10 ordering and grain growth using millisecond pulse laser processing

The structural and magnetic properties of ∼12 nm thick FePt thin films grown on Si substrates annealed using a 1064 nm wavelength laser with a 10 ms pulse have been examined. The A1 to L1₀ ordering phase transformation was confirmed by electron and X-ray diffraction. An order parameter near 50% and a maximum coercivity of 12 kOe were obtained with laser energy densities of 25-32 J/cm². Grain growth, quantified by dark field transmission electron microscopy, occurred during chemical ordering at the laser pulse widths studied.