小型高速直喷式柴油机的燃烧特性,排放及燃油经济性

应用试验研究与计算机仿真的方法，分析了车用小型高速直喷式柴油机的燃烧特性，排放与油经济性，并探讨了燃油喷射系统部分参数对诸项性能的影响。     

当代法国建筑新观察

本文以作者的法国建筑和建筑师专访和实地考察为第一手背景资料，从中整理出印象 深刻而又值得回味的若干片断，意在揭示当代法国建筑的最新发展动向及多样化、个性化的特征。     

乙烯基硅烷在聚乙烯中扩散行为的模拟计算

通过三种硅烷（A171,A172,A151）对LDPE,LLDPE,HDPE塑料试片的渗透实验,采用浸泡称重法,得到了渗透量随时间变化的曲线,利用Fick定律测得了不同温度下的扩散系数,同时采用有限差分法法,利用Visual Basic6．0语言,编制计算机程序,模拟了上述体系的扩散行为,得到的扩散系数与实测值一致。根据Arrhenius方程求得A171在HDPE,LDPE,LLDPE扩散活化能分别为38．2,24．0和22．0kJ。为硅烷接枝聚乙烯过程中硅烷浸泡时间的估算建立了快速便捷的方法。     

Synthesis and characteristic of self-assembled diamond/copper nanocomposites

Nanodiamond (ND) supported metal oxide or metal catalysts exhibit excellent catalytic activity. ND/Cu nanocomposites and Cu nanoparticles were prepared by reducing Cu(NO₃)₂ in reverses micelle solution. Products were analyzed by X-ray diffraction (XRD), electron paramagnetic resonance (EPR) spectra, UV-vis optical characteristic and transmission electron microscopy (TEM). From the point of nucleation and grow of crystal, ND contributed to heterogeneous nucleation of Cu nanocrystal. The reactive mechanism was explored based on theory of free energy. The formation of resultant self-assembled structures was explained through diffusion-limited aggregation model and Marangoni effect. Both Cu and ND/Cu nanoparticles were strong catalysts on decomposition of NH₄ClO₄ (AP), and ND/Cu is more effective.     

微机辅助课堂教学系统可靠性估算及环境试验

介绍了自行研制的语言机和微机构成的多媒体微机辅助课堂教学系统的可靠性估算及环境试验。     

Voltammetric behavior and the determination of quercetin at a flowerlike Co<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles modified glassy carbon electrode

Flowerlike Co₃O₄ nanoparticles were used as a modifier on the glassy carbon electrode to fabricate a quercetin (Qu) sensor. The morphology and crystallinity of the prepared Co₃O₄ material were investigated by scanning electron microscopy and X-ray diffraction. Electrochemical behavior of Qu at the sensor was studied by cyclic voltammetry and semi-derivative voltammetry. Results suggested that the modified electrode exhibited a strong electrocatalytic activity toward the redox of Qu. The electron transfer coefficient (α), the number of electron transfer (n), and the diffusion coefficient (D) of Qu at the sensor were calculated. Under the optimum conditions, the catalytic peak currents of Qu were linearly dependent on the concentrations of Qu in the range from 5.0 × 10⁻⁷ to 3.3 × 10⁻⁴ M, with a detection limit of 1.0 × 10⁻⁷ M. This proposed method was successfully applied to determine the quercetin concentration in Ginkgo leaf tablet and human urine samples.     

Fire and thermal properties of PA 66 resin treated with poly‐N‐aniline‐phenyl phosphamide as a flame retardant

In this study, a halogen‐free phosphorous‐nitrogen synergistic flame retardant, poly‐N‐aniline‐phenyl phosphamide (PDPPD), was synthesized. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and elemental analysis data confirmed the structure of PDPPD. The essential FR PA66 was polymerized with PA66 pre‐polymer and PDPPD pre‐polymer, prepared from PDPPD and adipic acid. The limit oxygen index and UL‐94 test results of FR PA66 reached 28% and V‐0, respectively, when the contents of PDPPD pre‐polymer were 4.5 wt%. The thermo‐gravimetric and differential scanning calorimetry results demonstrated that the initial decomposition temperature of FR PA66 was 43 °C lower than that of pristine PA66 from 385 to 342 °C; however, the peak decomposition temperature was 36 °C higher than that of pure PA66 from 437 to 473 °C, when the contents of PDPPD pre‐polymer reached 4.5 wt%. Flame retardant mechanism was studied by cone calorimeter testing and SEM‐EDX, confirming that the heat release rate (HRR), total heat release (THR), and total smoke product (TSP) decreased slightly, and PDPPD followed the gas phase flame retardant mechanism. Copyright © 2016 John Wiley & Sons, Ltd.     

NUMERICAL ANALYSIS OF GASEOUS FLOW IN MICRO-CHANNELS

The algorithm of gaseous flow in bi-dimensional micro-channels is set up and the corre sponding program based on micro-flow theory is presented. Gaseous flow in micro-channels is numerically analyzed and the pressure drop along the duct as well as the velocity profile in the micro-channels is obtained. The numerical results agreed well with the experimental results in the references. Moreover, the effects of Kn, σv and Re on the velocity profiles are analyzed. It is found that for Kn>0.001, with increasing Kn number, the slip velocity on the wall boundary increases; the tangential momentum coefficient σv affects the slip velocity greatly. The slip velocity increases with decreasing σv In the slip flow regime and for low Re numbers, the slip velocity is little influenced by the Re number.     

Optimization of preparation conditions of poly(vinylidene fluoride)/graphene oxide microfiltration membranes by the Taguchi experimental design

Poly(vinylidene fluoride) (PVDF)/graphene oxide (GO) microfiltration membranes were prepared via phase inversion process. The Taguchi experiments were designed to optimize the preparation conditions of composite membranes. PVDF content, solution type, GO content, and poly-(N-vinyl-2-pyrrolidone) (PVP) content were chosen as important effecting parameters. Membrane filtration resistance was optimized by calculating the signal-to-noise (S/N) ratio of the parameters. The group of PVDF = 12 wt.%, solution type = N, N-dimethylacetamide (DMAC), GO = 3 wt.%, and PVP = 5 wt.% was the optimal combination, and solution type was the most effective factor. Scanning electron microscope (SEM) images showed that all membranes had thicker finger-like substructures. To further investigate the influence of GO on antifouling and mechanical properties, the pure PVDF and PVDF/GO composite membranes (3.0 wt.%) were prepared according to the optimum conditions. The PVDF/GO composite membranes presented better antifouling performances due to the improvement of membrane hydrophilicity. The tensile strength and Young's modulus reached values of 10.33 and 148.47 MPa, which corresponded to a 55.11% and 67.14% increase, respectively.