我国个人所得税功能定位问题的思考

2009年我国税改的主基调是结构性减税,对于个人所得税改革的研究成为各界普遍关注的焦点之一。文章旨在探讨个税改革的一个前提性问题,即:我国个税的功能定位问题。文章借鉴西方经验,结合我国实际认为,现阶段个税成为我国税收体系主体税种的条件尚不具备,因此,目前我国个税应以调节收入分配功能优先。     

Evaluation of processing effects in injection‐molded amorphous and crystalline thermoplastics using an excimer laser

The ablation behavior of amorphous [polystyrene (PS), polycarbonate (PC)] and crystalline [PET, glass‐filled poly(butylene terephthalate) (PBT)] polymers by 248‐nm KrF excimer laser irradiation were investigated for different injection‐molding conditions, namely, injection flow rate, injection pressure, and mold temperature, as a possible method for evaluating processing effects in the specimens. For this purpose, dumbbell‐shaped samples were injection‐molded under different sets of processing conditions, and weight loss measurements were carried out for the different injection‐molding conditions. Some of the crystalline (PET) samples were annealed at different annealing times and temperatures. For PET, the weight loss decreased with increasing mold temperature and remained insensitive to injection flow rate. Annealing time and temperature significantly reduced weight loss in PET. For PBT, the weight loss due to laser ablation decreased with increasing material packing due to pressure, and it also showed some sensitivity to flow rate variation. The major effect was seen with glass‐filled PBT samples. The weight loss decreased drastically with increasing glass fiber content. Laser ablation allowed us to observe process‐induced fiber orientation by scanning electron microscopy in PBT samples. For PS and PC, the weight loss increased with increasing injection flow rate and mold temperature and decreased with increasing injection pressure. The position near the gate showed higher ablation than the position at the end for all the conditions. A decrease in the material orientation with injection speed and mold temperature led to an increase in the weight loss, whereas an increase in the injection pressure, and consequently orientation, led to a lower weight loss for PS and PC. Higher residual stress samples showed higher weight losses. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 2006     

Pore Propagation Directions in P+ Porous Silicon

A comparative study is presented on the pore propagation directions of porous silicon layers (PSL) formed on p⁺-type substrates of different orientations. PSLs were formed on plain (0 0 1) and (1 1 1) silicon wafers as well as on structured (0 0 1) wafers containing facets of various orientations. During anodization, regular pores follow the 0 0 1 direction on the (0 0 1) planes. While on the (1 1 1) planes fewer regular pores develop and seemingly propagate closely to the 1 1 1 direction. These results indicate that the pores propagate perpendicular to the surface i.e. along the field lines when the surface orientation is either (0 0 1) or (1 1 1).When the silicon surface provided (1 1 0) orientation (Chuang, Collins, and Smith, 1989), or its position is in between the (0 0 1) and (1 1 1) planes then the pores do not propagate perpendicular to the surface but along the 0 0 1 direction.All the phenomena exhibited might be explained by presuming that during formation, the pores propagate along the 1 0 0 directions, and that those 1 0 0 directions are preferred which are closely to the field lines. In PSLs formed on (0 0 1) surfaces the field lines and the 0 0 1 crystallographic direction are coincident. However, in the (1 1 1) oriented wafer where three equally probable 1 0 0 directions exist around the field lines, more irregular structure of PSLs will develop.     

Relationship between processing,microstructure, and mechanical properties of injection molded thermotropic LCP

A commercial thermotropic liquid crystalline polymer (LCP), Vectra A950, was injection molded into rectangular sheets of thickness ranging from 1 to 4 mm. By changing the thickness of the mold, the shear rate experienced by the TLCP melt in the mold could be varied. The 1‐mm test sample was highly anisotropic while that with larger thickness (4 mm) was less anisotropic. X‐ray diffraction profile at various depths for each of the test sample corresponded to the degree in the fiber orientation present in the test samples. The anisotropy can be described macroscopically by measuring the tensile strength and modulus in the longitudinal and transverse direction. The ratio between the longitudinal and transverse property decreases proportionally to the thickness of the test sample. This reduction corresponded to the reduction in the shear field as the thickness of the mold was increased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1713–1718, 2003     

基于粒子群算法的计算机网络路由优化研究

针对计算机网络规模日益扩大所带来的网络路由优化问题,将其数学本质规划为NP问题,提出使用粒子群优化算法求得路由优化的近似最优解.同时,为了提高粒子群算法的性能引入了变异机制,使粒子群算法的进化速度得到明显提升.仿真实验表明,提出的方法可以在较短时间内得到路由优化的结果,具有较好的有效性和实用性.     

Diffusion of ellipsoidal granular particles in shear flow

The diffusion of nonspherical particles has not been well understood due to the complexity of their contact mechanics and self-organization of their orientations. We perform discrete element method simulations of monodisperse ellipsoids in a shear flow with Lees-Edwards boundary conditions to quantify the relation between the diffusion coefficient and the flow parameters. The results indicate that the particle aspect ratio strongly affects the diffusion coefficient by influencing the particle orientation and alignment. We develop a scaling law for the diffusion coefficient perpendicular to the flow direction, D_yy, which combines the influences of the shear rate , the solids fraction f, the effective particle diameter d_eff and the particle aspect ratio Z. We show that , where k_d is a dimensionless pre-factor, and a fit is obtained for the functional form of χ(f, Z). This scaling law will be useful in developing continuum transport models for applications.     

基于VDES的船联网移动自组织路由协议研究

基于甚高频数据交换系统(VHF Data Exchange System,VDES),通过分析海上真实船舶运动特征,提出一种符合船舶移动特征的移动模型——船舶平滑转向的高斯马尔可夫移动模型。针对性地研究了不同船舶节点密度环境中的自组织网络路由协议,仿真分析了不同自组织网络路由协议应用于VDES时的数据传输性能。结果表明,按需距离矢量(Ad Hoc on-demand Distance Vector,AODV)路由协议明显优于其他路由协议,可将其作为VDES下船联网系统最优路由选择方案。     

横向整合战略下异质车辆库存路径优化模型

以实现供货商联盟期望物流成本最小化为目标,针对需求随机波动下的多供货商多产品库存路径问题（IRP）进行了研究。基于横向整合战略,设计了供货商联盟成员间车辆配送成本的合理分摊方式。考虑零售商配送软硬时间窗和库存服务水平要求,构建了多供货商多产品的异质车辆库存路径混合整数随机规划模型,并利用需求累积分布逆函数将其转化为确定型规划模型。然后设计改进遗传算法求解该确定型规划模型。算例分析结果显示,使用异质车辆配送可以比使用同质重型和轻型车辆分别降低供货商联盟总成本8.3%和11.92%,分别提升配送车辆装载率24%和17%。敏感性分析结果表明,无论供货商供货数量占联盟总供货数量比例和零售商商品需求变异系数如何变化,采用异质车辆配送的供货商联盟总成本都能得到有效降低;且需求变异系数越大,采用异质车辆配送的优势越明显。     

MANET中基于蚁群算法的改进DSR协议*

为提高移动Ad hoc网络中DSR协议的服务质量,提出基于蚁群算法的改进DSR协议---ACOIDSR。ACOIDSR协议路由发现过程中,建立稀疏模式和稠密模式弥补DSR协议泛洪策略的不足;ACOIDSR协议路由选择过程中,利用路径长度、拥塞程度和链接可靠度计算每条路径的信息素数量,进而做出最佳路径的选择;ACOIDSR协议路由维护过程中,提出一种新的信息素衰退策略用于路由维护。最后,仿真实验用于ACOIDSR协议在端到端的延迟、路由负载以及能量消耗等方面分析。     

丝绸之路经济带（中国段）节点城市空间差异及发展布局

“丝绸之路经济带”作为多维度的国家战略构想,是新政经周期下中国总体区域发展重大战略之一,而沿线城市点、带、群是推进该项重大战略实施的现实载体。当前,“丝绸之路经济带”战略下的城市定位,往往与区域自身发展及利益诉求并不完全吻合,亟待对区域总体特征及发展现实以理性认知,防范城市“标签化”的盲动倾向。以“丝绸之路经济带”沿线区域关键节点城市客观空间状况与基本产业布局概貌为基础,采用多层次综合测度模型定量评价各城市综合竞争力,提出采取差异化的“点-轴”式带动策略是推进经济带整体发展的建设性思路,并结合城市经济地理特征探讨节点城市未来的发展布局定位问题。