国内模具产品目前水平及今后发展趋势

按我国产品分类标准,模具产品共分十大类46小类,这十大类是:冲压模具、塑料模具、铸造模具、锻造模具、粉末冶金模具、橡胶模具、拉丝模具、无机材料或成型模具、模具标准件及其它模具。十大类产品中,冲压模具和塑料模具占的比重最大,约占模具总量的80％以上;压铸模是铸造模具中的一类,近年来发展较快。

The global response of temperature to high-latitude vegetation greening in a two-dimensional energy balance model

The relationship between vegetation greening and climate change remains unclear due to its complexity, especially in drylands. Against the background of global warming, arid and semi-arid areas, including mid-latitude deserts, are most sensitive to climate change. In recent decades, the mechanisms underlying the relationship between vegetation greening and climate change have been widely discussed in the literature. However, the influence of vegetation greening in high latitudes on regional climate has not been fully studied. In this paper, a two-dimensional energy balance model was used to study the influence of greening in high latitudes on mid-latitude deserts. The authors found that when greening occurs in high latitudes, the mid-latitude desert recedes at the south boundary, while the polar ice belt and low-latitude vegetation belt both expand. Simultaneously, greening in high latitudes can induce a negative temperature anomaly in northern latitudes and a positive temperature anomaly in southern latitudes. The mid-latitude desert expands at its north and south boundaries until the CO2 concentration reaches 600 ppm(saturated state). The greening in high latitudes could result in a lower global-mean temperature in the ‘saturated’ state, due to the stronger cooling in high latitudes.

Dynamics Model and Simulation of Polyethylene Terephthalate (PET) Hollow Fiber

On the basis of melt-spinning, the dynamics model of polyethylene terephthalate （PET） hollow fiber is established. The effects of spinning conditions on hollow ratio are discussed and verified. Because of the different quenching conditions, there exist differences of the hollow ratio and the vitrification distances between different cycles. The important role of the quenching conditions on the meltspinning of PEr hollow fiber is also mentioned.

Life Cycle Evaluation of Energy Supply Technologies in China by Energy Chain Multi Layered Model

China has a large potential to reduce CO2 emission in the Asian region. In this study, life cycle analyses of energy supply technologies in China were evaluated for enforcing the clean development mechanism （CDM）. Wind power, integrated coal gasification combined cycle （IGCC）, natural gas combined cycle （NGCC）, and ultra super critical power plant （USC） were chosen as new power generation technologies. The system function of the developed model was enhanced to extend coverage to new technologies for power generation systems in China. CO2 intensities, energy profit ratios, and CO2 emission reductions are estimated based on the assumption that these power plants were constructed at Shanxi, Xinjiang, and Shanghai. Wind power showed the best results with regard to CO2 intensity and energy profit ratio. However, it also has some disadvantages with regard to the utilization factor and the lifetime. It is considered that wind power will become an important part of CDM activities as the utilization factor and the lifetime improve. An NGCC using a natural gas pipeline was found to be most advantageous in reducing CO2 emission. IGCC and USC were inferior to NGCC with regard to energy profit ratios and CO2 emission reductions.

A decomposition model to analyze effect of SO_2 emission density of China

A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93% and 61.07% are contributed to environment-friendly and resource-saving effects,respectively,by the dramatic decrease in industrial SO2 emission density(nearly 70% from 2001 to 2010).This indicates that China has achieved important progress during the 11th FYP(five-year plan) compared with the 10th FYP.A simultaneous equations model was also employed to analyze the influencing factors by using data from 30 provinces in China.The results imply that the influence of environmental regulation on environment-friendly effect is not obvious during the 10th FYP but obvious during the 11th FYP.Thus,the government should continue promoting the environment-friendly effect by further enhancing environmental regulation and strengthening the role of environmental management.

Thermal convection thinning of the North China Craton: Numerical simulation

We used twodimensional numerical simulations to investigate smallscale convection in the upper mantlelithosphere system with depth and temperaturedependent viscosity. Our aim was to examine the mechanism of craton thinning by thermal con vection. The model domain is 700 km deep and 700 km wide with a resolution of 71x71 nodes and 160000 markers. The ve locity boundary conditions are freeslip along all the boundaries. A thermal insulation condition was applied at the two side walls, with constant temperatures for the top and bottom boundaries. We assumed an initial temperature of 273 K at the upper boundary and 1673 K at the lower boundary, and 1573 K at the bottom of the lithosphere （200 km depth） for the thick, cold, and stable North China Craton （NCC）. We calculated the thermal evolution in the upper mantle when the temperature at its bottom is raised because of lower mantle convection or plumes. The temperature at the bottom of the upper mantle was set at 1773, 1873, 1973, and 2073 K for different models to study the temperature effect on the lithospheric thinning processes. Our endmember calculations show that with the bottom boundary raising the lithosphere can be thinned from a depth of 200 km to a depth of between 100 and 126.25 km. The thinning rates are at mm/y order of magnitude, and the thinning timescale is about 10 Ma.

Tropical cyclone spiral band extraction and center locating by binary ant colony optimization

Tropical cyclone (TC) center locating is crucial because it lays the foundation for TC forecasting. Locating TC centers, usually by manual means, continues to present many difficulties. Not least is the problem of inconsistency between TC center locations forecast by different agencies. In this paper, an objective TC center locating scheme is developed, using infrared satellite images. We introduce a pattern-matching concept, which we illustrate using a spiral curve model. A spiral band model, based on a spiral band region, is designed to extract the spiral cloud-rain bands (SCRBs) of TCs. We propose corresponding criteria on which to score the fitting value of a candidate template defined by our models. In the proposed scheme, TC location is an optimization problem, solved by an ant colony optimization algorithm. In numerical experiments, a minimal mean distance error of 17.9 km is obtained when the scheme is tested against best-track data. The scheme is suitable for TCs with distinct SCRBs or symmetrical central dense overcast, and for TCs both with and without clear eyes.

Exact solutions of a spin-orbit coupling model in two-dimensional central-potentials and quantum-classical correspondence

In this paper we present both the classical and quantum periodic-orbits of a neutral spinning particle constrained in two-dimensional central-potentials with a cylindrically symmetric electric-field in addition,which leads to an effective non-Abelian gauge field generated by the spin-orbit coupling.Coherent superposition of orbital angular-eigenfunctions obtained explicitly under the condition of zero-energy exhibits the quantum-classical correspondence in the meaning of exact coincidence between classical orbits and spatial patterns of quantum wave-functions,which as a consequence results in the fractional quantization of orbital angular-momentum by the requirement of the same rotational symmetry of quantum and classical orbits.A non-Abelian anyon-model emerges in a natural way.

A comparison of atmospheric CO_2 concentration GOSAT-based observations and model simulations

Satellite observations of atmospheric CO2 are able to truly capture the variation of global and regional CO2 concentration.The model simulations based on atmospheric transport models can also assess variations of atmospheric CO2 concentrations in a continuous space and time,which is one of approaches for qualitatively and quantitatively studying the atmospheric transport mechanism and spatio-temporal variation of atmospheric CO2 in a global scale.Satellite observations and model simulations of CO2 offer us two different approaches to understand the atmospheric CO2.However,the difference between them has not been comprehensively compared and assessed for revealing the global and regional features of atmospheric CO2.In this study,we compared and assessed the spatio-temporal variation of atmospheric CO2 using two datasets of the column-averaged dry air mole fractions of atmospheric CO2(XCO2)in a year from June 2009 to May 2010,respectively from GOSAT retrievals(V02.xx)and from Goddard Earth Observing System-Chemistry(GEOS-Chem),which is a global 3-D chemistry transport model.In addition to the global comparison,we further compared and analyzed the difference of CO2 between the China land region and the United States(US)land region from two datasets,and demonstrated the reasonability and uncertainty of satellite observations and model simulations.The results show that the XCO2 retrieved from GOSAT is globally lower than GEOS-Chem model simulation by 2 ppm on average,which is close to the validation conclusion for GOSAT by ground measures.This difference of XCO2 between the two datasets,however,changes with the different regions.In China land region,the difference is large,from 0.6 to 5.6 ppm,whereas it is 1.6 to 3.7 ppm in the global land region and 1.4 to 2.7 ppm in the US land region.The goodness of fit test between the two datasets is 0.81 in the US land region,which is higher than that in the global land region(0.67)and China land region(0.68).The analysis results further indicate that the inconsistency of CO2concentration between satellite observations and model simulations in China is larger than that in the US and the globe.This inconsistency is related to the GOSAT retrieval error of CO2 caused by the interference among input parameters of satellite retrieval algorithm,and the uncertainty of driving parameters in GEOS-Chem model.