论中国传统农业的“效率空间”及相关问题

本文提出一个“效率空间”的概念 ,然后从农业起源方式、生活方式和继承制度等三个方面 ,论证中国传统农业不存在效率空间 ,是一种“效率”较高但是没有“效率空间”的农业类型 ,而西方古代农业是一种“效率”较低但是有“效率空间”的农业类型。文章还认为 ,黄宗智教授的“过密型增长”是一种比较典型的、晚期的表现形式。实际上 ,早在秦汉时期 ,中国单一种植业占主导地位的生产模式 ,无需太多的土地即可养活较多的人口 ,对劳动力有较高的需求 ,局部地区已经出现“过密型增长” ,只是因为存在异地移民 ,才使得这种“过密”表现得较隐蔽。近代以后 ,中国东南地区已经无可垦之地 ,才会出现典型的“过密型增长”。

Pattern Change and Regional Disparity Tendency of Cultivated Land Use in Jiangsu Province

The study has examined the tempo-spatial patterns of cultivated land use change in Jiangsu province. A principal component analysis （PCA） of 18 selected indicators of cultivated land use during the period 1970-2010 identified 2 main pat- terns of change in planting productivity and economic efficiency. A major shift from production-centered pattern to profit-oriented one occurred in 1984, the time of grain yield surplus and the mitigation of population pressure. In response to the impending Opened Market System, there was a notable tendency of higher efficiency and less productivity since 1997, as well as remarkable regional disparity of cultivated land use change spatially. It revealed a relative decrease in grain cropping share, crop- ping scale and cultivation intensity in South Jiangsu, especially in Tai-Lake region, and the reverse in North Jiangsu. Some suggestions for the future were finally dis- cussed from the above findings.

Measuring Chinese Marine Environmental Efficiency:A Spatiotemporal Pattern Analysis

Environmental efficiency standards are often used to evaluate the costs of oceanic economic development. A variety of statistical analyses were applied in this study to quantify the marine environmental efficiency of 11 Chinese coastal provinces and municipalities between 2000 and 2014. Results initially reveal that environmental efficiency measures that incorporate undesirable outputs are more consistent with real production conditions and thus the use of marine economic and environmental efficiencies supplement and complement one another. Second, overall marine environmental efficiency across China tends to be low and can be spatially characterized by a transformation such that the inefficiencies noted in 2000 have subsequently been transformed to comprise a three-tiered structure that encompasses northern, central, and southern cores. Third, variation in absolute and relative marine environmental efficiency differences for the coastal regions of China have been consistent over time; values initially decreased before increasing again in a fluctuating manner over the time period of this analysis. Fourth, data show that the Pearl River Delta area has experienced the highest rate of change in marine environmental efficiency over time when economic zones are used as basic research units, although values have nevertheless fluctuated significantly. Fifth, values for total factor productivity as well as technical efficiency and change across the Chinese marine economy all fluctuated over time but increased. Data show that changes in marine environmental efficiency across China can primarily be attributed to progress in marine science and technology. Finally, levels of capital investment and marine industrial pollution intensity are not significantly correlated with marine environmental efficiency. Indeed, both marine industrial structural levels and environmental protection technologies have had a positive effect on environmental efficiency while levels of investment in marine scientific research as well as the scale of economic development, the marine economy, and the degree of external openness have all exerted negative effects on this key variable.

Spatio-Temporal Adaptive Super-Resolution Reconstruction Model Based on Zemike Moment for Spatial Video Sequences

Video Super-Resolution （SR） reconstruction produces video sequences with High Resolution （HR） via the fusion of several Low-Resolution （LR） video frames. Traditional methods rely on the accurate estimation of subpixel motion, which constrains their applicability to video sequences with relatively simple motions such as global translation. We propose an efficient iterative spatio-temporal adaptive SR reconstruction model based on Zemike Moment （ZM）, which is effective for spatial video sequences with arbitrary motion. The model uses region correlation judgment and self-adaptive threshold strategies to improve the effect and time efficiency of the ZM-based SR method. This leads to better mining of non-local self-similarity and local structural regularity, and is robust to noise and rotation. An efficient iterative curvature-based interpolation scheme is introduced to obtain the initial HR estimation of each LR video frame. Experimental results both on spatial and standard video sequences demonstrate that the proposed method outperforms existing methods in terms of both subjective visual and objective quantitative evaluations, and greatly improves the time efficiency.

Seasonal and Spatial Variability of Water Quality and Nutrient Removal Efficiency of Restored Wetland： A Case Study in Fujin National Wetland Park, China

To investigate the spatio-temporal and compositional variation of selected water quality parameters and understand the puri- fying effects of wetland in Fujin National Wetland Park （FNWP）, China, the trophic level index （TLI）, paired samples t-test and correla- tion analysis were used for the statistical analysis of a set of 10 water quality parameters. The analyses were based on water samples collected from 22 stations in FNWP between 2014 and 2016. Results initially reveal that total nitrogen （TN） concentrations are above class V levels （2 mg/L）, total phosphorus （TP） concentrations are below class III levels （0.2 mg/L）, and that all other parameters fall within standard ranges. Highest values for TN, pH, and Chlorophyll-a were recorded in 2016, while the levels of chemical oxygen de- mand （CODMn） and biochemical oxygen demand （BODs） were lowest during this year. Similarly, TN values were highest between 2014 and 2016 while dissolved oxygen （DO） concentrations were lowest in the summer and TP concentrations were highest in the autumn. Significant variations were also found in Secchi depth （SD）, TN, CODMn （P 〈 0.01）, TP, and DO levels （P 〈 0.05） between the inlet and outlet of the park. High-to-low levels of TN, TP, and TDS were found in cattails, reeds, and open water （the opposite trend was seen in SD levels）. Tested wetland water had a light eutrophication status in most cases and TN and TP removal rates were between 7.54%-84.36% and 37.50%-70.83%, respectively. Data also show no significant annual changes in water quality within this wetland, although obvious affects from surrounding agricultural drainage were nevertheless recorded. Results reveal a high major nutrient removal efficiency （N and P）. The upper limits of these phenomena should be addressed in future research alongside a more efficient and scientific agricultural layout for the regions in and around the FNWP.

Estimation of Site Effects on Stations in the Capital Circle Region Using the Generalized Inversion Method

Generalized Inversion Method has been used to estimate the spatial variation of site effects,using the digital data of SH-waves recorded by 63 stations in the Capital Circle Region of China from 2001 to 2006.We gained the site effects of all stations participating in the calculation.We found that the site effect of rock was stabile and about 1.0 from 1.0Hz to 10.0Hz,while the site effect of deposit was high in low frequencies,about 3 ～ 7 from 1.0Hz to 8.0Hz,and the site effect was protuberant at about 5.0Hz,then fell as the frequency increased.The result shows the shape and intensity of station site effects are mainly influenced by the lithology below the station,and possibly also by the local geological structure.

Spatial Analysis on the Contribution of Industrial Structural Adjustment to Regional Energy Efficiency:ACase Study of 31 Provinces across China

Energy is an important production factor. When more energy is put into production activities, labor productivity increases and the economy and social development improve. Industrial structural change is an important factor that affects the growth of regional energy efficiency. In modern development, industrial structural improvement is closely related to regional energy efficiency and the status of industrial structure. Energy efficiency can together reflect a country＇s development level, sustainable development and the direction in which its economy will head. This paper discusses the contribution of industrial structural adjustment to regional energy efficiency growing with a spatial perspective. This study based on 31 mainland provinces in China, uses statistics of industrial structure and corresponding energy utilization data, adopting mathematic model and spatial analysis approaches, reveals that the 31 provinces in China differed in their contribution to industrial structural adjustment to regional energy efficiency. The outcome reflected contribution is obvious in those provinces with appropriate industrial structure and good economies or the ones developed late as well as the undeveloped middle and western provinces that are in initial stage of industrial restructuring. But that is not obvious in those provinces with the undeveloped leading industries, with weak economic basis, and with a relatively low level of industrial structure.

Novel internal photoemission in manganite/ZnO heterostructure

A novel photovoltaic phenomenon of internal photoemission was found in a low cost manganite La0.62Ca0.29K0.09MnO3 （LCKMO）/zinc oxide （ZnO） heterojunction bilayers grown on ITO substrate by pulsed laser deposition （PLD） at relative low growth temperature. The heterostructure ITO/LCKMO/ZnO/A1 exhibits reproducible rectifying characteristics and light cur- rent under continuous laser irradiation of 2 = 325 nm. We report here the influence of LCKMO/ZnO bilayers＇ thickness on the electrical and photoelectric properties of the heterostructure at room temperature. The power conversion efficiency （PCE） is achieved when the LCKMO and ZnO layers are thin enough or the full space charge layer is sufficient. We obtained the maximum value of PCE of 0.0145% when the thicknesses of LCKMO and ZnO layers are 25 and 150 nm, respectively. The open circuit voltage is 0.04 V under this condition due to the internal photoemission.

Anti-proton contamination design of the imaging energetic electron spectrometer based on Geant4 simulation

The measurement of energetic particles plays an important role in the space environment monitoring and space weather forecasting.The accuracy of the energetic electron measurement is seriously influenced by the proton contamination.An anti-proton contamination design for the sensor of imaging energetic electron spectrometer is introduced in this paper.According to the electron and proton spectrum on the typical satellite orbits calculated by the radiation belt models,the efficiency of the anti-proton contamination design is estimated by the Geant4 simulation and the design is optimized based on the simulation results.

The Monte-Carlo simulation on a scintillator neutron detector

A simulation of the properties of the shifting scintillator neutron detector using 6LiF/ZnS(Ag) scintillation screens is performed.The simulation results show that the light attenuation length of standard BC704 scintillator is about 0.65 mm.Its thermal neutron detection efficiency,gamma sensitivity and intrinsic spatial resolution can achieve around 50.0%,10 5and 0.18 mm(along X-axis) respectively.For the detector,air coupling position resolution is better than the silicone oil coupling.Some of the simulation results are compared with experimental results.They are in agreement.This work will be helpful for constructing neutron detector for high intensity powder diffractometer at Chinese spallation neutron source.