中医学理论的特点

恒久弥坚和与时求新是经典两个方面的品格，中医学理论就是以经典为筑基发展起来的。希腊特尔菲（Delphi）神庙内题有诸神的一句至言：“认识你自己”!明经而知本，方可堪“因虑而处物之智”（《灵枢·本神》）。我认为，中医学理论有如下特点。一是生成论的人体观。认为人体是“天生人成”生机与生气共具而生机成命的“生生之具”。

试论《周易》的美学思想

《周易》是中国传统文化的源头,也是中国传统美学思想的母体。它将最高的和谐"太和"作为自己的美学理想,以"贵时通变"的审美态度,在对生命本体的殷殷关注中体认出生生不已的生命之美。

Temporal and Spatial Distribution Characteristics of Potential Evapotranspiration and Its Sensitivity to Meteorological Factors in Guizhou Province

[Objective] The study aims to discuss the changes of potential evapotran- spiration and its sensitivity to meteorological factors in Guizhou Province, so as to provide important references for assessment of water resources, research of agri- cultural water conservancy and climate change. [Method] Temporal and spatial dis- tribution characteristics of potential evapotranspiration in Guizhou Province from 1961 to 2010 were analyzed, and the sensitivity of potential evapotranspiration to meteo- rological factors in Guizhou Province was studied through correlation analysis. [Re- sult] On the whole, potential evapotranspiration in Guizhou Province was higher in the southwest and the west compared with the northeast and the east. In various seasons, it was the highest in summer, followed by spring and autumn, while it was the lowest in winter. In recent 40 years, annual potential evapotranspiration showed an obvious decreasing trend in most stations of Guizhou Province. The main meteo- rological factors influencing changes of potential evapotranspiration in Guizhou Province were sunshine duration, daily maximum temperature, and daily average relative humidity. [Conclusion] Daily average temperature was not the main meteoro- logical factor affecting changes of potential evapotranspiration in Guizhou Province, while sunshine duration, daily maximum temperature, and daily average relative hu- midity had important effects on potential evapotranspiration in Guizhou Province.

Analysis on Temporal and Spatial Variation Characteristics of Potential Evapotranspiration in Guizhou Province

[Objective] The aim was to analyze temporal and spatial variation charac- teristics of potential evapotranspiration in Guizhou Province. [Method] According to information from 19 meteorological stations of Guizhou Province from 1960 to 2007, with the formulas of optimizational Penman-Monteith and SEBAL net radiation mod- el, the reference crop evapotranspiration ETo was calculated. Also with the spatial interpolation method of Arcgis 9.3, climate tendency rate statistics, K-M test, wavelet analysis and so on, the related regional differentiation and spatial and temporal change characteristics between meteorological factors from each monitoring station and ETo were analyzed. [Result] The results show that the correlation of potential evapotranspiration and meteorological factors in Guizhou Province demonstrates re- gional differentiation; there was no direct connection between the correlation of po- tential evapotranspiration and meteorological factors and the amount of meteorologi- cal factors in the year; there were 3 cycles in potential evapotranspiration, namely, 1 year, 5 years and 10 years, with 3 mutation points, respectively, in 1965, 1984 and 1999, mainly affected by air temperature, precipitation and solar radiation. [Conclusion] The research is of great significance in developing irrigation approach- es, adjusting agricultural structure and ecological construction.

Recovery of Gold, Silver, Copper and Niobium from Printed Circuit Boards Using Leaching Column Technique

Nowadays, over 300 tons of Au are used in electronic equipment each year with other precious and strategic metals such as Ag, Pt, Pd, Cu, Nb, Ta, etc.. After the use-phase, the electronic devices become electronic waste （e-waste）; consequently it is important to consider e-waste as a secondary supply for the recovery of these metals. This paper presents the recovery ofAu, Ag, Cu and Nb from PCBs （printed circuit boards） of discarded computers using leaching column technique. The PCBs were crushed with a hammer mill until reaching a particle size between 3.33 mm to 0.43 mm, Then, it was leached with a sodium cyanide solution in a glass column using the following conditions： sodium cyanide concentration 4 g/L, flux 20 L/d kg PCBs day, pH between 10.5 to 11 and leaching time 15 days. Every day, after leaching, the pregnant solutions passed through a column with activated carbon to complete the closed loop system. The following recoveries were obtained： Au 46.6%, Ag 51.3%, Nb 47.2% and Cu 62.3%. A preliminary technical-economic study shows the feasibility to create a small-scale PCBs recycling plant. The initial investment is on the order of USS155,639, considering the recovered metals from the loaded carbon. The internal rate of return for a 10 years period IRR （internal rate of return） and NPV （net present value） estimated are 27% and US$105,926 respectively.

Spatial-temporal Changes of Vegetation Cover in Guizhou Province, Southern China

Guizhou Province is an important karst area in the world and a fragile ecological area in China. Ecological risk assessment is very necessary to be conducted in this region. This study investigates different characteristics of the spatial-temporal changes of vegetation cover in Guizhou Province of Southern China using the data set of SPOT VEGETATION(1999–2015) at spatial resolution of 1-km and temporal resolution of 10-day. The coefficient of variation, the Theil-Sen median trend analysis, and the Mann-Kendall test are used to investigate the spatial-temporal change of vegetation cover and its future trend. Results show that: 1) the spatial distribution pattern of vegetation cover in Guizhou Plateau is high in the east whereas low in the west. The average annual normalized difference vegetation index(NDVI) from west to east is higher than that from south to north. 2) Average annual NDVI improved obviously in the past 17 years. The growth rate of average annual NDVI is 0.028/10 yr, which is slower than that of vegetation in the country(0.048/10 yr) from 1998 to 2007. Average annual NDVI in karst area is lower than that in non-karst area. However, the growing rate of average annual NDVI in karst area(0.030/10 yr) is faster than that in non-karst area(0.023/10 yr), indicating that vegetation coverage increases more rapidly in karst area. 3) Vegetation coverage in the study area is stable overall, but fluctuates in the local scales. 4) Vegetation coverage presents a continuous increasing trend. The Hurst exponent of NDVI in different vegetation types has an obvious threshold in various elevations. 5) The proportion of vegetation cover with sustainable increase is higher than that of vegetation cover with sustainable decrease. The improvement in vegetation cover may expand to most parts of the study area.

Spillovers among China’s precious and industrial metals markets:Evidence from higher moments and jumps

This study reveals the time-varying spillover effects of higher moments(realized volatility,realized skewness and realized kurtosis)and jumps between China’s precious metals and industrial metals markets.Using 5-min high-frequency data from May 10,2012 to October 21,2021,the dynamic effects of spillovers are uncovered using the time-frequency domain spillover index framework.The results show that the system connectedness weakens as the moment order gets higher whereas the total jumps connectedness is the smallest,and the spillovers of all estimators are more evident in the short term.The overall information spillovers are time-varying and influenced by major market events.Specifically,for realized volatility,copper is the largest net transmitter and silver is always a net transmitter,while zinc is the largest net receiver.For realized skewness,copper is the largest net transmitter and silver is always a net transmitter,while lead is the largest net receiver.For realized kurtosis and jumps,copper is the largest net transmitter,while aluminum is the largest net receiver.Overall,copper and silver play dominant roles in China’s precious and industrial metals markets system.