Temporal-spatial Changes in Inner Mongolian Grassland Degradation during Past Three Decades

[Objective] This study aimed to analyze the temporal-spatial variation of Inner Mongolian grassland degradation during past three decades. [Method] The dis- tribution characteristics of grassland were described by land use types supervised classification with TM/ETM. Then, temporal-spatial changes of grassland coverage were quantified by the mean of maximum vegetation coverage in last 30 years. Lastly, the grassland degradation reasons were explored through statistic analysis between the grassland coverage and precipitation, temperature and grazing intensity. [Result] The grassland degradation index of Inner Mongolia was increased from 1.38 to 1.68, and the smallest was 1.28 in 2005s. Grassland degradation and improve- ment were concurrent after 1980s, but grassland degradation was the major change trend for Inner Mongolia grassland. The area of grassland degradation was enlarged from 18.08×10^4 km2 in 1980s to 22.47×10^4 km2 in 2010s on the whole and distribu- tion range was shifted from central-eastern to west in Inner Mongolia that mainly distributed on Hulun Buir and Xilin Gol grassland in 1980s and Ordos and Alax grassland in 2010s. The grassland area of degradation had a rising trend form 1980s to 1995s, then reduced to 10.8x104 km2 in 2005s, and decreased in 2010s, which mainly speared in the west of Xilin Gol grassland. [Conclusion] Inner Mongo-lian grassland degradation were become more seriously in last 30 years because that temperature, precipitation and graze intensities change, which not performance on decreasing coverage but grassland areas.

贾谊社会批判思想简论

贾谊是西汉初期一位具有重要历史地位和作用的政治家、哲学家。他深通先秦诸子学说,并且吸收了前人思想中有价值的遗产,结合汉初社会现实,形成了比较深刻的社会批判思想。贾谊这一思想的基本线索是:以维护中央集权为基本原则,在“因时而变”的历史辩证法思想指导下,实行从中央到郡县的一系列改革;他主张“移风易俗”、“明君贤吏”,在“重民”的基础上实行比较开明的政治统治。

贾谊法律思想初探

根据贾谊的思想言论集《新书》，论述贾谊如下的政治法律思想：（１）制定法律应适应时代变迁，即“变法因时”。（２）兴礼义、定经制，主张以礼义为中心对旧法进行改革和重建。（３）尊君重民，省刑慎罚。（４）从重礼思想出发，提出“黥劓之罪不及大夫”的别刑罚观点。（５）主张实行“权势法制”削藩。

Spatial and Temporal Variability of N, P and K Balances for Agroecosystems in China

Nitrogen, phosphorus, and potassium balances for agroecosystems in China from 1993 to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and temporal variabilities were analyzed with GIS to estimate the potential impacts of nutrient N, P and K surpluses or deficits to soil, water and air. At the national scale, the N and P balances from 1993 to 2001 showed a surplus, with the nitrogen surplus remaining relatively stable from 1997—2001. Although during this period the P surplus pattern was similar to N, it had smaller values and kept increasing as the use of phosphate fertilizer increased year by year. However, K was deficient from 1993 to 2001 even though from 1999 to 2001 the K deficit decreased. The spatial analysis revealed higher N surpluses in the more developed southeastern provinces and lowest in the western and northern provinces where there was less chemical fertilizer input. The serious K deficit mainly occurred in Shanghai and Beijing municipalities, Jiangsu, Zhejiang and Hubei provinces, and Xinjiang autonomous regions. For the years 1992, 1996 and 2001, N surpluses and K deficits had significant positive spatial correlations with per capita gross domestic product (GDP), per capita gross industrial output value, and per capita net income of rural households. This showed that the level of economic development played an important role on nutrient balances in the agroecosystems.

Spatiotemporal Variations and Influencing Factors Analysis of PM_(2.5) Concentrations in Jilin Province,Northeast China

High PM_(2.5) concentrations and frequent air pollution episodes during late autumn and winter in Jilin Province have attracted attention in recent years. To describe the spatial and temporal variations of PM_(2.5) concentrations and identify the decisive influencing factors, a large amount of continuous daily PM_(2.5) concentration data collected from 33 monitoring stations over 2-year period from 2015 to 2016 were analyzed. Meanwhile, the relationships were investigated between PM_(2.5) concentrations and the land cover, socioeconomic and meteorological factors from the macroscopic perspective using multiple linear regressions(MLR) approach. PM_(2.5) concentrations across Jilin Province averaged 49 μg/m^3, nearly 1.5 times of the Chinese annual average standard, and exhibited seasonal patterns with generally higher levels during late autumn and over the long winter than the other seasons. Jilin Province could be divided into three kinds of sub-regions according to 2-year average PM_(2.5) concentration of each city. Most of the spatial variation in PM_(2.5) levels could be explained by forest land area, cultivated land area, urban greening rate, coal consumption and soot emissions of cement manufacturing. In addition, daily PM_(2.5) concentrations had negative correlation with daily precipitation and positive correlation with air pressure for each city, and the spread and dilution effect of wind speed on PM_(2.5) was more obvious at mountainous area in Jilin Province. These results indicated that coal consumption, cement manufacturing and straw burning were the most important emission sources for the high PM_(2.5) levels, while afforestation and urban greening could mitigate particulate air pollution. Meanwhile, the individual meteorological factors such as precipitation, air pressure, wind speed and temperature could influence local PM_(2.5) concentration indirectly.

Runoff Change of Naoli River in Northeast China in 1955–2009 and Its Influencing Factors

Runoff change and trend of the Naoli River Basin were studied through the time series analysis using the data from the hydrological and meteorological stations. Time series of hydrological data were from 1957 to 2009 for Bao′an station, from 1955 to 2009 for Baoqing station, from 1956 to 2009 for Caizuizi station and from 1978 to 2009 for Hongqiling station. The influences of climate change and human activities on runoff change were investigated, and the causes of hydrological regime change were revealed. The seasonal runoff distribution of the Naoli River was extremely uneven, and the annual change was great. Overall, the annual runoff showed a significant decreasing trend. The annual runoff of Bao′an, Baoqing, and Caizuizi stations in 2009 decreased by 64.1%, 76.3%, and 84.3%, respectively, compared with their beginning data recorded. The wet and dry years of the Naoli River have changed in the study period. The frequency of wet year occurrence decreased and lasted longer, whereas that of dry year occurrence increased. The frequency of dry year occurrence increased from 25.0%-27.8% to 83.9%-87.5%. The years before the 1970s were mostly wet, whereas those after the 1970s were mostly dry. Precipitation reduction and land use changes contributed to the decrease in annual runoff. Rising temperature and water project construction have also contributed important effects on the runoff change of the Naoli River.

Sensitivity Study on Durability Variables of Marine Concrete Structures

In order to study the influence of parameters on durability of marine concrete structures, the parameter＇s sensitivity analysis was studied in this paper. With the Fick＇s 2nd law of diffusion and the deterministic sensitivity analysis method （DSA）, the sensitivity factors of apparent surface chloride content, apparent chloride diffusion coefficient and its time dependent attenuation factor were analyzed. The results of the analysis show that the impact of design variables on concrete durability was different. The values of sensitivity factor of chloride diffusion coefficient and its time dependent attenuation factor were higher than others. Relative less error in chloride diffusion coefficient and its time dependent attenuation coefficient induces a bigger error in concrete durability design and life prediction. According to probability sensitivity analysis （PSA）, the influence of mean value and variance of concrete durability design variables on the durability failure probability was studied. The results of the study provide quantitative measures of the importance of concrete durability design and life prediction variables. It was concluded that the chloride diffusion coefficient and its time dependent attenuation factor have more influence on the reliability of marine concrete structural durability. In durability design and life prediction of marine concrete structures, it was very important to reduce the measure and statistic error of durability design variables.

Changes of Bone Remodeling-related Factors of HPDLF Regulated by Estrogen and Tensile Strain

Estrogen deficiency has been proposed as a risk factor for alveolar bone loss, but whether or not estrogen will influcence the bone rebuilting process during orthodontic tooth movement and what the mechanisms involved remain unclear. The paper aims to provide new information that may elucidate the modulatory effect of estrogen on the bone-resorbing cytokines RANKL and its anti-resorptive factor OPG secrected by HPLFs which are already force-stimulated. The expression of OPG mRNA is rising after mechanical loading either with or without stimulated by estrogen before. But HPDL cells exposured to estrogen for 24 h before loaded tend to express more OPG mRNA. Compared with the no-estrogen group, the inhibit trend of RANKL mRNA is much more apparent in with-estrogen group. Moreover, estrogen and mechanic force time-dependently increased OPG expression and attenuated the RANKL expression.

张居正法制改革的理论和实践

张居正是明代著名的政治家、思想家和法制改革家。他生活的年代正好是明朝由兴盛转入衰败的时期。此时，明朝政治腐败，官场贪污成风，宦官主持朝政现象极为严重。大地主大官僚肆意兼并土地，出现了“私家日富，公室日贫”的状况。张居正出任内阁首辅后，从维护封建王朝的...

Spatio-temporal Distribution Pattern of Vegetation Net Primary Productivity and Its Response to Climate Change in Buryatiya Republic,Russia

As a critical index for monitoring the response of terrestrial ecosystems to climate change, net primary productivity （NPP） is widely used to reflect the vegetation productivity under natural conditions. However, little is known about vegetation NPP in Buryatiya Republic, Russia. To fully understand temporal and spatial variations in vegetation NPP and its response to climate change, satellite images of Moderate-resolution Imaging Spectroradiometer （MODIS） Normalized Difference Vegetation Index （NDVI） products in conjunction with ground-based observations of climatology were used to estimate vegetation NPP in Buryatiya Republic from 2000 to 2008. Observed values of vegetation NPP and MODIS NPP products were jointly utilized to verify simulations of vegetation NPP in this area. The Carnegie Ames Stanford Approach （CASA） model was improved by adjusting its parameters with bio-temperature instead of monthly average temperature in a sub-model of soil water content. Model reliability was tested with observed vegetation NPP. Variation in vegetation NPP, and its relationship with climatic factors, was analyzed in detail. Results showed that the modified CASA model can be used to estimate vegetation NPP in Buryatiya Republic, and that the accuracy of the model was generally high with a correlation coefficient of 0.91 （P0.01）. The vegetation average annual NPP was 542.45 g C m^-2 y^ -1 and the total NPP was estimated as 1.91E＋14 g C y^ -1 from 2000 to 2008. Monthly vegetation NPP increased significantly from April to July, decreased rapidly from August to November, and remained steady from December to March of the next year. Vegetation NPP increased with increasing longitude and decreased with increasing latitude. Different vegetation types differ in total NPP, with the highest NPP in forests, followed by forest-steppe, high mountain vegetation, steppe and meadow-swamp. Temperature and precipitation were the primary factors limiting vegetation NPP in this area.

Temporal Variations and Driving Factors of Cultivated Land Use Intensity in Shandong Province from 1980 to 2015

Based on the cost-income data of agricultural products and relevant statistical data, taking major grain crops and economic crops in the process of cultivated land use as study cases, we studied characteristics of the temporal variation of cultivated land use intensity and its composition in Shandong Provinee from 1980 to 2015, and then analyzed its main driving factors. The results showed that:(1) The total intensity of major crops in Shandong Province showed a rising trend from 919.73 Yuan ha^-1 in 1980 to 3285.06 Yuan ha^-1 in 2015, and the average annual in tensity of economic crops was higher than that of grain crops. The labor cost and material cost of major crops both showed an increasing trend, but the material input was much higher than labor input for grain crops, while the labor in put was much higher tha n material in put for economic crops.(2) The labor intensity of major crops in Shandong Province showed a decreasing trend from 501.75 man-day ha^-1 in 1980 to 161.93 man-day ha^-1 in 2015. The labor intensity of grain crops was lower than that of economic crops and its decline rate was fast. On the contrary, the capital intensity showed an increasing trend from 518.33 Yuan ha^-1 in 1980 to 1159.95 Yuan ha^-1 in 2015. In the internal composition of capital internsity, the proportion of yield-increasing inputs such as seed, farm-yard manure, fertilizer, pesticide and drainage and irrigation decreased gradually, while the proportion of la-bor-saving inputs such as agricultural machinery increased significantly.(3) The cultivated land use intensity in Shandong Provinee had significant negative correlations with the amount of agricultural labor and cultivated land area per capita. The primary direct driving factor was the net income per unit cost of major crops, but the time re-sponse lagged by 1-3 years. The main indirect driving factor was the reform of agricultural policy.

Current hypotheses to explain genetic chaos under the sea

Chaotic genetic patchiness （CGP） refers to surprising patterns of spatial and temporal genetic structure observed in some marine species at a scale where genetic variation should be efficiently homogenized by gene flow via larval dispersal. Here we review and discuss 4 mechanisms that could generate such unexpected patterns： selection, sweepstakes reproductive success, collective dispersal, and temporal shifts in local population dynamics. First, we review examples where genetic differentiation at specific loci was driven by diversifying selection, which was historically the first process invoked to explain CGP. Second, we turn to neutral demographic processes that may drive genome-wide effects, and whose effects on CGP may be enhanced when they act together. We discuss how sweepstakes reproductive success accelerates genetic drift and can thus generate genetic structure, provided that gene flow is not too strong. Collective dispersal is another mechanism whereby genetic structure can be maintained regardless of dispersal intensity, because it may prevent larval cohorts from becoming entirely mixed. Theoretical analyses of both the sweepstakes and the collective dispersal ideas are presented. Finally, we discuss an idea that has received less attention than the other ones just mentioned, namely temporal shifts in local population dynamics.