mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Dynamic Mechanism of Interannual Sea Surface Height Variability in the North Pacific Subtropical Gyre

In this study, the dynamic mechanisms of interannual sea surface height (SSH) variability are investigated based on the first-mode baroclinic Rossby wave model, with a focus on the effects of different levels of wind stress curl (WSC). Maximum covariance analysis (MCA) of WSC and SSH anomalies displays a mode with significant WSC anomalies located primarily in the mid-latitude eastern North Pacific and central tropical Pacific with corresponding SSH anomalies located to the west. This leading mode can be attributed to Ekman pumping induced by local wind stress and the westward-propagating Rossby wave driven by largescale wind stress. It is'further found that in the middle latitudes, the SSH anomalies are largely determined by WSC variations associated with the North Pacific Gyre Oscillation (NPGO), rather than the Pacific Decadal Oscillation (PDO). The sensitivity of the predictive skill of the linear first-mode baroclinic model to different wind products is also examined
Observational Evidence for Poleward Expansion of the Hadley Circulation

How the Hadley circulation changes in response to global climate change and how its change impacts upon regional and global climates has generated a lot of interest in the literature in the past few years. In this paper, consistent and statistically significant poleward expansion of the Hadley circulation in the past few decades is demonstrated, using independent observational datasets as proxy measures of the Hadley circulation. Both observational outgoing longwave radiation and precipitation datasets show an annual average total poleward expansion of the Hadley cells of about 3.6° latitude. Sea level pressure from observational and reanalysis datasets show smaller magnitudes of poleward expansion, of about 1.2° latitude. Ensemble general circulation model simulations forced by observed time-varying sea surface temperatures were found to generate a total poleward expansion of about 1.23° latitude. Possible mechanisms behind the changes in the horizontal extent of the Hadley circulation are discussed
环境因子对药用植物三萜皂苷合成影响的研究进展

三萜皂苷类化合物是一类具有多种生物及药理活性的植物次生代谢产物, 除去遗传因素外, 环境对植物体内三萜皂苷的生物合成产生较大的影响. 总结三萜皂苷类化合物的生物合成途径及其关键酶, 并综述了环境中光照、温度、水分、盐、土壤状况等因子对药用植物三萜皂苷合成的影响和可能的作用机制, 以期为优化药用植物的栽培环境和提高药材质量提供参考
不同温度下丛枝菌根对苍术根茎生物量和挥发油的影响

目的研究高温胁迫下根内球囊霉Glomus intraradices(AM真菌)对苍术根茎生物量及其根茎挥发油成分的影响. 方法采用盆栽试验, 接种AM真菌, 测定苍术地下部分生物量和根茎挥发油的量. 结果高温胁迫显著降低了栽培苍术在自然条件下的AM真菌侵染率, 而接种AM真菌苍术根系的侵染率无影响. 高温胁迫下, 接种AM真菌苍术根系的侵染率与未接种的苍术相比超过4倍. 高温胁迫下, 接种AM真菌可显著提高苍术根茎鲜质量、根茎含水量、根干质量、地下总干质量、挥发油组分数, 显著降低苍术根茎挥发油中愈创醇与茅术醇的量. 结论高温胁迫下接种AM真菌, 有利于提高苍术根系侵染率、促进苍术地下部分生物量的积累, 并影响苍术根茎挥发油总数和主要组分的量
HPLC法测定独一味根中环烯醚萜苷和苯乙醇苷

目的建立HPLC法, 同时测定独一味根中4种环烯醚萜苷胡麻属苷、山栀苷甲酯、7,8-dehydropenstemoside、 8-O-乙酰山栀苷甲酯和2种苯乙醇苷连翘酯苷、毛蕊花糖苷. 方法采用高效液相色谱法, Waters Symmetry柱(100 mm× 3.5 mm, 3.5μm), 柱温25℃, 流动相为甲醇-水, 梯度洗脱; 体积流量1.0 mL/min, 检测波长235、332 nm. 结果胡麻属苷在0.236~1.410μg、山栀苷甲酯在0.440~2.640μg、7,8-dehydropenstemoside在0.094~0.564μg、8-O-乙酰山栀苷甲酯在0.750~4.500μg、连翘酯苷在0.698~4.180μg、毛蕊花糖苷在0.455~2.730μg线性关系良好, 回收率均在96.75%~ 103.97%, RSD均小于2%. 结论此方法同时测定了独一味根中6种化学成分, 方法分离度好, 快速, 简便, 结果稳定
天然环烯醚萜类化合物研究进展

环烯醚萜类化合物结构繁多, 在自然界中分布广泛, 多存在于木犀科、唇形科、茜草科、玄参科等双子叶植物中. 近年来对于此类化合物的广泛研究发现其具有多种生物活性, 如抗炎、抗肿瘤、治疗糖尿病、保肝、神经系统保护作用及对心血管系统的作用等. 此外, 环烯醚萜类可作为DNA合成酶抑制剂也有报道. 从结构类型、构效关系、生物活性等方面, 对环烯醚萜类化合物近年的研究成果进行概述, 为基于环烯醚萜类化合物的新药发现和药物设计提供参考
莪术油的HPLC指纹图谱研究

目的建立莪术油的HPLC指纹图谱鉴别方法. 方法以呋喃二烯为参照物, 采用HPLC检测方法; 色谱条件: Agilent Extend C18色谱柱(250 mm×4.6 mm, 5μm), 乙腈-水二元梯度洗脱, 体积流量1.0 mL/min, 检测波长216 nm, 柱温30℃. 结果确定了8个共有峰, 建立了莪术油的HPLC指纹图谱, 可区别同属其他植物的挥发油. 结论本法操作简便, 专属性强, 重现性好, 可有效控制莪术油的质量
Naphthalene decomposition in a DC corona radical shower discharge

The naphthalene decomposition in a corona radical shower discharge(CRS)was investigated, with attention paid to the influences of voltage and initial naphthalene density. The OH emission spectra were investigated so as to know the naphthalene decomposing process. The by-products were analyzed and a decomposing theory in discharge was proposed. The results showed that higher voltage and relative humidity were effective on decomposition. The initial concentration affected the decomposing efficiency of naphthalene. When the initial naphthalene density was 17 mg/m~3, the decomposition rate was found to be 70%under 14 kV.The main by-products were carbon dioxide and water. However,a small amount of carbonic oxide,1,2-ethanediol and acetaldehyde were found due to the incomplete oxidization
Impacts of socio-economic factors on sediment yield in the Upper Yangtze River

In recent years, the role of human activities in changing sediment yield has become more apparent for the construction of hydraulic engineering and water conservation projections in the Upper Yangtze River, but it has not been evaluated at the macro scale. Taking Sichuan Province and Chongqing City as an example, this paper studies the relationship between socio-economic factors and sediment yield in the Upper Yangtze River based on section data in 1989 and 2007. The results show that sediment yield is significantly correlated with population density and cultivated area, in which the former appears to be more closely related to sediment yield. Moreover, in the relation of sediment yield vs. population density, a critical value of population density exists, below which the sediment yield increases with the increase of population density and over which the sediment yield increases with the decrease of population density. The phenomenon essentially reflects the influence of natural factors, such as topography, precipitation and soil property, and some human activities on sediment yield. The region with a higher population density than critical value is located in the east of the study area and is characterized by plains, hills and low mountains, whereas the opposite is located in the west and characterized by middle and high mountains. In the eastern region, more people live on the lands with a low slope where regional soil erosion is slight; therefore, sediment yield is negatively related with population density. In contrast, in the western region, the population tends to aggregate in the areas with abundant soil and water resources which usually lead to a higher intensity of natural erosion, and in turn, high-intensity agricultural practices in these areas may further strengthen local soil erosion. It is also found that population tends to move from the areas with bad environment and high sediment yield to the areas with more comfortable environment and less sediment yield. The natural factors have greater influence on sediment yield of western region than that of eastern region. Generally, the natural factors play a dominant role on sediment yield in the Upper Yangtze River
Evaluation on the human settlements environment suitability in the Three Gorges Reservoir Area of Chongqing based on RS and GIS

To explore geographical differences in quantitative characteristics and spatial pattern of human settlements environmental suitability (HSES) in the Three Gorges Reservoir Area (TGRA), terrain, climate, hydrology, vegetation and other natural factors were selected to build the livable environmental evaluation, and the quantitative analysis was conducted through Remote Sensing(RS) and Geographic Informational System (GIS) to reveal geographical characteristics and spatial patterns of HSES. The results are obtained as follows: (1) inhabitants of the TGRA of Chongqing are concentrated in the area with moderate high HSES, which is 78% of the total population distributed in 48% of the study area; (2) the HSES is closely related to the terrain, and it forms an arc-banded spatial succession pattern: relatively low in the northeast and the southeast while comparatively high in the west and the south; (3) large numbers of people are distributed in the area with low suitability (with higher population density than the average of the western China), but economic development level in these areas is quite low. Moreover, these areas are ecological sensitive and fragile, many kinds of eco-environmental problems have been caused by human activities. Therefore, population migration and layout are reasonable options for the development of these areas
Carbon footprint of different industrial spaces based on energy consumption in China

Using energy consumption and land use data of each region of China in 2007, this paper established carbon emission and carbon footprint model based on energy consumption, and estimated the carbon emission amount of fossil energy and rural biomass energy of different regions of China in 2007. Through matching the energy consumption items with industrial spaces, this paper divided industrial spaces into five types: agricultural space, living & industrial-commercial space, transportation industrial space, fishery and water conservancy space, and other industrial space. Then the author analyzed the carbon emission intensity and carbon footprint of each industrial space. Finally, advices of decreasing industrial carbon footprint and optimizing industrial space pattern were put forward. The main conclusions are as following: (1) Total amount of carbon emission from energy consumption of China in 2007 was about 1.65 GtC, in which the proportion of carbon emission from fossil energy was 89%. (2) Carbon emission intensity of industrial space of China in 2007 was 1.98 t/hm2, in which, carbon emission intensity of living & industrial-commercial space and of transportation industrial space was 55.16 t/hm2 and 49.65 t/hm2 respectively, they were high-carbon-emission industrial spaces among others. (3) Carbon footprint caused by industrial activities of China in 2007 was 522.34x106 hm2, which brought about ecological deficit of 28.69x106 hm2, which means that the productive lands were not sufficient to compensate for carbon footprint of industrial activities, and the compensating rate was 94.5%. As to the regional carbon footprint, several regions have ecological profit while others have not. In general, the present ecological deficit caused by industrial activities was small in 2007. (4) Per unit area carbon footprint of industrial space in China was about 0.63 hm2/hm2 in 2007, in which that of living & industrial-commercial space was the highest (17.5 hm2/hm2). The per unit area carbon footprint of different industrial spaces all presented a declining trend from east to west of China
Assessment of spatial and temporal dynamics of tropical forest cover: A case study in Malkangiri district of Orissa, India

Tropical forests have been recognized as having global conservation importance. However, they are being rapidly destroyed in many regions of the world. Regular monitoring of forests is necessary for an adaptive management approach and the successful implementation of ecosystem management. The present study analyses the temporal changes in forest ecosystem structure in tribal dominated Malkangiri district of Orissa, India, during 1973-2004 period based on digitized forest cover maps using geographic information system (GIS)and interpretation of satellite data. Three satellite images Landsat MSS(1973), Landsat TM(1990)and IRS P6 LISS III(2004)were used to determine changes. Six land cover types were delineated which includes dense forest, open forest, scrub land, agriculture, barren land and water body. Different forest types were also demarcated within forest class for better understanding the degradation pattern in each forest types. The results showed that there was a net decrease of 475.7 km~2forest cover(rate of deforestation=2.34)from 1973 to 1990 and 402.3 km~2(rate of deforestation=2.27)from 1990 to 2004. Forest cover has changed over time depending on a few factors such as large-scale deforestation, shifting cultivation, dam and road construction, unregulated management actions, and social pressure. A significant increase of 1222.8 km~2agriculture area(1973-2004)clearly indicated the conversion of forest cover to agricultural land. These alterations had resulted in significant environmental consequences, including decline in forest cover, soil erosion, and loss of biodiversity. There is an urgent need for rational management of the remaining forest for it to be able to survive beyond next decades. Particular attention must be paid to tropical forests, which are rapidly being deforested
Drought hazard assessment and spatial characteristics analysis in China

Based on the monthly precipitation data for the period 1960-2008 from 616 rainfall stations and the phenology data of main grain crops, the spatial characteristics of drought hazard in China were investigated at a 10 kmx10 km grid-cell scale using a GIS-based drought hazard assessment model, which was constructed by using 3-month Standard Precipitation Index (SPI). Drought-prone areas and heavy drought centers were also identified in this study. The spatial distribution of drought hazard in China shows apparent east-west difference, with the eastern part of China being far more hazardous than the western part. High hazard areas are common in the eastern and central parts of Inner Mongolian Plateau, the central part of Northeast China Plain, the northern part of Heilongjiang, the southeastern part of Qinghai-Tibet Plateau, the central and southern parts of Loess Plateau, the southern part of North China Plain, the northern and southern parts of Yangtze River Plain, and Yunnan-Guizhou Plateau. Furthermore, obvious differences in drought hazard were found both within and between different agricultural zonings
The variation in soil moisture and the appropriate groundwater table for desert riparian forest along the Lower Tarim River

Based on data collected over five years of monitoring the Lower Tarim River,we analyzed the variability of soil moisture content(SMC)and the relationship between SMC, groundwater table depth(GWD)and vegetation by using the methods of coefficient of variation(Cv), Pearson correlation and regression. The results of the variability of SMC indicate that it rose with increase in depth of soil layer-SMC in the soil layer of 0-60 cm was relatively small compared to SMC in the soil layer of 100-260 cm which showed a significant increase in variability. SMC and GWD before and after ecological water diversions exhibited significant differences at the site of the Yingsu transect and its vicinity of the watercourse, especially SMC in the soil layer of 100-260 cm increased significantly with a significant rise of GWD and reached maximum values at a GWD of about 4 m. Plant coverage and species diversity significantly improved with increases in SMC in the soil layer of 100-260 cm, both of them approached the maximum values and 92.3%of major plant species were able to grow when SMC was>10%.To restore the ecosystem of desert riparian forest along the Lower Tarim River, the GWD must be maintained at<4 m in the vicinity of the watercourse and at about 4 m for the rest of this arid region
Research and compilation of the Geomorphologic Atlas of the People's Republic of China (1:1,000,000)

Geomorphologic maps are one of the most fundamental materials of the natural environment. They have been widely used in scientific research, resource exploration and extraction, education and military affairs etc. An editorial committee was established in 2001 to collect materials for researching and compiling a set of new 1:1,000,000 geomorphologic atlas of China. A digital geomorphologic database was created with visual interpretation from Landsat TM/ETM imageries and SRTM-DEM etc. The atlas compiled from the database was finished. The main characteristics of the atlas are as follows: Firstly, Landsat TM/ETM imageries, published geomorphologic maps or sketches, geographical base maps, digital geological maps, and other thematic maps were collected, which were uniformly geometrically rectified, clipped into uniform sheets, and stored in the foundation database. Secondly, based on the legends of 15 sheets 1:1,000,000 maps published in the 1980s,a geomorphologic classification system was built by combining morphology and genesis types. The system comprised seven hierarchical layers:basic morphology, genesis, sub-genesis, morphology, micro-morphology, slope and aspect, material composition and lithology. These layers were stored in the database during visual image interpretation. About 2000 kinds of morpho-genesis and 300 kinds of morpho-structure were interpreted. Thirdly, the legend system was built, which included color, symbol bases and note bases etc., compilation standards and procedures were developed,74 sheets of 1:1,000,000 covering all land and sea territories of China were compiled, the 1:1,000,000 geomorphologic atlas of the People's Republic of China was finished and published. The atlas will fill the blanks in national basic scale thematic maps, and the geomorphologic database could be applied widely in many fields in the future
Effects of afforestation on soil carbon turnover in China's subtropical region

Afforestation in China's subtropics plays an important role in sequestering CO2 from the atmosphere and in storage of soil carbon(C). Compared with natural forests, plantation forests have lower soil organic carbon(SOC)content and great potential to store more C.To better evaluate the effects of afforestation on soil C turnover,we investigated SOC and its stable C isotope(δ~(13)C)composition in three planted forests at Qianyanzhou Ecological Experimental Station in southern China. Litter and soil samples were collected and analyzed for total organic C,δ~(13)C and total nitrogen. Similarly to the vertical distribution of SOC in natural forests,SOC concentrations decrease exponentially with depth. The land cover type(grassland)before plantation had a significant influence on the vertical distribution of SOC.The SOCδ~(13)C composition of the upper soil layer of two plantation forests has been mainly affected by the grass biomass~(13)C composition. Soil profiles with a change in photosynthetic pathway had a more complex 13C isotope composition distribution. During the 20 years after plantation establishment, the soil organic matter sources influenced both theδ~(13)C distribution with depth, and C replacement. The upper soil layer SOC turnover in masson pine(a mean 34%of replacement in the 10 cm after 20 years)was more than twice as fast as that of slash pine(16%of replacement)under subtropical conditions. The results demonstrate that masson pine and slash pine plantations cannot rapidly sequester SOC into long-term storage pools in subtropical China
Analysis of vegetation response to rainfall with satellite images in Dongting Lake

We analyzed the Normalized Difference Vegetation Index(NDVI)from satellite images and precipitation data from meteorological stations from 1998 to 2007 in the Dongting Lake wetland watershed to better understand the eco-hydrological effect of atmospheric precipitation and its relationship with vegetation. First,we analyzed its general spatio-temporal distribution using its mean, standard deviation and linear trend. Then,we used the Empirical Orthogonal Functions(EOF)method to decompose the NDVI and precipitation data into spatial and temporal modes. We selected four leading modes based on North and Scree test rules and analyzed the synchronous seasonal and inter-annual variability between the vegetation index and precipitation, distinguishing time-lagged correlations between EOF modes with the correlative degree analysis method. According to our detailed analyses, the vegetation index and precipitation exhibit a prominent correlation in spatial distribution and seasonal variation. At the 90%confidence level, the time lag is around 110 to 140 days, which matches well with the seasonal variation
An analysis of land use pattern in the industrial development city using high resolution satellite imagery

The spatial differentiation of land use changes of Tuticorin is studied using high resolution LISS III satellite imagery and Maximum Likelihood algorithms. The classification accuracy of 95.2%was obtained. In this study, the land use of Tuticorin is classified as settlement, salt pan, agricultural land, wasteland, water bodies and shrubs. The settlement area is increased to 4.6 km~2during the year 2001 and 2006.The settlement area change is mainly driven by growth of industries and migration of people from peripheral villages. Shrub is increased to 3.63 km~2in the six year period. Water logging due to growth of shrubs in Tuticorin leads to several environmental and health hazard. This study warrants proper urban planning for Tuticorin for sustainable use of resource and environment
Aboveground biomass and nutrient allocation in an age-sequence of Larix olgensis plantations

Biomass and nutrient(N,P,K, Ca, Mg)stock in various aboveground tree components(stemwood, stembark, branches and leaves)were quantified in an age sequence of pure Larix olgensis plantations(20,35,53 and 69 years old)in Northeast China. The results show that the aboveground biomass allocation in various tree components was in the order of stemwood(62%-83%), branches(9%-21%), stembark (7%-11%)and leaves(1%-6%)for all stands. The proportion of stemwood biomass to total aboveground biomass increased whereas that of other tree components decreased consistently with stand age from 20 to 53 years old, but kept relatively constant with stand age from 53 and 69 years old. The nutrient allocation in various tree components generally followed the same pattern as the biomass allocation(i.e.stemwood> branches>stembark>leaves).The proportion of nutrient stock in leaves to total aboveground nutrient stock decreased consistently with increasing stand age, while that in stemwood increased with stand age from 20 to 53 years old but then decreased from 53 to 69 years old. The rate of nutrient removal for stands was estimated at different stand ages under different logging schemes, showing that the rate of nutrient removal would be unchanged when the rotation length was shortened to 20 years by the harvest of stem only, but greatly increased by the harvest of total aboveground biomass. The rate of nutrient removal would be a considerable reduction for all elements by debarking, especially for Ca
Assessment of the effects of the shelterbelt on the soil temperature at regional scale based on MODIS data

At present, the most researches on the protected effect of shelterbelt are on the basis of the two scales of forest belts and networks. However, with the further research on the global environmental change, more attention was paid to the regional climate effect of shelterbelt. In present study,we analyzed the temperature effect of the shelterbelt at regional scale by using the land surface temperature(LST)data from the moderate resolution imaging spectroradiometer(MODIS)at Yushu, Nong'an, Dehui, and Fuyu in Jilin Province of China from March to October in 2008. Results show that the shelterbelt can increase the soil temperature of the protected farmland as compared with no shelterbelt zone, with the increment of 0.57℃ per day in fine shelterbelt and 0.38℃ per day in the normal shelterbelt. Moreover, the correlation analysis of the air temperature, precipitation and the soil type and the shelterbelt effect shows that the air temperature and precipitation are negatively correlated with the shelterbelt effects, that is, the more the temperature and precipitation are, the less the effect produced. While the impact of the soil types on the shelterbelt's effect is not very obvious as a whole. This paper draws significance in terms of analyzing the effects of the shelterbelt on the soil temperature at regional scale utilizing the remotely sensed data and GIS technique