Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater.However,the structure of bimetallic has been much less investigated for ...Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater.However,the structure of bimetallic has been much less investigated for catalyst optimization.Herein,two main types of Pd-Cu bimetallic nanocrystal structures,heterostructure and intermetallic,were prepared and characterized using high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The results show that two individual Pd and Cu nanocrystals with a mixed interface exist in the heterostructure nanocrystals,while Pd and Cu atoms are uniformly distributed across the intermetallic Pd-Cu nanocrystals.The catalytic nitrate reduction experiments were carried out in a semibatch reactor under constant hydrogen flow.The nitrate conversion rate of the heterostructure Pd-Cu nanocrystals supported onα-Al_(2)O_(3),γ-Al_(2)O_(3),SBA-15,and XC-72R exhibited 3.82-,6.76-,4.28-,2.44-fold enhancements relative to the intermetallic nanocrystals,and the nitrogen and nitrite were the main products for the heterostructure and intermetallic Pd-Cu nanocrystals,respectively.This indicates that the catalytic nitrate reduction over Pd-Cu catalyst is sensitive to the bimetallic structures of the catalysts,and heterostructure bimetallic nanocrystals exhibit better catalytic performances on both the activity and selectivity,which may provide new insights into the design and optimization of catalysts to improve catalytic activity and selectivity for nitrate reduction in water.展开更多
This article discusses the achievements and major changes in China's rural development, elaborates on the prominent problems related to agriculture, rural areas and farmers in China, and discusses some key policy ...This article discusses the achievements and major changes in China's rural development, elaborates on the prominent problems related to agriculture, rural areas and farmers in China, and discusses some key policy issues concerning the building of a new socialist countryside, especially from the perspective of balancing urban and rural development. The underlying viewpoint of this article is that to promote the building of a new countryside, a system and mechanism of balancing urban and rural development must be gradually established and improved. The policies should focus on improving the social mobility mechanism to remove the institutional barriers to the social mobility of farmers; establishing public finances to cover both urban and rural areas to narrow the gap in basic public service provision between cities and the countryside; expediting the establishment of a social security network to protect the interests of rural disadvantaged groups; improving the mechanism of protecting land-use rights and interests of farmers; effectively organizing the mechanism of ensuring allocations for the building of a new countryside; improving the organizational structure of rural society to support self-organized farmers' groups; and changing the concept of rural governance and the operation of social governance.展开更多
Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in ...Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in the SRB. A modified monthly degree-day model was applied to quantify the glacier mass balance, area, and changes in glacier runoff in the SRB during 1961–2050. The comparison between the simulated and observed snow line altitude, annual glacier runoff, and mass balance from1961 to 2008 suggests that the degree-day model may be used to analyze the long-term change of glacier mass balance and runoff in the SRB. The glacier accumulation shows a significant(p<0.01) decreasing trend of-0.830 mm a-1. The mass balance also shows a significant(p<0.01) decreasing trend of-5.521 mm a-1. The glacier total runoff has significantly(p<0.05)increased by 0.079 × 105 m3 from 1961 to 2008. The monthly precipitation and air temperature are projected to significant(p<0.005) increase during2015 to 2050 under three different scenarios. The ablation is projected to significant(p<0.001) increase,while the accumulation has no significant(p=0.05)trend. The mass balance is projected to decrease, theglacier area is projected to decrease, and the glacier runoff depth is projected to increase. However, the glacier total runoff is projected to decrease. These results indicate that the glacier total runoff over glacier areas observed in 1970 reached its peak in the 2000 s. This will exacerbate the contradiction between water supply and downstream water demands in the SRB.展开更多
|Editorial Note|Land has become an issue of increasing social concern as demand continues to surge in the midst of economic development,urbanization and industrialization.The crux of the issue is the land regime. Chin...|Editorial Note|Land has become an issue of increasing social concern as demand continues to surge in the midst of economic development,urbanization and industrialization.The crux of the issue is the land regime. China has a unique dualistic land regime under which the land market has not been well developed.Based on a review and commentary of the existing land polices,this article elaborates on the deficiencies inherent in China’s dualistic land rights system and land market and offers policy recommendations for promoting land system reform and market development.This study will help us gain an in-depth understanding of the problems in China’s land regime.展开更多
A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the...A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the existing system for the needed tractor-implement performance, measurements. This system is capable of measuring, displaying and recording, in real-time, the tractor＇s theoretical travel speed, the actual travel speed, the engine speed, the fuel consumption rate, and the drawbar pull. Static calibration tests on various associated sensors for the required measurements show excellent linearity with correlation coefficients that are close to 1. The developed system was extensively and successfully field demonstrated for tractor-implement performance with offset disc harrows on dry, undisturbed loamy soils. Under these conditions, a ratio of tractor power to implement width is suggested. The data also show the existence of a linear relationship between fuel consumption per hectare and specific draught, for the 4 to 9 kN m^-1 range, which suggests the possibility of extending the American Society of Agricultural and Biological Engineers model of draught prediction to forecast fuel consumption. The configuration of the tractor-harrow combination, based on the measurement of the draught required under operational conditions, provides the manufacturers with a reliable indication of the recommended power required for each harrow model. With this type of information farmers can make decisions regarding selection of a suitable tractor-implement combination for their farms. As a consequence, there is improved tractor-harrow productivity and field efficiency.展开更多
This study evaluated the effects of sky conditions (measured by the clearness index, KT) on the estimation of solar radiation and its components. Solar radiation was calculated by a digital elevation model derived fro...This study evaluated the effects of sky conditions (measured by the clearness index, KT) on the estimation of solar radiation and its components. Solar radiation was calculated by a digital elevation model derived from the Shuttle Radar Topography Mission (SRTM). The calculated radiation was parameterized and validated with measured solar radiation from two stations inside the urban perimeter of the city of Cuiabá, Brazil, during 2006 to 2008. The measured solar radiation varied seasonally, with the highest values in December-March and the lowest in June-September. Comparisons between calculated and measured values for two sites in Cuiabá demonstrate that the model is accurate for daily Rg estimates under clear sky conditions based on Root Mean Square Error, Mean Bias Error and Willmott’s index. However, under partially cloudy and cloudy sky conditions the model was not able to provide robust estimates. Spatially, the highest values of incident Rg occurred on strands with North, Northeast and Northwest orientations and were lowest on those oriented to the South, Southeast and Southwest.展开更多
A total of 25 strains were isolated from the intestinal tract of Mystus macropterus. The inhibitory effects of extracellular enzyme activity to common aquat- ic pathogenic bacteria were screened. A probiotic DQHY -7 s...A total of 25 strains were isolated from the intestinal tract of Mystus macropterus. The inhibitory effects of extracellular enzyme activity to common aquat- ic pathogenic bacteria were screened. A probiotic DQHY -7 strain was isolated, and its safety was detected. DQHY -7 strain was preliminarily identified by mor- phological observation, and physiological and biochemical test. Research results showed that DQHY -7 strain had relatively strong production capacities of amylase, cellulase and protease, and could restrict the growth of Escherichia coli, Aeromonas hydrophila and Pseudomonas fluorescens. Results of acute toxicity test showed that 1. 0 × 108 CFU/mL DQHY -7 bacterial suspension showed no pathogenicity to M. macropterus. According to the colony growth pattern and physiological-bio- chemical characteristics of DQHY -7, the strain was identified to be Bacillus subtilis. Research results showed that DQHY -7 strain could be used as a new candi- date strain for feeding microecologicalagent.展开更多
We investigate attenuation scattering and loss properties in Souss basin(SW of High-Atlas) as a transition zone between the High and Anti Atlas ranges. This district consists in a thinned crustal patch with shallow se...We investigate attenuation scattering and loss properties in Souss basin(SW of High-Atlas) as a transition zone between the High and Anti Atlas ranges. This district consists in a thinned crustal patch with shallow seismicity and loose sedimentary trenches that perform an important contribution to augment seismic attenuation. So far, no coda waves approach in our knowledge have been used to draw satisfying outputs about the attenuation properties in the region. Therefore, this update suggests to correlate the lateral changes of seismic attenuation to different characteristics and asperities i.e. seismic activity,crustal age and thickness, heat flow, and ground deformation rate. To do so, we analysed coda waves derived from waveform data of more than 23 local earthquakes from seven broadband seismometers recorded during 2010 e2012 period. As a starter, we utilized the backscattering model which defines theseismic attenuation as inversely proportional to quality factor by the equation A ?1=. QQcestimates c were deducted at various central frequency bands 1.5, 3.0, 6.0, 9.0, 12.0 and 18.0 Hz according to different lapses times. The estimated average frequency dependence quality factor gives relation Qc? 120 f1;01,while the average Qcvalues vary from 149 at 1.5 Hz to 1895 at 18 Hz central frequencies. We observed an intimate dependence between quality factor and frequency ranges, which reflects the complexity of geological/geophysical pattern in the Souss basin and the presence of a variety of heterogeneities within the underlying crust.展开更多
We investigate sedimentological and tectonic processes at the central High Atlas, in order to understand their functioning and to build a geodynamic model that placed the area in its current geological frame.The analy...We investigate sedimentological and tectonic processes at the central High Atlas, in order to understand their functioning and to build a geodynamic model that placed the area in its current geological frame.The analysis used here is based on the numerical enhancement of a Landsat image where the main goal is to map surface sedimentary deposits throughout the central High Atlas in order to delimit the large geological structures. The sediment distribution throughout central High Atlas indicates that this one is a large tectonic subsiding basin, where the ongoing tectonic events and the geodynamical evolution remain to be explained by other prospecting techniques.3-D structure velocities obtained by local seismic tomography and enhancement techniques of gravimetric anomalies are used to explore and define deep structure beneath the central High Atlas. The goal is to establish the evolution of the deep structure related to the geodynamical processes. Modest crustal thickness variation beneath the central High Atlas(~20-~40 km) define by local tomography and gravimetric anomalies, confirms that, a major part of the lower crust is detached into the lithosphere by delamination. Gravimetric anomaly, local seismic tomography and vertical cross sections throughout the central High Atlas, suggest that the lower crust detached is related to the broken slab of remain northward subduction beneath High and Middle Atlas. Meanwhile, extrusions of heated Asthenosphere materials induce the rifting stage concomitant to tectonic subsidence of the basin.展开更多
This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a signifi...This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.展开更多
Taking surface runoff of Coastal Highway in Liaoning Province as research object,this paper analyzed water quality characteristics of runoff and flow rules of pollutants. It proposed using constructed wetland treatmen...Taking surface runoff of Coastal Highway in Liaoning Province as research object,this paper analyzed water quality characteristics of runoff and flow rules of pollutants. It proposed using constructed wetland treatment technique in the drainage system from the perspective of effectively removing major pollutants. Using the constructed wetland k- C* model and relevant experience,parameters of constructed wetland can be obtained. The basic model is as follows: constructed wetland lies in two sides of the road,and surface runoff sewage is collected and treated separately with 1 km road section as the collection unit. The wetland area in one side is 191. 6 m2,average water depth is 0. 5 m,wetland width is 8 m,and wetland length is 24 m.展开更多
This paper analyzes the performance and operation of ecologically-based production systems in the Atlantic Forest in southern Brazil in an integrated approach to their multifunctional characteristics and rural develop...This paper analyzes the performance and operation of ecologically-based production systems in the Atlantic Forest in southern Brazil in an integrated approach to their multifunctional characteristics and rural development. Nowadays the Atlantic Forest is considered the most threatenet biome, because of exploitation of their biological resources and unsuitable agricultural purposes. Banana cultivation is one of biggest commercial productions in atlantic south portion of forest, showing two different cropping systems： one using conventional management tehniques and other antagonistic, ecological based. The ecological system is compatible with the conservation of sustainable use of forests. The article presents a comparative analysis-diagnosis of major production and cultivation systems of banana, using the production systems approach, with evaluation of economic and technical indicators. The database is composed by 17 interviews conducted under field conditions in 2007. As a result, the technical and economic functioning of ecological systems demonstrate achieve economic efficiency, in general, higher than conventional systems. Furthermore, some key characteristics of ecological based systems focus on food production and income generation for farmers without harming areas of the Atlantic Forest, being in equilibrium with tropical dynamic and being an important instrument for the restoration of degraded ecosystems and for local development.展开更多
Expanding the utilization of marginal land resources in rural areas is regarded as a significant supplement for the sustainable development of modern agriculture for its yield, economic and ecological good. Marginal a...Expanding the utilization of marginal land resources in rural areas is regarded as a significant supplement for the sustainable development of modern agriculture for its yield, economic and ecological good. Marginal areas, due to their natural limitations, are only productive for energy crops with strong resistance and tolerance. Cassava, in its longstanding cultivation practices, has marked its adaptability in tropical and subtropical regions. Farmers are allowed to improve reclaimed soils’ fertility, while plants’ canopy coverage could reduce soil erosion. Besides, cassava tubers to be produced as food or fodder can be counted as soil productivity. Breeding advanced cassava varieties on marginal land under proper intensification management and facilitating policies can indeed increase farmers’ income. Some of the projects implemented outside of China speak quite well on that. Additionally, intercropping modes for cassava bring higher incomes than monocropping mode, which simultaneously improves the ecosystem structure and soil conditions. The interspecific cooperation brought by the intercropping pattern has its buffering function and antagonistic effects to counter against plant diseases, pest attacks and weed infestations. It performs as a natural alternative for pesticides and fertilizers with minimal inputs and safe and productive outputs. Although a complete cassava industrial chain has been formed nationwide, there are still challenges like the inadequate use of marginal areas and risks triggered by unfavorable climate, changeable commodity markets, and the composition of the labor force. However, there will still be ample room for further growth of cassava, for recent years have witnessed the acceleration in the circulation of rural land management rights and the stratification of Chinese farmers, which gives an impetus to household management’s dominance as well as the improvements of rural social welfare systems for the overall agricultural efficiency.展开更多
International Maize and Wheat Improvement Center （CIMMYT） and Kazakhstan collaborative activities on wheat improvement are focused in the following main areas： （1） wheat germplasm enhancement： Kazakhstan-Siberia...International Maize and Wheat Improvement Center （CIMMYT） and Kazakhstan collaborative activities on wheat improvement are focused in the following main areas： （1） wheat germplasm enhancement： Kazakhstan-Siberian Network on Wheat Improvement （KASIB） and Shuttle Breeding ＂Mexico-KASIB＂ Programs; （2） Conservation agriculture （CA） for wheat production and crop diversification. Nineteen breeding programs of Kazakhstan and Russia are united by KASIB Network and Shuttle Breeding. By 2014, more than 15,000 wheat lines and varieties were involved in breeding programs of Kazakhstan and Russia; 10 varieties were developed and released. The KASIB Network and Shuttle Breeding Program were recognized as one of the best example of the effective regional and international cooperation in Kazakhstan and Russia. In the beginning of 2000 CIMMYT, National Agricultural Research System, the Ministry of Agriculture, FAO, World Bank in cooperation with farmers initiated large-scale activities based on CA in Kazakhstan. Due the joint efforts, area under CA-based practices has been increasing from virtually none to an estimated area of 500,000 ha in 2007, 1,200,000 ha in 2008, 2,000,000 ha in 2014 with continued rapid increases in area. Kazakhstan is now included among the top ten countries with the largest areas under no-tillage in the world.展开更多
National cotton production data released by the National Bureau of Statistics showed 6.096 million tons of cotton production in 2018, an increase of 444,000 tons from 2017, an increase of 7.8 percent. Of these, Xinji...National cotton production data released by the National Bureau of Statistics showed 6.096 million tons of cotton production in 2018, an increase of 444,000 tons from 2017, an increase of 7.8 percent. Of these, Xinjiang’s cotton output was 5.111 million tons, up 545,000 tons over the previous year, an increase of 11.9 tons. Xinjiang’s cotton output accounted for 83.8 percent of the country total, an increase of 3 percentage points over the previous year.展开更多
Raising Min pigs(MPs)in northern China is challenging,because of harsh environmental conditions in winter.There is a hypothesis that MPs can tolerate cold stress better than Large White pigs(LWPs)and their oocyte comp...Raising Min pigs(MPs)in northern China is challenging,because of harsh environmental conditions in winter.There is a hypothesis that MPs can tolerate cold stress better than Large White pigs(LWPs)and their oocyte competence is particularly protected.Over a period of 3 years,multiple cohorts of MPs and LWPs under different environmental conditions were studied in this paper.Follistatin(FST)serum level was used as a marker for swine oocyte competence.Oocytes were collected from the swine and their maturation rate,cleavage rate and blastocyst rate were measured.Lastly,mRNA expression in ovary and longissimus dorsi for the genes FST,luteinizing hormone receptor(LHR)and cold-inducible RNA-binding protein(CIRP)was measured.Under cold stress,serum follistatin concentrations of both LWPs and MPs were markedly increased,and they were more in LWPs than in MPs.However,oocyte competence was found to be unaffected by cold stress in MPs.It was found that in a separate group of LWPs,oocyte competence was lower in samples collected in winter than that in other seasons.Interestingly,follistatin levels in the follicular fluid of MPs showed no change with cold stress,and serum follistatin levels were increased in sows.Gene expression analysis showed a significant reduction in FST,LHR and CIRP expressions under cold stress in longissimus dorsi,but not in the ovaries.It was found that MPs were better able to maintain oocyte competence under cold stress,which might be due to improved regulation of follistatin in follicular fluid,and MPs appeared likely an adaptation to the harsh conditions that they faced under domestication in northern China.展开更多
Volatile flavor has prompted a great amount of influence in acceptance and view points in fruit products.Melon(Pyrus communis)is an aromadense fruit,thus,the evaluation of volatile flavor is crucial to melon-breeding....Volatile flavor has prompted a great amount of influence in acceptance and view points in fruit products.Melon(Pyrus communis)is an aromadense fruit,thus,the evaluation of volatile flavor is crucial to melon-breeding.The volatile compounds present in nine varieties of Xinjiang muskmelons were identified and analyzed using the headspace solid-phase microextraction and gas chromatography-mass spectrometry methods.In addition,transcriptomics were used to discover the differential genes in fatty acid degradation pathways.It was found that a total of 170 volatile substances,including 52 alcohols,41 esters,24 aldehydes,32 ketones,14 acids and seven phenols,were identified in the nine melons.Results of PCA showed that 3-nonanol,2-nonanol,bis(2-ethylhexyl)adipate,and 2-methylpropanal contributed more to the flavor of melon.It was verified that high activities of acyl-coenzyme A cholesterol acyltransferase(AAT)promoted the conversion of alcohols to esters,so that the melons have a high content of esters.Four genes of long-chain acyl-CoA synthetase were mainly responsible for the large difference in volatile substances.This practice may further undermine the primary rationale for the breeding and promotion in different cultivars of muskmelon.展开更多
There is a broad consensus that urban ecology science needs to be more effective in informing and supporting urban planning and design.How to bridge the two disciplines is still a grand challenge because scientific re...There is a broad consensus that urban ecology science needs to be more effective in informing and supporting urban planning and design.How to bridge the two disciplines is still a grand challenge because scientific research often cannot find its way into practice.Underlying reasons have often been explored around governance,policies and institutional aspects.From a scientific research perspective,this paper briefly outlines the divergence between the two disciplines and seeks potential intersections of them.Overall,starting from the practical needs,this paper argues that there are many“plug-in”opportunities that should be explored in the whole research chain to accommodate successful co-development of research in practice,such as sharing similar research interests,jointly identifying research questions and objectives,adopting suitable research methods,well-designed research experiments and parameters(e.g.,matched scales,resolution levels,metrics and indicators),co-collection of site-specific data.Furthermore,this exploration can be enhanced,particularly at a local scale,where urban dwellers’perceptions,interests and the consequent influences on decision-making and actions can be well incorporated.展开更多
The health benefits resulting from the usual ingestion of red wines have been studied in humans and animals.However,the evaluation of benefits in antioxidant,hypoglycemic and hypolipemic activity concomitant with the ...The health benefits resulting from the usual ingestion of red wines have been studied in humans and animals.However,the evaluation of benefits in antioxidant,hypoglycemic and hypolipemic activity concomitant with the use of an obesogenic diet in adult Wistar rats has been little explored.The present study investigated the use of red wine derived from Northeast Brazil in adult rats fed with an obesogenic diet on antioxidant activity,glucose tolerance,adipose,glycemic and lipemic profile.Sixty 45-day old male Wistar rats formed two groups:standard diet and westernized diet.After changes in body mass and glycemic levels,the animals were subdivided into six subgroups (n = 10 per group) and received water,red wine or hydroalcoholic solution by gavage.The data reveal that the moderate and chronic use of red wine improves the glycemic,lipid and oxidative stress profile,being favorable in preventing the risk of cardiovascular diseases in rats fed with an obesogenic diet.展开更多
基金support from the National Natural Science Foundation of China(Nos.52370100,52000146,and 51978098)China Postdoctoral Science Foundation(No.2020M673351).
文摘Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater.However,the structure of bimetallic has been much less investigated for catalyst optimization.Herein,two main types of Pd-Cu bimetallic nanocrystal structures,heterostructure and intermetallic,were prepared and characterized using high-resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The results show that two individual Pd and Cu nanocrystals with a mixed interface exist in the heterostructure nanocrystals,while Pd and Cu atoms are uniformly distributed across the intermetallic Pd-Cu nanocrystals.The catalytic nitrate reduction experiments were carried out in a semibatch reactor under constant hydrogen flow.The nitrate conversion rate of the heterostructure Pd-Cu nanocrystals supported onα-Al_(2)O_(3),γ-Al_(2)O_(3),SBA-15,and XC-72R exhibited 3.82-,6.76-,4.28-,2.44-fold enhancements relative to the intermetallic nanocrystals,and the nitrogen and nitrite were the main products for the heterostructure and intermetallic Pd-Cu nanocrystals,respectively.This indicates that the catalytic nitrate reduction over Pd-Cu catalyst is sensitive to the bimetallic structures of the catalysts,and heterostructure bimetallic nanocrystals exhibit better catalytic performances on both the activity and selectivity,which may provide new insights into the design and optimization of catalysts to improve catalytic activity and selectivity for nitrate reduction in water.
文摘This article discusses the achievements and major changes in China's rural development, elaborates on the prominent problems related to agriculture, rural areas and farmers in China, and discusses some key policy issues concerning the building of a new socialist countryside, especially from the perspective of balancing urban and rural development. The underlying viewpoint of this article is that to promote the building of a new countryside, a system and mechanism of balancing urban and rural development must be gradually established and improved. The policies should focus on improving the social mobility mechanism to remove the institutional barriers to the social mobility of farmers; establishing public finances to cover both urban and rural areas to narrow the gap in basic public service provision between cities and the countryside; expediting the establishment of a social security network to protect the interests of rural disadvantaged groups; improving the mechanism of protecting land-use rights and interests of farmers; effectively organizing the mechanism of ensuring allocations for the building of a new countryside; improving the organizational structure of rural society to support self-organized farmers' groups; and changing the concept of rural governance and the operation of social governance.
基金supported by the Global Change Research Program of China (Grant No. 2013CBA01806)the China National Natural Science Foundation (Grants Nos. 41130641, 41130638, and 41271090)Shanxi key science and technology innovation team (2014KCT-27)
文摘Glacier runoff in mountain areas of the Shiyang River Basin(SRB), Qilian Mountain, western China is important for the river and water supply downstream. Small glaciers with area of less than 1km2 are dominant(87%) in the SRB. A modified monthly degree-day model was applied to quantify the glacier mass balance, area, and changes in glacier runoff in the SRB during 1961–2050. The comparison between the simulated and observed snow line altitude, annual glacier runoff, and mass balance from1961 to 2008 suggests that the degree-day model may be used to analyze the long-term change of glacier mass balance and runoff in the SRB. The glacier accumulation shows a significant(p<0.01) decreasing trend of-0.830 mm a-1. The mass balance also shows a significant(p<0.01) decreasing trend of-5.521 mm a-1. The glacier total runoff has significantly(p<0.05)increased by 0.079 × 105 m3 from 1961 to 2008. The monthly precipitation and air temperature are projected to significant(p<0.005) increase during2015 to 2050 under three different scenarios. The ablation is projected to significant(p<0.001) increase,while the accumulation has no significant(p=0.05)trend. The mass balance is projected to decrease, theglacier area is projected to decrease, and the glacier runoff depth is projected to increase. However, the glacier total runoff is projected to decrease. These results indicate that the glacier total runoff over glacier areas observed in 1970 reached its peak in the 2000 s. This will exacerbate the contradiction between water supply and downstream water demands in the SRB.
文摘|Editorial Note|Land has become an issue of increasing social concern as demand continues to surge in the midst of economic development,urbanization and industrialization.The crux of the issue is the land regime. China has a unique dualistic land regime under which the land market has not been well developed.Based on a review and commentary of the existing land polices,this article elaborates on the deficiencies inherent in China’s dualistic land rights system and land market and offers policy recommendations for promoting land system reform and market development.This study will help us gain an in-depth understanding of the problems in China’s land regime.
文摘A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the existing system for the needed tractor-implement performance, measurements. This system is capable of measuring, displaying and recording, in real-time, the tractor＇s theoretical travel speed, the actual travel speed, the engine speed, the fuel consumption rate, and the drawbar pull. Static calibration tests on various associated sensors for the required measurements show excellent linearity with correlation coefficients that are close to 1. The developed system was extensively and successfully field demonstrated for tractor-implement performance with offset disc harrows on dry, undisturbed loamy soils. Under these conditions, a ratio of tractor power to implement width is suggested. The data also show the existence of a linear relationship between fuel consumption per hectare and specific draught, for the 4 to 9 kN m^-1 range, which suggests the possibility of extending the American Society of Agricultural and Biological Engineers model of draught prediction to forecast fuel consumption. The configuration of the tractor-harrow combination, based on the measurement of the draught required under operational conditions, provides the manufacturers with a reliable indication of the recommended power required for each harrow model. With this type of information farmers can make decisions regarding selection of a suitable tractor-implement combination for their farms. As a consequence, there is improved tractor-harrow productivity and field efficiency.
文摘This study evaluated the effects of sky conditions (measured by the clearness index, KT) on the estimation of solar radiation and its components. Solar radiation was calculated by a digital elevation model derived from the Shuttle Radar Topography Mission (SRTM). The calculated radiation was parameterized and validated with measured solar radiation from two stations inside the urban perimeter of the city of Cuiabá, Brazil, during 2006 to 2008. The measured solar radiation varied seasonally, with the highest values in December-March and the lowest in June-September. Comparisons between calculated and measured values for two sites in Cuiabá demonstrate that the model is accurate for daily Rg estimates under clear sky conditions based on Root Mean Square Error, Mean Bias Error and Willmott’s index. However, under partially cloudy and cloudy sky conditions the model was not able to provide robust estimates. Spatially, the highest values of incident Rg occurred on strands with North, Northeast and Northwest orientations and were lowest on those oriented to the South, Southeast and Southwest.
基金Supported by the Planning Project of Basic Scientific Research Funds of Chongqing(2012-esfc-jbky-00405)
文摘A total of 25 strains were isolated from the intestinal tract of Mystus macropterus. The inhibitory effects of extracellular enzyme activity to common aquat- ic pathogenic bacteria were screened. A probiotic DQHY -7 strain was isolated, and its safety was detected. DQHY -7 strain was preliminarily identified by mor- phological observation, and physiological and biochemical test. Research results showed that DQHY -7 strain had relatively strong production capacities of amylase, cellulase and protease, and could restrict the growth of Escherichia coli, Aeromonas hydrophila and Pseudomonas fluorescens. Results of acute toxicity test showed that 1. 0 × 108 CFU/mL DQHY -7 bacterial suspension showed no pathogenicity to M. macropterus. According to the colony growth pattern and physiological-bio- chemical characteristics of DQHY -7, the strain was identified to be Bacillus subtilis. Research results showed that DQHY -7 strain could be used as a new candi- date strain for feeding microecologicalagent.
基金supported by the Scientific Institute, Rabat, Morocco
文摘We investigate attenuation scattering and loss properties in Souss basin(SW of High-Atlas) as a transition zone between the High and Anti Atlas ranges. This district consists in a thinned crustal patch with shallow seismicity and loose sedimentary trenches that perform an important contribution to augment seismic attenuation. So far, no coda waves approach in our knowledge have been used to draw satisfying outputs about the attenuation properties in the region. Therefore, this update suggests to correlate the lateral changes of seismic attenuation to different characteristics and asperities i.e. seismic activity,crustal age and thickness, heat flow, and ground deformation rate. To do so, we analysed coda waves derived from waveform data of more than 23 local earthquakes from seven broadband seismometers recorded during 2010 e2012 period. As a starter, we utilized the backscattering model which defines theseismic attenuation as inversely proportional to quality factor by the equation A ?1=. QQcestimates c were deducted at various central frequency bands 1.5, 3.0, 6.0, 9.0, 12.0 and 18.0 Hz according to different lapses times. The estimated average frequency dependence quality factor gives relation Qc? 120 f1;01,while the average Qcvalues vary from 149 at 1.5 Hz to 1895 at 18 Hz central frequencies. We observed an intimate dependence between quality factor and frequency ranges, which reflects the complexity of geological/geophysical pattern in the Souss basin and the presence of a variety of heterogeneities within the underlying crust.
基金supported by the Institut Scientifique, Rabat, Morocco
文摘We investigate sedimentological and tectonic processes at the central High Atlas, in order to understand their functioning and to build a geodynamic model that placed the area in its current geological frame.The analysis used here is based on the numerical enhancement of a Landsat image where the main goal is to map surface sedimentary deposits throughout the central High Atlas in order to delimit the large geological structures. The sediment distribution throughout central High Atlas indicates that this one is a large tectonic subsiding basin, where the ongoing tectonic events and the geodynamical evolution remain to be explained by other prospecting techniques.3-D structure velocities obtained by local seismic tomography and enhancement techniques of gravimetric anomalies are used to explore and define deep structure beneath the central High Atlas. The goal is to establish the evolution of the deep structure related to the geodynamical processes. Modest crustal thickness variation beneath the central High Atlas(~20-~40 km) define by local tomography and gravimetric anomalies, confirms that, a major part of the lower crust is detached into the lithosphere by delamination. Gravimetric anomaly, local seismic tomography and vertical cross sections throughout the central High Atlas, suggest that the lower crust detached is related to the broken slab of remain northward subduction beneath High and Middle Atlas. Meanwhile, extrusions of heated Asthenosphere materials induce the rifting stage concomitant to tectonic subsidence of the basin.
文摘This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.
基金Supported by Project of National Natural Science Foundation of Liaoning Province(20102200)
文摘Taking surface runoff of Coastal Highway in Liaoning Province as research object,this paper analyzed water quality characteristics of runoff and flow rules of pollutants. It proposed using constructed wetland treatment technique in the drainage system from the perspective of effectively removing major pollutants. Using the constructed wetland k- C* model and relevant experience,parameters of constructed wetland can be obtained. The basic model is as follows: constructed wetland lies in two sides of the road,and surface runoff sewage is collected and treated separately with 1 km road section as the collection unit. The wetland area in one side is 191. 6 m2,average water depth is 0. 5 m,wetland width is 8 m,and wetland length is 24 m.
文摘This paper analyzes the performance and operation of ecologically-based production systems in the Atlantic Forest in southern Brazil in an integrated approach to their multifunctional characteristics and rural development. Nowadays the Atlantic Forest is considered the most threatenet biome, because of exploitation of their biological resources and unsuitable agricultural purposes. Banana cultivation is one of biggest commercial productions in atlantic south portion of forest, showing two different cropping systems： one using conventional management tehniques and other antagonistic, ecological based. The ecological system is compatible with the conservation of sustainable use of forests. The article presents a comparative analysis-diagnosis of major production and cultivation systems of banana, using the production systems approach, with evaluation of economic and technical indicators. The database is composed by 17 interviews conducted under field conditions in 2007. As a result, the technical and economic functioning of ecological systems demonstrate achieve economic efficiency, in general, higher than conventional systems. Furthermore, some key characteristics of ecological based systems focus on food production and income generation for farmers without harming areas of the Atlantic Forest, being in equilibrium with tropical dynamic and being an important instrument for the restoration of degraded ecosystems and for local development.
文摘Expanding the utilization of marginal land resources in rural areas is regarded as a significant supplement for the sustainable development of modern agriculture for its yield, economic and ecological good. Marginal areas, due to their natural limitations, are only productive for energy crops with strong resistance and tolerance. Cassava, in its longstanding cultivation practices, has marked its adaptability in tropical and subtropical regions. Farmers are allowed to improve reclaimed soils’ fertility, while plants’ canopy coverage could reduce soil erosion. Besides, cassava tubers to be produced as food or fodder can be counted as soil productivity. Breeding advanced cassava varieties on marginal land under proper intensification management and facilitating policies can indeed increase farmers’ income. Some of the projects implemented outside of China speak quite well on that. Additionally, intercropping modes for cassava bring higher incomes than monocropping mode, which simultaneously improves the ecosystem structure and soil conditions. The interspecific cooperation brought by the intercropping pattern has its buffering function and antagonistic effects to counter against plant diseases, pest attacks and weed infestations. It performs as a natural alternative for pesticides and fertilizers with minimal inputs and safe and productive outputs. Although a complete cassava industrial chain has been formed nationwide, there are still challenges like the inadequate use of marginal areas and risks triggered by unfavorable climate, changeable commodity markets, and the composition of the labor force. However, there will still be ample room for further growth of cassava, for recent years have witnessed the acceleration in the circulation of rural land management rights and the stratification of Chinese farmers, which gives an impetus to household management’s dominance as well as the improvements of rural social welfare systems for the overall agricultural efficiency.
文摘International Maize and Wheat Improvement Center （CIMMYT） and Kazakhstan collaborative activities on wheat improvement are focused in the following main areas： （1） wheat germplasm enhancement： Kazakhstan-Siberian Network on Wheat Improvement （KASIB） and Shuttle Breeding ＂Mexico-KASIB＂ Programs; （2） Conservation agriculture （CA） for wheat production and crop diversification. Nineteen breeding programs of Kazakhstan and Russia are united by KASIB Network and Shuttle Breeding. By 2014, more than 15,000 wheat lines and varieties were involved in breeding programs of Kazakhstan and Russia; 10 varieties were developed and released. The KASIB Network and Shuttle Breeding Program were recognized as one of the best example of the effective regional and international cooperation in Kazakhstan and Russia. In the beginning of 2000 CIMMYT, National Agricultural Research System, the Ministry of Agriculture, FAO, World Bank in cooperation with farmers initiated large-scale activities based on CA in Kazakhstan. Due the joint efforts, area under CA-based practices has been increasing from virtually none to an estimated area of 500,000 ha in 2007, 1,200,000 ha in 2008, 2,000,000 ha in 2014 with continued rapid increases in area. Kazakhstan is now included among the top ten countries with the largest areas under no-tillage in the world.
文摘National cotton production data released by the National Bureau of Statistics showed 6.096 million tons of cotton production in 2018, an increase of 444,000 tons from 2017, an increase of 7.8 percent. Of these, Xinjiang’s cotton output was 5.111 million tons, up 545,000 tons over the previous year, an increase of 11.9 tons. Xinjiang’s cotton output accounted for 83.8 percent of the country total, an increase of 3 percentage points over the previous year.
基金Supported by the National Natural Science Foundation of China(32172696,U20A2052,31872980)Heilongjiang Provincial Scientific Research Business Fund Project(CZKYF2020A004,CZKYF2021-2-C025)Heilongjiang Provincial Natural Science Foundation(LH2019C064)。
文摘Raising Min pigs(MPs)in northern China is challenging,because of harsh environmental conditions in winter.There is a hypothesis that MPs can tolerate cold stress better than Large White pigs(LWPs)and their oocyte competence is particularly protected.Over a period of 3 years,multiple cohorts of MPs and LWPs under different environmental conditions were studied in this paper.Follistatin(FST)serum level was used as a marker for swine oocyte competence.Oocytes were collected from the swine and their maturation rate,cleavage rate and blastocyst rate were measured.Lastly,mRNA expression in ovary and longissimus dorsi for the genes FST,luteinizing hormone receptor(LHR)and cold-inducible RNA-binding protein(CIRP)was measured.Under cold stress,serum follistatin concentrations of both LWPs and MPs were markedly increased,and they were more in LWPs than in MPs.However,oocyte competence was found to be unaffected by cold stress in MPs.It was found that in a separate group of LWPs,oocyte competence was lower in samples collected in winter than that in other seasons.Interestingly,follistatin levels in the follicular fluid of MPs showed no change with cold stress,and serum follistatin levels were increased in sows.Gene expression analysis showed a significant reduction in FST,LHR and CIRP expressions under cold stress in longissimus dorsi,but not in the ovaries.It was found that MPs were better able to maintain oocyte competence under cold stress,which might be due to improved regulation of follistatin in follicular fluid,and MPs appeared likely an adaptation to the harsh conditions that they faced under domestication in northern China.
基金This study was funded by China Agriculture Research System of Modern Agro-industry Technology Research(CARS-25)public welfare scientific research institutes of Xinjiang(KY2021118 and KY2020108)China Postdoctor(No.299580).
文摘Volatile flavor has prompted a great amount of influence in acceptance and view points in fruit products.Melon(Pyrus communis)is an aromadense fruit,thus,the evaluation of volatile flavor is crucial to melon-breeding.The volatile compounds present in nine varieties of Xinjiang muskmelons were identified and analyzed using the headspace solid-phase microextraction and gas chromatography-mass spectrometry methods.In addition,transcriptomics were used to discover the differential genes in fatty acid degradation pathways.It was found that a total of 170 volatile substances,including 52 alcohols,41 esters,24 aldehydes,32 ketones,14 acids and seven phenols,were identified in the nine melons.Results of PCA showed that 3-nonanol,2-nonanol,bis(2-ethylhexyl)adipate,and 2-methylpropanal contributed more to the flavor of melon.It was verified that high activities of acyl-coenzyme A cholesterol acyltransferase(AAT)promoted the conversion of alcohols to esters,so that the melons have a high content of esters.Four genes of long-chain acyl-CoA synthetase were mainly responsible for the large difference in volatile substances.This practice may further undermine the primary rationale for the breeding and promotion in different cultivars of muskmelon.
基金This work was based on“Effects of urban designed environment on urban plant biodiversity and feedback to urban planning and design practice”,financed by the National Natural Science Foundation of China(NSFC)[Grant No.52078346]It is with great gratitude to NSFC for supporting this transdisciplinary research.I received the acceptance letter on my tenth anniversary of professional work.I regard this perspective as summarizing me having a foot in both camps–one foot in ecological science and the other in planning and design practice.Thank anonymous reviewers and editors for their constructive comments。
文摘There is a broad consensus that urban ecology science needs to be more effective in informing and supporting urban planning and design.How to bridge the two disciplines is still a grand challenge because scientific research often cannot find its way into practice.Underlying reasons have often been explored around governance,policies and institutional aspects.From a scientific research perspective,this paper briefly outlines the divergence between the two disciplines and seeks potential intersections of them.Overall,starting from the practical needs,this paper argues that there are many“plug-in”opportunities that should be explored in the whole research chain to accommodate successful co-development of research in practice,such as sharing similar research interests,jointly identifying research questions and objectives,adopting suitable research methods,well-designed research experiments and parameters(e.g.,matched scales,resolution levels,metrics and indicators),co-collection of site-specific data.Furthermore,this exploration can be enhanced,particularly at a local scale,where urban dwellers’perceptions,interests and the consequent influences on decision-making and actions can be well incorporated.
文摘The health benefits resulting from the usual ingestion of red wines have been studied in humans and animals.However,the evaluation of benefits in antioxidant,hypoglycemic and hypolipemic activity concomitant with the use of an obesogenic diet in adult Wistar rats has been little explored.The present study investigated the use of red wine derived from Northeast Brazil in adult rats fed with an obesogenic diet on antioxidant activity,glucose tolerance,adipose,glycemic and lipemic profile.Sixty 45-day old male Wistar rats formed two groups:standard diet and westernized diet.After changes in body mass and glycemic levels,the animals were subdivided into six subgroups (n = 10 per group) and received water,red wine or hydroalcoholic solution by gavage.The data reveal that the moderate and chronic use of red wine improves the glycemic,lipid and oxidative stress profile,being favorable in preventing the risk of cardiovascular diseases in rats fed with an obesogenic diet.
