The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos Basin.The geological storage of CO_(2) in saline aquifers is an ef...The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos Basin.The geological storage of CO_(2) in saline aquifers is an effective backup way to achieve carbon neutrality.In this case,the potential of saline aquifers for CO_(2) storage serves as a critical basis for subsequent geological storage project.This study calculated the technical control capacities of CO_(2) of the saline aquifers in the fifth member of the Shiqianfeng Formation(the Qian-5 member)based on the statistical analysis of the logging and the drilling and core data from more than 200 wells in the northeastern Ordos Basin,as well as the sedimentary facies,formation lithology,and saline aquifer development patterns of the Qian-5 member.The results show that(1)the reservoirs of saline aquifers in the Qian-5 member,which comprise distributary channel sand bodies of deltaic plains,feature low porosities and permeabilities;(2)The study area hosts three NNE-directed saline aquifer zones,where saline aquifers generally have a single-layer thickness of 3‒8 m and a cumulative thickness of 8‒24 m;(3)The saline aquifers of the Qian-5 member have a total technical control capacity of CO_(2) of 119.25×10^(6) t.With the largest scale and the highest technical control capacity(accounting for 61%of the total technical control capacity),the Jinjie-Yulin saline aquifer zone is an important prospect area for the geological storage of CO_(2) in the saline aquifers of the Qian-5 member in the study area.展开更多
The issue of China＇s energy supply security is not only the key problem which af- fects China＇s rapid and sustainable development in the 21st century, but also the one which international attention focuses on. Based...The issue of China＇s energy supply security is not only the key problem which af- fects China＇s rapid and sustainable development in the 21st century, but also the one which international attention focuses on. Based on the notable characteristic of spatial imbalance between energy production and consumption in China, this paper takes the evolution of China＇s primary energy resources development（excluding hydropower） from 1949 to 2007 as the study object, with the aim to sum up the evolutive characteristics and laws of China＇s energy resources development in the past nearly 60 years. Then, based on comprehensive considerations of coal＇s, oil＇s and natural gas＇s basic reserves, qualities, geological conditions production status, and ecological service function of every province, this paper adopts development potential index （DP）to evaluate the development potential of every province＇s en- ergy resources, and divide them into different ranks. Conclusions are drawn as follows： （1） Generally speaking, China＇s gross energy production was increasing in waves from 1949 to 2007. From the viewpoint of spatial patterns, China＇s energy resources development has shown a characteristic of ＂concentrating to the north and central areas, and evolving from linear-shaped to ＂T-shaped＂ pattern gradually since 1949. （2） The structure evolution of China＇s energy resources development in general has shown a trend of ＂coal proportion is dominant but decreasing, while oil and gas proportions are increasing＂ since 1949. （3） At the provincial scale, China＇s energy resources development potential could be divided into large, sub-large, general and small ranks, four in all. In the future, the spatial pattern of China＇s energy production will evolve from ＂T-shaped＂ to ＂R-shaped pattern＂. These conclusions will help to clarify the temporal and spatial characteristics and laws of China＇s energy resources development, and will be beneficial for China to design scientific and rational energy development strategies and plans, coordinate spatial imbalance of energy production and consumption, ensure national energy supply, avoid energy resources waste and disorderly development, and promote regional sustainable development under the globalization back-ground with changeful international energy market.展开更多
CO_(2)-EGR,i.e.enhanced gas recovery by injecting CO_(2),is to displace natural gas by injecting CO_(2) in the supercritical phase.It can both enhance the recovery of gas reservoirs and realize CO_(2) storage.Currentl...CO_(2)-EGR,i.e.enhanced gas recovery by injecting CO_(2),is to displace natural gas by injecting CO_(2) in the supercritical phase.It can both enhance the recovery of gas reservoirs and realize CO_(2) storage.Currently,this technique is still at its exploring stage.The effect of CO_(2)-EGR is not clarified,the geologic conditions for CO_(2)-EGR are not definite,and the rational working system for CO_(2)-EGR is not available.In this paper,the long-core experiment was conducted to determine whether and how much the recovery of low-permeability reservoirs can be enhanced by injecting CO_(2).According to the experimental results,the recovery can be enhanced by 12%when CO_(2) content in produced gas is more than 10%.Moreover,the multi-component seepage mathematical model was built for displacing natural gas by injecting supercritical CO_(2),and the model accuracy was verified using laboratory data.With this mathematical model,the influence factors for displacing natural gas by injecting supercritical CO_(2) were analyzed in order to define the conditions for selecting favorable zones.The Well DK13 area in the Daniudi gas field,Ordos Basin,was selected for potential evaluation of CO_(2)-EGR.As indicated by the numerical simulation results,when CO_(2) content of producing wells in the Well DK13 area is 10%(with a lower cost for corrosion prevention),the ratio of CO_(2)-EGR is 8.0–9.5%,and 31.1%HCPV(hydrocarbon pores volume)of CO_(2) storage can be realized.It is thus concluded that the CO_(2)-EGR technique can enhance the recovery of gas reservoirs and also store CO_(2) underground,contributing to the increase of both social and economic benefits.展开更多
Public buildings present substantial demand re sponse(DR)potential,which can participate in the power sys tem operation.However,most public buildings exhibit a high degree of uncertainties due to incomplete informatio...Public buildings present substantial demand re sponse(DR)potential,which can participate in the power sys tem operation.However,most public buildings exhibit a high degree of uncertainties due to incomplete information,varying thermal parameters,and stochastic user behaviors,which hin ders incorporating the public buildings into power system oper ation.To address the problem,this paper proposes an interval DR potential evaluation method and a risk dispatch model to integrate public buildings with uncertainties into power system operation.Firstly,the DR evaluation is developed based on the equivalent thermal parameter(ETP)model,actual outdoor tem perature data,and air conditioning(AC)consumption data.To quantify the uncertainties of public buildings,the interval evalu ation is given employing the linear regression method consider ing the confidence bound.Utilizing the evaluation results,the risk dispatch model is proposed to allocate public building re serve based on the chance constrained programming(CCP).Fi nally,the proposed risk dispatch model is reformulated to a mixed-integer second-order cone programming(MISOCP)for its solution.The proposed evaluation method and the risk dis patch model are validated based on the modified IEEE 39-bus system and actual building data obtained from a southern city in China.展开更多
The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.U...The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.展开更多
As an important element of urban renewal in highly urbanized areas, pocket parks with small size, flexible layout and daily accessibility are becoming a major component of green infrastructure and the mainstay of outd...As an important element of urban renewal in highly urbanized areas, pocket parks with small size, flexible layout and daily accessibility are becoming a major component of green infrastructure and the mainstay of outdoor recreation space expansion in high-density urban centers. Nevertheless, the absence of a comprehensive framework for evaluating the potential of pocket park construction (PPC), one that integrates diverse influencing factors on a macro scale, has resulted in the random installation of such spaces, often failing to optimize the utilization of urban land. Addressing this critical lacuna, we propose an approach to evaluate PPC potential from a city-scale perspective, which is used to support the determination of which land units should be prioritized for PPC. A complete and feasible workflow was also established to identify potential land units, construct an index system for PPC combining demand and supply levels, quantitatively calculate indices based on remote sensing (RS) and geographic information system (GIS), accurately evaluate PPC potential using an entropy-weighted TOPSIS model, and develop targeted renewal strategies. A case study in Dalian, China, demonstrated the applicability and implications of the workflow. The results showed that it is flexible and easy to adapt to different local contexts, allowing evaluators to introduce parameters considering the availability of local data, and will help decision makers to build pocket parks in the most effective plots, providing a strong reference for high-quality development in other high-density urban centers facing the contradiction between ecological construction and land scarcity.展开更多
The Early Cambrian Yuertusi Formation(Є_(1)y)in the Tarim Basin of China deposits a continuously developed suite of organic-rich black mudstones,which constitute an important source of oil and gas reservoirs in the Pa...The Early Cambrian Yuertusi Formation(Є_(1)y)in the Tarim Basin of China deposits a continuously developed suite of organic-rich black mudstones,which constitute an important source of oil and gas reservoirs in the Paleozoic.However,its hydrocarbon generation and evolution characteristics and resource potential have long been constrained by deeply buried strata and previous research.In this paper,based on the newly obtained ultra-deep well drilling data,the hydrocarbon generation and expulsion model ofЄ_(1)y shale was established by using data-driven Monte Carlo simulation,upon which the hydrocarbon generation,expulsion,and retention amounts were calculated by using the diagenetic method.The research indicates that theЄ_(1)y shale reaches the hydrocarbon generation and expulsion threshold at equivalent vitrinite reflectances of 0.46%and 0.72%,respectively.The cumulative hydrocarbon generation is 68.88×10^(10)t,the cumulative hydrocarbon expulsion is 35.59×10^(10)t,and the cumulative residual hydrocarbon is 33.29×10^(10)t.This paper systematically and quantitatively calculates the hydrocarbon expulsion at various key geological periods for theЄ_(1)y source rocks in the study area for the first time,more precisely confirming that the black shale of theЄ_(1)y is the most significant source rock contributing to the marine oil and gas resources in the Tarim Basin,filling the gap in hydrocarbon expulsion calculation in the study area,and providing an important basis for the formation and distribution of Paleozoic hydrocarbon reservoirs.The prospect of deep ultra-deep oil and gas exploration in the Tarim Basin is promising.Especially,the large area of dolomite reservoirs under the Cambrian salt and source rock interiors are the key breakthrough targets for the next exploration in the Tarim Basin.展开更多
From 2010 to 2012, the China Geological Survey Center for Hydrogeology and Environmental Geology Survey （CHEGS） carried out the project ＂Potential evaluation and demonstration project of CO2 Geological Storage in C...From 2010 to 2012, the China Geological Survey Center for Hydrogeology and Environmental Geology Survey （CHEGS） carried out the project ＂Potential evaluation and demonstration project of CO2 Geological Storage in China＂. During this project, we developed an evaluation index system and technical methods for the potential and suitability of CO2 geological storage based on China＇s geological conditions, and evaluated the potential and suitability of the primary basins for COz geological storage, in order to draw a series of regional scale maps （at a scale of 1：5000000） and develop an atlas of the main sedimentary basins in China. By using these tools, we delineated many potential targets for CO2 storage. We also built techniques and methods for site selection and the exploration and assessment of CO2 geological storage in deep saline aquifers. Furthermore, through cooperation with the China Shenhua Coal to Liquid and Chemical Co., Ltd., we successfully constructed the first coal-based demonstration project for CO2 geological storage in deep saline aquifers in the Yijinhuoluo Banner of Ordos in the Inner Mongolia Autonomous Region, which brought about the basic preliminary theories, techniques, and methods of geological CO2 storage in deep saline aquifers under China＇s geological conditions.展开更多
The general situation of the total land resources in Wulushan, West China was studied by field investigations with the aid of a GIS software, called Region Manager. The current status of land use in Wulushan is descri...The general situation of the total land resources in Wulushan, West China was studied by field investigations with the aid of a GIS software, called Region Manager. The current status of land use in Wulushan is described. The potential land productivity was evaluated by a fuzzy comprehensive method, We take each plot as a basic unit of evaluation on the basis of an index system of land resources in Wulushan which was developed from the investigation data. Evaluation of potential land productivity is the key part of land management. A guideline is presented in this paper for a proper utilization of the land resources and to develop the productive capacity of the land.展开更多
The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Platea...The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Plateau. A systems engineering model was developed and used to evaluate the total allelopathic potential of crop cultivars. In addition, a method for quantifying the total allelopathic potential in crop accessions was presented. Total allelopathic potential of four winter wheat accessions from the Loess Plateau was estimated and compared using a systems theory approach. The model assessed allelopathic potential in different parts of the plants from the time wheat turned green in spring until maturity. Results from these models indicated that the four wheat accessions had very weak allelopathic potential. Allelopathic potential declined in the order Xiaoyan 22 〉 Ningdong 1 〉 Fengchan 3 〉 Bima 1. This system engineering evaluation method allows for the assessment of allelopathic potential among crop varieties. It will help plant breeders to select and develop allelopathic crop accessions that combine weed suppression properties with agronomic traits related to yield and quality.展开更多
BACKGROUND ： The recordings of evoked spinal cord potentials following epidural spinal cord stimulation are thought to be generated by volleys traversing the dorsal column pathway, and it may not directly reflect con...BACKGROUND ： The recordings of evoked spinal cord potentials following epidural spinal cord stimulation are thought to be generated by volleys traversing the dorsal column pathway, and it may not directly reflect conduction defects in corticospinat tracts of cervical spinal cord. To our knowledge there has been few report using several evoked spinal cord potentials in function evaluation of the cervical spinal cord in eldedy patients with cervical spondylotic myelopathy （CSM）. OBJECTIVE： To investigate the function states of the cervical spinal cord in elderly patients with CSM and explore its pathophysictogic mechanism. DESIGN： Case observation SETTING ： Department of Orthopedics for the aged, Shenzhen Pingle Hospital of Orthopedics. Department of Orthopedic Surgery, Yamaguchi University School of Medicine. PARTICIPANTS ： A total of 23 eldedy patients with CSM who received treatment in the Department of Orthopedic Surgery, Yamaguchi University School of Medicine of Japan from January 2003 to February 2004 were enrolled in this study. Inclusive criteria： ① Multiple intervertebral levels of cervical spinal cord compression confirmed by MRI, e.g. 3 or more than 3 levels of compressin. ② Age ≥ 70 years old. ③ Numbness and sensory disturbance in the upper limbs and showed hyperreflexia in the lower limbs. Exclusive criteria： Patients with abnormal motor and sensory nerve conduction velocities in both upper and lower limbs were excluded. METHODS： Evoked spinal cord potentials （ESCPs） following transcranial electric stimulation （TCE-ESCPs）, epidural spinal cord stimulation （SpinaI-ESCPs） and median nerve stimulation （MN-ESCPs） were recorded in 23 patients from posterior epidural space intreoperatively. The abnormalities of TCE-ESCPs were defined as attenuation of amplitude of the D wave. The most cranial intervertebral level showing abnormal TCE-ESCPs with a marked reduction in size of the negative peak （reduction of over 50%） was considered as the upper level of the spinal cord lesion with respect to the corticospinal tract in white matter. The abnormalities of SpinaI-ESCPs were defined as marked reduction in the size of negative peak （reduction of over 50%）. The most caudal intervertebral level showing abnormal SpinaI-ESCPs was considered as the lower level of the spinal cord lesion with respect to the dorsal column pathway in white matter. The abnormalities of MN-ESCPs were defined as attenuation of the N13 amplitude,which was considered as the lesion level of the spinal cord with respect to the dorsal horn in gray matter. Radiological investigation： Lateral view of plain X-ray films was obtained in flexion and extension of the cervical spine. Instability of the cervical intervertebral level was determined as horizontal displacement of the vertebral body of over 3 mm. MAIN OUTCOME MEASURES ： The results of examination of TCE-ESCPs, SpinaI-ESCPs and MN-ESCPs in el- dedy patients with CSM. RESULTS： The 23 eldedy patients with CSM were participated in the result analysis. ①TCE-ESCPs： The impairment of the corticospinal tract in white matter at single intervertebral level was revealed in 18 of 23 patients by recordings of TCE-ESCPs （sensitivity 78%）. In the 18 patients, the lesion level was shown at the up- per cervical segment in 14 patients （C3-4n=10 and C4-5n=4）, and at the lower cervical segment in 4 patients （C5-6n=4）. ②Spinal-ESCPs： The impairment of the dorsal column pathway of white matter at single intervertebral level was revealed in 17 of 23 patients, by recordings of Spinal-ESCPs （sensitivity 74%）. In the 17 patients, the lesion level was presented at the upper cervical segment in 14 patients （C3-4n=10 and C4-5n=4）, and at the lower cervical segment in 3 patients （C5-6 n=3）. ③MN-ESCPs： All patients revealed abnormal MN-ESCPs at one or more intervertebral levels （sensitivity 100%）. The impairment at single intervertebral level was demonstrated in 17 patients, and the impairment at multiple intervertebral levels was shown in 4 patients （3 patients at the C3-4, C4-4, and C5-4~6, and one patient at the C4-5, C5-6, and C6-7）. ④Radiological findings： The Instability of the intervertebral level at the C3-4 or C4-5 motion segment was seen in 15 patients, with a total of 20 levels, and where 10 were at the C3-4 intervertebral level and 5 were at the C3-4, C4-5 intervertebral level. CONCLUSION ： The results suggest that in most elderly patients with CSM who have multiple intervertebral level compressions of the cervical spinal cord on MRI, white matter is impaired at the single cervical intervertebral level, and not only the dorsal column pathway, but also the corticospinal tract can be affected. Combined the findings of radiography, the excessive motion and instability of the C3-4 or C4-5 intervertebral level plays an important role in inducing the long tract lesion in elderly patients with CSM.展开更多
Paleofluid-rock interaction results in the modification of the ultra-deep reservoir quality,but the coupling effects of the paleofluid evolution on reservoir quality modification are still underestimated.Here,the mult...Paleofluid-rock interaction results in the modification of the ultra-deep reservoir quality,but the coupling effects of the paleofluid evolution on reservoir quality modification are still underestimated.Here,the multi-stage dolomite cements have been studied by means of core observations,thin section identification,fluid inclusions,and in situ elements and isotopic analyses in order to reaveal the paleofluid evolution processes and their effects on the reservoir quality.The fibrous dolomite cement(FDC)and bladed dolomite cement(BDC)both have similar geochemical properties and homogenization temperature(Th)to the matrix dolostone.Subsequent early silicification occurs(QZ1).However,silt-to fine-sized crystalline dolomite cement(CD2)has higher concentration of Fe and medium rare earth element,more negativeδ^(18)O than for FDC and BDC,and 103.4-150.2℃in Th.The first petroleum charge episode solid bitumen 1(SB1)followed the CD2.The medium to coarse sized crystalline dolomite cement(CD3)is characterized by the higher Mn and lower Sr concentration than CD2,positiveδEu anomaly,negativeδ^(13)C andδ^(18)O,high^(87)Sr/^(86)Sr ratio and 138.9℃-184.3℃in Th.The solid bitumen 2(SB2)occurs after CD3.Subsequently,the saddle dolomite(SD)has higher Fe and Mn concentration and lower Na and Sr than others cement,δEu positive anomaly,negativeδ^(13)C andδ^(18)O,high ^(87)Sr/^(86)Sr ratio and 177.5℃-243.6℃in Th.Eventually massive silicification(QZ2)took place.The FDC,BDC,QZ1 and SB1 formed in the early diagenetic stage and have little negative effect on the reservoir quality.But the CD2 and CD3 dramatically decreased the reservoir quality related to a quantity of hydrothermal fluids entrance in the mesodiagenetic stage along the strike-slip faults and the unconformity surface at top of the Deng-2 Member during the late stage of the Caledonian orogeny.The reservoir spaces were retained and enlarged during the late diagenetic stage when the peak petroleum charge occurred,massive silicification and thermochemical sulfate reduction took place with SB2,SD and QZ2 being formed.The research outcome may update our understanding on the retention mechanism and the insights for further hydrocarbon exploration of Precambrian ultra-deep microbial reservoirs.展开更多
The scientific evaluation of arable land remediation potential can be used to formulate remediation policies based on local conditions. This study took arable land resources in Tongxu County, China as the research obj...The scientific evaluation of arable land remediation potential can be used to formulate remediation policies based on local conditions. This study took arable land resources in Tongxu County, China as the research object and administrative villages as the evaluation unit, constructed an evaluation index system by integrating three aspects—quantity, quality and ecology. Based on the evaluation of arable land remediation potential, the K-means++ spatial clustering algorithm combined with elbow method is used to divide the remediation partition and give the remediation strategy. The results showed that: 1) the evaluation index system of arable land improvement potential, which integrated “quantity-quality-ecology”, was more systematic in analyzing the potential of arable land improvement than the previous single target evaluation index, and explored its internal linkage. 2) There are some spatial differences in the quantitative, qualitative and ecological potentials in Tongxu County, with the quantitative potential being higher in Changzhi Township, the intersection of Lizhuang Township and the southern part of Yuhuangmiao Township, the qualitative potential being more evenly distributed, and the ecological potential being higher around Chengguan Township. 3) Through K-means++ clustering algorithm combined with elbow method, Tongxu County was divided into five subzones: quality improvement zone, intensive improvement zone, quantity improvement zone, comprehensive improvement zone and health improvement zone, among which the highest percentage of quality improvement zone and the lowest percentage of comprehensive improvement zone were 49.2% and 1.5% respectively, and differentiated remediation strategies were provided by research for each sub-district to promote high quality of arable land.展开更多
Rural revitalization strategy is an important strategic layout of rural development in the new era of the CPC Central Committee,and scientific and reasonable determination of village types is an important measure to p...Rural revitalization strategy is an important strategic layout of rural development in the new era of the CPC Central Committee,and scientific and reasonable determination of village types is an important measure to promote rural revitalization by classification.The villages of Wan’an County were selected as the research object.Firstly,the factors that have a key impact on the development of the villages were extracted and qualitatively analyzed to preliminarily screen and judge their types.Secondly,the evaluation index system of development potential of the villages was constructed to quantitatively evaluate and reasonably classify the villages.Finally,the spatial distribution characteristics and quantity of different villages were revealed,and differentiated development strategies were proposed.展开更多
An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed throug...An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.展开更多
The reduction of pesticide aerial spraying drift is still one of the major challenges in modern agriculture.The aim of this study was to evaluate the drift potential of different types of unmanned aerial vehicle(UAV)a...The reduction of pesticide aerial spraying drift is still one of the major challenges in modern agriculture.The aim of this study was to evaluate the drift potential of different types of unmanned aerial vehicle(UAV)and adjuvant products for reducing spray drift in aerial applications.Three types of UAV(3WQF120-12 and 3CD-15 fuel oil powered single-rotor UAV and HY-B-15L battery powered single-rotor UAV)were selected in this study with regular application parameters to compare each spray drift,and 3WQF120-12 fuel oil powered UAV was selected to quantify spray drift of 6 adjuvants dissolved in water under field conditions.Solutions were marked with brillant sulfoflavin dye(BSF)at 0.1%.Petri dishes and rotary impactors were used to collect airborne and sediment drift,respectively.Drift deposits were evaluated by spectrophotometry in order to quantify deposits.The results showed that when the flight height was 1.5-2.0 m above the crop at the flight speed of 4-5 m/s and the average wind speed of 1.63-1.73 m/s,3WQF120-12 fuel oil powered UAV had lower drift potential than the other two types;DV0.5 and percentage of droplets with diameter≤75μm had very significant effects on spray drift percentage(p=0.01);the risk of drift in agricultural spraying could be significantly decreased not only by reducing the percentage of fine droplets but also by changing droplet spectra.Compared to water,Silwet DRS-60,ASFA+B,T1602,Break-thru Vibrant,QF-LY and Tmax could reduce by 65%,62%,59%,46%,42%,and 19%spray drift,respectively.when water without adjuvants were sprayed,90%of drift droplets were located within a range of 10.1 m of the target area while with 0.8%Silwet DRS-60 adjuvant in water,the distance was shortened to 6.4 m.展开更多
Carbon dioxide(CO_(2))geological utilization and storage(CGUS)is the key link of CO_(2)capture,utilization,and storage(CCUS).The accurate characterization of the geological body structure is a vital prerequisite of CG...Carbon dioxide(CO_(2))geological utilization and storage(CGUS)is the key link of CO_(2)capture,utilization,and storage(CCUS).The accurate characterization of the geological body structure is a vital prerequisite of CGUS.This paper gives a review of the multi-scale three-dimensional geological structure characterization and site selection of CO_(2)storage.It shows that there is a lack of systematic and high-precision methods for transparency characterization of multi-scale three-dimensional engineering geological structure and hydrogeological structure of a CO_(2)storage site.There is no clear understanding of the fracture evolution and gas-liquid migration process of multi-scale geological body structure under the disturbance of CO_(2)injection.There is a lack of sufficient quantitative methods for the dynamic evaluation of CO_(2)geological storage potential.The geological suitability evaluation method for site selection of CO_(2)storage is rough and has poor applicability,which is difficult to satisfy the urgent needs of CGUS site selection in the whole process of CO_(2)sequestration industrialization in the future.Thus,it is required to conduct studies on the transparency characterization of geological body structure and intelligent site selection for CO_(2)storage,which is of great importance for CGUS engineering practice.展开更多
As essential pillars of passenger mobility and freight transport,road and rail transportation have experienced a rapid increase over the past years.This trend indicates an increase in energy consumption,especially ele...As essential pillars of passenger mobility and freight transport,road and rail transportation have experienced a rapid increase over the past years.This trend indicates an increase in energy consumption,especially electricity,due to higher energy efficiency and less carbon emission,but it exacerbates the contradiction between the power supply and demand.Nowadays,for additional power sources,increased solar power generation has been widely installed in their own available spaces for road and rail transportation,which has attracted a great deal of attention.This paper reviews the current status of solar power generation and its integrated application in the transport sector.Then,the photovoltaic generation potential of road and rail transportation in China are evaluated.Finally,further developments and perspectives of solar energy-powered road and rail transportation are presented,which not only contributes to lower-carbon and green transportation,but also promotes the development of renewable power generation for energy transformation.It is confirmed that solar energy-powered road and rail transportation is a promising approach for sustainable transportation with more renewable energy and less carbon emission.展开更多
基金funded by the Top 10 key scientific and technological projects of CHN Energy in 2021 entitled Research and Demonstration of Technology for Carbon Dioxide Capture and Energy Recycling Utilization(GJNYKJ[2021]No.128,No.:GJNY-21-51)the Carbon Neutrality College(Yulin)Northwest University project entitled Design and research of large-scale CCUS cluster construction in Yulin area,Shaanxi Province(YL2022-38-01).
文摘The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos Basin.The geological storage of CO_(2) in saline aquifers is an effective backup way to achieve carbon neutrality.In this case,the potential of saline aquifers for CO_(2) storage serves as a critical basis for subsequent geological storage project.This study calculated the technical control capacities of CO_(2) of the saline aquifers in the fifth member of the Shiqianfeng Formation(the Qian-5 member)based on the statistical analysis of the logging and the drilling and core data from more than 200 wells in the northeastern Ordos Basin,as well as the sedimentary facies,formation lithology,and saline aquifer development patterns of the Qian-5 member.The results show that(1)the reservoirs of saline aquifers in the Qian-5 member,which comprise distributary channel sand bodies of deltaic plains,feature low porosities and permeabilities;(2)The study area hosts three NNE-directed saline aquifer zones,where saline aquifers generally have a single-layer thickness of 3‒8 m and a cumulative thickness of 8‒24 m;(3)The saline aquifers of the Qian-5 member have a total technical control capacity of CO_(2) of 119.25×10^(6) t.With the largest scale and the highest technical control capacity(accounting for 61%of the total technical control capacity),the Jinjie-Yulin saline aquifer zone is an important prospect area for the geological storage of CO_(2) in the saline aquifers of the Qian-5 member in the study area.
基金Key Project of National Science and Technology Supporting Program, No.2006038053001 Key Project of National Natural Science Foundation of China, No.40535026 Environment Protection and Public Welfare Project of Ministry of Science and Technology, No.08L80370AJ
文摘The issue of China＇s energy supply security is not only the key problem which af- fects China＇s rapid and sustainable development in the 21st century, but also the one which international attention focuses on. Based on the notable characteristic of spatial imbalance between energy production and consumption in China, this paper takes the evolution of China＇s primary energy resources development（excluding hydropower） from 1949 to 2007 as the study object, with the aim to sum up the evolutive characteristics and laws of China＇s energy resources development in the past nearly 60 years. Then, based on comprehensive considerations of coal＇s, oil＇s and natural gas＇s basic reserves, qualities, geological conditions production status, and ecological service function of every province, this paper adopts development potential index （DP）to evaluate the development potential of every province＇s en- ergy resources, and divide them into different ranks. Conclusions are drawn as follows： （1） Generally speaking, China＇s gross energy production was increasing in waves from 1949 to 2007. From the viewpoint of spatial patterns, China＇s energy resources development has shown a characteristic of ＂concentrating to the north and central areas, and evolving from linear-shaped to ＂T-shaped＂ pattern gradually since 1949. （2） The structure evolution of China＇s energy resources development in general has shown a trend of ＂coal proportion is dominant but decreasing, while oil and gas proportions are increasing＂ since 1949. （3） At the provincial scale, China＇s energy resources development potential could be divided into large, sub-large, general and small ranks, four in all. In the future, the spatial pattern of China＇s energy production will evolve from ＂T-shaped＂ to ＂R-shaped pattern＂. These conclusions will help to clarify the temporal and spatial characteristics and laws of China＇s energy resources development, and will be beneficial for China to design scientific and rational energy development strategies and plans, coordinate spatial imbalance of energy production and consumption, ensure national energy supply, avoid energy resources waste and disorderly development, and promote regional sustainable development under the globalization back-ground with changeful international energy market.
基金Project supported by the National Major Science and Technology Project“Research on Optimum Design Technology for Gas Injection Development in North Hubei Tight Gas Reservoir”(No.2016ZX05048003-004)the Project of the Science and Technology Department of China Petroleum&Chemical Corporation“Study on the Recovery Mechanism by Injecting CO_(2) to improve the Development of Condensate Gas Reservoir”(No.P15031)the Basic and Prospective Project of the Science and Technology Department of China Petroleum&Chemical Corporation“Feasibility Evaluation of CO_(2) EGR in Daniudi Gas Field”(G5800-14-ZS-KJB033-5).
文摘CO_(2)-EGR,i.e.enhanced gas recovery by injecting CO_(2),is to displace natural gas by injecting CO_(2) in the supercritical phase.It can both enhance the recovery of gas reservoirs and realize CO_(2) storage.Currently,this technique is still at its exploring stage.The effect of CO_(2)-EGR is not clarified,the geologic conditions for CO_(2)-EGR are not definite,and the rational working system for CO_(2)-EGR is not available.In this paper,the long-core experiment was conducted to determine whether and how much the recovery of low-permeability reservoirs can be enhanced by injecting CO_(2).According to the experimental results,the recovery can be enhanced by 12%when CO_(2) content in produced gas is more than 10%.Moreover,the multi-component seepage mathematical model was built for displacing natural gas by injecting supercritical CO_(2),and the model accuracy was verified using laboratory data.With this mathematical model,the influence factors for displacing natural gas by injecting supercritical CO_(2) were analyzed in order to define the conditions for selecting favorable zones.The Well DK13 area in the Daniudi gas field,Ordos Basin,was selected for potential evaluation of CO_(2)-EGR.As indicated by the numerical simulation results,when CO_(2) content of producing wells in the Well DK13 area is 10%(with a lower cost for corrosion prevention),the ratio of CO_(2)-EGR is 8.0–9.5%,and 31.1%HCPV(hydrocarbon pores volume)of CO_(2) storage can be realized.It is thus concluded that the CO_(2)-EGR technique can enhance the recovery of gas reservoirs and also store CO_(2) underground,contributing to the increase of both social and economic benefits.
基金supported by the National Science Fund for Distinguished Young Scholars(No.52125702)the Key Science and Technology Project of China Southern Power Grid Corporation(No.090000KK52220020).
文摘Public buildings present substantial demand re sponse(DR)potential,which can participate in the power sys tem operation.However,most public buildings exhibit a high degree of uncertainties due to incomplete information,varying thermal parameters,and stochastic user behaviors,which hin ders incorporating the public buildings into power system oper ation.To address the problem,this paper proposes an interval DR potential evaluation method and a risk dispatch model to integrate public buildings with uncertainties into power system operation.Firstly,the DR evaluation is developed based on the equivalent thermal parameter(ETP)model,actual outdoor tem perature data,and air conditioning(AC)consumption data.To quantify the uncertainties of public buildings,the interval evalu ation is given employing the linear regression method consider ing the confidence bound.Utilizing the evaluation results,the risk dispatch model is proposed to allocate public building re serve based on the chance constrained programming(CCP).Fi nally,the proposed risk dispatch model is reformulated to a mixed-integer second-order cone programming(MISOCP)for its solution.The proposed evaluation method and the risk dis patch model are validated based on the modified IEEE 39-bus system and actual building data obtained from a southern city in China.
基金the financial support of the National Natural Science Foundation of China(42176212,41976074 and 41302034)the Marine S&T Fund of Shandong Province for Laoshan Laboratory(2021QNLM020002)the Marine Geological Survey Program(DD20221704)。
文摘The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.
基金This study was supported by the National Natural Science Foundation of China(Grant No.52208045).
文摘As an important element of urban renewal in highly urbanized areas, pocket parks with small size, flexible layout and daily accessibility are becoming a major component of green infrastructure and the mainstay of outdoor recreation space expansion in high-density urban centers. Nevertheless, the absence of a comprehensive framework for evaluating the potential of pocket park construction (PPC), one that integrates diverse influencing factors on a macro scale, has resulted in the random installation of such spaces, often failing to optimize the utilization of urban land. Addressing this critical lacuna, we propose an approach to evaluate PPC potential from a city-scale perspective, which is used to support the determination of which land units should be prioritized for PPC. A complete and feasible workflow was also established to identify potential land units, construct an index system for PPC combining demand and supply levels, quantitatively calculate indices based on remote sensing (RS) and geographic information system (GIS), accurately evaluate PPC potential using an entropy-weighted TOPSIS model, and develop targeted renewal strategies. A case study in Dalian, China, demonstrated the applicability and implications of the workflow. The results showed that it is flexible and easy to adapt to different local contexts, allowing evaluators to introduce parameters considering the availability of local data, and will help decision makers to build pocket parks in the most effective plots, providing a strong reference for high-quality development in other high-density urban centers facing the contradiction between ecological construction and land scarcity.
基金supported by the CNPC Science and Technology Major Project of the Fourteenth Five-Year Plan(2021DJ0101)the National Natural Science Foundation of China(U19B600302,41872148)。
文摘The Early Cambrian Yuertusi Formation(Є_(1)y)in the Tarim Basin of China deposits a continuously developed suite of organic-rich black mudstones,which constitute an important source of oil and gas reservoirs in the Paleozoic.However,its hydrocarbon generation and evolution characteristics and resource potential have long been constrained by deeply buried strata and previous research.In this paper,based on the newly obtained ultra-deep well drilling data,the hydrocarbon generation and expulsion model ofЄ_(1)y shale was established by using data-driven Monte Carlo simulation,upon which the hydrocarbon generation,expulsion,and retention amounts were calculated by using the diagenetic method.The research indicates that theЄ_(1)y shale reaches the hydrocarbon generation and expulsion threshold at equivalent vitrinite reflectances of 0.46%and 0.72%,respectively.The cumulative hydrocarbon generation is 68.88×10^(10)t,the cumulative hydrocarbon expulsion is 35.59×10^(10)t,and the cumulative residual hydrocarbon is 33.29×10^(10)t.This paper systematically and quantitatively calculates the hydrocarbon expulsion at various key geological periods for theЄ_(1)y source rocks in the study area for the first time,more precisely confirming that the black shale of theЄ_(1)y is the most significant source rock contributing to the marine oil and gas resources in the Tarim Basin,filling the gap in hydrocarbon expulsion calculation in the study area,and providing an important basis for the formation and distribution of Paleozoic hydrocarbon reservoirs.The prospect of deep ultra-deep oil and gas exploration in the Tarim Basin is promising.Especially,the large area of dolomite reservoirs under the Cambrian salt and source rock interiors are the key breakthrough targets for the next exploration in the Tarim Basin.
文摘From 2010 to 2012, the China Geological Survey Center for Hydrogeology and Environmental Geology Survey （CHEGS） carried out the project ＂Potential evaluation and demonstration project of CO2 Geological Storage in China＂. During this project, we developed an evaluation index system and technical methods for the potential and suitability of CO2 geological storage based on China＇s geological conditions, and evaluated the potential and suitability of the primary basins for COz geological storage, in order to draw a series of regional scale maps （at a scale of 1：5000000） and develop an atlas of the main sedimentary basins in China. By using these tools, we delineated many potential targets for CO2 storage. We also built techniques and methods for site selection and the exploration and assessment of CO2 geological storage in deep saline aquifers. Furthermore, through cooperation with the China Shenhua Coal to Liquid and Chemical Co., Ltd., we successfully constructed the first coal-based demonstration project for CO2 geological storage in deep saline aquifers in the Yijinhuoluo Banner of Ordos in the Inner Mongolia Autonomous Region, which brought about the basic preliminary theories, techniques, and methods of geological CO2 storage in deep saline aquifers under China＇s geological conditions.
文摘The general situation of the total land resources in Wulushan, West China was studied by field investigations with the aid of a GIS software, called Region Manager. The current status of land use in Wulushan is described. The potential land productivity was evaluated by a fuzzy comprehensive method, We take each plot as a basic unit of evaluation on the basis of an index system of land resources in Wulushan which was developed from the investigation data. Evaluation of potential land productivity is the key part of land management. A guideline is presented in this paper for a proper utilization of the land resources and to develop the productive capacity of the land.
文摘The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Plateau. A systems engineering model was developed and used to evaluate the total allelopathic potential of crop cultivars. In addition, a method for quantifying the total allelopathic potential in crop accessions was presented. Total allelopathic potential of four winter wheat accessions from the Loess Plateau was estimated and compared using a systems theory approach. The model assessed allelopathic potential in different parts of the plants from the time wheat turned green in spring until maturity. Results from these models indicated that the four wheat accessions had very weak allelopathic potential. Allelopathic potential declined in the order Xiaoyan 22 〉 Ningdong 1 〉 Fengchan 3 〉 Bima 1. This system engineering evaluation method allows for the assessment of allelopathic potential among crop varieties. It will help plant breeders to select and develop allelopathic crop accessions that combine weed suppression properties with agronomic traits related to yield and quality.
文摘BACKGROUND ： The recordings of evoked spinal cord potentials following epidural spinal cord stimulation are thought to be generated by volleys traversing the dorsal column pathway, and it may not directly reflect conduction defects in corticospinat tracts of cervical spinal cord. To our knowledge there has been few report using several evoked spinal cord potentials in function evaluation of the cervical spinal cord in eldedy patients with cervical spondylotic myelopathy （CSM）. OBJECTIVE： To investigate the function states of the cervical spinal cord in elderly patients with CSM and explore its pathophysictogic mechanism. DESIGN： Case observation SETTING ： Department of Orthopedics for the aged, Shenzhen Pingle Hospital of Orthopedics. Department of Orthopedic Surgery, Yamaguchi University School of Medicine. PARTICIPANTS ： A total of 23 eldedy patients with CSM who received treatment in the Department of Orthopedic Surgery, Yamaguchi University School of Medicine of Japan from January 2003 to February 2004 were enrolled in this study. Inclusive criteria： ① Multiple intervertebral levels of cervical spinal cord compression confirmed by MRI, e.g. 3 or more than 3 levels of compressin. ② Age ≥ 70 years old. ③ Numbness and sensory disturbance in the upper limbs and showed hyperreflexia in the lower limbs. Exclusive criteria： Patients with abnormal motor and sensory nerve conduction velocities in both upper and lower limbs were excluded. METHODS： Evoked spinal cord potentials （ESCPs） following transcranial electric stimulation （TCE-ESCPs）, epidural spinal cord stimulation （SpinaI-ESCPs） and median nerve stimulation （MN-ESCPs） were recorded in 23 patients from posterior epidural space intreoperatively. The abnormalities of TCE-ESCPs were defined as attenuation of amplitude of the D wave. The most cranial intervertebral level showing abnormal TCE-ESCPs with a marked reduction in size of the negative peak （reduction of over 50%） was considered as the upper level of the spinal cord lesion with respect to the corticospinal tract in white matter. The abnormalities of SpinaI-ESCPs were defined as marked reduction in the size of negative peak （reduction of over 50%）. The most caudal intervertebral level showing abnormal SpinaI-ESCPs was considered as the lower level of the spinal cord lesion with respect to the dorsal column pathway in white matter. The abnormalities of MN-ESCPs were defined as attenuation of the N13 amplitude,which was considered as the lesion level of the spinal cord with respect to the dorsal horn in gray matter. Radiological investigation： Lateral view of plain X-ray films was obtained in flexion and extension of the cervical spine. Instability of the cervical intervertebral level was determined as horizontal displacement of the vertebral body of over 3 mm. MAIN OUTCOME MEASURES ： The results of examination of TCE-ESCPs, SpinaI-ESCPs and MN-ESCPs in el- dedy patients with CSM. RESULTS： The 23 eldedy patients with CSM were participated in the result analysis. ①TCE-ESCPs： The impairment of the corticospinal tract in white matter at single intervertebral level was revealed in 18 of 23 patients by recordings of TCE-ESCPs （sensitivity 78%）. In the 18 patients, the lesion level was shown at the up- per cervical segment in 14 patients （C3-4n=10 and C4-5n=4）, and at the lower cervical segment in 4 patients （C5-6n=4）. ②Spinal-ESCPs： The impairment of the dorsal column pathway of white matter at single intervertebral level was revealed in 17 of 23 patients, by recordings of Spinal-ESCPs （sensitivity 74%）. In the 17 patients, the lesion level was presented at the upper cervical segment in 14 patients （C3-4n=10 and C4-5n=4）, and at the lower cervical segment in 3 patients （C5-6 n=3）. ③MN-ESCPs： All patients revealed abnormal MN-ESCPs at one or more intervertebral levels （sensitivity 100%）. The impairment at single intervertebral level was demonstrated in 17 patients, and the impairment at multiple intervertebral levels was shown in 4 patients （3 patients at the C3-4, C4-4, and C5-4~6, and one patient at the C4-5, C5-6, and C6-7）. ④Radiological findings： The Instability of the intervertebral level at the C3-4 or C4-5 motion segment was seen in 15 patients, with a total of 20 levels, and where 10 were at the C3-4 intervertebral level and 5 were at the C3-4, C4-5 intervertebral level. CONCLUSION ： The results suggest that in most elderly patients with CSM who have multiple intervertebral level compressions of the cervical spinal cord on MRI, white matter is impaired at the single cervical intervertebral level, and not only the dorsal column pathway, but also the corticospinal tract can be affected. Combined the findings of radiography, the excessive motion and instability of the C3-4 or C4-5 intervertebral level plays an important role in inducing the long tract lesion in elderly patients with CSM.
基金supported by the National Natural Science Foundation of China(Nos.41872150,42230310)the Joint Funds of National Natural Science Foundation of China(Grant No.U19B6003)。
文摘Paleofluid-rock interaction results in the modification of the ultra-deep reservoir quality,but the coupling effects of the paleofluid evolution on reservoir quality modification are still underestimated.Here,the multi-stage dolomite cements have been studied by means of core observations,thin section identification,fluid inclusions,and in situ elements and isotopic analyses in order to reaveal the paleofluid evolution processes and their effects on the reservoir quality.The fibrous dolomite cement(FDC)and bladed dolomite cement(BDC)both have similar geochemical properties and homogenization temperature(Th)to the matrix dolostone.Subsequent early silicification occurs(QZ1).However,silt-to fine-sized crystalline dolomite cement(CD2)has higher concentration of Fe and medium rare earth element,more negativeδ^(18)O than for FDC and BDC,and 103.4-150.2℃in Th.The first petroleum charge episode solid bitumen 1(SB1)followed the CD2.The medium to coarse sized crystalline dolomite cement(CD3)is characterized by the higher Mn and lower Sr concentration than CD2,positiveδEu anomaly,negativeδ^(13)C andδ^(18)O,high^(87)Sr/^(86)Sr ratio and 138.9℃-184.3℃in Th.The solid bitumen 2(SB2)occurs after CD3.Subsequently,the saddle dolomite(SD)has higher Fe and Mn concentration and lower Na and Sr than others cement,δEu positive anomaly,negativeδ^(13)C andδ^(18)O,high ^(87)Sr/^(86)Sr ratio and 177.5℃-243.6℃in Th.Eventually massive silicification(QZ2)took place.The FDC,BDC,QZ1 and SB1 formed in the early diagenetic stage and have little negative effect on the reservoir quality.But the CD2 and CD3 dramatically decreased the reservoir quality related to a quantity of hydrothermal fluids entrance in the mesodiagenetic stage along the strike-slip faults and the unconformity surface at top of the Deng-2 Member during the late stage of the Caledonian orogeny.The reservoir spaces were retained and enlarged during the late diagenetic stage when the peak petroleum charge occurred,massive silicification and thermochemical sulfate reduction took place with SB2,SD and QZ2 being formed.The research outcome may update our understanding on the retention mechanism and the insights for further hydrocarbon exploration of Precambrian ultra-deep microbial reservoirs.
文摘The scientific evaluation of arable land remediation potential can be used to formulate remediation policies based on local conditions. This study took arable land resources in Tongxu County, China as the research object and administrative villages as the evaluation unit, constructed an evaluation index system by integrating three aspects—quantity, quality and ecology. Based on the evaluation of arable land remediation potential, the K-means++ spatial clustering algorithm combined with elbow method is used to divide the remediation partition and give the remediation strategy. The results showed that: 1) the evaluation index system of arable land improvement potential, which integrated “quantity-quality-ecology”, was more systematic in analyzing the potential of arable land improvement than the previous single target evaluation index, and explored its internal linkage. 2) There are some spatial differences in the quantitative, qualitative and ecological potentials in Tongxu County, with the quantitative potential being higher in Changzhi Township, the intersection of Lizhuang Township and the southern part of Yuhuangmiao Township, the qualitative potential being more evenly distributed, and the ecological potential being higher around Chengguan Township. 3) Through K-means++ clustering algorithm combined with elbow method, Tongxu County was divided into five subzones: quality improvement zone, intensive improvement zone, quantity improvement zone, comprehensive improvement zone and health improvement zone, among which the highest percentage of quality improvement zone and the lowest percentage of comprehensive improvement zone were 49.2% and 1.5% respectively, and differentiated remediation strategies were provided by research for each sub-district to promote high quality of arable land.
文摘Rural revitalization strategy is an important strategic layout of rural development in the new era of the CPC Central Committee,and scientific and reasonable determination of village types is an important measure to promote rural revitalization by classification.The villages of Wan’an County were selected as the research object.Firstly,the factors that have a key impact on the development of the villages were extracted and qualitatively analyzed to preliminarily screen and judge their types.Secondly,the evaluation index system of development potential of the villages was constructed to quantitatively evaluate and reasonably classify the villages.Finally,the spatial distribution characteristics and quantity of different villages were revealed,and differentiated development strategies were proposed.
基金supported by the National Natural Science Foundation of China (No. 61378064)the National High Technology Research and Development Program of China (No. 2015AA020510)
文摘An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.
基金The authors gratefully acknowledge the financial support provided by the Project 31761133019the National Natural Science Foundation of China and China Agriculture Research System CARS-28-20the Special Fund for Agro-scientific Research in the Public Interest (201503130) by Ministry of Agriculture of China.
文摘The reduction of pesticide aerial spraying drift is still one of the major challenges in modern agriculture.The aim of this study was to evaluate the drift potential of different types of unmanned aerial vehicle(UAV)and adjuvant products for reducing spray drift in aerial applications.Three types of UAV(3WQF120-12 and 3CD-15 fuel oil powered single-rotor UAV and HY-B-15L battery powered single-rotor UAV)were selected in this study with regular application parameters to compare each spray drift,and 3WQF120-12 fuel oil powered UAV was selected to quantify spray drift of 6 adjuvants dissolved in water under field conditions.Solutions were marked with brillant sulfoflavin dye(BSF)at 0.1%.Petri dishes and rotary impactors were used to collect airborne and sediment drift,respectively.Drift deposits were evaluated by spectrophotometry in order to quantify deposits.The results showed that when the flight height was 1.5-2.0 m above the crop at the flight speed of 4-5 m/s and the average wind speed of 1.63-1.73 m/s,3WQF120-12 fuel oil powered UAV had lower drift potential than the other two types;DV0.5 and percentage of droplets with diameter≤75μm had very significant effects on spray drift percentage(p=0.01);the risk of drift in agricultural spraying could be significantly decreased not only by reducing the percentage of fine droplets but also by changing droplet spectra.Compared to water,Silwet DRS-60,ASFA+B,T1602,Break-thru Vibrant,QF-LY and Tmax could reduce by 65%,62%,59%,46%,42%,and 19%spray drift,respectively.when water without adjuvants were sprayed,90%of drift droplets were located within a range of 10.1 m of the target area while with 0.8%Silwet DRS-60 adjuvant in water,the distance was shortened to 6.4 m.
基金supported by the National Natural Science Foundation of China(Grant No.42141009)the Key Research Program of the Institute of Geology and Geophysics,CAS(Grant No.IGGCAS-202201).
文摘Carbon dioxide(CO_(2))geological utilization and storage(CGUS)is the key link of CO_(2)capture,utilization,and storage(CCUS).The accurate characterization of the geological body structure is a vital prerequisite of CGUS.This paper gives a review of the multi-scale three-dimensional geological structure characterization and site selection of CO_(2)storage.It shows that there is a lack of systematic and high-precision methods for transparency characterization of multi-scale three-dimensional engineering geological structure and hydrogeological structure of a CO_(2)storage site.There is no clear understanding of the fracture evolution and gas-liquid migration process of multi-scale geological body structure under the disturbance of CO_(2)injection.There is a lack of sufficient quantitative methods for the dynamic evaluation of CO_(2)geological storage potential.The geological suitability evaluation method for site selection of CO_(2)storage is rough and has poor applicability,which is difficult to satisfy the urgent needs of CGUS site selection in the whole process of CO_(2)sequestration industrialization in the future.Thus,it is required to conduct studies on the transparency characterization of geological body structure and intelligent site selection for CO_(2)storage,which is of great importance for CGUS engineering practice.
基金This work was supported in part by the National Natural Science Foundation of China(No.51807182).
文摘As essential pillars of passenger mobility and freight transport,road and rail transportation have experienced a rapid increase over the past years.This trend indicates an increase in energy consumption,especially electricity,due to higher energy efficiency and less carbon emission,but it exacerbates the contradiction between the power supply and demand.Nowadays,for additional power sources,increased solar power generation has been widely installed in their own available spaces for road and rail transportation,which has attracted a great deal of attention.This paper reviews the current status of solar power generation and its integrated application in the transport sector.Then,the photovoltaic generation potential of road and rail transportation in China are evaluated.Finally,further developments and perspectives of solar energy-powered road and rail transportation are presented,which not only contributes to lower-carbon and green transportation,but also promotes the development of renewable power generation for energy transformation.It is confirmed that solar energy-powered road and rail transportation is a promising approach for sustainable transportation with more renewable energy and less carbon emission.
