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Relationship between sonographically measured median nerve cross-sectional area and presence of peripheral neuropathy in diabetic subjects 被引量:8
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作者 Fredrick ANDrew Attah Christianah Mopelola Asaleye +3 位作者 Adeleye Dorcas Omisore Babatope Ayodeji Kolawole Adeniyi Sunday Aderibigbe Mathew Alo 《World Journal of Diabetes》 SCIE CAS 2019年第1期47-56,共10页
BACKGROUND Neuropathy is a common complication of diabetes mellitus resulting from direct damage by hyperglycemia to the nerves and/or ischemia by microvascular injury to the endoneurial vessels which supply the nerve... BACKGROUND Neuropathy is a common complication of diabetes mellitus resulting from direct damage by hyperglycemia to the nerves and/or ischemia by microvascular injury to the endoneurial vessels which supply the nerves. Median nerve is one of the peripheral nerves commonly affected in diabetic neuropathy. The median nerve size has been studied in non-Nigerian diabetic populations. In attempt to contribute to existing literature, a study in a Nigerian population is needed.AIM To evaluate the cross-sectional area(CSA) of the median nerve using B-mode ultrasonography(USS) and the presence of peripheral neuropathy(PN) in a cohort of adult diabetic Nigerians.METHODS Demographic and anthropometric data of 85 adult diabetes mellitus(DM) and 85 age-and sex-matched apparently healthy control(HC) subjects were taken. A complete physical examination was performed on all study subjects to determine the presence of PN and modified Michigan Neuropathy Screening Instrument(MNSI) was used to grade its severity. Venous blood was taken from the study subjects for fasting lipid profile(FLP), fasting blood glucose(FBG) and glycated haemoglobin(HbA1 c) while their MN CSA was evaluated at a point 5 cm proximal to(5 cmCATL) and at the carpal tunnel(CATL) by high-resolution Bmode USS. Data was analysed using SPSS version 22.RESULTS The mean MN CSA was significantly thicker in DM subjects compared to the HC at 5 cmCATL(P < 0.01) and at the CATL(P < 0.01) on both sides. The presence of diabetic peripheral neuropathy(DPN) further increased the MN CSA at the CATL(P < 0.05) but not at 5 cmCATL(P > 0.05). However, the severity of DPN had no additional effect on MN CSA 5 cm proximal to and at the CATL. There was no significant association between MN CSA and duration of DM and glycemic control.CONCLUSION Thickening of the MN CSA at 5 cmCATL and CATL is seen in DM. Presence of DPN is associated with worse thickening of the MN CSA at the CATL but not at5 cmCATL. Severity of DPN, duration of DM, and glycemic control had no additional effect on the MN CSA. 展开更多
关键词 MEDIAN nerve cross-sectional area SONOGRAPHY DIABETICS Peripheral NEUROPATHY
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Estimation of projected surface area of irregularly shaped fragments 被引量:2
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作者 Elvedin Kljuno Alan Catovic 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第2期198-209,共12页
The essence and the main contribution of this paper are consisted of the suggested novel method for estimation of a projected surface area of an irregularly shaped fragment, which represents a significant step toward ... The essence and the main contribution of this paper are consisted of the suggested novel method for estimation of a projected surface area of an irregularly shaped fragment, which represents a significant step toward a new method of an aerodynamic force estimation of a fragment motion through a resistive medium. The suggested method is to use a tri-axial ellipsoid that has a continuous surface(given as a mathematical function) to approximate an irregularly shaped fragment so that the fragment trajectory can be estimated faster taking into consideration that the aerodynamic force is proportional to a projected surface area of the fragment.During their motion, fragments can take any orientation relative to the velocity vector and aerodynamic force is proportional to a projected surface area of fragment perpendicular to the velocity vector,so it is necessary to have a method for correct estimation of the projected area in an arbitrary direction relatively to the fragment.The model was validated with analytical and CAD techniques, and verified using 3D model of a real fragment. The comparison of the projected surface area values for the fragment, obtained using the CAD tools and using our model, are generally in good agreement, This method represents a step toward modeling that does not require a CFD result for estimation of the aerodynamic force of irregularly shaped bodies. 展开更多
关键词 projected area FRAGMENTS TRAJECTORY
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Ultrasonographic measurement of median nerve cross-sectional area reference values in a healthy Han population from Guiyang,China 被引量:3
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作者 Jun Chen Shan Wu Jun Ren 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第24期1883-1887,共5页
High-resolution ultrasonography was used to analyze the nerve cross-sectional area (CSA) of the median nerve at 7 sites: the wrist crease, pisiform bone, hamate bone, 6 cm proximal to the tip of the wrist crease, p... High-resolution ultrasonography was used to analyze the nerve cross-sectional area (CSA) of the median nerve at 7 sites: the wrist crease, pisiform bone, hamate bone, 6 cm proximal to the tip of the wrist crease, proximal forearm (where the nerve enters the pronator teres muscle), 4 cm proximal to the tip of the medial epicondyle, and mid-humerus (mid-point between elbow crease and axilla) in 200 healthy volunteers from Guiyang, China. Results showed similar CSA values between the left and right sides, but the CSA 6 cm proximal to the tip of the wrist crease, proximal forearm, 4 cm proximal to tip of the medial epicondyle, and mid-humerus in males was greater than that of females. Moreover, CSA values at the wrist crease, pisiform bone, and hamate bone were greater in the middle-aged and old groups when compared to the young group, and correlated with body mass and height. Thus, reference values of median nerve CSA of the upper limbs can facilitate the analysis of abnormal nerve conditions. 展开更多
关键词 ULTRASONOGRAPHY median nerve cross-sectional area Guiyang Han nationality
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Does the ratio of the carpal tunnel inlet and outlet cross-sectional areas in the median nerve reflect carpal tunnel syndrome severity? 被引量:6
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作者 Li Zhang Aierken Rehemutula +3 位作者 Feng Peng Cong Yu Tian-bin Wang Lin Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第7期1172-1176,共5页
Although ultrasound measurements have been used in previous studies on carpal tunnel syndrome to visualize injury to the median nerve, whether such ultrasound data can indicate the severity of carpal tunnel syndrome r... Although ultrasound measurements have been used in previous studies on carpal tunnel syndrome to visualize injury to the median nerve, whether such ultrasound data can indicate the severity of carpal tunnel syndrome remains controversial. The cross-sectional areas of the median nerve at the tunnel inlet and outlet can show swelling and compression of the nerve at the carpal. We hypothesized that the ratio of the cross-sectional areas of the median nerve at the carpal tunnel inlet to outlet accurately reflects the severity of carpal tunnel syndrome. To test this, high-resolution ultrasound with a linear array transducer at 5–17 MHz was used to assess 77 patients with carpal tunnel syndrome. The results showed that the cut-off point for the inlet-to-outlet ratio was 1.14. Significant differences in the inlet-to-outlet ratio were found among patients with mild, moderate, and severe carpal tunnel syndrome. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.29 between mild and more severe(moderate and severe) carpal tunnel syndrome patients with 64.7% sensitivity and 72.7% specificity. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.52 between the moderate and severe carpal tunnel syndrome patients with 80.0% sensitivity and 64.7% specificity. These results suggest that the inlet-to-outlet ratio reflected the severity of carpal tunnel syndrome. 展开更多
关键词 nerve regeneration peripheral nerve injury ultrasonography carpal tunnel syndrome diagnosis cross-sectional area classification clinical laboratory technique electrodiagnosis median nerve 973 Program neural regeneration
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Usefulness of the acromioclavicular joint cross-sectional area as a diagnostic image parameter of acromioclavicular osteoarthritis
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作者 Young Joo Jee Youn Moon +5 位作者 Jung Youn Han Yun-Sic Bang Keum Nae Kang Young Su Lim Young-SoonChoi Young-Uk Kim 《World Journal of Clinical Cases》 SCIE 2022年第7期2087-2094,共8页
BACKGROUND Acromioclavicular joint(ACJ)space narrowing has been considered to be an important diagnostic image parameter of ACJ osteoarthritis(ACJO).However,the morphology of the ACJ space is irregular because of oste... BACKGROUND Acromioclavicular joint(ACJ)space narrowing has been considered to be an important diagnostic image parameter of ACJ osteoarthritis(ACJO).However,the morphology of the ACJ space is irregular because of osteophyte formation,subchondral irregularity,capsular distention,sclerosis,and erosion.Therefore,we created the ACJ cross-sectional area(ACJCSA)as a new diagnostic image parameter to assess the irregular morphologic changes of the ACJ.AIM To hypothesize that the ACJCSA is a new diagnostic image parameter for ACJO.METHODS ACJ samples were obtained from 35 patients with ACJO and 30 healthy individuals who underwent shoulder magnetic resonance(S-MR)imaging that revealed no evidence of ACJO.Oblique coronal,T2-weighted,fat-suppressed SMR images were acquired at the ACJ level from the two groups.We measured the ACJCSA and the ACJ space width(ACJSW)at the ACJ on the S-MR images using our imaging analysis program.The ACJCSA was measured as the cross-sectional area of the ACJ.The ACJSW was measured as the narrowest point between the acromion and the clavicle.RESULTS The average ACJCSA was 39.88±10.60 mm;in the normal group and 18.80±5.13 mm;in the ACJO group.The mean ACJSW was 3.51±0.58 mm in the normal group and 2.02±0.48 mm in the ACJO group.ACJO individuals had significantly lower ACJCSA and ACJSW than the healthy individuals.Receiver operating characteristic curve analyses demonstrated that the most suitable ACJCSA cutoff score was 26.14 mm^(2),with 91.4%sensitivity and 90.0%specificity.CONCLUSION The optimal ACJSW cutoff score was 2.37 mm,with 88.6%sensitivity and 96.7%specificity.Even though both the ACJCSA and ACJSW were significantly associated with ACJO,the ACJCSA was a more sensitive diagnostic image parameter. 展开更多
关键词 Acromioclavicular joint OSTEOARTHRITIS cross-sectional area DIAGNOSIS
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Correlation between current and cross-sectional area of parallel fixed-movable dual electrodes in ESC
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作者 Li-ting Zhao Yun-long Xiong +2 位作者 Rui Chen Zeng-rui Wang An-guo Wang 《China Foundry》 SCIE 2020年第3期245-249,共5页
Electroslag casting with parallel fixed-movable dual electrodes is a new method for achieving better quality of castings in complex mold cavities.In this work,a mathematical model,y=kx^2+(k+1)x,was established to desc... Electroslag casting with parallel fixed-movable dual electrodes is a new method for achieving better quality of castings in complex mold cavities.In this work,a mathematical model,y=kx^2+(k+1)x,was established to describe the ideal correlation between the current ratio(y)and the cross-sectional area ratio(x)of the dual electrodes,where k is the filling ratio.Investigation was conducted on the electroslag casting process with dual electrodes of various cross-sectional areas,but at a constant k value.The experimental results indicated that the ideal correlation was obtained at the stable casting stage,and the fitting results were consistent with the experimental results at certain k values.The experimental findings show that better castings can be obtained when the current ratio is greater than 1.536 and the cross-sectional area ratio is greater than 0.5. 展开更多
关键词 electroslag casting fixed-movable dual electrode current ratio cross-sectional area ratio
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Coupling interaction between biodiversity and aquatic habitat area in Western Route Project vicinity 被引量:1
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作者 Shi-min TIAN Zhao-yin WANG +1 位作者 Xiang-jun LIU Shi-kui LIANG 《Water Science and Engineering》 EI CAS 2010年第3期354-360,共7页
The Western Route of the South-to-North Water Transfer Project will divert water from the upper Yangtze River and its tributaries, the Dadu River and Yalong River, to the upper Yellow River. The project may ease the w... The Western Route of the South-to-North Water Transfer Project will divert water from the upper Yangtze River and its tributaries, the Dadu River and Yalong River, to the upper Yellow River. The project may ease the water shortage in the Yellow River Basin. However, it may also have some effects on the ecosystem in the upper Yangtze River Basin. Benthic invertebrates play an important role in the river ecosystem, particularly in the circulation of materials and nutrition. Benthic invertebrates are widely used to quickly assess river ecosystems because of their rapid response to changes in the water environment. The diversity of benthic invertebrates is closely associated with the aquatic habitat area. This study examined this interaction by sampling the benthic invertebrates in an expanding area. The conclusions are that the diversity of benthic invertebrates begins to decrease when the aquatic habitat area is reduced to 45% of the original area, and decreases dramatically when the aquatic habitat area is reduced to 10% of the original area. The aquatic habitat area should be kept at more than 45% of the original area in order to maintain the significant diversity of benthic invertebrates. 展开更多
关键词 Western Route project South-to-North Water Transfer project river ecosystem benthic invertebrates BIODIVERSITY aquatic habitat area
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Effects of ecological projects on vegetation in the Three Gorges Area of Chongqing, China 被引量:1
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作者 LI Feng ZHOU Wen-zuo +1 位作者 SHAO Zhou-ling ZHOU Xin-yao 《Journal of Mountain Science》 SCIE CSCD 2022年第1期121-135,共15页
The construction of the Three Gorges Reservoir and the resettlement project have caused increasing contradictions between human and land,and led to the deterioration of the ecological environment. In order to ameliora... The construction of the Three Gorges Reservoir and the resettlement project have caused increasing contradictions between human and land,and led to the deterioration of the ecological environment. In order to ameliorate ecological environment of the Three Gorges Area, the government carried out several ecological restoration projects to improve the vegetation coverage from 1990 s. This paper aims to quantitatively analyze the impact of ecological projects on the vegetation in the Three Gorges Area of Chongqing, China. Landsat and MODIS data from 1992 to 2015 were used to estimate vegetation coverage. In addition, the land cover data of the European Space Agency(ESA) was used to explore the impact of ecological projects on land cover change. The cropland accounted for about 62% and the forestland accounted for about 34% of the total area. There was more than 90% of the study area covered with high or very high vegetation coverage.From 1992 to 2015, a total of 272.7 km;croplands were converted into forestland in the Ecological Migration Project(EMP), 795.6 km;in the Grain for Green Project(GGP), and 13.77 km;in the Ecological Restoration Zone Project(ERZP). Among the three projects, the GGP was the most powerful measure,with a contribution rate of 1.6%. The implementation of the ecological projects improved vegetation coverage, which indicated that the ecological projects measures were effective in ecological restoration. 展开更多
关键词 Land cover change Fractional vegetation coverage Vegetation restoration Ecological projects MODIS Three Gorges area
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ANALYSIS OF EFFECT OF APOPLECTIC HEMIPLEGIA TREATED BY NEEDLING AROUND THE PROJECTIVE AREA ON THE SCALP OF FOCUS LOCATED WITH NUCLEAR MAGNETIC RESONANCE(NMR)
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作者 李艳慧 林凯玲 《World Journal of Acupuncture-Moxibustion》 1999年第3期25-28,共4页
Sixty-one patients of ischemic apoplectic hemiplegia were randomly divided into group ofneedling around the ipsilateral projective area on the scalp of the fOcus (group A) and group of scalpacupuncture (group B). Afte... Sixty-one patients of ischemic apoplectic hemiplegia were randomly divided into group ofneedling around the ipsilateral projective area on the scalp of the fOcus (group A) and group of scalpacupuncture (group B). After 30 treatments, there is a significant difference between the therapeuticeffects of two groups (P < 0. 05 ), the former is better than the latter. It suggests that the method ofneedling around the projective area on the scalp of the focus is an effective and a feasible 展开更多
关键词 Apoplectic HEMIPLEGIA NEEDLING AROUND the projectIVE area on the SCALP of the FOCUS SCALP acupuncture Location with NMR
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LAND USE CHANGE AND ITS SOCIO-ECONOMIC DRIVING FORCES UNDER STRESS OF PROJECT IN OLD RESERVOIR AREA——Case Study of Linshui Reservoir Area of Dahonghe Reservoir in Sichuan Province 被引量:3
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作者 SHAO Jing-an HUANG Xue-qin +2 位作者 QU Ming WEI Chao-fu XIE De-ti 《Chinese Geographical Science》 SCIE CSCD 2005年第4期315-324,共10页
The old reservoir areas built in 1950s-1970s left behind many socio-economic problems, because of the administrative backward migration and little migration fund, and all these problems would be tied to land. Based on... The old reservoir areas built in 1950s-1970s left behind many socio-economic problems, because of the administrative backward migration and little migration fund, and all these problems would be tied to land. Based on interviewing with peasant households, combining land use survey and socio-economic statistical index, this paper analyzed land use change and its corresponding driving forces in Linshui reservoir area of Dahonghe Reservoir. Results showed that land use change in the reservoir area was mainly embodied on low-lying land submergence and migration requisition land. The former changed the land use patterns, and the latter mainly reconstructed original land property and made land over-fragmented. Cultivated land per capita was 0.041ha in this area, below the cordon of cultivated land per capita enacted by FAO. Currently, there were still 30.25% of peasant households being short of grain in trimester of one year, and there were 35.27% of people living under the poverty line. The conditions of eco-environment in Linshui Reservoir Area were worse, and healthy and sub-healthy eco-environment accounted for less proportion, composed of green belt around the reservoir area and paddy field ecosystem, and economic forest and orchard ecosystem, respectively. The stress of the reservoir project was macroscopic background to analyze the driving factors of land use change, and real underlying diving factor of the land use change in the area was the change of cultural landscape under the stress of reservoir project. The rapid increase of population was the key factor to induce the change of man-land relationship in the reservoir area, the low level of rural economy was the crucial factor to decide how migrants input for production, and the belief of migrants, influencing the land use patterns in a certain extent, was the inducing factor to keep land use stable. The low-lying submergence and infrastructure construction accompanied the reservoir project were leading factors driving land use change in the area, while changes in land use patterns, after the reservoir being built, were the responses of peasant households’ behaviors to land use change. 展开更多
关键词 四川 土地利用变化 社会效益 经济效益
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Kuche Depression in Tarim is Main Gas Supply Area for Gas Transmission Project 被引量:1
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《China Oil & Gas》 CAS 2000年第2期12-14,共3页
关键词 Kuche Depression in Tarim is Main Gas Supply area for Gas Transmission project
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Control Measures of Soil Erosion in a Typical Construction Project Area ( Dina 2 Gas Field)
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作者 Huiming Lv 《Meteorological and Environmental Research》 CAS 2013年第2期53-58,共6页
To treat the relationship between project construction and ecological environment and effectively prevent new soil erosion during the construction, according to the project layout, soil erosion distribution as well as... To treat the relationship between project construction and ecological environment and effectively prevent new soil erosion during the construction, according to the project layout, soil erosion distribution as well as natural and socio-economic conditions, the control measures of newly increased soil erosion along the project were carried out based on site survey and analysis of relevant information. In addition, adhering to the prin- ciple of partition prevention and treatment, some guiding prevention and control measures of the natural zone passed by the project and soil erosion control district were determined, which provided scientific references and technical support for the rational layout of water and soil conservation and ecological restoration measures in Dina 2 gas field. 展开更多
关键词 Typical construction project area Dina 2 gas field Ecological environment Soil erosion Control measures China
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Impact on Mountainous Agricultural Development in the Three Gorges Reservoir Area forced by Migrants of the Three Gorges Project 被引量:1
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作者 Zhang Baolei 《Chinese Journal of Population,Resources and Environment》 北大核心 2008年第3期83-89,共7页
The Three Gorges Project attracts worldwide attention because of the Three Gorges migrants, and the agriculture of the Three Gorges Reservoir Area is a foundation for the development of the Three Gorges migrants. The ... The Three Gorges Project attracts worldwide attention because of the Three Gorges migrants, and the agriculture of the Three Gorges Reservoir Area is a foundation for the development of the Three Gorges migrants. The Three Gorges Reservoir Area is situated at the mountainous area with bad agricultural development conditions and relatively low levels of development. As a result, the large-scale migration has special influence on its agricultural development, which has attracted much attention. The paper analyzes influence that the migrants have forced on its agricultural development based on the scientific data, and makes some explorations on the models that are suitable for the development of mountainous agriculture in the Three Gorges Reservoir 展开更多
关键词 农业 发展计划 三峡库区 移民 三峡工程
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Assessment of Diversity, Distribution, Conservation Status and Preparation of Management Plan for Medicinal Plants in the Catchment Area of Parbati Hydroelectric Project Stage-Ⅲ in Northwestern Himalaya 被引量:4
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作者 S.S. Samant Jitendra S. Butola Aman Sharma 《Journal of Mountain Science》 SCIE CSCD 2007年第1期34-56,共23页
The developmental activities, particularly the construction of hydroelectric projects are causing a great loss of biodiversity in the Indian Himalayan Region. The Himachal Pradesh, a part of IHR is well known for the ... The developmental activities, particularly the construction of hydroelectric projects are causing a great loss of biodiversity in the Indian Himalayan Region. The Himachal Pradesh, a part of IHR is well known for the development of hydroelectric projects. The Parbati H.E. Project is amongst the major projects of the State. The different stages of the project are all causing loss of biodiversity of the area. Stage Ⅲ of the Parbati H.E. Project is a run of the river scheme on the Sainj River downstream of Power House of Parbati H.E. Project Stage Ⅱ. The project shall utilize regulated discharge of Parbati H.E. Project Stage Ⅱ and inflow of River Sainj for power generation, and has been contemplated as a peaking station operating in tandem with Stage Ⅱ. The present study has been undertaken to see the impact of hydroelectric project on the biodiversity, particularly on medicinal plants. A total of 104 species of medicinal plants, belonging to different life forms, i.e., trees (23 spp.), shrubs (22 spp.), herbs (57 spp.) and ferns (2 spp.) were recorded. The species have been analyzed and studied for their distribution, classification, altitudinal zones, part (s) used, indigenous uses, nativity, endemism and rarity.Different parts of these species, such as whole plants, roots (including rhizomes and tubers), leaves, flowers, fruits, seeds, stems, barks, spikes, nuts and insect galls are used by the inhabitants for curing various diseases and ailments. 30 species are native to the Himalayan region, 9 species native to the Himalayan region and adjacent countries also and 65 species are non-natives. 9 species are near endemics. Considering the whole Himalaya as a biogeographic unit (sensu lato), the near endemics are endemic to the Himalaya. Among these species, Zanthoxylum armatum is categorized as Endangered and Valeriana wallichii as Vulnerable. Hedychium spicatum, Rhus javanica, Berberis lycium, Thalictrum foliolossum, Salvia lanata, Rubia cordifolia and Bergenia ligulata may be considered as threatened species due to their over exploitation for trade. 90 species are propagated by seeds, 8 species by seeds and rhizomes/roots/tubers, 4 species by seeds and cuttings, and 2 species by sori. A management plan for the cultivation and conservation of the medicinal plants in the dam submergence area, and the commercially viable medicinal plants with high value in the catchment area is suggested. 展开更多
关键词 喜马拉雅西北地区 印度 Parbati水电三期工程 汇流区 药用植物 多样性评价 分布 保护状况 管理计划
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A Trans-century Archaeological Project--The Rescue of the Cultural Relics in the Three Gorges Area
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《China & The World Cultural Exchange》 1999年第1期25-26,共2页
关键词 A Trans-century Archaeological project The Rescue of the Cultural Relics in the Three Gorges area
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The Poverty Alleviation Model for the Solitary Elderly People in the Poor Mountainous Areas of Southwest China: Analysis of "Five Batches Project" in Xundian County
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作者 Yuting DONG Zisheng YANG 《Asian Agricultural Research》 2019年第8期23-27,共5页
The solitary elderly people in rural areas are not only an important part of the rural population,but also an important issue that can not be ignored in the battle to get rid of poverty. In recent years,according to t... The solitary elderly people in rural areas are not only an important part of the rural population,but also an important issue that can not be ignored in the battle to get rid of poverty. In recent years,according to the working thinking of ' accurate statistics,scientific arrangement,classified implementation,and rapid progress',Xundian County has gone through joint exploration and practice at the county and township levels,and has found out the path of work of ' Five Batches Project' to solve the problem of poverty alleviation for the solitary elderly people and make them live in their own homes. This has effectively solved the problem of safe and stable housing for 4 443 solitary elderly people in the county. It has found a new way to solve the housing problem of the solitary elderly people. At the end of 2017,the incidence of poverty in the county dropped to 0. 35%,and it was successfully listed as one of the first counties in Yunnan Province to get rid of poverty. Based on field research and interviews,this paper analyzes and summarizes the concrete methods,main achievements,practical experience,lessons and reference of the poverty alleviation model of ' Five Batches Project' in Xundian County to solve the problem of housing for the elderly,in order to provide necessary reference for the poor counties in Yunnan Province and other similar provinces( cities,autonomous regions) to solve the problem of housing for ' solitary elderly people' in Yunnan Province. 展开更多
关键词 POOR mountain areas SOLITARY elderly people POVERTY alleviation 'Five Batches project'
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基于节段模型测力方法的塔式起重机风荷载特性研究
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作者 李寿科 雷佳妍 +4 位作者 杨易归 林斌 郭凡 彭雄 孙洪鑫 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第7期2884-2896,共13页
塔式起重机被广泛应用于铁道工程和土木工程施工过程,属于高耸结构体系,风荷载是塔式起重机结构设计的控制性荷载。为完善《塔式起重机设计规范》(GB/T 13752—2017)和《建筑结构荷载规范》(GB 50009—2012)中的塔式起重机斜风向设计风... 塔式起重机被广泛应用于铁道工程和土木工程施工过程,属于高耸结构体系,风荷载是塔式起重机结构设计的控制性荷载。为完善《塔式起重机设计规范》(GB/T 13752—2017)和《建筑结构荷载规范》(GB 50009—2012)中的塔式起重机斜风向设计风荷载计算方法,解决风向、吊臂、平衡臂位置等因素对塔式起重机遮挡和干扰引起的设计风荷载计算问题。选取平头塔式起重机为研究对象,对塔身、吊臂、平衡臂进行多工况的节段模型测力风洞试验,研究湍流强度、节段干扰和遮挡等因素对塔式起重机节段风荷载特性的影响规律,研究不同风向下节段阻力系数分布规律,对比标准化阻力系数与当前主要规范的异同,进而探讨节段斜风向标准化阻力系数计算方法。研究结果表明湍流强度对节段阻力系数影响较小,可忽略,而平衡臂和吊臂相邻节段的干扰会减小测试节段的阻力系数;在斜风向下,由于吊臂和平衡臂之间存在相邻节段干扰,国内外规范方法的计算值均会大于干扰工况的节段风洞试验值;当前主要国家规范规定的垂直风向塔身、吊臂、平衡臂阻力系数与风洞试验测得的阻力系数值较为接近,基于风洞试验结果给出典型风向的塔式起重机各节段的风荷载系数取值可用于结构设计;基于风洞试验测试结果推导的塔式起重机斜风向风荷载计算方法具有较好的拟合效果。研究成果可推荐相关工程应用,可为相关规范的修改或补充提供参考。 展开更多
关键词 塔式起重机 风洞试验 节段模型 阻力系数 有效投影面积 角度风荷载
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南水北调西线工程水源区可调水量“十问”
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作者 胡鹏 王浩 +13 位作者 赵勇 宁远 蒋云钟 刘欢 曾庆慧 杨泽凡 周毓彦 董宁澎 闫龙 阿膺兰 张丰博 唐家璇 王玉莲 王建华 《中国工程科学》 CSCD 北大核心 2024年第2期210-223,共14页
南水北调西线工程是我国“四横三纵”国家水网主骨架尚待建设的最后一环,而水源区可调水量是西线工程规划论证面临的焦点和难点问题。本文从水资源本底条件与演变趋势,生态环境与经济社会发展需水,调蓄水库与输水工程规模,调水对水源区... 南水北调西线工程是我国“四横三纵”国家水网主骨架尚待建设的最后一环,而水源区可调水量是西线工程规划论证面临的焦点和难点问题。本文从水资源本底条件与演变趋势,生态环境与经济社会发展需水,调蓄水库与输水工程规模,调水对水源区及其下游水资源开发利用、水生态环境、水力发电、航运等方面影响的角度,提出了与水源区可调水量相关的10个问题;以长江上游分布式水文模型为基础,建立了南水北调西线工程水源区可调水量模拟分析模型,力图系统、定量地回答所提问题。本文的主要研究结论有:在仅考虑满足水源区河道内外生态环境和经济社会需水的前提下,“上线+下线”组合方案多年平均可调水量为1.59×10^(10)m^(3),“完全下线”方案在建设岗托水库进行联调时,多年平均可调水量将达到1.74×10^(10)m^(3);在综合考虑调水对水源区水平衡、水力发电和航运影响及其可接受程度后,南水北调西线水源区可调水量为1.22×10^(10)~1.26×10^(10)m^(3)。长远来看,应谋划西南片区水网与国家水网主骨架、“大动脉”的连接与融合,在减小南水北调西线工程调水影响的同时,提高南水北调西线工程的整体供水能力以及对气候变化等外部条件的适应性。 展开更多
关键词 南水北调西线工程 水源区 可调水量 生态需水 跨流域调水
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长江口横沙地区演化过程及保护利用思考
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作者 郭兴杰 《上海国土资源》 2024年第1期16-20,26,共6页
长江口横沙地区的保护和利用一直是近年来的热门话题。本文对横沙岛、横沙新洲的成陆过程以及浅滩的近期演化特征进行了总结和回顾,基于国家战略和前人的利用设想,提出了横沙地区目前面临的灾害和未来利用需要论证的制约因素。横沙岛于1... 长江口横沙地区的保护和利用一直是近年来的热门话题。本文对横沙岛、横沙新洲的成陆过程以及浅滩的近期演化特征进行了总结和回顾,基于国家战略和前人的利用设想,提出了横沙地区目前面临的灾害和未来利用需要论证的制约因素。横沙岛于1958年定界成陆,横沙新洲(东滩)在历史大洪水切割以及航道工程和促淤圈围等作用下于2021年成陆,横沙浅滩目前“长高不长大”,处于萎缩性演化态势。文章基于“长江大保护”国家战略,总结了前人提出的一些利用设想,认为需要综合研判横沙地区的保护利用模式。目前横沙地区主要面临流域输沙偏低和海平面上升带来的浅滩侵蚀问题,建议结合固沙保滩工程利用周围航道的疏浚土资源,未来利用也需要深入研究横沙地区生态保护、基底稳定、航道冲淤、盐水入侵以及极端气候等承载力问题。 展开更多
关键词 长江口 横沙地区 演化过程 保滩工程 利用思考
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机织钩面粘扣带表面质量的机器视觉检测方法
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作者 金守峰 李政 +2 位作者 徐畅 昝杰 郭彩霞 《毛纺科技》 CAS 北大核心 2024年第4期103-110,共8页
针对机织钩面粘扣带表面质量人工检测中存在的精度低等问题,提出了基于机器视觉的机织钩面粘扣带表面质量检测方法。通过单目视觉的切向成像获得粘扣带表面的单行图像,避免了粘扣带相邻行之间的干扰。对单行粘扣带图像进行预处理后,采... 针对机织钩面粘扣带表面质量人工检测中存在的精度低等问题,提出了基于机器视觉的机织钩面粘扣带表面质量检测方法。通过单目视觉的切向成像获得粘扣带表面的单行图像,避免了粘扣带相邻行之间的干扰。对单行粘扣带图像进行预处理后,采用投影法对其进行水平投影和垂直投影,提取粘扣带表面单行图像中的每个钩扣状区域,基于连通域统计法判别钩扣状区域的切割状态,计算其切开率,通过统计数据表征粘扣带表面质量。实验结果表明,该方法对机织钩面粘扣带表面质量的检测相对误差为1%,具有较高的稳定性。 展开更多
关键词 机织钩面粘扣带 切向成像 投影法 钩扣状区域 连通域
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