低空经济作为国家的重要战略部署,日益成为学术研究的焦点。基于Web of Science和中国知网数据库,运用科学计量与知识图谱分析方法,系统梳理2015-2025年低空经济领域的研究概况、知识基础、研究热点和演进脉络。研究发现,英文文献以技...低空经济作为国家的重要战略部署,日益成为学术研究的焦点。基于Web of Science和中国知网数据库,运用科学计量与知识图谱分析方法,系统梳理2015-2025年低空经济领域的研究概况、知识基础、研究热点和演进脉络。研究发现,英文文献以技术开发、场景应用、空域管理及商业模式创新为核心,注重技术驱动与商业生态融合;中文文献聚焦政策分析、空域划分与区域经济效益,注重制度创新与经济模式优化。当前,英文研究突出技术跨界融合,而中文研究在技术创新、商业模式和产业化路径方面具有潜力。未来研究需结合多学科视角,深化低空经济理论体系,关注其与数字经济的协同效应、社会经济影响评估及投融资模式创新,提升我国低空经济可持续发展能力和国际竞争力。展开更多
Field data of outcrop spectrums provide important basis for modeling of hyper-spectral remote sensing aiming at mineral prospecting. We make an approach to the application of rough set theory in spectral discriminatio...Field data of outcrop spectrums provide important basis for modeling of hyper-spectral remote sensing aiming at mineral prospecting. We make an approach to the application of rough set theory in spectral discrimination of rocks. We build a decision table with an adequate number of samples (outcrops) of known rock type (the universe), of which the conditional attributes are discretized 'area spectrum absorption indexes' (ASAI) corresponding to wavelength intervals, and the decision attribute is rock type. We search to obtain the exhaustive set of reducts of the table, each of which will serve as a variable number of deduction rules. Suppose we have n (usually a very big number) rules in total and there are m types of rocks in our universe, for any unknown sample, we judge its rock type by each of those rules. An unknown sample may be recognized as a different type by different rules because it is outside our universe, and we accept the most frequent judgment result and ignore the other m-1 types of results. Our ASAI is an improvement upon the traditional spectrum absorption index (SAI), better applicable to field spectrums: given a spectrum curve and a wavelength interval, we take the average reflectance within the interval as a base line and let ASAI=a below/(a above+a below), where a below and a above stand for total areas, bounded by the curve, the base line and the borders of the intervalbelow and above the base line respectively. With the equipments of FieldSpectr Fr (made by ASD Co., US), we collected data from Baiya gold deposit, Yunnan, and applied the above method to discriminate altered rocks as an experiment. The results show satisfactory performance of the method.展开更多
Objective: to analyze the clinical efficacy of Orem self-care theory in patients with multiple myeloma. Methods: we selected 28 multiple myeloma patients received by our hospital from October 2020 to October 2021, div...Objective: to analyze the clinical efficacy of Orem self-care theory in patients with multiple myeloma. Methods: we selected 28 multiple myeloma patients received by our hospital from October 2020 to October 2021, divided them into two groups, control group (routine care intervention mode, n14 cases) and experimental group (n14 cases based on Orem self-care theory, n 14 cases). All patients received guidance and training according to the established clinical care strategy, urged patients to conduct 6 months month clinical guidance and intervention, and evaluated the following clinical care efficacy. Results: according to the comparison of the mental state, infection rate, regular review rate and disease improvement rate of the two groups before and after nursing, the observation group was significantly better than the control group, and the comparison difference was prominent, with statistical advantages, P 0.05. Conclusion: orem self-care theory of orem has some positive significance for improving patient quality of life, reducing infection rate and improving prognosis, which is worth being widely applied and promoted in clinical practice.展开更多
Under the interval uncertainties, by incorporating the discretization form offinite volume method and interval algebra theory, an Interval Finite Volume Method (IF-VM) wasdeveloped to solve water quality simulation is...Under the interval uncertainties, by incorporating the discretization form offinite volume method and interval algebra theory, an Interval Finite Volume Method (IF-VM) wasdeveloped to solve water quality simulation issues for two-dimensional river when lacking effectivedata of flow velocity and flow quantity. The IFVM was practically applied to a segment of theXiangjiang River because the Project of Hunan Inland Waterway Multipurpose must be started workingafter the environmental impact assessment for it. The simulation results suggest that there existrather apparent pollution zones of BOD_5 downstream the Dongqiaogang discharger and that of CODdownstream Xiaoxiangjie discharger, but the pollution sources have no impact on the safety of thethree water plants located in this river segment. Although the developed IFVM is to be perfected, itis still a powerful tool under interval uncertainties for water environmental impact assessment,risk analysis, and water quality planning, etc. besides water quality simulation studied in thispaper.展开更多
In the middle and lower reaches of the YangtzRiver,Poyang Lake and Dongting Lake are the towbiggest freshwater lakes in China and are also two ofthe most famous bird reserves in the country.Themagnificent scene of the...In the middle and lower reaches of the YangtzRiver,Poyang Lake and Dongting Lake are the towbiggest freshwater lakes in China and are also two ofthe most famous bird reserves in the country.Themagnificent scene of the large number of migrantbirds that fly over every winter is attracting more andmore bird lovers.展开更多
文摘低空经济作为国家的重要战略部署,日益成为学术研究的焦点。基于Web of Science和中国知网数据库,运用科学计量与知识图谱分析方法,系统梳理2015-2025年低空经济领域的研究概况、知识基础、研究热点和演进脉络。研究发现,英文文献以技术开发、场景应用、空域管理及商业模式创新为核心,注重技术驱动与商业生态融合;中文文献聚焦政策分析、空域划分与区域经济效益,注重制度创新与经济模式优化。当前,英文研究突出技术跨界融合,而中文研究在技术创新、商业模式和产业化路径方面具有潜力。未来研究需结合多学科视角,深化低空经济理论体系,关注其与数字经济的协同效应、社会经济影响评估及投融资模式创新,提升我国低空经济可持续发展能力和国际竞争力。
基金ThisresearchisjointlysupportedbytheNationalNaturalScienceFoun dationofChina (No .4 0 2 72 0 2 2 )andtheKeyBrainstormProjectoftheMinistryofLandandResourcesofChina (No .2 0 0 1 0 30 5)
文摘Field data of outcrop spectrums provide important basis for modeling of hyper-spectral remote sensing aiming at mineral prospecting. We make an approach to the application of rough set theory in spectral discrimination of rocks. We build a decision table with an adequate number of samples (outcrops) of known rock type (the universe), of which the conditional attributes are discretized 'area spectrum absorption indexes' (ASAI) corresponding to wavelength intervals, and the decision attribute is rock type. We search to obtain the exhaustive set of reducts of the table, each of which will serve as a variable number of deduction rules. Suppose we have n (usually a very big number) rules in total and there are m types of rocks in our universe, for any unknown sample, we judge its rock type by each of those rules. An unknown sample may be recognized as a different type by different rules because it is outside our universe, and we accept the most frequent judgment result and ignore the other m-1 types of results. Our ASAI is an improvement upon the traditional spectrum absorption index (SAI), better applicable to field spectrums: given a spectrum curve and a wavelength interval, we take the average reflectance within the interval as a base line and let ASAI=a below/(a above+a below), where a below and a above stand for total areas, bounded by the curve, the base line and the borders of the intervalbelow and above the base line respectively. With the equipments of FieldSpectr Fr (made by ASD Co., US), we collected data from Baiya gold deposit, Yunnan, and applied the above method to discriminate altered rocks as an experiment. The results show satisfactory performance of the method.
文摘Objective: to analyze the clinical efficacy of Orem self-care theory in patients with multiple myeloma. Methods: we selected 28 multiple myeloma patients received by our hospital from October 2020 to October 2021, divided them into two groups, control group (routine care intervention mode, n14 cases) and experimental group (n14 cases based on Orem self-care theory, n 14 cases). All patients received guidance and training according to the established clinical care strategy, urged patients to conduct 6 months month clinical guidance and intervention, and evaluated the following clinical care efficacy. Results: according to the comparison of the mental state, infection rate, regular review rate and disease improvement rate of the two groups before and after nursing, the observation group was significantly better than the control group, and the comparison difference was prominent, with statistical advantages, P 0.05. Conclusion: orem self-care theory of orem has some positive significance for improving patient quality of life, reducing infection rate and improving prognosis, which is worth being widely applied and promoted in clinical practice.
文摘Under the interval uncertainties, by incorporating the discretization form offinite volume method and interval algebra theory, an Interval Finite Volume Method (IF-VM) wasdeveloped to solve water quality simulation issues for two-dimensional river when lacking effectivedata of flow velocity and flow quantity. The IFVM was practically applied to a segment of theXiangjiang River because the Project of Hunan Inland Waterway Multipurpose must be started workingafter the environmental impact assessment for it. The simulation results suggest that there existrather apparent pollution zones of BOD_5 downstream the Dongqiaogang discharger and that of CODdownstream Xiaoxiangjie discharger, but the pollution sources have no impact on the safety of thethree water plants located in this river segment. Although the developed IFVM is to be perfected, itis still a powerful tool under interval uncertainties for water environmental impact assessment,risk analysis, and water quality planning, etc. besides water quality simulation studied in thispaper.
文摘In the middle and lower reaches of the YangtzRiver,Poyang Lake and Dongting Lake are the towbiggest freshwater lakes in China and are also two ofthe most famous bird reserves in the country.Themagnificent scene of the large number of migrantbirds that fly over every winter is attracting more andmore bird lovers.
