针对非同构分布式阵列无法使用旋转不变子空间算法(estimation of signal parameters via rotation invariant technique algorithm,ESPRIT),同时为了提高非同构分布式阵列的角度估计精度,提出基于求根降秩算法(root rank reduction est...针对非同构分布式阵列无法使用旋转不变子空间算法(estimation of signal parameters via rotation invariant technique algorithm,ESPRIT),同时为了提高非同构分布式阵列的角度估计精度,提出基于求根降秩算法(root rank reduction estimator,root-RARE)的目标波达方向估计方法。由于分布式阵列的基线长度远大于半波长,合成方向图出现栅瓣,导致测角模糊。算法以root-RARE与多重信号分类算法(multiple signal classification,MUSIC)联合解模糊,以root-RARE得到的粗估计为参考,解整个非同构分布式阵列MUSIC谱估计的模糊,从而得到高精度无模糊的估计。推导非同构分布式阵列方向估计的克拉美罗界,分析算法的波达方向估计性能,同时分析分布式阵列方向估计时的基线模糊门限与信噪比门限之间的关系。仿真结果验证所提算法方向估计的正确性及有效性。展开更多
Let Φ be an irreducible root system of classical type. In t his short note, we study the irreducible subsystems of Φ and compute the nu mber of irreducible subsystems of any rank k in Φ.
The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. Field experiments were conducted during 2008-2010 to study the eff...The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. Field experiments were conducted during 2008-2010 to study the effect of drip fertigation with water soluble fertilizer on root growth of maize under maize based intercropping system. The experiment was laid out in strip plot design with three replications. The treatment consists of nine fertigation levels in main plots and four inter crops in sub plots. Root spread and root dry mass were increased under drip fertigation practices while rooting depth was more under surface irrigation. Drip fertigation with water soluble fertilizer improved the root system by inducing new secondary roots which are succulent and actively involved in physiological responses. Drip fertigation has pronounced effect on the root architecture especially in the production of highly fibrous root system.展开更多
An analysis of a base-isolated structure for multi-component random ground motion is presented. The mean square respond of the system is Obtained under different parametric variations. The effectiveness of main param...An analysis of a base-isolated structure for multi-component random ground motion is presented. The mean square respond of the system is Obtained under different parametric variations. The effectiveness of main parameters and the torsional component during an earthquake is quantified with the help of the response ratio and the root mean square response with and without base isolation. It is observed that the base isolation has considerable influence on the response and the effect of the torsional component is not ignored.展开更多
Agricultural pollution is a major issue in the United States (U.S.) and the world. Biotic and abiotic farming byproducts adversely affect the ecosystem and human health. While pesticides and fertilizers are the primar...Agricultural pollution is a major issue in the United States (U.S.) and the world. Biotic and abiotic farming byproducts adversely affect the ecosystem and human health. While pesticides and fertilizers are the primary sources of agricultural pollution, organic agriculture can help remediate the negative effects on humans and the ecosystem. However, many factors like chemical drift can limit this advantage. This paper presents a feasibility study of a web-based (Geografic Information System) GIS application which can model and predict the areas affected by agricultural chemicals drift. Other applications exist with limited assumptions that make their outcomes far from reality. A root definition and a rich picture are developed as well as a Strengths Weaknesses Opportunities and Threats (SWOT) analysis. Because of the huge geographical context, data requirements and analyses requirements are expected to be massive. Nonetheless, despite the expected challenges, the advantages of the proposed application outweigh the risks.展开更多
背景老年群体中多重慢性病共病现象已成为当前公共卫生领域亟待关注的重要问题,因此深入探究老年群体共病相关影响因素具有重要意义。目的了解我国不同地区老年群体共病患病率及其患病影响因素,以期更好管理和干预不同地区老年群体的共...背景老年群体中多重慢性病共病现象已成为当前公共卫生领域亟待关注的重要问题,因此深入探究老年群体共病相关影响因素具有重要意义。目的了解我国不同地区老年群体共病患病率及其患病影响因素,以期更好管理和干预不同地区老年群体的共病发展和预后。方法利用计算机检索PubMed、Embase、Web of Science、Cochrane Library、Scopus、中国生物医学文献服务系统、中国知网、万方数据知识服务平台中有关老年人共病患病影响因素的队列研究、病例对照研究、横断面研究等观察性研究,检索时限为建库至2024年7月。2名研究者独立检索、筛选文献、数据提取并交叉核对,出现分歧时请第3名研究者进行判定。用Stata 18.0软件进行Meta分析。结果纳入来自南北方的文献各有10篇,样本量分别为2342507例和75871例。南北方老年患者共病患病率分别为34%(95%CI=29%~38%,P<0.001)和36%(95%CI=22%~50%,P<0.001)。其中,南方老年共病患者的影响因素有年龄(OR=1.92,95%CI=1.26~2.94,P=0.003)、性别(OR=1.51,95%CI=1.03~2.21,P=0.034)、家庭人均月收入(OR=1.62,95%CI=1.03~2.54,P=0.036)、文化程度(OR=1.47,95%CI=1.25~1.73,P<0.001)、BMI(OR=1.72,95%CI=1.52~1.96,P<0.001)、吸烟(OR=1.53,95%CI=1.11~2.11,P=0.009)、饮酒(OR=1.39,95%CI=1.26~1.54,P<0.001)、经常进行体育锻炼(OR=0.67,95%CI=0.55~0.80,P<0.001);北方老年共病患者的影响因素有年龄(OR=1.67,95%CI=1.00~2.79,P=0.048)、BMI(OR=2.39,95%CI=1.80~3.18,P<0.001)、饮酒(OR=1.63,95%CI=1.32~2.02,P<0.001)、经常进行体育锻炼(OR=0.84,95%CI=0.71~0.99,P<0.037)。敏感性分析结果表明Meta分析结果较稳定,Egger's检验(老年人共病患病率P=0.826、老年人共病影响因素P=0.841)提示纳入文献的发表偏倚风险不显著。结论南北方老年人共病率均较高。年龄在70岁及以上、BMI达到超重或肥胖水平、饮酒是南北方老年人共病患病的危险因素;经常进行体育锻炼是南北方老年人共病患病的保护因素;性别为男性、家庭人均月收入在2000元及以上、文化程度在大专以下、吸烟仅为南方老年人共病患病的危险因素。这种差异可能与饮食结构、经济发展水平、生活节奏及医疗资源分配不均等因素密切相关。建议加强区域间医疗资源的协调与共享,以促进健康公平性和医疗资源的均衡分配,从而提升老年人的整体健康水平。同时,医务或社区工作者应根据老年共病患者的影响因素,定制个性化干预方案,精准优化多重慢性病患者的疾病管理效果。展开更多
文摘针对非同构分布式阵列无法使用旋转不变子空间算法(estimation of signal parameters via rotation invariant technique algorithm,ESPRIT),同时为了提高非同构分布式阵列的角度估计精度,提出基于求根降秩算法(root rank reduction estimator,root-RARE)的目标波达方向估计方法。由于分布式阵列的基线长度远大于半波长,合成方向图出现栅瓣,导致测角模糊。算法以root-RARE与多重信号分类算法(multiple signal classification,MUSIC)联合解模糊,以root-RARE得到的粗估计为参考,解整个非同构分布式阵列MUSIC谱估计的模糊,从而得到高精度无模糊的估计。推导非同构分布式阵列方向估计的克拉美罗界,分析算法的波达方向估计性能,同时分析分布式阵列方向估计时的基线模糊门限与信噪比门限之间的关系。仿真结果验证所提算法方向估计的正确性及有效性。
文摘Let Φ be an irreducible root system of classical type. In t his short note, we study the irreducible subsystems of Φ and compute the nu mber of irreducible subsystems of any rank k in Φ.
文摘The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. Field experiments were conducted during 2008-2010 to study the effect of drip fertigation with water soluble fertilizer on root growth of maize under maize based intercropping system. The experiment was laid out in strip plot design with three replications. The treatment consists of nine fertigation levels in main plots and four inter crops in sub plots. Root spread and root dry mass were increased under drip fertigation practices while rooting depth was more under surface irrigation. Drip fertigation with water soluble fertilizer improved the root system by inducing new secondary roots which are succulent and actively involved in physiological responses. Drip fertigation has pronounced effect on the root architecture especially in the production of highly fibrous root system.
文摘An analysis of a base-isolated structure for multi-component random ground motion is presented. The mean square respond of the system is Obtained under different parametric variations. The effectiveness of main parameters and the torsional component during an earthquake is quantified with the help of the response ratio and the root mean square response with and without base isolation. It is observed that the base isolation has considerable influence on the response and the effect of the torsional component is not ignored.
文摘Agricultural pollution is a major issue in the United States (U.S.) and the world. Biotic and abiotic farming byproducts adversely affect the ecosystem and human health. While pesticides and fertilizers are the primary sources of agricultural pollution, organic agriculture can help remediate the negative effects on humans and the ecosystem. However, many factors like chemical drift can limit this advantage. This paper presents a feasibility study of a web-based (Geografic Information System) GIS application which can model and predict the areas affected by agricultural chemicals drift. Other applications exist with limited assumptions that make their outcomes far from reality. A root definition and a rich picture are developed as well as a Strengths Weaknesses Opportunities and Threats (SWOT) analysis. Because of the huge geographical context, data requirements and analyses requirements are expected to be massive. Nonetheless, despite the expected challenges, the advantages of the proposed application outweigh the risks.
文摘背景老年群体中多重慢性病共病现象已成为当前公共卫生领域亟待关注的重要问题,因此深入探究老年群体共病相关影响因素具有重要意义。目的了解我国不同地区老年群体共病患病率及其患病影响因素,以期更好管理和干预不同地区老年群体的共病发展和预后。方法利用计算机检索PubMed、Embase、Web of Science、Cochrane Library、Scopus、中国生物医学文献服务系统、中国知网、万方数据知识服务平台中有关老年人共病患病影响因素的队列研究、病例对照研究、横断面研究等观察性研究,检索时限为建库至2024年7月。2名研究者独立检索、筛选文献、数据提取并交叉核对,出现分歧时请第3名研究者进行判定。用Stata 18.0软件进行Meta分析。结果纳入来自南北方的文献各有10篇,样本量分别为2342507例和75871例。南北方老年患者共病患病率分别为34%(95%CI=29%~38%,P<0.001)和36%(95%CI=22%~50%,P<0.001)。其中,南方老年共病患者的影响因素有年龄(OR=1.92,95%CI=1.26~2.94,P=0.003)、性别(OR=1.51,95%CI=1.03~2.21,P=0.034)、家庭人均月收入(OR=1.62,95%CI=1.03~2.54,P=0.036)、文化程度(OR=1.47,95%CI=1.25~1.73,P<0.001)、BMI(OR=1.72,95%CI=1.52~1.96,P<0.001)、吸烟(OR=1.53,95%CI=1.11~2.11,P=0.009)、饮酒(OR=1.39,95%CI=1.26~1.54,P<0.001)、经常进行体育锻炼(OR=0.67,95%CI=0.55~0.80,P<0.001);北方老年共病患者的影响因素有年龄(OR=1.67,95%CI=1.00~2.79,P=0.048)、BMI(OR=2.39,95%CI=1.80~3.18,P<0.001)、饮酒(OR=1.63,95%CI=1.32~2.02,P<0.001)、经常进行体育锻炼(OR=0.84,95%CI=0.71~0.99,P<0.037)。敏感性分析结果表明Meta分析结果较稳定,Egger's检验(老年人共病患病率P=0.826、老年人共病影响因素P=0.841)提示纳入文献的发表偏倚风险不显著。结论南北方老年人共病率均较高。年龄在70岁及以上、BMI达到超重或肥胖水平、饮酒是南北方老年人共病患病的危险因素;经常进行体育锻炼是南北方老年人共病患病的保护因素;性别为男性、家庭人均月收入在2000元及以上、文化程度在大专以下、吸烟仅为南方老年人共病患病的危险因素。这种差异可能与饮食结构、经济发展水平、生活节奏及医疗资源分配不均等因素密切相关。建议加强区域间医疗资源的协调与共享,以促进健康公平性和医疗资源的均衡分配,从而提升老年人的整体健康水平。同时,医务或社区工作者应根据老年共病患者的影响因素,定制个性化干预方案,精准优化多重慢性病患者的疾病管理效果。
