This study investigates the size-dependent wave propagation behaviors under the thermoelectric loads of porous functionally graded piezoelectric(FGP) nanoplates deposited in a viscoelastic foundation.It is assumed tha...This study investigates the size-dependent wave propagation behaviors under the thermoelectric loads of porous functionally graded piezoelectric(FGP) nanoplates deposited in a viscoelastic foundation.It is assumed that(i) the material parameters of the nanoplates obey a power-law variation in thickness and(ii) the uniform porosity exists in the nanoplates.The combined effects of viscoelasticity and shear deformation are considered by using the Kelvin-Voigt viscoelastic model and the refined higher-order shear deformation theory.The scale effects of the nanoplates are captured by employing nonlocal strain gradient theory(NSGT).The motion equations are calculated in accordance with Hamilton’s principle.Finally,the dispersion characteristics of the nanoplates are numerically determined by using a harmonic solution.The results indicate that the nonlocal parameters(NLPs) and length scale parameters(LSPs) have exactly the opposite effects on the wave frequency.In addition,it is found that the effect of porosity volume fractions(PVFs) on the wave frequency depends on the gradient indices and damping coefficients.When these two values are small,the wave frequency increases with the volume fraction.By contrast,at larger gradient index and damping coefficient values,the wave frequency decreases as the volume fraction increases.展开更多
Land resource is the material foundation of human survival and economic development, and the cultivated land is the essence of land resources. This paper takes the county scale, by using the method of GIS spatial anal...Land resource is the material foundation of human survival and economic development, and the cultivated land is the essence of land resources. This paper takes the county scale, by using the method of GIS spatial analysis and statistical analysis unifies, to explore the quality of cultivated land in Binchuan County using level, and explain the utilization level of county cultivated land quality spatial differentiation characteristics. The results showed that:(1) in the quantity of cultivated land quality and utilization level, the average utilization of paddy land was greater than that of dry land, and the comprehensive utilization of cultivated land and so on. Among them, the paddy land ranged from grade 6 to 15, the average utilization was grade 11.6; dry land ranged from grade 2 to 11, the average utilization was grade 5.9; comprehensive range of cultivated land is grade 2 to 15, the average utilization was grade 8.1;(2) the quality of cultivated land utilization spatial differentiation. Paddy field, dry land and cultivated land and large value distribution in the central and southern, inverted V shape distribution; the smaller the value distribution in the East and West, a dumbbell shaped distribution. Among them, they don't use a larger value of paddy land distributed in the central, South and southwest, the maximum value is 14.3, the smaller the value distribution in the West and East, the minimum value is grade 7; the larger the value distribution by the dry land in the South and West, the maximum value is grade 10.2, the smaller the value distribution in the West and East. The minimum value is grade 2.3; the comprehensive utilization of cultivated land don't distributed larger value in the central, South and south-west, the maximum value is grade 12.7, the smaller the value distribution in the West and East, the minimum value is grade 3.5. This paper can provide scientific basis for the dynamic monitoring of cultivated land quality, the transformation of low yield farmland and the early warning of cultivated land pressure.展开更多
目的:评估灸法治疗类风湿性关节炎的系统评价/Meta分析的文献质量,以期为RA临床决策提供依据。方法:计算机检索中国知网(CNKI)、万方(Wan fang)、维普(VIP)、PubMed、CBM、Web of science、Embase、Elsevier等数据库中公开发表的建库至2...目的:评估灸法治疗类风湿性关节炎的系统评价/Meta分析的文献质量,以期为RA临床决策提供依据。方法:计算机检索中国知网(CNKI)、万方(Wan fang)、维普(VIP)、PubMed、CBM、Web of science、Embase、Elsevier等数据库中公开发表的建库至2022年9月的灸法治疗RA的SR/Meta分析,采用PRISMA2020声明评价纳入文献的报告质量,采用AMSTAR2量表评价方法学质量,应用GRADE系统评估证据等级。结果:共纳入10篇SR。PRISMA2020声明评分大多在18~23.5分之间;AMSTAR2量表评价结果表明:10篇SR均为极低质量,且一半未报告发表偏倚;GRADE系统评价显示:纳入的54个主要结局指标中,中等质量结局13个,低质量27个,极低质量14个。所纳入的主要结局指标质量评级不理想。结论:灸法或灸法联合其他疗法治疗RA可明显改善患者的症状,临床疗效显著。灸法治疗RA的SR和meta分析论文的方法学质量和文献报告质量较低、结局指标等级不高,临床研究应结合相关评价指南加强规范,以期今后提供更可靠的临床证据。展开更多
Evaluation of the quality of small-bowel cleansing is required to assess the reliability of findings in capsule endoscopy(CE). Moreover, consensus regarding the need of intestinal preparation for CE remains to be achi...Evaluation of the quality of small-bowel cleansing is required to assess the reliability of findings in capsule endoscopy(CE). Moreover, consensus regarding the need of intestinal preparation for CE remains to be achieved. The presence of multiple grading scales for smallbowel preparation in CE, which are time-consuming and complicated, adds difficulty to the comparison of different small-bowel cleansing regimens and their application in clinical practice. Nowadays, a validated scale universally accepted for grading small-bowel cleansing is lacking. In fact, there are numerous grading systems with very different technical characteristics, namely, the parameters and the portion of the CE video that are analyzed, the objectivity of the analysis, the lesser or greater dependency on the operator, and the validation of the score. The authors performed a review which aims to systematize and summarize currently available smallbowel grading scales in CE.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.11502218 and 11672252)。
文摘This study investigates the size-dependent wave propagation behaviors under the thermoelectric loads of porous functionally graded piezoelectric(FGP) nanoplates deposited in a viscoelastic foundation.It is assumed that(i) the material parameters of the nanoplates obey a power-law variation in thickness and(ii) the uniform porosity exists in the nanoplates.The combined effects of viscoelasticity and shear deformation are considered by using the Kelvin-Voigt viscoelastic model and the refined higher-order shear deformation theory.The scale effects of the nanoplates are captured by employing nonlocal strain gradient theory(NSGT).The motion equations are calculated in accordance with Hamilton’s principle.Finally,the dispersion characteristics of the nanoplates are numerically determined by using a harmonic solution.The results indicate that the nonlocal parameters(NLPs) and length scale parameters(LSPs) have exactly the opposite effects on the wave frequency.In addition,it is found that the effect of porosity volume fractions(PVFs) on the wave frequency depends on the gradient indices and damping coefficients.When these two values are small,the wave frequency increases with the volume fraction.By contrast,at larger gradient index and damping coefficient values,the wave frequency decreases as the volume fraction increases.
基金supported by the Public Welfare Special Science Research Fund Project of Ministry of Land and Resources (Grant No. 201511003-3)
文摘Land resource is the material foundation of human survival and economic development, and the cultivated land is the essence of land resources. This paper takes the county scale, by using the method of GIS spatial analysis and statistical analysis unifies, to explore the quality of cultivated land in Binchuan County using level, and explain the utilization level of county cultivated land quality spatial differentiation characteristics. The results showed that:(1) in the quantity of cultivated land quality and utilization level, the average utilization of paddy land was greater than that of dry land, and the comprehensive utilization of cultivated land and so on. Among them, the paddy land ranged from grade 6 to 15, the average utilization was grade 11.6; dry land ranged from grade 2 to 11, the average utilization was grade 5.9; comprehensive range of cultivated land is grade 2 to 15, the average utilization was grade 8.1;(2) the quality of cultivated land utilization spatial differentiation. Paddy field, dry land and cultivated land and large value distribution in the central and southern, inverted V shape distribution; the smaller the value distribution in the East and West, a dumbbell shaped distribution. Among them, they don't use a larger value of paddy land distributed in the central, South and southwest, the maximum value is 14.3, the smaller the value distribution in the West and East, the minimum value is grade 7; the larger the value distribution by the dry land in the South and West, the maximum value is grade 10.2, the smaller the value distribution in the West and East. The minimum value is grade 2.3; the comprehensive utilization of cultivated land don't distributed larger value in the central, South and south-west, the maximum value is grade 12.7, the smaller the value distribution in the West and East, the minimum value is grade 3.5. This paper can provide scientific basis for the dynamic monitoring of cultivated land quality, the transformation of low yield farmland and the early warning of cultivated land pressure.
文摘目的:评估灸法治疗类风湿性关节炎的系统评价/Meta分析的文献质量,以期为RA临床决策提供依据。方法:计算机检索中国知网(CNKI)、万方(Wan fang)、维普(VIP)、PubMed、CBM、Web of science、Embase、Elsevier等数据库中公开发表的建库至2022年9月的灸法治疗RA的SR/Meta分析,采用PRISMA2020声明评价纳入文献的报告质量,采用AMSTAR2量表评价方法学质量,应用GRADE系统评估证据等级。结果:共纳入10篇SR。PRISMA2020声明评分大多在18~23.5分之间;AMSTAR2量表评价结果表明:10篇SR均为极低质量,且一半未报告发表偏倚;GRADE系统评价显示:纳入的54个主要结局指标中,中等质量结局13个,低质量27个,极低质量14个。所纳入的主要结局指标质量评级不理想。结论:灸法或灸法联合其他疗法治疗RA可明显改善患者的症状,临床疗效显著。灸法治疗RA的SR和meta分析论文的方法学质量和文献报告质量较低、结局指标等级不高,临床研究应结合相关评价指南加强规范,以期今后提供更可靠的临床证据。
文摘Evaluation of the quality of small-bowel cleansing is required to assess the reliability of findings in capsule endoscopy(CE). Moreover, consensus regarding the need of intestinal preparation for CE remains to be achieved. The presence of multiple grading scales for smallbowel preparation in CE, which are time-consuming and complicated, adds difficulty to the comparison of different small-bowel cleansing regimens and their application in clinical practice. Nowadays, a validated scale universally accepted for grading small-bowel cleansing is lacking. In fact, there are numerous grading systems with very different technical characteristics, namely, the parameters and the portion of the CE video that are analyzed, the objectivity of the analysis, the lesser or greater dependency on the operator, and the validation of the score. The authors performed a review which aims to systematize and summarize currently available smallbowel grading scales in CE.
