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Study into the Applicability of Laser Beam Quality Factor M^2 被引量:2
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作者 杨静 田小红 辛建国 《Defence Technology(防务技术)》 SCIE EI CAS 2006年第1期33-36,共4页
The applicable condition of single-frequency laser beam quality factor M^2 is studied. Any real single-frequency laser beam can be classified as Gaussian mode and non-Gaussian mode according to the transverse field di... The applicable condition of single-frequency laser beam quality factor M^2 is studied. Any real single-frequency laser beam can be classified as Gaussian mode and non-Gaussian mode according to the transverse field distribution. Non-Gaussian transverse field distribution can be analytically expressed as the sum of Hermite-Gaussian functions. The propagation function and M^2 factor expression for non-Gaussian mode can be obtained by the second moment definition of laser beam spot. The analytical results show, the same as that of Gaussian mode, that the propagation function follows the hyperbolic law and the value of M^2 factor is a constant for non-Gaussian mode. But, different non-Gaussian field distributions may have the same M^2 value. That means M^2 factor cannot reflect the quality of non-Gaussian laser beams correctly. We conclude that the M^2 factor is applicable only to ideal Gaussian laser beam generated by stable resonators. 展开更多
关键词 高斯波束 激光束 适用性 激光武器
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Measurement of the cavity-loaded quality factor in superconducting radio-frequency systems with mismatched source impedance
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作者 Jin-Ying Ma Cheng-Ye Xu +12 位作者 An-Dong Wu Guo-Dong Jiang Yue Tao Zong-Heng Xue Long-Bo Shi Tian-Cai Jiang Zheng-Long Zhu Zi-Qin Yang Zheng Gao Lie-Peng Sun Gui-Rong Huang Feng Qiu Yuan He 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第8期12-23,共12页
The accurate measurement of parameters such as the cavity-loaded quality factor(Q_(L))and half bandwidth(f_(0.5))is essential for monitoring the performance of superconducting radio-frequency cavities.However,the conv... The accurate measurement of parameters such as the cavity-loaded quality factor(Q_(L))and half bandwidth(f_(0.5))is essential for monitoring the performance of superconducting radio-frequency cavities.However,the conventional"field decay method"employed to calibrate these values requires the cavity to satisfy a"zero-input"condition.This can be challenging when the source impedance is mismatched and produce nonzero forward signals(V_(f))that significantly affect the measurement accuracy.To address this limitation,we developed a modified version of the"field decay method"based on the cavity differential equation.The proposed approach enables the precise calibration of f_(0.5) even under mismatch conditions.We tested the proposed approach on the SRF cavities of the Chinese Accelerator-Driven System Front-End Demo Superconducting Linac and compared the results with those obtained from a network analyzer.The two sets of results were consistent,indicating the usefulness of the proposed approach. 展开更多
关键词 Loaded quality factor Field decay method Superconducting cavity MISMATCH Calibration Cavity differential equation Measurement Accelerator-driven system
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A WSN Node Fault Diagnosis Model Based on BRB with Self-Adaptive Quality Factor
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作者 Guo-Wen Sun Gang Xiang +3 位作者 Wei He Kai Tang Zi-Yi Wang Hai-Long Zhu 《Computers, Materials & Continua》 SCIE EI 2023年第4期1157-1177,共21页
Wireless sensor networks (WSNs) operate in complex and harshenvironments;thus, node faults are inevitable. Therefore, fault diagnosis ofthe WSNs node is essential. Affected by the harsh working environment ofWSNs and ... Wireless sensor networks (WSNs) operate in complex and harshenvironments;thus, node faults are inevitable. Therefore, fault diagnosis ofthe WSNs node is essential. Affected by the harsh working environment ofWSNs and wireless data transmission, the data collected by WSNs containnoisy data, leading to unreliable data among the data features extracted duringfault diagnosis. To reduce the influence of unreliable data features on faultdiagnosis accuracy, this paper proposes a belief rule base (BRB) with a selfadaptivequality factor (BRB-SAQF) fault diagnosis model. First, the datafeatures required for WSN node fault diagnosis are extracted. Second, thequality factors of input attributes are introduced and calculated. Third, themodel inference process with an attribute quality factor is designed. Fourth,the projection covariance matrix adaptation evolution strategy (P-CMA-ES)algorithm is used to optimize the model’s initial parameters. Finally, the effectivenessof the proposed model is verified by comparing the commonly usedfault diagnosis methods for WSN nodes with the BRB method consideringstatic attribute reliability (BRB-Sr). The experimental results show that BRBSAQFcan reduce the influence of unreliable data features. The self-adaptivequality factor calculation method is more reasonable and accurate than thestatic attribute reliability method. 展开更多
关键词 Self-adaptive quality factor belief rule base wireless sensor networks fault diagnosis
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Factors Associated with Diet Quality in Women of Childbearing Age in Southern Benin in 2022
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作者 Charles Sossa-Jerome Reynald Santos +3 位作者 Lamidhi Salami Clemence Metonnou Colette Azandjeme Moussiliou N Paraiso 《Open Journal of Epidemiology》 2023年第4期421-435,共15页
Background: The nutritional status of women while in pregnancy influences foetus growth, infant development, and the mother’s health. The objective of this study was to assess diet quality and associated factors amon... Background: The nutritional status of women while in pregnancy influences foetus growth, infant development, and the mother’s health. The objective of this study was to assess diet quality and associated factors among women of childbearing age in the Comè community, Benin. Methods: The cross-sectional and analytical study involved 215 participants randomly selected by multi-stage sampling technique. Two non-consecutive dietary recall data were collected as well as sociodemographic information. The International Food Quality Index (IQD-I) was used to assess diet quality. Factors associated with the nutritional quality of the diet were identified by using linear regression. Results: Among 212 women, a diet quality of 175 (82.55%) was fair while 14.62% had good diet quality. Factors associated with the diet quality were the level of household possession, health issues, and nutritional advice at the health care facilities. Conclusion: Nutritional education interventions and income-generating activities may improve the diet quality among women of childbearing age in the Comè in Benin. 展开更多
关键词 Diet quality WOMEN Associated factors BENIN
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Quality of life of hospitalized patients after lung cancer operation and analysis of influencing factors
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作者 HU Yi‑fan HUANG Xiu‑ming +8 位作者 XIAO Sha ZHOU Jing WANG Shuo‑min WU Qi‑sheng ZHOU Bing‑xian FAN Shi‑heng FAN Ya‑yan CHEN Xian‑shan ZHANG Jing 《Journal of Hainan Medical University》 CAS 2023年第12期41-46,共6页
Objective:To explore the current status and influencing factors of quality of life in patients with lung cancer after surgery in a tertiary hospital in Hainan province.Methods:To investigate the influencing factors of... Objective:To explore the current status and influencing factors of quality of life in patients with lung cancer after surgery in a tertiary hospital in Hainan province.Methods:To investigate the influencing factors of quality of life of lung cancer patients after surgery in a tertiary hospital in Hainan province by cross‑sectional survey method.Results:The scores of insomnia,appetite loss,constipation and pain in 186 lung cancer patients after surgery in a tertiary hospital in Hainan Province were significantly higher than the reference value.Multiple linear regression analysis showed that older patients(>60 years)had lower scores in physical function domain(β=-0.193),and female patients had more appetite loss symptoms(β=0.245).Compared with other minority ethnic groups,Han ethnic group had lower scores in role function domain(β=0.179),more severe fatigue symptoms(β=-0.162),and higher general health level(β=0.166).Patients with employee medical insurance had lower scores of emotional function(β=0.194),cognitive function(β=0.281),the lowest score in social function(β=0.188),and severe pain in other parts(β=-0.227).Smokers had less cough symptoms(β=0.175)and more arm and shoulder pain symptoms(β=-0.21)than non‑smokers.Patients with secondhand smoke exposure had lower cognitive function scores(β=-0.158)and more obvious symptoms of oral ulcer(β=0.185).Patients who drank alcohol frequently(drinking frequency>1 time/day)had more severe cough symptoms(β=0.27).Patients with small number of children(0‑1)had milder cough symptoms(β=0.178).Patients who did not understand the disease had obvious symptoms of arm and shoulder pain(β=0.151).Patients with early pathological stage(stageⅠ‑Ⅱ)had more severe shortness of breath(β=-0.159)and pain(β=-0.181).The symptoms of appetite loss were more obvious in patients living in cities(β=0.192).The symptoms of peripheral neuropathy were more obvious(β=0.174).Patients who often consumed pickulated food had severe pain symptoms(β=-0.219),and pain in other parts was obvious(β=-0.149).Male patients had obvious alopecia symptoms(β=-0.306).Conclusion:Age,ethnicity,residence,type of medical insurance,number of children,pathological stage of lung cancer,smoking,second‑hand smoke exposure,alcohol consumption,and frequent consumption of pickled food were related to the quality of life of lung cancer patients in hospital after surgery.Medical staff and family members should pay attention to the emotional communication of patients during the treatment of lung cancer patients in hospital after surgery.Patients should avoid exposure to smoking,alcohol and second‑hand smoke,and reduce consumption of pickled food. 展开更多
关键词 Lung cancer Patients in hospital after lung cancer SURGERY quality of life The influencing factors Regression analysis
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Structural characteristics and influencing factors of spatial correlation network for regional high-quality development in China
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作者 LIU Jian-jun LIU He 《Ecological Economy》 2023年第4期329-343,共15页
On the basis of measuring the regional high-quality development in China from 2011 to 2020,this study uses gravity model to build spatial correlation network,and uses social network analysis method to analyze the stru... On the basis of measuring the regional high-quality development in China from 2011 to 2020,this study uses gravity model to build spatial correlation network,and uses social network analysis method to analyze the structural characteristics and influencing factors of correlation network.The results are shown as follows.First,from 2011 to 2020,the level of regional high-quality development in China is rising gradually,and the discrete characteristics between regions are gradually obvious,showing a step-like distribution structure decreasing from east to west.Second,the network density of regional high-quality development is generally low and tends to decline,but it has strong stability and correlation strength.Third,the spatial correlation network has an obvious core-edge structure.Shanghai is always at the center of the network and plays a significant intermediary role,while Qinghai and Xinjiang are always at the edge of the network.Fourth,the regional high-quality development association network can be divided into four major sectors:main benefit,net benefit,net spillover,and broker,showing the spatial correlation characteristics of inter-plate contact and intra-plate agglomeration.Fifth,the level of economic development,the level of urbanization and geographical proximity have a significant impact on the formation of regional high-quality development correlation network. 展开更多
关键词 high quality development spatial association network influencing factors social network analysis
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Factors influencing quality of life in Chinese patients with dementia: a systematic review
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作者 Jin-Long Ma Bao-Jian Wei Yan-Mei Lang 《Aging Communications》 2023年第2期35-42,共8页
Background:Dementia is a group of nervous system diseases characterized by progressive cognitive decline,leading to a loss of self-care ability and a decline in well-being.This places a significant burden on the globa... Background:Dementia is a group of nervous system diseases characterized by progressive cognitive decline,leading to a loss of self-care ability and a decline in well-being.This places a significant burden on the global healthcare system,with Chinese patients accounting for approximately one-quarter of the world’s dementia cases.Therefore,it is crucial to identify factors that impact the quality of life(QOL)among elderly Chinese individuals with dementia.Method:To achieve this,we conducted a comprehensive search of several databases,including PubMed,Embase,Web of Science,the Cochrane Library,China National Knowledge Infrastructure,Wanfang Data,China VIP Database and China Biomedical Literature Database.We reviewed cross-sectional studies from the inception of these databases until March 27,2022.QOL outcomes were assessed using standardized scales in the studies included in this review.Results:The search yielded a total of 1,235 relevant articles,from which we finally included 21 cross-sectional studies and one longitudinal study after rigorous quality assessment.Among these,10 studies were classified as high quality,while 12 were classified as fair quality.Through our analysis,we identified 28 patient-rated QOL factors and 14 caregiver-rated QOL factors.These factors were categorized into three groups:patient,disease-related and caregiver.Factors commonly found to influence patient-rated QOL included age,education,marital status,depression,self-care ability,dementia severity,cognitive function,behavioral and psychological symptoms of dementia and caregiver burden.Similarly,factors commonly influencing caregiver-rated QOL included economic status,depression,self-care ability,dementia severity,cognitive function,behavioral and psychological symptoms of dementia and caregiving time.Conclusion:This review clarifies the factors that influence the QOL of Chinese individuals with dementia.When implementing interventions,it is crucial to consider the differences between patient-rated QOL and caregiver-proxy-rated QOL,as well as their respective influencing factors. 展开更多
关键词 DEMENTIA Alzheimer’s disease quality of life social support protective factors
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Block Incremental Dense Tucker Decomposition with Application to Spatial and Temporal Analysis of Air Quality Data
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作者 SangSeok Lee HaeWon Moon Lee Sael 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期319-336,共18页
How can we efficiently store and mine dynamically generated dense tensors for modeling the behavior of multidimensional dynamic data?Much of the multidimensional dynamic data in the real world is generated in the form... How can we efficiently store and mine dynamically generated dense tensors for modeling the behavior of multidimensional dynamic data?Much of the multidimensional dynamic data in the real world is generated in the form of time-growing tensors.For example,air quality tensor data consists of multiple sensory values gathered from wide locations for a long time.Such data,accumulated over time,is redundant and consumes a lot ofmemory in its raw form.We need a way to efficiently store dynamically generated tensor data that increase over time and to model their behavior on demand between arbitrary time blocks.To this end,we propose a Block IncrementalDense Tucker Decomposition(BID-Tucker)method for efficient storage and on-demand modeling ofmultidimensional spatiotemporal data.Assuming that tensors come in unit blocks where only the time domain changes,our proposed BID-Tucker first slices the blocks into matrices and decomposes them via singular value decomposition(SVD).The SVDs of the time×space sliced matrices are stored instead of the raw tensor blocks to save space.When modeling from data is required at particular time blocks,the SVDs of corresponding time blocks are retrieved and incremented to be used for Tucker decomposition.The factor matrices and core tensor of the decomposed results can then be used for further data analysis.We compared our proposed BID-Tucker with D-Tucker,which our method extends,and vanilla Tucker decomposition.We show that our BID-Tucker is faster than both D-Tucker and vanilla Tucker decomposition and uses less memory for storage with a comparable reconstruction error.We applied our proposed BID-Tucker to model the spatial and temporal trends of air quality data collected in South Korea from 2018 to 2022.We were able to model the spatial and temporal air quality trends.We were also able to verify unusual events,such as chronic ozone alerts and large fire events. 展开更多
关键词 Dynamic decomposition tucker tensor tensor factorization spatiotemporal data tensor analysis air quality
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Investigation and Analysis of Factors Influencing the Quality of Community Nursing Services in Laishan District,Yantai City
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作者 Jianjun Sun Qing Ji +1 位作者 Arby James Abonalla Minerva B.De Ala 《Journal of Clinical and Nursing Research》 2023年第6期230-234,共5页
Objective:The purpose of this study is to conduct an in-depth investigation and analysis of the factors affecting the quality of community nursing services in Laishan District,Yantai City,and provide suggestions for i... Objective:The purpose of this study is to conduct an in-depth investigation and analysis of the factors affecting the quality of community nursing services in Laishan District,Yantai City,and provide suggestions for improving the quality of the services.Method:The community nursing services in Laishan District,Yantai City were investigated through questionnaires and on-site observations.Result:The content of nursing services was correlated with the professional titles of the staff.The guidance given to patients and caregivers was significantly correlated with the educational level of community nursing personnel.Therefore,this indicates that the professional titles and educational backgrounds of the community nursing personnel have a significant impact on the quality of service provided.Conclusion:The role of professional title evaluation can be optimized,further enhancing the educational level of nurses in surrounding communities,optimizing service content and methods,etc.,in order to improve the quality of community nursing services in the region. 展开更多
关键词 Laishan District Community nursing Service quality Influencing factors
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Dynamic Response Impact of Vehicle Braking on Simply Supported Beam Bridges with Corrugated Steel Webs Based on Vehicle-Bridge Coupled Vibration Analysis
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作者 Yan Wang Siwen Li Na Wei 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期3467-3493,共27页
A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle braking.Efficient modeling and solu... A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle braking.Efficient modeling and solution of bridge vibrations induced by vehicle deceleration are realized using this method.The method’s validity and reliability are substantiated through numerical examples.A simply supported beam bridge with a corrugated steel web is taken as an example and the effects of parameters such as the initial vehicle speed,braking acceleration,braking location,and road surface roughness on the mid-span displacement and impact factor of the bridge are analyzed.The results show that vehicle braking significantly amplifies mid-span displacement and impact factor responses in comparison to uniform vehicular motion across the bridge.Notably,the influence of wheelto-bridge friction forces is of particular significance and cannot be overlooked.When the vehicle initiates braking near the middle of the span,both the mid-span displacement and impact factor of the bridge exhibit substantial increases,further escalating with higher braking acceleration.Under favorable road surface conditions,the midspan displacement and the impact factor during vehicle braking may exceed the design values stipulated by codes.It is important to note that road surface roughness exerts a more pronounced effect on the impact factor of the bridge in comparison to the effects of vehicle braking. 展开更多
关键词 Corrugated steel web girder bridges simply supported beam bridges vehicle-bridge coupled vibration BRAKING impact factor
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Lifestyle: an underrated but potentially important influencing factor on semen quality
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作者 Wen-Kang Chen He-De Zou +2 位作者 Han-Fei Liu Bo-Lin Li Jia-You Zhao 《Clinical Research Communications》 2023年第3期16-21,共6页
Lifestyle factors play a crucial role in the influence of semen quality,and they are especially significant in the context of traditional Chinese medicine(TCM)clinical treatment for poor semen quality.TCM theory empha... Lifestyle factors play a crucial role in the influence of semen quality,and they are especially significant in the context of traditional Chinese medicine(TCM)clinical treatment for poor semen quality.TCM theory emphasizes the importance of healthy lifestyle habits for overall well-being.Therefore,it is essential to consider lifestyle factors in the clinical management of TCM and semen quality.Lifestyle can act as a bias factor that affects research quality,making it vital to pay special attention to its impact in clinical trial research on male semen quality.This article aims to improve the quality and design of clinical research on male sperm quality by examining the effects of various lifestyle factors on semen quality,including physical activities,dietary patterns,smoking,alcohol consumption,coffee intake,sleep,and psychological stress.Each lifestyle factor has its own distinct influence on semen quality,and there is a synergistic effect when multiple lifestyle factors are combined.These findings emphasize the need for careful consideration of lifestyle factors and their interactions in the design and implementation of TCM clinical trial research. 展开更多
关键词 lifestyle factors semen quality traditional Chinese medicine clinical trial research synergistic effect
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Epidemiological, Clinical Aspects and Factors Associated with Typical Gastroesophageal Reflux Disease in the General Population of Parakou, Republic of Benin
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作者 Saké Khadidjatou Tamou Sambo Bio Elie +3 位作者 Zinsou Jocelyne Abla Dovonou Comlan Albert Sehonou Jean Kodjoh Nicolas 《Open Journal of Gastroenterology》 CAS 2024年第2期41-58,共18页
Introduction: Gastroesophageal reflux disease (GERD) is a benign and chronic disease that can impair the quality of life. Objective: To study the epidemiological, clinical aspects and factors associated with typical G... Introduction: Gastroesophageal reflux disease (GERD) is a benign and chronic disease that can impair the quality of life. Objective: To study the epidemiological, clinical aspects and factors associated with typical GERD in the general population of Parakou in the Republic of Benin. Methods: This was a descriptive and analytical cross-sectional study with prospective data collection which took place from May 1, 2019 to June 30, 2019. The study population consisted of any subject aged at least 15 years and living in Parakou. Subjects aged at least 15 years, present on the day of the survey and having given their free and informed verbal consent were included. The Short form of QRS®(Reflux-Qual Short form) questionnaire and the “Hospital Anxiety and Depression” score were used to assess the quality of life and anxiety/depression, respectively. The sampling was probabilistic through a 2-stage cluster sampling. The variable of interest was the presence of GERD. Results: Out of 390 subjects surveyed, 28 had symptoms of typical GERD, representing a prevalence of 7.18%. The average age of these subjects was 27.11 ± 7.88 years. Fifteen subjects (53.57%) were male, giving a sex ratio of 1.15. Fourteen (50%) had a secondary level of education, 12 (42.86%) were pupils/students, 18 (64.29%) were single. The monthly income of 22 subjects (78.57%) was lower than the guaranteed interprofessional minimum wage (40,000 FCFA). The average duration of progression of symptoms was 15.89 ± 4.97 months. Symptoms occurred less than twice a week in 22 subjects (78.57%). The clinical manifestations were both diurnal and nocturnal in 12 subjects (42.86%). None of the 28 subjects with GERD had clinical warning signs. Asthma, diabetes, consumption of high fat or spice foods, carbonated drinks, non-steroidal anti-inflammatory drugs, alcoholic beverages and tobacco were statistically associated with the occurrence of GERD. Each of the 28 subjects had at least one associated factor. A significant impair in quality of life was observed in 27 patients (96.43%). Conclusion: Typical GERD is relatively common in the general population of Parakou in the Republic of Benin. It often affects young males. Among the risk factors identified, the most common are carbonated drinks, spicy meals and diabetes. GERD significantly impairs quality of life. Raising awareness about the disease and its associated factors is necessary among the general population. 展开更多
关键词 Gastroesophageal Reflux Disease EPIDEMIOLOGY General Population Associated factors quality of Life Parakou
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Investigation on photonic crystal nanobeam cavity based on mixed diamond–circular holes
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作者 Jingtong Bin Kerui Feng +4 位作者 Shang Ma Ke Liu Yong Cheng Jing Chen Qifa Liu 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第1期63-70,共8页
A photonic crystal nanobeam cavity(M-PCNC)with a structure incorporating a mixture of diamond-shaped and circular air holes is pro-posed.The performance of the cavity is simulated and studied theoretically.Using thefin... A photonic crystal nanobeam cavity(M-PCNC)with a structure incorporating a mixture of diamond-shaped and circular air holes is pro-posed.The performance of the cavity is simulated and studied theoretically.Using thefinite-difference time-domain method,the parameters of the M-PCNC,including cavity thickness and width,lattice constant,and radii and numbers of holes,are optimized,with the quality factor Q and mode volume Vm as performance indicators.Mutual modulation of the lattice constant and hole radius enable the proposed M-PCNC to realize outstanding performance.The optimized cavity possesses a high quality factor Q 1.45105 and an ultra-small mode=×volume Vm 0.01(λ/n)[Zeng et al.,Opt Lett 2023:48;3981–3984]in the telecommunications wavelength range.Light can be progres-=sively squeezed in both the propagation direction and the perpendicular in-plane direction by a series of interlocked anti-slots and slots in the diamond-shaped hole structure.Thereby,the energy can be confined within a small mode volume to achieve an ultra-high Q/Vm ratio. 展开更多
关键词 Photonic crystal nanobeam cavity Mixed diamond–circular holes Slots and anti-slots FDTD simulation quality factor Mode volume
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Analysis of quality factors for Rayleigh channel waves 被引量:5
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作者 杨小慧 曹思远 +2 位作者 李德春 于鹏飞 张浩然 《Applied Geophysics》 SCIE CSCD 2014年第1期107-114,118,共9页
To facilitate investigation of the effect of imperfect elastic dissipation on thepropagation of Rayleigh-type channel waves and use of their quality factors in investigationsof the properties of coal seams, a simple m... To facilitate investigation of the effect of imperfect elastic dissipation on thepropagation of Rayleigh-type channel waves and use of their quality factors in investigationsof the properties of coal seams, a simple method for calculating the quality factor QR isproposed in this paper. Introduction of complex velocities into the dispersion function allowscalculation of the dispersion function of Rayleigh-type channel waves in coal seams. By thecontrol variable method, we analyzed changes in QR with changes in coal seam thickness andP- and S-wave Q-factors within the coal seam and adjacent rock layers. The numerical resultsshow that the trend of the QR curve is consistent with the group velocity curve. The minimumQR value occurs at the Airy phase frequency; the Airy phase frequency decreases as coal seamthickness increases. The value of QR increases with increasing Qs2 (quality factor for S wavein coal seam). We can compensate for the absorption of Rayleigh-type channel waves usingthe computed QR curve. Inversion of the QR curve can also be used to predict the thicknessesand litholoeies of coal seams. 展开更多
关键词 Coal seam RAYLEIGH channel wave DISPERSION curve attenuation quality factor
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Factors influencing quality of bowel preparation for colonoscopy 被引量:13
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作者 Ronald V Romero Sanjiv Mahadeva 《World Journal of Gastrointestinal Endoscopy》 CAS 2013年第2期39-46,共8页
Recent technological advances in colonoscopy have led to improvements in both image enhancement and procedural performance.However,the utility of these technological advancements remain dependent on the quality of bow... Recent technological advances in colonoscopy have led to improvements in both image enhancement and procedural performance.However,the utility of these technological advancements remain dependent on the quality of bowel preparation during colonoscopy.Poor bowel preparation has been shown to be associated with lower quality indicators of colonoscopy performance,such as reduced cecal intubation rates,increased patient discomfort and lower adenoma detection.The most popular bowel preparation regimes currently used are based on either Polyethylene glycol-electrolyte,a non-absorbable solution,or aqueous sodium phosphate,a lowvolume hyperosmotic solution.Statements from various international societies and several reviews have suggested that the efficacy of bowel preparation regimes based on both purgatives are similar,although patients' compliance with these regimes may differ somewhat.Many studies have now shown that factors other than the type of bowel preparation regime used,can influence the quality of bowel preparation among adult patients undergoing colonoscopy.These factors can be broadly categorized as either patient-related or procedure-related.Studies from both Asia and the West have identified patient-related factors such as an increased age,male gender,presence of co-morbidity and socioeconomic status of patients to be associated with poor bowel preparation among adults undergoing routine out-patient colonoscopy.Additionally,procedure-related factors such as adherence to bowel preparation instructions,timing of bowel purgative administration and appointment waiting times for colonoscopy are recognized to influence the quality of colon cleansing.Knowledge of these factors should aid clinicians in modifying bowel preparation regimes accordingly,such that the quality of colonoscopy performance and delivery of service to patients can be optimised. 展开更多
关键词 BOWEL PREPARATION COLONOSCOPY RISK factorS quality
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Factor input structure,environmental policies,and the export quality upgrade:a perspective of heterogeneity 被引量:3
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作者 Jiayue Liu Jing Xie 《Chinese Journal of Population,Resources and Environment》 2018年第1期67-76,共10页
In the analysis of how environmental regulation affects the comparative advantage of trade,existing literature ignores industry's inherent heterogeneity, which draws remarkably different conclusions. In view of th... In the analysis of how environmental regulation affects the comparative advantage of trade,existing literature ignores industry's inherent heterogeneity, which draws remarkably different conclusions. In view of this, the paper analyzed the mechanism of environmental regulation on the export quality of different industries from the perspective of factor input structure heterogeneity. Based on the panel data of China's manufacturing industry, the paper used the system generalized method of moments method to examine the heterogeneity influence of environmental regulation on manufacturing export quality. The study found that, first, environmental regulation affected the export quality upgrade of the manufacturing sector through offset effect and compensation effect, and the direction of the impact would mainly depend on the industry's factor input structure. Second, for industries with larger fixed-asset investment(FAI) ratio in the factor input structure, the current environmental regulation policy was not conducive to the export quality upgrading of the industries. However, there was a significant U-shaped dynamic relationship between them. As environmental regulations became stricter, when regulatory stringency went beyond the inflection point, the policy would promote the upgrading of export quality. But for industries with smaller proportion of FAI, environmental regulation exerted a favorable impact on the export quality upgrade, following a J-shaped marginal growth curve.Third, for industries with different factor input structure, their export quality had been effectively upgraded as expected by factors like human capital investment, independent R&D, technology introduction, and foreign direct investment; but raising per capita capital stock and expanding enterprise size did not produce significant direct impact on export quality upgrade. These conclusions remained robust after using different measurement methods and replacing with other variables. Therefore, this paper suggests that governments should take industry heterogeneity into consideration and formulate differentiated hierarchical environmental policies.Besides, they should strengthen the enforcement of the current environmental regulation policies. By doing so, enterprises are forced to improve their technology and product quality so that they can better cope with rising compliance costs, eliminate backward industries, and resolve excess capacity. In this way, the economic structure would be transformed and upgraded from the supply side. 展开更多
关键词 Environmental regulation export quality factor input structure industry heterogeneity
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Effects of Meteorological Factors on the Yield and Quality of Special Rice in Different Periods after Anthesis 被引量:3
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作者 Ying Xuan Yang Yi +5 位作者 He Liang Shanqing Wei Ligeng Jiang Izhar Ali Saif Ullah Quan Zhao 《Agricultural Sciences》 2019年第4期451-475,共25页
In order to investigate the effect of meteorological factors on the yield and quality of special rice during the filling stage, an experiment was conducted with 10 special rice varieties which were planted in three di... In order to investigate the effect of meteorological factors on the yield and quality of special rice during the filling stage, an experiment was conducted with 10 special rice varieties which were planted in three different regions during spring 2017. The results showed that the quality traits and yields from different regions of the same variety were different, which reached up to a significant level in most varieties. Among the quality traits, the grain chalkiness rate and chalkiness degree were the most sensitive to different climatic factors, and changes were found among them in different regions, while minor variation was found between brown rice rate and white rice rate. The parameters that were severely affected by temperature were gel consistency, gelatinization temperature, brown rice rate and yield during the filling stage. The critically affected factors by heat were brown rice rate, protein content, essential amino acid and amylose content while brown rice rate, chalkiness rate and gelatinization temperature were substantially affected by water factors. Grain yield and quality were closely related to meteorological factors on different stages after heading. Our results revealed that yield and quality of special rice were significantly influenced by meteorological factors during the grain filling stage. 展开更多
关键词 NOODLE RICE FEED RICE METEOROLOGICAL factors quality YIELD
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Changing trends and influencing factors of the quality of life of chemotherapy patients with breast cancer 被引量:1
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作者 Zhong-Ping Ai Xiao-Lan Gao +2 位作者 Jin-Feng Li Jian-Rong Zhou You-Feng Wu 《Chinese Nursing Research》 CAS 2017年第1期18-23,共6页
Objective: To understand the changing trajectory of quality of life(QOL) during the treatment courses of breast cancer patients during chemotherapy and to investigate the factors in each treatment course that affect Q... Objective: To understand the changing trajectory of quality of life(QOL) during the treatment courses of breast cancer patients during chemotherapy and to investigate the factors in each treatment course that affect QOL.Methods: The M.D. Anderson Symptom Inventory Scale, the Hospital Anxiety and Depression Scale(HADS), and the Functional Assessment of Cancer Therapy-Breast(FACT-B) scale were used to perform a survey on 174 breast cancer patients who received the TAC(docetaxel, Adriamycin, and cyclophosphamide) chemotherapy regimen before postoperative chemotherapy and 5-7 days after each chemotherapy course.Results: The QOL scores of the breast cancer patients were the lowest before the postoperative chemotherapy(81.2 ± 19.6) and the highest after the second chemotherapy course(94.5 ± 14.4). After the fourth and fifth chemotherapy courses, the scores were much lower again, with values of 82.7 ± 13.9and 82.6 ± 13.1, respectively. The scores improved again after the sixth chemotherapy course(93.9 ± 18.7). Furthermore, each treatment course had different related symptoms that affected the QOL of the patients.Conclusions: More attention should be paid to the changing trajectory of QOL of patients in all treatment courses and to the influence of treatment-related symptoms on the QOL of patients; moreover, interventions should be adopted by medical care personnel to increase QOL in cancer patients. 展开更多
关键词 Breast cancer CHEMOTHERAPY quality of life Changing trajectory Influencing factor
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Research on quality changes and influencing factors of groundwater in the Guanzhong Basin 被引量:1
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作者 TAO Hong ZHENG Miao-miao +5 位作者 FAN Li-min LI Wen-li DING Jia LI Hui HE Xu-bo TAO Fu-ping 《Journal of Groundwater Science and Engineering》 2017年第3期296-302,共7页
This paper studies the distribution features, the chemical elements beyond standards and the influencing factors of shallow groundwater quality in the Guanzhong Basin through the data monitored in the last twenty year... This paper studies the distribution features, the chemical elements beyond standards and the influencing factors of shallow groundwater quality in the Guanzhong Basin through the data monitored in the last twenty years. The final purpose is to comprehensively evaluate the divisions of groundwater quality in the Guanzhong Basin. Results show that, the groundwater quality is in good shape, and suitable for drinking. Drinking accounts for 16.02% of the total, most of which are distributed in the lubotan of Weibei. Some come from loess plateau of Qian-Liquan County and some are generated by the industrial pollution of Xingping City. Materials exceeding standards include chloride, sulfate, three nitrogen, fluoride, manganese, iron, hexavalent chromium and so on. The main factors influencing the quality of shallow groundwater include groundwater exploitation, natural background value of special components and precipitation, among which the groundwater exploitation poses the greatest impact. The depth of water is positively correlated with the concentration of sulfate, nitrate and total hardness. 展开更多
关键词 Groundwater quality Comprehensive assessment Influencing factor Excessive substance Guanzhong Basin
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Ultrahigh accelerating gradient and quality factor of CEPC 650 MHz superconducting radio-frequency cavity 被引量:1
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作者 Peng Sha Wei-Min Pan +9 位作者 Song Jin Ji-Yuan Zhai Zheng-Hui Mi Bai-Qi Liu Chao Dong Fei-Si He Rui Ge Liang-Rui Sun Shi-Ao Zheng Ling-Xi Ye 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第10期33-40,共8页
Two 650 MHz single-cell superconducting radio-frequency(SRF)cavities used for the Circular Electron Positron Collider(CEPC)were studied to achieve a high accelerating gradient(E_(acc))and high intrinsic quality factor... Two 650 MHz single-cell superconducting radio-frequency(SRF)cavities used for the Circular Electron Positron Collider(CEPC)were studied to achieve a high accelerating gradient(E_(acc))and high intrinsic quality factor(Q_(0)).The 650 MHz single-cell cavities were subjected to a combination of buffered chemical polishing(BCP)and electropolishing(EP),and their E_(acc) exceeded40 MV/m.Such a high E_(acc) may result from the cold EP with more uniform removal.BCP is easy,cheap,and rough,whereas EP is complicated,expensive,and precise Therefore,the combination of BCP and EP investigated in this study is suitable for surface treatments of mass SRF cavities.Medium temperature(mid-T)furnace baking was also conducted,which demonstrated an ultrahigh Q_(0) of 8×10^(10) at 22 MV/m for both cavities,and an extremely low BCS resistance(R_(BCS))of~1.0 nΩwas achieved a2.0 K. 展开更多
关键词 SRF cavity Accelerating gradient quality factor ELECTROPOLISHING Vertical test
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