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Three-Channel Interference Interpretation of Fano Profile
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作者 李波 李天钧 +3 位作者 马子茹 王希源 黄新朝 朱林繁 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第5期30-34,共5页
Fano resonance is a ubiquitous phenomenon, and it is commonly interpreted as a two-channel interference of the discrete and continuous channels. The present work investigates the Fano profile from a perspective of the... Fano resonance is a ubiquitous phenomenon, and it is commonly interpreted as a two-channel interference of the discrete and continuous channels. The present work investigates the Fano profile from a perspective of the temporal evolution of the wave function. By exciting the atom with a δ pulse and calculating the evolution of the wave function, the Fano formula is deduced. The results clearly show that the Fano resonance is of a three-channel interference, which is different from the traditional understanding. The three channels are revealed as the groundcontinuum, ground-discrete-continuum, and a previously unmentioned third channel, i.e., ground-continuumdiscrete-continuum. The present three-channel interpretation can be easily generalized to other physical systems,contributing to a deeper understanding of the Fano profile. 展开更多
关键词 function profile CONTINUUM
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Basis functions for shallow-water temperature profiles based on the internal-wave eigenmodes
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作者 Qianqian Li Shoulian Cao +2 位作者 Yu Luo Kai Zhang Fanlin Yang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第2期56-64,共9页
The shallow-water temperature profile is typically parameterized using a few empirical orthogonal function(EOF)coefficients.However,when the experimental area is poorly known or highly variable,the adaptability of the... The shallow-water temperature profile is typically parameterized using a few empirical orthogonal function(EOF)coefficients.However,when the experimental area is poorly known or highly variable,the adaptability of the EOFs will be significantly reduced.In this study,a new set of basis functions,generated by combining the internal-wave eigenmodes with the average temperature gradient,is developed for characterizing the temperature perturbations.Temperature profiles recorded by a thermistor chain in the South China Sea in 2015 are processed and analyzed.Compared to the EOFs,the new set of basis functions has higher reconstruction accuracy and adaptability;it is also more stable in ocean regions that have internal waves. 展开更多
关键词 temperature profile basis function internal-wave eigenmode EOF sound speed profile
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An Analysis of Stylistic Functions of Chinese Enterprise Profile and Its Translation Strategies
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作者 王雪霜 陈影 《海外英语》 2014年第23期109-111,共3页
Enterprise profile plays an important role in promoting company in the international market, showing its strength, expanding its influence, and advancing their business. At present, the translation of Chinese enterpri... Enterprise profile plays an important role in promoting company in the international market, showing its strength, expanding its influence, and advancing their business. At present, the translation of Chinese enterprise profile is not very good. The problems of inappropriate words, grammatical mistakes, and pragmatic errors have deeply influenced the delivery of correct information of Chinese enterprises. Wrong translation or informal translation not only seriously affects the corporate image, but also damages China's international image. Based on this, this paper focuses on studying stylistic functions of Chinese enterprise profile and its translation strategies. 展开更多
关键词 CHINESE ENTERPRISE profile STYLISTIC functionS TRA
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Investigation of Peak Separation for X-ray Diffraction Profiles of Spinodal Decomposition by a Kind of Optimized Voigt Function 被引量:2
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作者 LiudingWANG JunqiangZHOU +1 位作者 QuanxiCAO ZhaoCHEN 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第4期371-373,共3页
The intensity and position of sidebands (satellites) on both sides of main diffraction peak in a great number of X-ray diffraction profiles of alloys always change with progress of aging. The sidebands position is det... The intensity and position of sidebands (satellites) on both sides of main diffraction peak in a great number of X-ray diffraction profiles of alloys always change with progress of aging. The sidebands position is determined by a newly optimized Voigt function in present investigation. Furthermore, for Cu-4 wt pet Ti alloy aged at 400℃ for 720 min and 1080 min, after introducing the weight factor of above two satellites intensity, the relative error between the fitting curves and X-ray diffraction profiles is less than 0.185%, which is more precise than the previously calculating result. 展开更多
关键词 X-ray diffraction Diffraction profile Peak separation Voigt function
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Profile function properties & optical transition formulae
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作者 张庆礼 孙贵花 +6 位作者 高进云 孙敦陆 罗建乔 刘文鹏 张德明 施朝淑 殷绍唐 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第7期403-407,共5页
Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and... Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and some confusing issues are clarified. 展开更多
关键词 optical transition profile function
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Executive and Non-Executive Functions in Attention Deficit Hyperactivity Disorder of the Inattentive Type (ADHD-I): A Cognitive Profile
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作者 Yongning Song Yuji Hakoda 《Journal of Behavioral and Brain Science》 2014年第1期1-10,共10页
Objective: This study examined the hypothesis that individuals with attention deficit hyperactivity disorder, predominantly inattentive type (ADHD-I), show both executive function (EF) deficits and non-EF deficits. Me... Objective: This study examined the hypothesis that individuals with attention deficit hyperactivity disorder, predominantly inattentive type (ADHD-I), show both executive function (EF) deficits and non-EF deficits. Method: A group with ADHD-I (n = 16) and a paired control group (n = 21) completed a battery of tasks covering the major domains of EF (planning, working memory, flexibility and inhibition) and non-EF (alertness, divided attention, flexibility, sustained attention, visual field and visual scanning). Results: EF impairments in planning, spatial working memory, flexibility, and inhibition as well as non-EF impairments in divided attention, flexibility, sustained attention and visual scanning were observed in the ADHD-I group. Conclusion: Our results do not support the traditional model of ADHD. Given that neither EF nor non-EF tests typically distinguish ADHD-I from ADHD-C, alternative methodologies are required to confirm the validity of ADHD subtypes in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. 展开更多
关键词 ADHD-I EXECUTIVE function Non-Executive function Cognitive profile
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Health Profiles and Functional Independence in Former Cane Cutters from a Biofuel Plant in Bahia
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作者 Jaqueline Silva Veloso Kaliane Pamponet Prazeres Bomfim Mabel Barbosa Esteves 《Occupational Diseases and Environmental Medicine》 2019年第4期124-134,共11页
Introduction: Brazil leads the production of sugarcane and its derived commodities, sugar and ethanol. The fact that it is predominantly manually harvested exposes the workers to a variety of health hazards. Since the... Introduction: Brazil leads the production of sugarcane and its derived commodities, sugar and ethanol. The fact that it is predominantly manually harvested exposes the workers to a variety of health hazards. Since the harvest is a labor activity that exacts from the worker a heavy physical toll, involving the exertion of quick, repetitive movements that intensely overburden both one’s muscles and skeletal frame. Objective: To assess the health profile and functional independence in former workers who operated in a biofuel plant in Bahia. Methods: This is a descriptive, exploration-oriented study conducted with 42 workers formerly employed as cane cutters, both male and female and over 18 years old, all of them living in the town of Amélia Rodrigues (BA). The self-administered Nottingham Health Profile (NHP) was used to measure their quality of life, based on the World Health Organization’s classification of disabilities;the Functional Independence Measure (FIM) metrics was employed to keep track of functional independence. The FIM focuses on two aspects, motile and cognitive, subdivided further into categories designed to assess individual independence in tackling basic activities effectively and satisfactorily. Results: 42 individuals were assessed, most of them men (54.8%), predominantly adults (73.8%) of African descent (61.9%). Evidence, along with the correlation coefficient to analyze the FIM and the NHP, presents a significance level of 0.05 in the categories: Total NHP, Energy Level, Pain and Physical Abilities. Conclusion: This study found that there is harm to the health of former cane cutters as far as their sleep, energy levels and physical abilities are concerned. With these remarks, the authors expect to motivate health surveillance efforts regarding the risks in those work environments and the associated health issues, so that preventive and interventive public health measures can be implemented. 展开更多
关键词 Rural WORKER HEALTH profile functionality
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PROFIBUS PA应用行规(PA-Profile)新版V3.02点评 被引量:4
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作者 惠敦炎 刘丹 《仪器仪表标准化与计量》 2009年第4期39-42,共4页
PROFIBUS PA应用行规是过程自动化仪表设备的标准,始终以市场要求为发展动力,通过不断的修订和增补,以满足过程工业日新月异的和持续增长的要求。最新版PROFIBUS PA行规V3.02于2009年初发布,与前版V3.0和V3.01相比增补了一些极为重要的... PROFIBUS PA应用行规是过程自动化仪表设备的标准,始终以市场要求为发展动力,通过不断的修订和增补,以满足过程工业日新月异的和持续增长的要求。最新版PROFIBUS PA行规V3.02于2009年初发布,与前版V3.0和V3.01相比增补了一些极为重要的新内容,包括参数处理、PROFIsafe、仪表设备版本的上下兼容等,以更加贴近用户和适应市场需求。 展开更多
关键词 PROFIBUSPA行规 浓缩状态和诊断 设备版本识别与兼容 参数处理 PROFISAFE I&M功能
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Toxicity profile of ethanolic extract of Azadirachta indica stem bark in male Wistar rats 被引量:4
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作者 Anofi Omotayo Tom Ashafal Latifat Olubukola Orekoya Musa Toyin Yakubu 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第10期811-817,共7页
Objective:To investigate the loxic implications of ethanolic stem bark extract of Azadirachta indica(A-indica)at 50,100,200 and 300 mg/kg body weight in Wistar rats.Methods:Fifty male rats of Wistar strains were rando... Objective:To investigate the loxic implications of ethanolic stem bark extract of Azadirachta indica(A-indica)at 50,100,200 and 300 mg/kg body weight in Wistar rats.Methods:Fifty male rats of Wistar strains were randomly grouped into five(A-F.)of ten animals each.Animals in Group A(control)were orally administered 1 mL of distilled water on daily basis for 21 days while those in Groups B-E received same volume of the extract corresponding to 50,100,200 and 300mg/kg body weight.Results:The extract did not significantly(P>0.05)alter the levels of albumin,total protein,red blood cells and factors relating to it whereas the white blood cell,platelets,serum triacylglycerol and high-density lipoprotein cholesterol decreased significantly(P<0.05).In contrast,the final body weights,absolute weights of the liver,kidney,lungs and heart as well as their organ-body weight ratios,serum globulins,total and conjugated bilirubin,serum cholesterol,low-density lipoprotein cholesterol and computed atherogenic index increased significantly.The spleen-body weight ratio,alkaline phosphatase,alanine and aspartate transaminases,sodium,potassium,calcium,feed and water intake were altered at specific doses.Conclusions:Overall,the alterations in the biochemical parameters of toxicity have consequential effects on the normal functioning of the organs of the animals.Therefore,the ethanolic extract of A.indica stem bark at the doses of 50,100,200 and 300 mg/kg body weight may not be completely safe as an oral remedy and should be taken with caution if absolutely necessary. 展开更多
关键词 AZADIRACHTA INDICA Feed INTAKE functional indices Haematological parameters LIPID profile MELIACEAE
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Beach Profiles Characteristics Along Giao Thuy and Hai Hau Coasts,Vietnam:A Field Study 被引量:2
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作者 NGUYEN Viet Thanh 郑金海 张弛 《China Ocean Engineering》 SCIE EI 2012年第4期699-712,共14页
Giao Thuy and Hai Hau coasts are located in Nam Dinh province, Vietnam, with a total coastline of 54.42 km in length. The sea-dike system has been seriously damaged and there have been many dike breaches which caused ... Giao Thuy and Hai Hau coasts are located in Nam Dinh province, Vietnam, with a total coastline of 54.42 km in length. The sea-dike system has been seriously damaged and there have been many dike breaches which caused floods and losses. This situation is considered of a general representative for coastal area in the northern part of Vietnam. A variety of studies have shown that the gradient in the longshore sediment transport rate and the offshore fine sediment lost are the main mechanisms causing the beach erosion. This study presents a field investigation of the beach profiles at Giao Thuy and Hai Hau beaches. Three types of empirical functions for the equilibrium beach profile are applied and compared with the observations. Results show that all observed beach profiles can be described by a single function. However, one specific equilibrium profile equation is not sufficient to assess all beach profiles. In Section 1 of Giao Thuy and Section 3 of Hai Thinh beaches, beach profiles are consistent with the logarithmic function, while the exponential function fits well in Section 2. This difference is explained with respect to coastal morphology, sediment characteristics and hydrodynamic conditions which vary in site. An analysis of the validity of the beach profile functions is recommended for the numerical modeling and engineering designs in this area. 展开更多
关键词 beach profile field study power function exponential function logarithmic function
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Value of inflammatory mediator profiles and procalcitonin in predicting postoperative infection in patients with hypertensive cerebral hemorrhage 被引量:12
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作者 Rang-Hua Yin Bin Zhang +2 位作者 Xing-He Zhou Lu-Ping Cao Ming Li 《World Journal of Clinical Cases》 SCIE 2022年第35期12936-12945,共10页
BACKGROUND Hypertensive cerebral hemorrhage(HICH)is a common clinical cerebrovascular disease and one of the most serious complications of hypertension.Early warning of the occurrence of infection during treatment and... BACKGROUND Hypertensive cerebral hemorrhage(HICH)is a common clinical cerebrovascular disease and one of the most serious complications of hypertension.Early warning of the occurrence of infection during treatment and timely anti-infective treatment are of great significance for the early prevention and treatment of postoperative infection in patients with HICH.Changes in the levels of inflammatory mediators,which are closely related to the occurrence and development of postoperative infection,and procalcitonin(PCT),which is a sensitive indicator for diagnosing bacterial infections,are widely used in clinical practice.AIM To explore the application value of inflammatory mediator profiles and PCT in predicting postoperative infection in patients with HICH.METHODS A total of 271 patients who underwent HICH surgery at our hospital between March 2019 and March 2021 were selected and divided into the infection(n=80)and non-infection(n=191)groups according to whether postoperative infection occurred.The postoperative infection status and etiological characteristics of the infective pathogens in the infection group were analyzed.Changes in inflammatory mediator profile indices and PCT levels were compared between the two groups,pre-and postoperatively.RESULTS A total of 109 strains of pathogenic bacteria were detected in the infection group,including 67 strains(61.47%)of gram-negative bacteria,32 strains(29.36%)of gram-positive bacteria,and 10 strains(9.17%)of fungi.The main infection site of the patients in the infection group was the respiratory system(63.75%).Preoperative interleukin(IL)-4,IL-6,IL-10,tumor necrosis factor-α,interferon-γ,and PCT levels were higher in the infection group than in the non-infection group(P<0.05),and there were no significant differences in the IL-2 Levels between the two groups(P>0.05).The inflammatory mediator profile indices and PCT levels were higher in the two groups of patients on the first postoperative day than preoperatively(P<0.05),and were higher than those in the non-infection group(P<0.05).Logistic regression analysis showed that preoperative IL-6 and PCT levels correlated with postoperative infection(P<0.05).Operating characteristic curve analysis results showed that the area under the curve(AUC)values of preoperative IL-6 and PCT levels in predicting postoperative infection in patients with HICH were 0.755 and 0.824,respectively.The AUC value of joint detection was 0.866,which was significantly higher than that of the single index(P<0.05).CONCLUSION Preoperative IL-6 and PCT levels are correlated with postoperative infection in patients with HICH.Their detection is clinically significant for early identification of patients at high risk for postoperative infection. 展开更多
关键词 Hypertensive cerebral hemorrhage Postoperative infection Inflammatory mediator profiles PROCALCITONIN PREDICTION Immune function
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Effect of Tooth Profile Modification on Vibration of Power Split Gear Transmission System 被引量:2
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作者 Jincheng Dong Sanmin Wang +1 位作者 Jiashun Guo He Lin 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2016年第3期61-68,共8页
Based on Newton ' s second law,the bend-torsion-shaft coupling nonlinear dynamic model and equations of power split gear transmission system are established.According to the principle of tooth profile modification... Based on Newton ' s second law,the bend-torsion-shaft coupling nonlinear dynamic model and equations of power split gear transmission system are established.According to the principle of tooth profile modification,the tooth profile modification is considered as time-varying gear backlash function acting along the line of action.Then the dynamic functions are solved by using Runge-Kutta numerical method.After analyzing the effect of tooth profile modification quantity( TPMQ) and relative tooth profile modification length( TPML) to the nonlinear dynamic characteristics of power split gear transmission,the following conclusions are drawn:1 The TPMQ of a certain stage transmission affects the vibration of its own stage more significantly than the other stage,and the coupling effect between two stages can be ignored usually in the modification design;2 If the first stage TPMLs are less than 0.3,the influence of the first stage TPMLs to the first stage transmission vibration is much more greatly than the influence of the second stage TPMLs to the first stage transmission vibration,or else both the first and second stage TPMLs affect the first stage transmission vibration largely.The same is true for the second stage TPMLs,and the cutoff value is 0.2;3 The TPMQ affects the vibration of power split gear transmission system more principally than the TPML,and should be top-priority in the modification design. 展开更多
关键词 power SPLIT GEAR transmission system TOOTH profile MODIFICATION nonlinear dynamic characteristics TIME-VARYING GEAR BACKLASH function
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Monte Carlo Simulations of Density Profiles for Hard-Sphere Chain Fluids Confined Between Surfaces 被引量:2
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作者 王丙强 蔡钧 +1 位作者 刘洪来 胡英 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2001年第2期156-161,共6页
Covering a wide range of bulk densities, density profiles for hard-sphere chain fluids (HSCFs) with chain length of 3,4,8,20,32 and 64 confined between two surfaces were obtained by Monte Carlo simulations using exten... Covering a wide range of bulk densities, density profiles for hard-sphere chain fluids (HSCFs) with chain length of 3,4,8,20,32 and 64 confined between two surfaces were obtained by Monte Carlo simulations using extended continuum configurational-bias (ECCB) method. It is shown that the enrichment of beads near surfaces is happened at high densities due to the bulk packing effect, on the contrary, the depletion is revealed at low densities owing to the configurational entropic contribution. Comparisons with those calculated by density functional theory presented by Cai et al. indicate that the agreement between simulations and predictions is good. Compressibility factors of bulk HSCFs calculated using volume fractions at surfaces were also used to test the reliability of various equations of state of HSCFs by different authors. 展开更多
关键词 molecular simulation Monte Carlo method hard-sphere chain fluid density profile density functional theory compressibility factor
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Inversion Method for Sound Velocity Profile of Eddy in Deep Ocean
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作者 邱晓芳 彭临慧 +1 位作者 王宁 朱建相 《China Ocean Engineering》 SCIE EI 2001年第4期589-596,共8页
The modal wave number tomography approach is used to obtain sound speed profile of water column in deep ocean. The approach consists of estimation of the local modal eigenvalues from complex pressure field and use of ... The modal wave number tomography approach is used to obtain sound speed profile of water column in deep ocean. The approach consists of estimation of the local modal eigenvalues from complex pressure field and use of these data as input to modal perturbative inversion method for obtaining the local sound speed profile. The empirical orthonormal function (EOF) is applied to reduce the parameter search space. The ocean environment used for numerical simulations includes the Munk profile as the unperturbed background speed profile and a weak Gaussian eddy as the sound speed profile perturbation. The results of numerical simulations show the method is capable of monitoring the oceanic interior structure. 展开更多
关键词 MODAL TOMOGRAPHY sound velocity profile inverse empirical orthonormal function
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Investigation on Instantaneous Meshing Stiffness and Profile Modification of Involute Helical Gear
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作者 孟祥生 常山 陈谌闻 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1996年第4期54-58,共5页
An efficient finite element model of involute helical gear is presented. A program based on compliance matrix method is developed for the calculation of instantaneous meshing stiffness, and the relationship between th... An efficient finite element model of involute helical gear is presented. A program based on compliance matrix method is developed for the calculation of instantaneous meshing stiffness, and the relationship between the rate of meshing stiffness and overlap ratio is given. On the basis of stiffness calculation, an optimization program for the optimal design of profile modification is developed according to the principle of internal point punishment function method. 展开更多
关键词 ss: Instantaneous MESHING STIFFNESS profile MODIFICATION compliance matrix METHOD internal point PUNISHMENT function METHOD
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Analytical Solutions and Computer Simulations of the Evolution of Flat Temperature Profiles in Spherical FRRPP Systems
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作者 Gerard T. Caneba Mathkar A. Alharthi 《Journal of Minerals and Materials Characterization and Engineering》 2013年第4期184-191,共8页
The free-radical retrograde-precipitation (FRRPP) process was recently brought into the quantitative areas of work, based on the discovery of possibility of flat temperature profiles in spherical reactive domain syste... The free-radical retrograde-precipitation (FRRPP) process was recently brought into the quantitative areas of work, based on the discovery of possibility of flat temperature profiles in spherical reactive domain systems. With an approximate decoupling analysis of the energy equation from the component-balance equations, these flat temperature profiles were found to be either stable or unstable. Moreover, resulting evolution of the flat profiles has been found to be expressed analytically through the so-called exponential Integral function, which has been shown to be quantitatively inaccurate during the early times of the process. This work tries to resolve this inaccuracy problem, by comparing the exponential integral results with polynomial approximation and numerical results. The result is that for the stable sys-tem, the linearized treatment of the evolution of flat temperature profiles is valid at the early 30% - 40% in the tem-perature axis, while the remainder of the evolution curve is well-represented by the application of the exponential integral function. For the unstable system, the only thing that can be generalized is that both linear and cubic polynomial approximations are reasonably accurate at very small times and temperatures close to initial values. 展开更多
关键词 FLAT Temperature profile FRRPP Polymerization NONISOTHERMAL Reaction SPHERICAL Reactive DOMAINS EXPONENTIAL Integral function
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Patterns of liver profile disturbance in patients with COVID-19
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作者 Hend Ibrahim Shousha Ahmed Ramadan +1 位作者 Rania Lithy Mohamed El-Kassas 《World Journal of Clinical Cases》 SCIE 2022年第7期2063-2071,共9页
Fever and cough are the most common clinical symptoms of coronavirus disease 2019(COVID-19),but complications(such as pneumonia,respiratory distress syndrome,and multiorgan failure)can occur in people with additional ... Fever and cough are the most common clinical symptoms of coronavirus disease 2019(COVID-19),but complications(such as pneumonia,respiratory distress syndrome,and multiorgan failure)can occur in people with additional comorbidities.COVID-19 may be a new cause of liver disease,as liver profile disturbance is one of the most common findings among patients.The molecular mechanism underlying this phenomenon,however,is still unknown.In this paper,we review the most current research on the patterns of change in liver profile among patients with COVID-19,the possible explanation for these findings,and the relation to pre-existing liver disease in these patients. 展开更多
关键词 Liver functions COVID-19 Liver profile Alanine transaminase aspartate transaminase BILIRUBIN
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Rapid environmental assessment in the South China Sea:Improved inversion of sound speed profile using remote sensing data
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作者 Ke Qu Binbin Zou Jianbo Zhou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第7期78-83,共6页
Complex perturbations in the profile and the sparsity of samples often limit the validity of rapid environmental assessment(REA)in the South China Sea(SCS).In this paper,the remote sensing data were used to estimate s... Complex perturbations in the profile and the sparsity of samples often limit the validity of rapid environmental assessment(REA)in the South China Sea(SCS).In this paper,the remote sensing data were used to estimate sound speed profile(SSP)with the self-organizing map(SOM)method in the SCS.First,the consistency of the empirical orthogonal functions was examined by using k-means clustering.The clustering results indicated that SSPs in the SCS have a similar perturbation nature,which means the inverted grid could be expanded to the entire SCS to deal with the problem of sparsity of the samples without statistical improbability.Second,a machine learning method was proposed that took advantage of the topological structure of SOM to significantly improve their accuracy.Validation revealed promising results,with a mean reconstruction error of 1.26 m/s,which is 1.16 m/s smaller than the traditional single empirical orthogonal function regression(sEOF-r)method.By violating the constraints of linear inversion,the topological structure of the SOM method showed a smaller error and better robustness in the SSP estimation.The improvements to enhance the accuracy and robustness of REA in the SCS were offered.These results suggested a potential utilization of REA in the SCS based on satellite data and provided a new approach for SSP estimation derived from sea surface data. 展开更多
关键词 South China Sea sound speed profile empirical orthogonal function self-organizing maps
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Theoretical Model of Diffraction Line Profiles as Combinations of Gaussian and Cauchy Distributions
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作者 Girija Bhushan Mitra 《Journal of Crystallization Process and Technology》 2014年第3期145-155,共11页
Previously we derived equations determining line broadening in ax-ray diffraction profile due to stacking faults. Here, we will consider line broadening due to particle size and strain which are the other factors affe... Previously we derived equations determining line broadening in ax-ray diffraction profile due to stacking faults. Here, we will consider line broadening due to particle size and strain which are the other factors affecting line broadening in a diffraction profile. When line broadening in a diffraction profile is due to particle size and strain, the theoretical model of the sample under study is either a Gaussian or a Cauchy function or a combination of these functions, e.g. Voigt and Pseudovoigt functions. Although the overall nature of these functions can be determined by Mitra’s R(x) test and the Pearson and Hartley x?test, details of a predicted model will be lacking. Development of a mathematical model to predict various parameters before embarking upon the actual experiment would enable correction of significant sources of error prior to calculations. Therefore, in this study, predictors of integral width, Fourier Transform, Second and Fourth Moment and Fourth Cumulant of samples represented by Gauss, Cauchy, Voigt and Pseudovoigt functions have been worked out. An additional parameter, the coefficient of excess, which is the ratio of the Fourth Moment to three times the square of the Second Moment, has been proposed. For a Gaussian profile the coefficient of excess is one, whereas for Cauchy distributions, it is a function of the lattice variable. This parameter can also be used for determining the type of distribution present in aggregates of distorted crystallites. Programs used to define the crystal structure of materials need to take this parameter into consideration. 展开更多
关键词 Line Broadening DIFFRACTION profile THEORETICAL Model GAUSSIAN function Cauchy function Voigt function Pseudovoigt function Fourier Transform Second MOMENT FOURTH MOMENT FOURTH Cumulant
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Research of NO_(2) vertical profiles with look-up table method based on MAX-DOAS
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作者 Yingying Guo Suwen Li +2 位作者 Fusheng Mou Hexiang Qi Qijin Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第1期332-338,共7页
Obtaining the vertical distribution profile of trace gas is of great significance for studying the diffusion procedure of air pollution.In this article,a look-up table method based on multi-axis differential optical a... Obtaining the vertical distribution profile of trace gas is of great significance for studying the diffusion procedure of air pollution.In this article,a look-up table method based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)technology is established for retrieving the tropospheric NO_(2) vertical distribution profiles.This method retrieves the aerosol extinction profiles with minimum cost function.Then,the aerosol extinction profiles and the atmospheric radiation transfer model(RTM)are employed to establish the look-up table for retrieving the NO_(2) vertical column densities(VCDs)and profiles.The measured NO_(2) differential slant column densities(DSCDs)are compared with the NO_(2) DSCDs simulated by the atmospheric RTM,and the NO_(2) VCDs,the weight factor of NO_(2) in the boundary layer,and the boundary layer height are obtained by the minimization process.The look-up table is established to retrieve NO_(2) VCDs based on MAX-DOAS measurements in Huaibei area,and the results are compared with the data from Copernicus Atmospheric Monitoring Service(CAMS)model.It is found that there are nearly consistent and the correlation coefficient R2 is more than 0.86.The results show that this technology provides a more convenient and accurate retrieval method for the stereoscopic monitoring of atmospheric environment. 展开更多
关键词 multi-axis differential optical absorption spectroscopy look-up table method the cost function NO_(2)vertical profile
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