期刊文献+
共找到1,140篇文章
< 1 2 57 >
每页显示 20 50 100
Influence of Anisotropic Permeability and Soret Effect on the Convective Heat and Mass Transfer through a Porous Cavity Saturated by a Non-Newtonian Fluid
1
作者 Dieudonné Kouke Julien Yovogan 《Engineering(科研)》 2023年第12期843-866,共24页
In this work, an analytical study is carried out on double-diffusive natural convection through a horizontal anisotropic porous layer saturated with a non-Newtonian fluid by using the Darcy model with the Boussinesq a... In this work, an analytical study is carried out on double-diffusive natural convection through a horizontal anisotropic porous layer saturated with a non-Newtonian fluid by using the Darcy model with the Boussinesq approximations. The horizontal walls of the system are subject to vertical uniform fluxes of heat and mass, whereas the vertical walls are assumed to be adiabatic and impermeable. The Soret effect is taken into consideration. Based on parallel flow approximation theory, the problem is solved in the limit of a thin layer and documented the effects of the physical parameters describing this investigation. 展开更多
关键词 Soret Number Heat and mass Transfer non-Newtonian Fluid ISOTROPY Ani-sotropy Supercritical Rayleigh Number
下载PDF
Breast non-mass-like lesions on contrast-enhanced ultrasonography: Feature analysis, breast image reporting and data system classification assessment 被引量:19
2
作者 Ping Xu Min Yang +3 位作者 Yong Liu Yan-Ping Li Hong Zhang Guang-Rui Shao 《World Journal of Clinical Cases》 SCIE 2020年第4期700-712,共13页
BACKGROUND Breast non-mass-like lesions(NMLs)account for 9.2%of all breast lesions.The specificity of the ultrasound diagnosis of NMLs is low,and it cannot be objectively classified according to the 5th Edition of the... BACKGROUND Breast non-mass-like lesions(NMLs)account for 9.2%of all breast lesions.The specificity of the ultrasound diagnosis of NMLs is low,and it cannot be objectively classified according to the 5th Edition of the Breast Imaging Reporting and Data System(BI-RADS).Contrast-enhanced ultrasound(CEUS)can help to differentiate and classify breast lesions but there are few studies on NMLs alone.AIM To analyze the features of benign and malignant breast NMLs in grayscale ultrasonography(US),color Doppler flow imaging(CDFI)and CEUS,and to explore the efficacy of the combined diagnosis of NMLs and the effect of CEUS on the BI-RADS classification of NMLs.METHODS A total of 51 breast NMLs verified by pathology were analyzed in our hospital from January 2017 to April 2019.All lesions were examined by US,CDFI and CEUS,and their features from those examinations were analyzed.With pathology as the gold standard,binary logic regression was used to analyze the independent risk factors for malignant breast NMLs,and a regression equation was established to calculate the efficiency of combined diagnosis.Based on the regression equation,the combined diagnostic efficiency of US combined with CEUS(US+CEUS)was determined.The initial BI-RADS-US classification of NMLs was adjusted according to the independent risk factors identified by CEUS,and the diagnostic efficiency of CEUS combined with BI-RADS(CEUS+BI-RADS)was calculated based on the results.ROC curves were drawn to compare the diagnostic values of the three methods,including US,US+CEUS,and CEUS+BI-RADS,for benign and malignant NMLs.RESULTS Microcalcification,enhancement time,enhancement intensity,lesion scope,and peripheral blood vessels were significantly different between benign and malignant NMLs.Among these features,microcalcification,higher enhancement,and lesion scope were identified as independent risk factors for malignant breast NMLs.When US,US+CEUS,and CEUS+BI-RADS were used to identify the benign and malignant breast NMLs,their sensitivity rates were 82.6%,91.3%,and 87.0%,respectively;their specificity rates were 71.4%,89.2%,and 92.9%,respectively;their positive predictive values were 70.4%,87.5%,and 90.9%,respectively;their negative predictive values were 83.3%,92.6%,and 89.7%,respectively;their accuracy rates were 76.5%,90.2%,and 90.2%,respectively;and their corresponding areas under ROC curves were 0.752,0.877 and 0.903,respectively.Z tests showed that the area under the ROC curve of US was statistically smaller than that of US+CEUS and CEUS+BI-RADS,and there was no statistical difference between US+CEUS and CEUS+BI-RADS.CONCLUSION US combined with CEUS can improve diagnostic efficiency for NMLs.The adjustment of the BI-RADS classification according to the features of contrastenhanced US of NMLs enables the diagnostic results to be simple and intuitive,facilitates the management of NMLs,and effectively reduces the incidence of unnecessary biopsy. 展开更多
关键词 Breast tumor Ultrasonography Contrast agents Feature exploration Diagnosis non-mass-like lesions
下载PDF
The kinetic of mass loss of grades A and B of melted TNT by isothermal and non-isothermal gravimetric methods 被引量:1
3
作者 Hamid Reza Pouretedal Sajjad Damiri +1 位作者 Parvaneh Nosrati Ehsan Forati Ghaemi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第2期126-131,共6页
The kintic and activation energy of mass loss of two grades of melted TNT explosive, grade A and grade B, with freezing points of 80.57 and 78.15 ℃, respectively, were studied by isothermal and nonisothermal gravimet... The kintic and activation energy of mass loss of two grades of melted TNT explosive, grade A and grade B, with freezing points of 80.57 and 78.15 ℃, respectively, were studied by isothermal and nonisothermal gravimetric methods. In isothermal method, the mass loss of samples in containers of glass and aluminum was followed in temperatures of 80, 90 and 100 ℃. The kinetic of the mass loss of the samples in the aluminum container was higher than the kinetic of it in the glass container that can be related to the effects of heat transfer and catalytic of aluminm metal. Also, the presence of impurities in grade B was due to increasing of kinetic of mass loss of it versus grade A. The non-isothermal curves were obtained in range of 30-330 ℃ at heating rates of 10,15 and 20 ℃·min^(-1).The TG/DTG data were used for determination of activation energy(E_a) of mass loss of TNT samples upon degradation by using Ozawa, Kissinger, Ozawa-Flynn-Wall(OFW) and Kissinger-Akahira-Sunose(KAS) methods as model free methods. The activation energies of grades of A and B of TNT was obtained 99-120 and 66-70 kJ mol^(-1)respectively. The lower values of activation energy of the degradation reaction of grade B confirm the effect of impurities in the kinetics of mass loss of this grade. 展开更多
关键词 TNT ISOTHERMAL non-ISOTHERMAL KINETIC mass LOSS
下载PDF
Numerical simulations of failure behavior around a circular opening in a non-persistently jointed rock mass under biaxial compression 被引量:6
4
作者 Yang Xuxu Jing Hongwen Chen Kunfu 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第4期729-738,共10页
Pre-existing discontinuities change the mechanical properties of rock masses,and further influence failure behavior around an underground opening.In present study,the failure behavior in both Inner and Outer zones aro... Pre-existing discontinuities change the mechanical properties of rock masses,and further influence failure behavior around an underground opening.In present study,the failure behavior in both Inner and Outer zones around a circular opening in a non-persistently jointed rock mass under biaxial compression was investigated through numerical simulations.First,the micro parameters of the PFC^(3D) model were carefully calibrated using the macro mechanical properties determined in physical experiments implemented on jointed rock models.Then,a parametrical study was undertaken of the effect of stress condition,joint dip angle and joint persistency.Under low initial stress,the confining stress improves the mechanical behavior of the surrounding rock masses;while under high initial stress,the surrounding rock mass failed immediately following excavation.At small dip angles the cracks around the circular opening developed generally outwards in a step-path failure pattern;whereas,at high dip angles the surrounding rock mass failed in an instantaneous intact rock failure pattern.Moreover,the stability of the rock mass around the circular opening deteriorated significantly with increasing joint persistency. 展开更多
关键词 节理岩体 破坏行为 数值模拟 双轴压缩 圆形 洞室围岩 宏观力学性能 岩体稳定性
下载PDF
Non-Noether Conserved Quantity for Relativistic Nonholonomic System with Variable Mass 被引量:1
5
作者 QIAOYong-Fen LIRen-Jie MAYong-Sheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2期197-200,共4页
Using form invariance under special infinitesimal transformations in which time is not variable, the non-Noether conserved quantity of the relativistic nonholonomic system with variable mass is studied. The differenti... Using form invariance under special infinitesimal transformations in which time is not variable, the non-Noether conserved quantity of the relativistic nonholonomic system with variable mass is studied. The differential equations of motion of the system are established. The definition and criterion of the form invariance of the system under infinitesimal transformations are studied. The necessaxy and sufficient condition under which the form invariance is a Lie symmetry is given. The condition under which the form invariance can be led to a non-Noether conserved quantity and the form of the conserved quantity are obtained. Finally, an example is given to illustrate the application of the result. 展开更多
关键词 解析力学 相对论 不守恒系统 变质量 非-Noether储存量
下载PDF
Multi-analysis with mathematic model of 3125 non-thyrogenous masses of the neck
6
作者 Yong Li Ming Gao Yun Niu Liying Zhang Yang Yu Yigong Li Xiaolong Li 《The Chinese-German Journal of Clinical Oncology》 CAS 2008年第6期319-325,共7页
Objective: To systematically analyze and summarize non-thyrogenous masses of the neck (NTMN) by consid-eration of new areas, a large sample size and multiple-aspect analysis. Methods: Our research involved 3125 NTMN c... Objective: To systematically analyze and summarize non-thyrogenous masses of the neck (NTMN) by consid-eration of new areas, a large sample size and multiple-aspect analysis. Methods: Our research involved 3125 NTMN cases. We summarized the proportion of various NTMN and the distribution of the neck diseases based on the new international clas-sification. The clinical traits such as sexual proportion and age, etc, were analyzed along with the unknown primary cervical metastatic carcinomas (UPCMC), and built up a mathematical model based on the data above. Results: There were 68 dif-ferent diseases identified. Among all the NTMN, the percentage of metastatic carcinomas was 63.3%. The neck masses with a focus above the clavicle comprised 62.3% of the metastatic carcinomas whose focuses were clear. Moreover, other results almost supported the "rule of 80%". There was an obvious distribution of traits at every sub level. For example, there were 23 different diseases in level III, of which the most common was lymphoma. UPCMC made up 12.3% of all metastatic carci-nomas. The clinic cases could be analyzed by our model even to form a primary diagnosis which showed a high coincident rate with clinic diagnosis. Conclusion: NTMN are complex and various, with a definite distribution in each neck level. Data relating component character, sex ratio and UPCMC et al to the clinical traits of NTMN will provide vigorous support for clinical applications. The mathematical model could be an efficient method to synthetically analyze complicate data of NTMN. 展开更多
关键词 颈部非甲状腺肿物疾病 多重分析 数学模型 治疗方法
下载PDF
Multi-Analysis of Non-Thyrogenous Masses of the Neck
7
作者 Yong Li Ming Gao Yang Yu Yigong Li Yan Zhang Xiaolong Li 《Chinese Journal of Clinical Oncology》 CSCD 2007年第3期172-178,共7页
OBJECTIVE To systematically analyze and summarize non-thyroge-nous masses of the neck(NTMN)by consideration of new areas,a large sample size and multiple-aspect analysis.METHODS Our research involved 3,125 NTMN cases.... OBJECTIVE To systematically analyze and summarize non-thyroge-nous masses of the neck(NTMN)by consideration of new areas,a large sample size and multiple-aspect analysis.METHODS Our research involved 3,125 NTMN cases.We summarized the proportion of various NTMN and the distribution of the neck diseases based on the new international classification.The clinical traits such as sexual proportion and age,etc,were analyzed along with the unknown pri-mary cervical metastatic carcinomas(UPCMC),multiple nodular NTMN and tubercular lymphadenitis.RESULTS There were 68 different diseases identified.Among all the NTMN,the percentage of metastatic carcinomas was 63.3%.The neck masses with a focus above the clavicle comprised 62.3% of the metastatic carcinomas whose focuses were clear.Moreover,other results almost sup-ported the “rule of 80%”.There was an obvious distribution of traits at every sub level.For example,there were 23 different diseases in level III,of which the most common was lymphoma.UPCMC made up 12.3% of all metastatic carcinomas.Multiple NTMN were composed of lymphoma,metastatic car-cinoma and tubercular lymphadenitis,etc.For tubercular lymphadenitis pa-tients,the patients without tubercular toxic symptoms comprised 77.1% of all tubercular lymphadenitis patients.CONCLUSION NTMN are complex and various,with a definite distribu-tion in each neck level.Data relating the sex ratio,UPCMC,multiple nodular NTMN and tubercular lymphadenitis to the clinical traits of NTMN will provide support for clinical applications. 展开更多
关键词 颈部 非甲状腺肿块 国际分类 肿瘤学
下载PDF
Measuring Herbage Mass by Non-Destructive Methods: A Review 被引量:1
8
作者 J. E. Lopez-Diaz A. I. Roca-Fernaindez Gonzalez-Rodriguez 《Journal of Agricultural Science and Technology(A)》 2011年第3X期303-314,共12页
关键词 非破坏性方法 牧草质量 技术测量 展望 牧场管理 放牧系统 模型校准 牧草产量
下载PDF
Dynamic modeling and simulation for the rigid flexible coupling system with a non-tip mass
9
作者 李崔春 孟秀云 刘藻珍 《Journal of Beijing Institute of Technology》 EI CAS 2015年第4期432-440,共9页
The rigid flexible coupling system with a mass at non-tip position of the flexible beam is studied in this paper. Using the theory about mechanics problems in a non-inertial coordinate sys- tem, the dynamic equations ... The rigid flexible coupling system with a mass at non-tip position of the flexible beam is studied in this paper. Using the theory about mechanics problems in a non-inertial coordinate sys- tem, the dynamic equations of the rigid flexible coupling system with dynamic stiffening are estab- lished. It is clearly elucidated for the first time that, dynamic stiffening is produced by the coupling effect of the centrifugal inertial load distributed on the beam and the transverse vibration deformation of the beam. The modeling approach in this paper successfully solves problems of popular modeling methods nowadays: the derivation process is too complex by using only one dynamic principle; a clearly theoretical mechanism for dynamic stiffening can' t be offered. First, the mass at non-tip po- sition is incorporated into the continuous dynamic equations of the system by use of the Dirac lunch tion and the Heaviside function. Then, based on the conclusions of orthogonalization about the nor- mal constrained modes, the finite dimensional state space equations suitable for controller design are obtained. The numerical simulation results show that: dynamic stiffening is included in the first-or- der model established in this paper, which indicates the dynamic responses of the rigid flexible cou- pling system with large overall motion accurately. The results also show that the mass has a soften- ing effect on the dynamic behavior of the flexible beam, and the effect would be more obvious when the mass has a larger mass, or lies closer to the tip of the beam. 展开更多
关键词 non-inertial coordinate system rigid flexible coupling dynamic stiffening mass at non-tip position constrained mode
下载PDF
Kinetic Mass Transfer Between Non-aqueous Phase Liquid and Gas During Soil Vapor Extraction 被引量:1
10
作者 李鑫钢 黄国强 沈铁孟 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第5期610-613,共4页
The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization ... The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization of three single-component NAPLs in a sandy soil, constant initial lumped mass transfer coefficient (λgN,0) canbe obtained if the relative saturation (ξ) between NAPL phase and gas phase is higher than a critical value (ξc), andthe lumped mass transfer coefficient decreases with ξ when ξ<ξc. It is also shown that the lumped mass transfercoefficient can be increased by blending porous micro-particles into the sandy soil because of the increasing of theinterfacial area. 展开更多
关键词 土壤气相抽提 非水相液体 气相 传质动力学 分离 土壤矫正
下载PDF
Form Invariance and Conserved Quantity for Non-holonomic Systems with Variable Mass and Unilateral Constraints
11
作者 WANG Jing LI Yuan-Cheng HOU Qi-Bao XIA Li-Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期213-216,共4页
纸学习形式不变性和保存数量把 Mei 称为的 non-Noethcr 的一种类型为有可变集体、单方的限制的 non-holonomic 系统的保存数量。Acoording 到在无穷小的转变下面的运动的微分方程的形式的不变性,这篇论文与可变集体、单方的限制为 non... 纸学习形式不变性和保存数量把 Mei 称为的 non-Noethcr 的一种类型为有可变集体、单方的限制的 non-holonomic 系统的保存数量。Acoording 到在无穷小的转变下面的运动的微分方程的形式的不变性,这篇论文与可变集体、单方的限制为 non-holonomic 系统给形式不变性的定义和标准。形式不变性能在下面导致 Mei 保存数量和保存数量 ared 的形式的条件引出了。一个例子被给说明结果的申请。 展开更多
关键词 非完整系统 形状不变性 守恒量 可变质量 单向约束
下载PDF
MASS TRANSFER AND HYDRODYNAMICS IN AN AIRLIFT REACTOR WITH VISCOUS NON-NEWTONIAN FLUID
12
作者 李国庆 杨守志 +1 位作者 蔡昭铃 陈家镛 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1995年第1期26-34,共9页
In an internal loop airlift reactor of 55L working volume,the gas-liquid volumetric oxygenmass transfer coefficient k_Lα,gas holdup ε_G and liquid circulation time t_c were measured with the sol-ution of carboxymeth... In an internal loop airlift reactor of 55L working volume,the gas-liquid volumetric oxygenmass transfer coefficient k_Lα,gas holdup ε_G and liquid circulation time t_c were measured with the sol-ution of carboxymethyl cellulose(CMC)to simulate the performance of a reactor with highly viscousbroth.Electric conductivity and oxygen probes were used to measure the local gas holdup,liquidcirculation time and oxygen mass transfer coefficient in the individual sections of the reactor(riser,downcomer and the gas-liquid separating section at the top of the reactor)and the total reactor,respectively.The values of k_Lα for the riser,downcomer and separation sections of the reactor were alsoestimated and compared with that for the total reactor.The results show that,both k_Lα and ε_G in-crease but t_c decreases with increasing gas velocity.Correlations and comparisons with works reportedin the literature are also presented.Data show that the methods developed for k_Lα measurements inthe individual section 展开更多
关键词 oxygen mass transfer AIRLIFT reactor non-Newtonian FLUID high-viscous FLUID
下载PDF
非肿块型DCIS影像学特点与临床病理特征及分子分型的相关性分析
13
作者 刘芳 周梦红 +3 位作者 王海娟 袁博 欧晓霞 李莉 《河北医学》 2024年第1期55-60,共6页
目的:探讨非肿块型乳腺导管内原位癌(DCIS)影像学特点,并分析影像学特点与临床病理特征及分子分型关系。方法:选取2020年6月至2021年6月在我院接受手术治疗的100例非肿块型DCIS患者作为研究对象,进行超声影像分分型,分别为Ⅰ型31例,Ⅱ... 目的:探讨非肿块型乳腺导管内原位癌(DCIS)影像学特点,并分析影像学特点与临床病理特征及分子分型关系。方法:选取2020年6月至2021年6月在我院接受手术治疗的100例非肿块型DCIS患者作为研究对象,进行超声影像分分型,分别为Ⅰ型31例,Ⅱ型15例、Ⅲ型43例及Ⅳ型11例。免疫组化检测病理组织雌激素受体(ER)、孕激素受体(PR)、人类表皮生长因子受体2(HER2)及Ki-67阳性表达;按照St.Gallen标准对患者进行Luminal A型及Luminal B型分子分型。结果:Ⅰ型:导管出现增粗,行走迂曲且管腔内出现低回声;Ⅱ型:乳腺内呈现片状的低回声区域,边界模糊;Ⅲ型:乳腺内呈现片状的低回声区域,可见分布不匀的点状强回声;Ⅳ型:乳腺内腺体及导管分布混乱,结构扭曲;Ⅰ型、Ⅱ型、Ⅲ型及Ⅳ型非肿块型DCIS患者临床病理资料年龄、肿瘤直径、月经状态、病灶部分、临床症状均无统计学差异(P>0.05),随着超声分型级别的升高细胞核分级也随之升高(P<0.05);Ⅰ型、Ⅱ型患者HER2阳性表达差异无统计学意义(P>0.05),与Ⅰ型相比,Ⅲ型及Ⅳ型的HER2阳性表达升高(P<0.05);与Ⅱ型相比,Ⅲ型的HER2阳性表达升高,但与Ⅳ型差异无统计学意义(P>0.05),Ⅲ型与Ⅳ型的HER2阳性表达组间比较差异无统计学意义(P>0.05);与Ⅰ型相比,Ⅲ型患者Luminal A型、Luminal B型分型分布升高(P<0.05),与Ⅰ型相比,Ⅳ型患者Luminal B型分型分布升高(P<0.05),Luminal A型差异无统计学意义(P>0.05)。结论:非肿块型DCIS患者超声主要为钙化型,认为结构紊乱型患者细胞核分级较高,且HER2阳性表达较多,Luminal A型占比降低,Luminal B型占比升高。 展开更多
关键词 非肿块型乳腺导管内原位癌 超声 分级 临床病理
下载PDF
多模态超声在乳腺非肿块型病变鉴别诊断中的应用价值探析
14
作者 李春雨 王艳 +1 位作者 宋文卿 陈艳丽 《智慧健康》 2024年第14期7-10,共4页
目的 探析多模态超声在乳腺非肿块型病变鉴别诊断中的应用价值。方法 选择2022年3月—2023年3月本院收治的94例乳腺非肿块型病变患者为研究对象,对其进行常规超声、超声血流成像、超声弹性成像检查,以病理检查结果作为金标准,分析多模... 目的 探析多模态超声在乳腺非肿块型病变鉴别诊断中的应用价值。方法 选择2022年3月—2023年3月本院收治的94例乳腺非肿块型病变患者为研究对象,对其进行常规超声、超声血流成像、超声弹性成像检查,以病理检查结果作为金标准,分析多模态超声(三者联合)在乳腺非肿块型病变鉴别诊断中的应用价值。结果 94例乳腺非肿块型病变患者经病理检查,其中41例确诊为乳腺癌,53例确诊为良性乳腺病变。常规超声、超声血流成像、超声弹性成像及多模态超声鉴别诊断乳腺非肿块型病变与病理检查的一致性kappa值分别为0.411、0.617、0.742、0.913。多模态超声检查鉴别诊断乳腺非肿块型病变的灵敏度为95.12%(39/41)、特异度为96.23%(51/53)、准确度为95.74%(90/94)、阳性预测值为95.12%(39/41)、阴性预测值为96.23%(51/53),高于单独的常规超声、超声血流成像、超声弹性成像的鉴别诊断结果,差异显著,具有统计学意义(P<0.05)。结论 多模态超声在乳腺非肿块型病变鉴别诊断中的应用价值较高,与病理结果的一致性较高,可提升诊断准确性。 展开更多
关键词 乳腺非肿块型病变 多模态超声 超声血流成像 剪切波超声弹性成像
下载PDF
Heat and Mass Transfers in a Two-Phase Stratified Turbulent Fluid Flow in a Geothermal Pipe with Chemical Reaction
15
作者 Eric M. Nyariki Mathew N. Kinyanjui Jeconia O. Abonyo 《Journal of Applied Mathematics and Physics》 2023年第2期484-513,共30页
This research focused on the study of heat and mass transfers in a two-phase stratified turbulent fluid flow in a geothermal pipe with chemical reaction. The derived non-linear partial differential equations governing... This research focused on the study of heat and mass transfers in a two-phase stratified turbulent fluid flow in a geothermal pipe with chemical reaction. The derived non-linear partial differential equations governing the flow were solved using the Finite Difference Method. The effects of various physical parameters on the concentration, skin friction, heat, and mass transfers have been determined. Analysis of the results obtained indicated that the coefficient of skin friction decreased with an increase in Reynolds number and solutal Grasholf number, the rate of heat transfer increased with an increase in Eckert number, Prandtl number, and angle of inclination, and the rate of mass transfer increased with increase in Reynolds number, Chemical reaction parameter and angle of inclination. The findings would be useful to engineers in designing and maintaining geothermal pipelines more effectively. 展开更多
关键词 TWO-PHASE Turbulence non-Newtonian INCLINATION Heat Transfer mass Transfer STRATIFIED
下载PDF
复合露酒的非挥发性成分鉴定及抗疲劳效应
16
作者 陈颖 朱禹哲 +4 位作者 余美丽 刘方美 李存玉 郑云枫 彭国平 《中国酿造》 CAS 北大核心 2024年第8期86-92,共7页
该研究采用高效液相色谱-四级杆飞行时间串联质谱联用(HPLC-Q-TOF-MS/MS)法对复合露酒(38%vol)中的非挥发性化合物进行检测,并将复合露酒灌胃至小鼠22 d,考察其对小鼠负重游泳的影响,评价其抗疲劳的保健作用。结果表明,从复合露酒(0.225... 该研究采用高效液相色谱-四级杆飞行时间串联质谱联用(HPLC-Q-TOF-MS/MS)法对复合露酒(38%vol)中的非挥发性化合物进行检测,并将复合露酒灌胃至小鼠22 d,考察其对小鼠负重游泳的影响,评价其抗疲劳的保健作用。结果表明,从复合露酒(0.2257 g生药/mL)中共鉴定出52种非挥发性物质,包括皂苷类24种、黄酮类6种、核苷类4种、氨基酸类4种、生物碱类3种、其他11种。与模型组相比,低、中、高剂量组小鼠体质量减少量均极显著减少(P<0.01);中、高剂量组小鼠负重游泳时间均极显著延长(P<0.01);低、中剂量组小鼠血尿素氮(BUN)含量显著增加(P<0.01,P<0.05);低、中、高剂量组小鼠乳酸脱氢酶(LDH)活力、肝糖原(LG)含量显著增加(P<0.01,P<0.05),说明该款复合露酒非挥发性成分丰富,可增强身体对负荷的适应性,具有明显的抗疲劳效果,对功能性食品开发提供一定的基础。 展开更多
关键词 复合露酒 高效液相色谱-四级杆飞行时间串联质谱 非挥发性成分 抗疲劳
下载PDF
THE EQUATION OF MOTION FOR THE SYSTEM OF THE VARIABLE MASS IN THE NON-LINEAR NON-HOLONOMIC SPACE
17
作者 邱荣 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1996年第4期379-386,共8页
The dot product of bases vectors on the super-surface of constraints of the nonlinear non-holonomic space and Mesherskii equations may act as the equations of fundamental dynamics of mechanical system for the variable... The dot product of bases vectors on the super-surface of constraints of the nonlinear non-holonomic space and Mesherskii equations may act as the equations of fundamental dynamics of mechanical system for the variable mass.These are very simple and convenient for computation.From these known equations,the equations of Chaplygin,Nielson,Appell,Mac-Millan et al.are deriv d;it is unnecessary to introduce the definition if Appell-Chetaev or Niu Qinping for the virtual displacement.These are compatible with the D'Alembert-Lagrange's principle. 展开更多
关键词 the non-linear non-holonomic constraints the system of the variable mass dot product.bases vectors on supersurface of constraints Misherskii equation
下载PDF
小车运行状态下岸桥结构动力响应分析
18
作者 胡雄 董凯 +2 位作者 郑培 孙志伟 穆森 《振动工程学报》 EI CSCD 北大核心 2024年第7期1200-1210,共11页
本文对在役岸桥整机金属结构的动力学响应机理进行分析。基于Euler-Bernoulli梁理论建立起重机单梁结构数值模型,分析不同工况对梁结构动力响应的影响,并分析动力学方程中“离心加速度项”对岸桥的动力学响应的影响。利用一岸桥结构数... 本文对在役岸桥整机金属结构的动力学响应机理进行分析。基于Euler-Bernoulli梁理论建立起重机单梁结构数值模型,分析不同工况对梁结构动力响应的影响,并分析动力学方程中“离心加速度项”对岸桥的动力学响应的影响。利用一岸桥结构数据建立包含结构重要分析部位如铰点、轨道梁等结构的几何特征的整机精细化数值模型。以简化质量点模拟小车,将质量与板壳单元接触,实现小车与大梁的相互作用,并应用于岸桥结构动力学分析中,考虑轨道梁非中心受力,计算得到大梁铰点的加速度响应,与实测信号结果基本一致。经计算分析发现,岸桥大梁铰点处测点的加速度实测信号频谱和计算信号频谱均表明小车运行对岸桥结构的主要影响为经过轨道接头时产生的高频冲击。同时,岸桥模型大梁上10个测点及小车的位移结果表明,当小车带额定载荷以额定速度匀速运行时,岸桥前大梁前端产生垂向拟静态位移,位移频谱表明小车主要受到垂向强迫振动。 展开更多
关键词 岸边集装箱起重机 小车运行 质量-板壳接触法 非中心受力 动力响应
下载PDF
体重指数对Ⅲ/Ⅳ期非小细胞肺癌患者冷冻消融术后生存期的影响
19
作者 冯瑞 郭鹏德 +1 位作者 李胜鳌 胡凯文 《中国CT和MRI杂志》 2024年第2期67-69,共3页
目的探讨体重指数(BMI)与接受冷冻消融治疗的Ⅲ/Ⅳ期非小细胞肺癌(NSCLC)患者的生存期关系。方法回顾性分析49例接受CT引导下冷冻消融治疗的Ⅲ/Ⅳ期NSCLC患者的临床资料。对BMI与消融术后生存期(COS)进行了相关性分析。结果49例患者中,... 目的探讨体重指数(BMI)与接受冷冻消融治疗的Ⅲ/Ⅳ期非小细胞肺癌(NSCLC)患者的生存期关系。方法回顾性分析49例接受CT引导下冷冻消融治疗的Ⅲ/Ⅳ期NSCLC患者的临床资料。对BMI与消融术后生存期(COS)进行了相关性分析。结果49例患者中,体重不足者3例,正常体重者33例,超重者13例,肥胖者0例。体重不足组、正常体重组、超重组平均COS分别为11.00月、10.79月,17.08月。LSD法两两比较,正常体重组与超重组COS差异有统计学意义,P=0.013<0.05。Spearman相关分析示,分期(r=-0.355,P=0.015<0.05)、BMI(r=0.399,P=0.006<0.05)与患者消融后生存期有相关关系;控制分期后行偏相关分析,BMI仍与COS存在相关(r=0.327,P=0.028<0.05)。结论BMI与冷冻消融治疗Ⅲ/Ⅳ期NSCLC患者的生存期独立相关,高BMI的患者COS更长。 展开更多
关键词 非小细胞肺癌 体重指数 冷冻消融术 计算机断层扫描 总生存期
下载PDF
基于DCE-MRI影像组学模型对乳腺NME病变诊断价值的研究
20
作者 李珍 刘磊 +1 位作者 仲海 王翠艳 《医学影像学杂志》 2024年第2期46-51,共6页
目的 探讨结合机器学习早期动态增强磁共振成像(DCE-MRI)的影像组学模型在鉴别良恶性乳腺非肿块强化(NME)病变中的价值。方法 选取行乳腺DCE-MRI检查并获得病理结果的NME病变患者242例,分为训练集163例、测试集55例,外部验证集24例。基... 目的 探讨结合机器学习早期动态增强磁共振成像(DCE-MRI)的影像组学模型在鉴别良恶性乳腺非肿块强化(NME)病变中的价值。方法 选取行乳腺DCE-MRI检查并获得病理结果的NME病变患者242例,分为训练集163例、测试集55例,外部验证集24例。基于早期DCE-MRI序列的特征选择,采用支持向量机(SVM)建立组学预测模型;由2位放射科医师独立评估MRI特征,建立传统诊断模型,预测病灶的良恶性;运用测试集和外部验证集进行测试和外部验证。采用受试者工作特征(ROC)曲线评价组学模型与放射医师的诊断效能。结果 影像组学模型鉴别乳腺NME病变良恶性达到了与高年资放射医师[曲线下面积(AUC)=0.82, 95%CI 0.66, 0.89]相当的诊断水平[(AUC=0.82, 95%CI 0.67, 0.90);P=0.30],均优于低年资放射医师的评估结果(Z=2.63,P=0.01;Z=2.41,P=0.02),同时利用外部验证集进一步验证该模型的预测效能。结论 基于早期DCE-MRI组学模型可以有效地鉴别NME病变的良恶性,与高年资放射医师诊断水平相当,并优于低年资医师诊断水平,可以辅助低年资医师做出更佳诊断。 展开更多
关键词 影像组学 磁共振成像 乳腺非肿块强化病变
下载PDF
上一页 1 2 57 下一页 到第
使用帮助 返回顶部