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Effects of foundation rocking and uplifting on displacement amplification factor 被引量:4
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作者 Mohammad Khanmohammadi Vahid Mohsenzadeh 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第3期511-525,共15页
Prediction of displacement demand to assess seismic performance of structures is a necessary step where nonlinear static procedures are followed.While such predictions have been well established in literature for fixe... Prediction of displacement demand to assess seismic performance of structures is a necessary step where nonlinear static procedures are followed.While such predictions have been well established in literature for fixed-base structures,fewer bodies of researches have been carried out on the effect of rocking and uplifting of shallow foundations supported by soil,on such prediction.This paper aimed to investigate the effect of soil structure interaction on displacement amplification factor C1 using the beam on nonlinear Winkler foundation concept.A practical range of natural period,force reduction factors,and wide range of anticipated behavior from rocking,uplifting and hinging are considered and using thousands nonlinear time history analysis,displacement amplification factors are evaluated.The results indicate that the suggested equations in current rehabilitation documents underestimate displacement demands in the presence of foundation rocking and uplift.Finally,using regression analyses,new equations are proposed to estimate mean values of C1. 展开更多
关键词 soil-structure interaction rocking and uplifting foundations displacement amplification factor
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Dynamic amplification factors for a system with multiple-degrees-of-freedom 被引量:4
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作者 Zhang Chao Hao Hong +1 位作者 Bi Kaiming Yan Xueyuan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2020年第2期363-375,共13页
It is well-known that the responses of a structure are different when subjected to a static load or a sudden step load.The dynamic amplification factor(DAF),which is defined as the ratio of the amplitude of the vibrat... It is well-known that the responses of a structure are different when subjected to a static load or a sudden step load.The dynamic amplification factor(DAF),which is defined as the ratio of the amplitude of the vibratory response to the static response,is normally used to depict the dynamic effect.For a single-degree-of-freedom system(SDOF)subjected to a sudden dynamic load,the maximum value of DAF is 2.Many design guidelines therefore use 2 as an upper bound to consider the dynamic effect.For a civil engineering structure,which is normally a multiple-degrees-of-freedom(MDOF)system,the DAF may exceed 2 in certain circumstances.The adoption of 2 as the upper bond as suggested by the design guidelines therefore may lead to unsafe structural design.Very limited studies systematically investigate the DAF of a MDOF sysCorrespondence to:Bi Kaiming,Centre for Infrastructure Monitoring and Protection,School of Civil and Mechanical Engineering,Curtin University,Kent Street,Bentley WA 6102,Australia Tel:(+61)892665139 E-mail:kaiming.bi@curtin.edu.autem.This study theoretically investigates the DAF of a MDOF system when it is subjected to a step load based on the fundamental theory of structural dynamics.The condition on which the DAF may exceed 2 is defined.Two numerical examples and one experimental study of a cable-stayed bridge subjected to sudden cable loss are presented to illustrate the problem. 展开更多
关键词 dynamic amplification factors(DAF) multiple-degrees-of-freedom(MDOF) step load
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Deflection amplification factor for estimating seismic lateral deformations of RC frames 被引量:2
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作者 Maryam Samimifar Asghar Vatani Oskouei Fayaz Rahimzadeh Rofooei 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2015年第2期373-384,共12页
Different values have been assigned to the ratio of the defl ection amplifi cation factor(Cd) to the response modifi cation factor(R) for a specifi ed force-resisting system in the seismic design provisions while the ... Different values have been assigned to the ratio of the defl ection amplifi cation factor(Cd) to the response modifi cation factor(R) for a specifi ed force-resisting system in the seismic design provisions while the same application is defi ned for it. An analytical study of the seismic responses of several reinforced concrete frames subjected to a suite of earthquake records performed in this research indicate that the stories’ overstrength and stiffness distribution along the structural height can affect local defl ections more than global ones. Therefore, the Cd/R ratio is calculated based on the ratio of both maximum inelastic to maximum elastic displacements and interstory drifts. Due to damage concentration in some specifi c stories, the defl ection amplifi cation factor calculated based on inelastic interstory drifts was larger than that of the inelastic displacements. Consequently, a minimum value of 1.0 is recommended for the Cd/R ratio in order to estimate maximum inelastic drifts. The ratio of inelastic to elastic displacement was generally found to increase slightly along the structural height for the studied RC models. In addition, it was detected that the story damage indices of the studied RC frames decrease when the inverted value of inelastic interstory drift ratios are increased through a(negative) power form. 展开更多
关键词 deflection amplification factor nonlinear dynamic
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Modified Sadowski formula-based model for the slope shape amplification effect under multistage slope blasting vibration
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作者 Xiaogang Wu Mingyang Wang +2 位作者 Hao Lu Yongjun Zhang Wen Nie 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第5期631-641,共11页
Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainl... Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainly focuses on blast center distance but neglects the amplification effect of blasting vibration waves by terraced terrain,from which the calculated blasting vibration velocities are smaller than the actual values,affecting the safety of the project.To address this issue,our model introduces the influences of slope and time into Sadowski formula to measure safety through blast vibration displacement.In the northern section of the open-pit quartz mine in Jinchang City,Gansu Province,China,the data of a continuous blasting slope project are referred to.Our findings reveal a noticeable vibration amplification effect during blasting when a multi-stage slope platform undergoes a sudden cross-sectional change near the upper overhanging surface.The amplification vibration coefficient increases with height,while vibration waves within rocks decrease from bottom to top.Conversely,platforms without distinct crosssectional changes exhibit no pronounced amplification during blasting.In addition,the vibration intensity decreases with distance as the rock height difference change propagates.The results obtained by the proposed blast vibration displacement equation incorporating slope shape influence closely agree with real-world scenarios.According to Pearson correlation coefficient(PPMCC)analysis,the average accuracy rate of our model is 88.84%,which exceeds the conventional Sadowski formula(46.92%). 展开更多
关键词 Multistage slope Slope shape influence factor Continuous blasting Sadowski formula amplification effect
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Amplification of chromosome 21q22.3 harboring trefoil factor family genes in liver fluke related cholangiocarcinoma is associated with poor prognosis 被引量:3
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作者 Kanuengnuch Muenphon Temduang Limpaiboon +3 位作者 Patcharee Jearanaikoon Chawalit Pairojkul Banchob Sripa Vajarabhongsa Bhudhisawasdi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第26期4143-4148,共6页
AIM: To determine allelic imbalance on chromosomal region 21q22-qter including trefoil factor family genes (TFF) in cholangiocarcinoma (CCA) patients and analyze the correlation between allelic imbalances and cli... AIM: To determine allelic imbalance on chromosomal region 21q22-qter including trefoil factor family genes (TFF) in cholangiocarcinoma (CCA) patients and analyze the correlation between allelic imbalances and clinicopathological parameters. METHODS: Quantitative PCR amplification was performed on four microsatellite markers and trefoil factor family genes (TFF1, TFF2, and TFF3) using a standard curve and SYBR Green I dye method. The relative copy number was determined by DNA copy number of tested locus to reference locus. The relative copy number was interpreted as deletion or amplification by comparison with normal reference range. Associations between allelic imbalance and clinicopathological parameters of CCA patients were evaluated by χ^2-tests. Kaplan-Meier method was used to analyze survival. RESULTS: The frequencies of amplification at D21S1890, D21S1893, and TFF3 were 32.5%, 30.0%, and 28.7%, respectively. Patients who had amplification at regions covering D21S1893, D21S1890, and TFF showed poor prognosis, whereas patients who had deletion showed favorable prognosis (mean: 51.7 wk vs 124.82 wk, P = 0.012). Multivariate Cox regression analysis revealed that amplification of D21S1893, D21S1890 and TFF, blood vessel invasion, and staging were associated with poor prognosis. CONCLUSION: D21S1893-D21S1890 region may harbor candidate genes especially TFF and serine protease family, which might be involved in tumor invasion and metastasis contributing to poor survival. The amplification in this region may be used as a prognostic marker in the treatment of CCA patients. 展开更多
关键词 CHOLANGIOCARCINOMA amplification on chromosome 21 Trefoil factor family Quantitative PCR Liver fluke
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Deep learning approaches to recover the plasma current density profile from the safety factor based on Grad–Shafranov solutions across multiple tokamaks
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作者 张瀚予 周利娜 +6 位作者 刘钺强 郝广周 王硕 杨旭 苗雨田 段萍 陈龙 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期17-28,共12页
Many magnetohydrodynamic stability analyses require generation of a set of equilibria with a fixed safety factor q-profile while varying other plasma parameters.A neural network(NN)-based approach is investigated that... Many magnetohydrodynamic stability analyses require generation of a set of equilibria with a fixed safety factor q-profile while varying other plasma parameters.A neural network(NN)-based approach is investigated that facilitates such a process.Both multilayer perceptron(MLP)-based NN and convolutional neural network(CNN)models are trained to map the q-profile to the plasma current density J-profile,and vice versa,while satisfying the Grad–Shafranov radial force balance constraint.When the initial target models are trained,using a database of semianalytically constructed numerical equilibria,an initial CNN with one convolutional layer is found to perform better than an initial MLP model.In particular,a trained initial CNN model can also predict the q-or J-profile for experimental tokamak equilibria.The performance of both initial target models is further improved by fine-tuning the training database,i.e.by adding realistic experimental equilibria with Gaussian noise.The fine-tuned target models,referred to as fine-tuned MLP and fine-tuned CNN,well reproduce the target q-or J-profile across multiple tokamak devices.As an important application,these NN-based equilibrium profile convertors can be utilized to provide a good initial guess for iterative equilibrium solvers,where the desired input quantity is the safety factor instead of the plasma current density. 展开更多
关键词 plasma equilibrium deep learning safety factor profile current density profile TOKAMAK
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Assessment of seismic amplification factor of excavation with support system 被引量:3
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作者 Hamidreza Tavakoli Saman Soleimani Kutanaei Seyed Hossein Hosseini 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2019年第3期555-566,共12页
Retaining walls have been used in many construction projects such as for road and inclined surfaces protection. The damage caused by an earthquake depends on the fundamental frequency, amplitude and the duration of th... Retaining walls have been used in many construction projects such as for road and inclined surfaces protection. The damage caused by an earthquake depends on the fundamental frequency, amplitude and the duration of the seismic motion. These parameters strongly depend on the seismic properties of the layers that are near the surface. In the study of retaining walls, in addition to the infl uence of soil, the infl uence of topography is also important. In the present study, site response analysis is performed by using fi nite element software PLAXIS to obtain the eff ect of various factors such as embedded length of the sheet pile, underground water table, length and angle of the nail, shear wave velocity of soil on site eff ect and dynamic response. Moreover, for better understanding of the eff ect of the above parameters, the stability analysis was performed by using shear reduction method. The results show that an increase in the embedded length of the sheet pile and the length of nailing causes an increase in the amplifi cation factor. Moreover, for shear-wave velocity in the range of 200- 600 m/s, the amplifi cation factor increases with increase of the shear-wave velocity due to the decrease of nonlinear behavior. 展开更多
关键词 amplifi CATION factor safety factor shear wave velocity NAILING sheet PILE
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Determination of the Amplification Factor for 2-Hydroxy-ethylperoxy Radicals in PERCA
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作者 Bin QI Yan MA +1 位作者 Xiao Qian LI Xiao Yan TANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第7期957-960,共4页
A new method is proposed to determine the amplification factor for 2-hydroxy ethylperoxy radicals (HOC2H4O2·) in chemical amplifier. The radical source comes from the reaction of excess ethene with HO· rad... A new method is proposed to determine the amplification factor for 2-hydroxy ethylperoxy radicals (HOC2H4O2·) in chemical amplifier. The radical source comes from the reaction of excess ethene with HO· radicals generated in the photolysis of water vapor at the wave length of 185 nm in air in a flow tube. This produces a radical source which contains equal amount of HO2·and HOC2H4O2·. The amplification factor is derived from the slopes of the lines between produced NO2 in chemical amplifier and total initial radical concentrations measured for the source of HO2· and that of the same amount of HO2· and HOC2H4O2· respectively. The amplification factor of HOC2H4O2· was similar to that of HO2·, indicating that HOC2H4O2· can be measured with the same sensitivity as HO2· by chemical amplifier. 展开更多
关键词 2-Hydroxy ethylperoxy radical amplification factor chemical amplification.
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Development of Detailed Micro-Land Form Database and Its Application to Site Amplification Characteristics in Kanagawa Prefecture, Japan 被引量:1
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作者 Tsutomu Ochiai Takahisa Enomoto 《Journal of Geographic Information System》 2019年第1期66-81,共16页
Structural characteristic of surface soil ground has great effect on the ground motion amplitude when earthquake happens. Recent studies in Japan on seismic zonings use a database that covers entire Japan with 1 km me... Structural characteristic of surface soil ground has great effect on the ground motion amplitude when earthquake happens. Recent studies in Japan on seismic zonings use a database that covers entire Japan with 1 km mesh size, which is useful for prefecture scale researches. However, it is hard, even with 500 m or 250 m mesh sizes to consider a city, a county or award as scale studies. Kanagawa Prefecture is highly urbanized and vulnerable to seismic disaster. The prefecture suffered a wide spread damage during the 1923 Kanto earthquake. In this paper, we deploy a very fine mesh 50 × 50 m mesh to develop a general seismic intensity map useful for micro scale disaster management for local governments and educational information for earthquake preparedness promotion. In this paper, first we prepared two detailed databases for 50 × 50 m mesh size over entire Kanagawa Prefecture. One was for geologic formations and the other the geomorphologic condition. Then these databases were used for preparation of high-resolution digital soil classification maps for 15 categories of micro landforms of prefecture. The later database was used for mapping the site amplification factors for 50 × 50 m mesh by applying the empirical relations for AVS30. We could create a GIS platform with sufficient accuracy to consider potential risk analysis. 展开更多
关键词 Micro-Landform GIS SITE Response SITE amplification factor GEOLOGIC DATABASE Geomorphologic DATABASE
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Effect of site amplification on inelastic seismic response 被引量:4
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作者 Adhikary S Singh Y 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2019年第3期535-554,共20页
The available models for eff ective periods of site and structure are reviewed in context of frequency tuning in the inelastic seismic response of soil-structure system. The eff ect of seismic intensity and ductility ... The available models for eff ective periods of site and structure are reviewed in context of frequency tuning in the inelastic seismic response of soil-structure system. The eff ect of seismic intensity and ductility demand, on the eff ective periods, is investigated, and inelastic site amplifi cation is shown to be strongly correlated to the normalized eff ective period. Two non-dimensional parameters, analogous to the conventional site amplifi cation factors in codes, are defi ned to quantify the inelastic site amplifi cation. It is shown that the inelastic site amplifi cation factor (i.e. ratio of constant ductility spectral ordinates at soil site to those at rock outcrop) is able to represent the site eff ects more clearly, as compared to the inelastic site amplifi cation ratio (i.e. ratio of inelastic spectral ordinates at soil site to the corresponding elastic spectral ordinates at rock outcrop). Further, the peak in the amplifi cation factor corresponding to the eff ective site period diminishes rapidly with increasing ductility demand. 展开更多
关键词 SITE amplifi CATION normalized RESPONSE SPECTRA eff ective period INELASTIC SEISMIC RESPONSE INELASTIC SITE amplifi CATION factor
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An Improved Non-isolated LED Converter with Power Factor Correction and Average Current Mode Control 被引量:1
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作者 Renbo Xu Hongjian Li +1 位作者 Yongzhi Li Changqian Zhang 《Circuits and Systems》 2011年第3期242-248,共7页
A new type of high power LED drivers is proposed by adopting an improved two-stages non-isolated configuration. In order to improve power factor and achieve accurate average current control under universal input volta... A new type of high power LED drivers is proposed by adopting an improved two-stages non-isolated configuration. In order to improve power factor and achieve accurate average current control under universal input voltages ranging from 100 Vrms to 240 Vrms, the power factor correction and average current mode control methods operating in continuous current conduction mode are designed and implemented. With the LUMILEDS emitter type LEDs, a laboratory prototype is built and measured. And from the measured results, it could be concluded that the proposed driver has many better performances such as high power factor, low current harmonic, accurate average current control and switch protection. 展开更多
关键词 High POWER LED POWER factor CORRECTION AVERAGE current Mode Control
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Amplification Effect of Peak Ground Motion Acceleration in ClassⅡ and Ⅲ Sites over Shandong Province 被引量:1
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作者 Diao Ting Chen Shijun Jiang Zaofeng 《Earthquake Research in China》 2011年第4期498-506,共9页
In this paper, the amplification factor (ks ) of peek ground motion with different exceedance probability in class Ⅱ and Ⅲ sites over Shandong Province was estimated by analyzing the seismic response data of soil ... In this paper, the amplification factor (ks ) of peek ground motion with different exceedance probability in class Ⅱ and Ⅲ sites over Shandong Province was estimated by analyzing the seismic response data of soil layers collected from 358 boreholes of class Ⅱ sites and 140 boreholes of class Ⅲ site. From the results, one can conclude that: (1) The scatter plot of ks generally obeys a normal distribution ; (2) ks decreases with the increase of the strength of input ground motion, which is more apparent in Class Ⅲ site than in class lI site; (3) for class Ⅱ site, with the increase of depth of the bedrock interface where ground motion inputs, ks increases gradually until to a stable value when the depth reaches up to approximately 20 meters or larger. Yet, for class Ⅲ site, ks is insensitive to the depth; (4) the average of ks for class Ⅱ site is 1.47, slightly larger than that used in the Seismic Ground Motion Parameters Zonation Map of China ( GB 18306-2001 ). Also, ks in class Ⅱ and Ⅲ sites at different levels of peak ground acceleration over Shandong Province is preliminarily discussed in the paper. 展开更多
关键词 Seismic ground motion Peak ground acceleration Site condition Exceedanceprobability amplification factor
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Macrophage migration inhibitory factor decreased T-type Ca^(2+) channel current through activating Src
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作者 RAO Fang,DENG Chun-yu,WU Shu-lin,YU Xi-yong,XIAO Ding-zhang,HUANG Wei,KUANG Su-juan,LIN Qiu-xiong, ShanZhi-xin (Department of Cardiology,Guangdong Cardiovascular Institute, Guangzhou 510100,China) 《岭南心血管病杂志》 2011年第S1期196-196,共1页
Aims T-type Ca<sup>2+</sup> current(I<sub>CaT</sub>)plays an important role in the pathogenesis of atrial fibrillation(AF).The present study sought to investigate the role of Macrophage migra... Aims T-type Ca<sup>2+</sup> current(I<sub>CaT</sub>)plays an important role in the pathogenesis of atrial fibrillation(AF).The present study sought to investigate the role of Macrophage migration inhibitory factor(MIF),a pleiotropic cytokine,in the regulation of T-type Ca<sup>2+</sup> channel in atrium myocytes.Methods We used whole-cell voltage-clamp technique and biochemical assays to study the regulation and expression of I<sub>Ca</sub>,T in mouse atrium myocytes(HL-1 cells).Results Serum MIF concentrations was slightly increased in patients with AF compared to sinus rhythm(SR) controls.In cultured HL-1 cells, significant amounts of MIF were produced in response to hydrogen peroxide(H<sub>2</sub>O<sub>2</sub>),but not AngiotensinⅡ(AngⅡ). Mouse recombinant MIF(rMIF)(20 or 40 nM,24 h) suppressed peak ICa,T by-38%and-60%in a concentration-dependent manner,impaired the voltage-dependent activation of I<sub>Ca</sub>,T,and down-regulated of TCC alG mRNA.Src inhibitors genistein and PPl significantly enhanced ICaT.The depression of ICa,T induced by rMIF could be reversed by genistein and PP1.Conclusions MIFis involved in the pathogenesis of AF,probably by decreasing ICa,T through impairment of the channel function and activation of c-Src kinases in atrium myocytes. 展开更多
关键词 type channel current through activating Src MIF Macrophage migration inhibitory factor decreased T-type Ca
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Physico−mathematical model of the voltage−current characteristics of light-emitting diodes with quantum wells based on the Sah−Noyce−Shockley recombination mechanism
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作者 Fedor I.Manyakhin Dmitry O.Varlamov +3 位作者 Vladimir P.Krylov Lyudmila O.Morketsova Arkady A.Skvortsov Vladimir K.Nikolaev 《Journal of Semiconductors》 EI CAS CSCD 2024年第8期25-33,共9页
Herein,a physical and mathematical model of the voltage−current characteristics of a p−n heterostructure with quantum wells(QWs)is prepared using the Sah−Noyce−Shockley(SNS)recombination mechanism to show the SNS reco... Herein,a physical and mathematical model of the voltage−current characteristics of a p−n heterostructure with quantum wells(QWs)is prepared using the Sah−Noyce−Shockley(SNS)recombination mechanism to show the SNS recombination rate of the correction function of the distribution of QWs in the space charge region of diode configuration.A comparison of the model voltage−current characteristics(VCCs)with the experimental ones reveals their adequacy.The technological parameters of the structure of the VCC model are determined experimentally using a nondestructive capacitive approach for determining the impurity distribution profile in the active region of the diode structure with a profile depth resolution of up to 10Å.The correction function in the expression of the recombination rate shows the possibility of determining the derivative of the VCCs of structures with QWs with a nonideality factor of up to 4. 展开更多
关键词 light-emitting diodes with quantum wells voltage−current relation nonideality factor recombination mechanism Sah−Noyce−Shockley model
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A High Power Factor Rectifier Based on Buck Converter Operating in Discontinuous Inductor Current Mode
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作者 Jianbo Yang Weiping Zhang +1 位作者 Faris Al-Naemi Xiaoping Chen 《Energy and Power Engineering》 2013年第4期842-849,共8页
By adding a suitable LC filter to the input of a Buck converter, a high-power-factor buck converter is proposed. The converter can operate in the discontinuous-output-current mode operation. A Buck converter in this o... By adding a suitable LC filter to the input of a Buck converter, a high-power-factor buck converter is proposed. The converter can operate in the discontinuous-output-current mode operation. A Buck converter in this operation mode features simple control as the constant duty cycle PWM used. The operation condition of the converter is studied. The validity of analysis is verified by Simulation and Experimental results. 展开更多
关键词 Discontinuous-output-current BUCK Converter Power factor Correction
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Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer
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作者 Yi Zhou Shuang Wu Fan-Jie Qu 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第6期2362-2379,共18页
More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but s... More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients. 展开更多
关键词 Metastatic colorectal cancer Epidermal growth factor receptor B-type RAF mutation Kirsten rat sarcoma viral oncogene wild type Kirsten rat sarcoma viral oncogene G12C mutation Human epidermal growth factor receptor 2 overexpression/amplification
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Hybrid Multi-Infeed Interaction Factor Calculation Method Considering Voltage Regulation Control Characteristics of Voltage Source Converter
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作者 Shan Liu Chengbin Chi +3 位作者 Fengze Han Yanan Wu Lin Zhu Tuo Wang 《Energy Engineering》 EI 2024年第8期2257-2273,共17页
Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluat... Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluate its influence on the voltage interaction between VSC-HVDC and line commutated converter based high voltage direct current(LCC-HVDC),this paper proposes a hybrid multi-infeed interaction factor(HMIIF)calculation method considering the voltage regulation control characteristics of VSC-HVDC.Firstly,for a hybrid multi-infeed high voltage direct current system,an additional equivalent operating admittance matrix is constructed to characterize HVDC equipment characteristics under small disturbance.Secondly,based on the characteristic curve between the reactive power and the voltage of a certain VSC-HVDC project,the additional equivalent operating admittance of VSC-HVDC is derived.The additional equivalent operating admittance matrix calculation method is proposed.Thirdly,the equivalent bus impedance matrix is obtained by modifying the alternating current(AC)system admittance matrix with the additional equivalent operating admittance matrix.On this basis,the HMIIF calculation method based on the equivalent bus impedance ratio is proposed.Finally,the effectiveness of the proposed method is verified in a hybrid dual-infeed high voltage direct current system constructed in Power Systems Computer Aided Design(PSCAD),and the influence of voltage regulation control on HMIIF is analyzed. 展开更多
关键词 Hybrid multi-infeed high voltage direct current system hybrid multi-infeed interaction factor control modes equivalent node impedance ratio voltage interaction characteristics
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Correlation of human epidermal growth factor receptor 2 expression with clinicopathological characteristics and prognosis in gastric cancer 被引量:29
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作者 Chao He Xue-Yi Bian +5 位作者 Xing-Zhi Ni Dan-Ping Shen Yan-Ying Shen Hua Liu Zhi-Yong Shen Qiang Liu 《World Journal of Gastroenterology》 SCIE CAS 2013年第14期2171-2178,共8页
AIM:To investigate human epidermal growth factor receptor 2(HER2) gene amplification and protein expression in Chinese patients with resectable gastric cancer and the association with clinicopathological characteristi... AIM:To investigate human epidermal growth factor receptor 2(HER2) gene amplification and protein expression in Chinese patients with resectable gastric cancer and the association with clinicopathological characteristics and survival.METHODS:One hundred and ninety-seven gastric cancer patients who underwent curative surgery procedures were enrolled into this study.HER2 gene amplification and protein expression were examined using fluorescence in-situ hybridization(FISH) and immunohistochemistry(IHC) analysis on formalin-fixed paraffinembedded gastric cancer samples from all patients.For scoring,Hofmann's HER2 gastric cancer scoring system was adopted.All cases showing IHC3+ or FISH positiv-ity were defined as HER2 positive.Patient clinicopathological data and survival information were collected.Finally,χ 2 statistical analysis was performed to analyze the HER2 positivity rate amongst the subgroups with different clinicopathological characteristics including;gender,age,tumor location,Lauren classification,differentiation,TNM staging,depth of invasion,lymph node metastases and distant metastasis.The probability of survival for different subgroups with different clinicopathological characteristics was calculated using the Kaplan-Meier method and survival curves plotted using log rank inspection.RESULTS:According to Hofmann's HER2 gastric cancer scoring criteria,31 cases(15.74%) were identified as HER2 gene amplified and 19 cases(9.64%) were scored as strongly positive for HER2 membrane staining(3+),25 cases(12.69%) were moderately positive(2+) and 153 cases(77.66%) were HER2 negative(0/1+).The concordance rate between IHC and FISH analyses was 88.83%(175/197).Thirty-six cases were defined as positive for HER2 gene amplification and/or protein expression,with 24 of these cases being eligible for Herceptin treatment according to United States recommendations,and 29 of these cases eligible according to EU recommendations.Highly consistent results were detected between IHC3+,IHC0/1 and FISH(73.68% and 95.42%),but low consistency was observed between IHC2+ and FISH(40.00%).The positivity rates in intestinal type and well-differentiated gastric cancer were higher than those in diffuse/mixed type and poorly-differentiated gastric cancer respectively(28.57% vs 13.43%,P = 0.0103;37.25% vs 11.64%,P < 0.0001),but were not correlated with gender,age,tumor location or TNM stage,depth of invasion,lymph node metastases and distant metastasis.In poorly-differentiated gastric cancer patients,those without lymph node metastasis showed a higher HER2 positivity rate than those with lymph node metastasis(26.47% vs 7.14%,P = 0.0021).This association was not present in thosepatients with well-differentiated gastric cancer(28.57% vs 43.33%,P = 0.2832).Within our patient cohort,26 cases were lost to follow-up.The median survival time for the remaining 171 patients was 18 mo.The median survival times of the HER2 positive and negative groups were 17 and 18.5 mo respectively.Overall survival was not significantly different between HER2-positive and negative groups(χ 2 = 0.9157,P = 0.3386),but in patients presenting well-differentiated tumors,the overall survival of the HER2-positive group was significantly worse than that of the HER2-negative group(P = 0.0123).In contrast,patients with poorly differentiated and diffuse/mixed subtype gastric cancers showed no significant differences in overall survival associated with HER2.Furthermore,the median survival time of the HER2 positive group did not show any statistically significant differences when compared to the subgroups of gender,age,tumor location,TNM classification,lymph node metastases and distant metastasis.CONCLUSION:Patients with intestinal type gastric cancer(GC),well-differentiated GC and poorly-differentiated GC without lymph node metastasis,may all represent suitable candidates for targeted therapy using Herceptin. 展开更多
关键词 GASTRIC cancer Human EPIDERMAL growth factor receptor 2 Gene amplification Protein EXPRESSION CLINICOPATHOLOGICAL characteristics
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Human epidermal growth factor receptor type 2 protein expression in Chinese metastatic prostate cancer patients correlates with cancer specific survival and increases after exposure to hormonal therapy 被引量:3
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作者 Bo Dai Yun-Yi Kong +3 位作者 Ding-Wei Ye Chun-Guang Ma Xiao-Yan Zhou Xu-Dong Yao 《Asian Journal of Andrology》 SCIE CAS CSCD 2008年第5期701-709,共9页
Aim: To investigate human epidermal growth factor receptor type 2 (HER2) protein expression and gene amplification in Chinese metastatic prostate cancer patients and their potential value as prognostic factors. Met... Aim: To investigate human epidermal growth factor receptor type 2 (HER2) protein expression and gene amplification in Chinese metastatic prostate cancer patients and their potential value as prognostic factors. Methods: Immunohistochemistry (IHC) was performed to investigate HER2 protein expression in prostate biopsy specimens from 104 Chinese metastatic prostate cancer patients. After 3-11 months of hormonal therapy, 12 patients underwent transurethral resection of the prostate (TURP). HER2 protein expression of TURP specimens was compared with that of the original biopsy specimens. Of these, 10 biopsy and 4 TURP specimens with HER2 IHC staining scores ≥ 2+ were investigated for HER2 gene amplification status by fluorescent in situ hybridization (FISH). Results: Of the 104 prostate biopsy specimens, HER2 protein expression was 0, 1+, 2+ and 3+ in 49 (47.1%), 45 (43.3%), 8 (7.7%) and 2 (1.9%) cases, respectively. There was a significant association between HER2 expression and Gleason score (P = 0.026). HER2 protein expression of prostate cancer tissues increased in 33.3% of patients after hormonal therapy. None of the 14 specimens with HER2 IHC scores 〉 2+ showed HER2 gene amplification. Patients with HER2 scores 〉 2+ had a significantly higher chance of dying from prostate cancer than those with HER2 scores of 0 (P = 0.004) and 1+ (P = 0.034). Multivariate Cox regression analysis showed that HER2 protein expression intensity was an independent predictor of cancer-related death (P = 0.039). Conclusion: An HER2 IHC score 〉 2+ should be defined as HER2 protein overexpression in prostate cancer. Overexpression of HER2 protein in cancer tissue might suggest an increased risk of dying from prostate cancer. HER2 protein expression increases in some individual patients after hormonal therapy. 展开更多
关键词 prostatic neoplasms human epidermal growth factor receptor type 2 IMMUNOHISTOCHEMISTRY gene amplification prostate cancer prognosis
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Epidermal growth factor receptor mutation analysis in cytological specimens and responsiveness to gefitinib in advanced non-small cell lung cancer patients 被引量:5
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作者 Lin Li Zijin Zhang +7 位作者 Zhixin Bie Zheng Wang Ping Zhang Xin Nie Yuanming Li Hui Wang Bin Ai Gang Cheng 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2015年第3期294-300,共7页
Background: Epidermal growth factor receptor(EGFR) mutation is the key predictor of EGFR tyrosine kinase inhibitors(TKIs) efficacy in non-small cell lung cancer(NSCLC). We conducted this study to verify the fea... Background: Epidermal growth factor receptor(EGFR) mutation is the key predictor of EGFR tyrosine kinase inhibitors(TKIs) efficacy in non-small cell lung cancer(NSCLC). We conducted this study to verify the feasibility of EGFR mutation analysis in cytological specimens and investigate the responsiveness to gefitinib treatment in patients carrying EGFR mutations.Methods: A total of 210 cytological specimens were collected for EGFR mutation detection by both direct sequencing and amplification refractory mutation system(ARMS). We analyzed EGFR mutation status by both methods and evaluated the responsiveness to gefitinib treatment in patients harboring EGFR mutations by overall response rate(ORR), disease control rate(DCR) and progression free survival(PFS).Results: Of all patients, EGFR mutation rate was 28.6%(60/210) by direct sequencing and 45.2%(95/210) by ARMS(P〈0.001) respectively. Among the EGFR wild type patients tested by direct sequencing, 26.7% of them were positive by ARMS. For the 72 EGFR mutation positive patients treated with gefitinib, the ORR, DCR and median PFS were 69.4%, 90.2% and 9.3 months respectively. The patients whose EGFR mutation status was negative by direct sequencing but positive by ARMS had lower ORR(48.0% vs. 80.9%, P=0.004) and shorter median PFS(7.4 vs. 10.5 months, P=0.009) as compared with that of EGFR mutation positive patients by both detection methods. Conclusions: Our study verified the feasibility of EGFR analysis in cytological specimens in advanced NSCLC. ARMS is more sensitive than direct sequencing in EGFR mutation detection. EGFR Mutation status tested on cytological samples is applicable for predicting the response to gefitinib. Abundance of EGFR mutations might have an influence on TKIs efficacy. 展开更多
关键词 Non-small cell lung cancer (NSCLC) epidermal growth factor receptor (EGFR) mutation cytological specimen amplification refractory mutation system (ARMS) GEFITINIB
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