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Frequency-controlable sine signal based on PWM and its implementation on FPGA

Lianzhen HUANG, Jiangang LI, Dongjun ZHANG

《机械工程前沿（英文）》 2012年 第7卷 第3期   页码 322-328 doi: 10.1007/s11465-012-0312-9

摘要：

A sine generation method that the different frequent sine signals can be generated by the different Pulse-Width Modulation (PWM) signals generated by Field-Programmable Gate Array (FPGA) through low-pass filter of fixed parameters was proposed. The method just takes a few FPGA resources and was proved feasible by the theory. The experiment results and theory analysis tally.

关键词： Pulse-Width Modulation (PWM)     Field-Programmable Gate Array (FPGA)     frequency controllable    

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Modeling and analysis of controllable output property of cantilever-beam inertial sensors based on magnetic

Guixiong LIU, Peiqiang ZHANG, Chen XU

《机械工程前沿（英文）》 2009年 第4卷 第2期   页码 129-133 doi: 10.1007/s11465-009-0035-8

摘要： Magnetic fluid is first introduced into the traditional cantilever-beam senor. Based on the property of the cantilever-beam and the novel controllable mag-viscosity of magnetic fluid, the output of cantilever-beam sensors is under control so that the controllable output of the sensors can be realized. The mathematical model of the sensors is established and analyzed. The dynamic control function and the following educational results, which include the two curves of the displacement ratio and phase function with the different damping ratio and frequency ratio, are obtained based on the model. The result shows that it is valid to realize the controllable output of the sensors by controlling the viscosity of the magnetic fluid, and finally the expanded measurement range can be realized.

关键词： sensors     magnetic fluid     property of mag-viscosity     controllable output    

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A chemical etching route to controllable fabrication of TiO

Weixin ZHANG, Jie XING, Zeheng YANG, Mei KONG, Hongxu YAO

《化学科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 192-201 doi: 10.1007/s11705-013-1319-4

摘要： The TiO hollow nanospheres with diameters of about 230 nm were prepared by a simple and controllable route based on hydrolysis of Ti(OBu) on the surfaces of the Cu O solid nanospheres followed by inward etching of the Cu O nanospheres. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The further post-heat treatment led to the high crystallization of the TiO hollow nanospheres. The photocatalytic performances of these samples were evaluated for the photodegradation of rhodamine B (RhB) under UV-light irradiation. The as-prepared TiO hollow nanospheres showed higher photocatalytic activity than the CuO and the CuO/TiO hollow nanospheres. Effects of temperature and time for post-heat treatment of TiO as well as initial RhB concentrations on the RhB photodegradation have also been studied. The results show that the TiO hollow nanospheres have the good reusability as photocatalysts and are promising in waste water treatment.

关键词： TiO2     hollow nanospheres     rhodamine B     photocatalytic activity    

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Size-controllable synthesis of monodispersed nitrogen-doped carbon nanospheres from polydopamine for

《化学科学与工程前沿（英文）》 2023年 第17卷 第11期   页码 1788-1800 doi: 10.1007/s11705-023-2326-8

摘要： Monodispersed nitrogen-doped carbon nanospheres with tunable particle size (100–230 nm) were synthesized via self-polymerization of biochemical dopamine in the presence of hexamethylenetetramine as a buffer and F127 as a size controlling agent. Hexamethylenetetramine can mildly release NH3, which in turn initiates the polymerization reaction of dopamine. The carbon nanospheres obtained exhibited a significant energy storage capability of 265 F·g–1 at 0.5 A·g–1 and high-rate performance of 82% in 6 mol·L–1 KOH (20 A·g–1), which could be attributed to the presence of abundant micro-mesoporous structure, doped nitrogen functional groups and the small particle size. Moreover, the fabricated symmetric supercapacitor device displayed a high stability of 94% after 5000 cycles, revealing the considerable potential of carbon nanospheres as electrode materials for energy storage.

关键词： carbon nanospheres     size-controlled     nitrogen-doped     high-rate     supercapacitors    

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二维可控细胞自动机伪随机序列发生方法研究

朱保平,马骞,刘凤玉

《中国工程科学》 2007年 第9卷 第6期   页码 43-47

摘要：

提出了一种新的细胞自动机———二维可控细胞自动机。根据二维可控细胞自动机的性质，提出了一 种具有梯型结构的二维可控细胞自动机的伪随机序列发生方法。计算机模拟表明，具有梯型结构的二维可控细 胞自动机伪随机序列发生器实现简单，产生的序列具有速度高、统计特性好等优点。新的细胞自动机在对称密 码学中有广泛地应用。

关键词： 细胞自动机     伪随机序列发生器     可控     密码学    

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A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0006-x

摘要： A frequency error estimation is presented for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells using both quadratic and cubic basis functions. By analyzing the discrete isogeometric equations with the aid of harmonic wave assumption, the frequency error measures are rationally derived for the quadratic and cubic formulations for Kirchhoff–Love cylindrical shells. In particular, the governing relationship of the continuum frequency for Kirchhoff–Love cylindrical shells is naturally embedded into the frequency error measures without the need of explicit frequency expressions, which usually are not trivial for the shell problems. In accordance with these theoretical findings, the 2nd and 4th orders of frequency accuracy are attained for the isogeometric schemes using quadratic and cubic basis functions, respectively. Numerical results not only thoroughly verify the theoretical convergence rates of frequency solutions, but also manifest an excellent magnitude match between numerical and theoretical frequency errors for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells.

关键词： isogeometric analysis     Kirchhoff–Love cylindrical shell     free vibration     frequency error     convergence    

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Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

《能源前沿（英文）》 2013年 第7卷 第4期   页码 506-510 doi: 10.1007/s11708-013-0275-5

摘要： The collision frequency function for aerosol particles has already been calculated for the free molecule regime and for the continuum range. The present work, taking into account the influence of internal force fields such as magnetic force, electric force and molecular forces, created by particles themselves, recalculated the collision frequency in the case of particles much smaller than the mean free path of the gas (free molecule regime). Attractive forces increase naturally the collision frequency, while repulsive forces decrease it. The calculation was performed for all types of central forces deriving from a potential, including Coulomb forces and Van der Waals forces.

关键词： aerosol particles     collision frequency function     coagulation    

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Fuel variability effect on flickering frequency of diffusion flames

Jizhao LI, Yang ZHANG

《能源前沿（英文）》 2009年 第3卷 第2期   页码 134-140 doi: 10.1007/s11708-009-0034-9

摘要： It is known that fuel variability of different gas suppliers may cause combustion instability in a gas turbine combustor. Mechanisms that control the time scale of the heat release oscillations and acoustic pressure perturbations are both physical and chemical in nature, and thus can be influenced by changes in fuel composition. The intent of this study is to investigate the fuel variability on the flickering frequency of diffusion flames in the hope of understanding some of the fundamental aspects of fuel variability effect on the dynamics of combustion. Experiments were conducted at atmospheric pressure with a matrix of methane and propane blends. An optical fibre system was applied to capture simultaneously the flame flickering at two different light frequencies (430 nm and 516 nm), which provided a means of comparing the chemistry change. It was found that the low frequency oscillation of flow and flame structures depended only weakly on the exit velocities of the fuel, while ambient conditions had a significant effect on flickering frequencies and spectrum. The results of using CH and C H as test fuels at different flow rates showed very little variations, with peak frequencies at 11-13 Hz. When the jet flame was not disturbed, harmonics to at least the third mode were obtained in most of these cases. However, the cases which included CH /C H splits of 90/10, 85/15 and 80/20 by volume showed that unstable flickering frequencies and flame harmonics were not observed. When a mixture of methane/propane at a ratio of 1:1 was used the peak flickering frequency was around 6 Hz, and slight disturbance in the environment would cause the harmonics to disappear. Mechanisms thought to produce changes in the dynamic response and frequency harmonics were discussed.

关键词： fuel variability     flickering frequency     diffusion flames     dynamics of combustion    

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Capacity limitation of nuclear units in grid based on analysis of frequency regulation

Yiping DAI, Pan JIANG, Lin GAO, Weimin KAN, Xiaoqing XIAO, Ge JIN

《能源前沿（英文）》 2012年 第6卷 第2期   页码 148-154 doi: 10.1007/s11708-012-0174-1

摘要： The increasing capacity of nuclear units in power grid poses threat to system stability and security. Load disturbance may cause overspeed of the units and trigger the overspeed protection controller (OPC). Repeating actions of valves have a strong impact on the security of the equipment and may result in a collapse of the power system. Based on the analysis of frequency regulation, mathematic models for nuclear units in the grid are established in this paper to simulate the dynamic process when load disturbance occurs. The critical action of the OPC is proposed as the constraint of safe operation for the units. The relationship between different styles of frequency regulation and the allowable capacity of the nuclear units in the grid is discussed. This research can help to estimate the capacity limitation of nuclear units in the grid.

关键词： nuclear units capacity     overspeed     primary frequency control (PFC)     second frequency control (SFC)    

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Oscillation frequency of simplified arterial tubes

Hui AN, Fan HE, Lingxia XING, Xiaoyang LI

《机械工程前沿（英文）》 2009年 第4卷 第3期   页码 300-304 doi: 10.1007/s11465-009-0038-5

摘要： To construct the spatial kinetic equation of an arterial tube and obtain its radial natural frequency, a linear-elastic and small deformation condition is assumed. The theoretical analysis is first presented and the finite element method is then used to numerically simulate the spatial kinematics. The results show that the first-order frequency is 15.8 Hz and the obtained exact analytical solutions agree well with numerical solutions, which proves that the theoretical analysis and numerical simulation are both correct.

关键词： spatial kinematics     natural frequency     finite element method    

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Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

《能源前沿（英文）》 2014年 第8卷 第3期   页码 386-393 doi: 10.1007/s11708-014-0323-9

摘要： Accurate modeling and parameters of high voltage (HV) grid are critical for stability research of system frequency. In this paper, simulation modeling of the system frequency was conducted of an interconnected power system with HV transmission lines in China. Based on recorded tripping data of the HV transmission lines, system parameters were identified by using genetic algorithm (GA). The favorable agreement between simulation results and recorded data verifies the validity of gird models and the accuracy of system parameters. The results of this paper can provide reference for the stability research of HV power grid.

关键词： high voltage (HV) grid     frequency stability parameter identification     primary frequency regulation (PFR)    

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Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer

Lili CHEN, Wu ZHOU

《机械工程前沿（英文）》 2013年 第8卷 第2期   页码 146-149 doi: 10.1007/s11465-013-0260-z

摘要：

To predict more precisely the frequency of force-balanced micro accelerometer with different bias voltages, the effects of bias voltages on error sensitivity of frequency is studied. The resonance frequency of accelerometer under closed loop control is derived according to its operation principle, and its error sensitivity is derived and analyzed under over etching structure according to the characteristics of Deep Reaction Ion Etching (DRIE). Based on the theoretical results, micro accelerometer is fabricated and tested to study the influences of AC bias voltage and DC bias voltage on sensitivity, respectively. Experimental results indicate that the relative errors between test data and theory data are less than 7%, and the fluctuating value of error sensitivity under the range of voltage adjustment is less than 0.01 μm . It is concluded that the error sensitivity with designed parameters of structure, circuit and process error can be used to predict the frequency of accelerometer with no need to consider the influence of bias voltage.

关键词： Micro-Electro-Mechanical Systems (MEMS)     micro accelerometer     force-balanced micro accelerometer     frequency     error sensitivity    

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Potential unreliability of ALK variant allele frequency in the efficacy prediction of targeted therapy

《医学前沿（英文）》 2023年 第17卷 第3期   页码 493-502 doi: 10.1007/s11684-022-0946-x

摘要： Anaplastic lymphoma kinase (ALK) is the most common fusion gene involved in non-small cell lung cancer (NSCLC), and remarkable response has been achieved with the use of ALK tyrosine kinase inhibitors (ALK-TKIs). However, the clinical efficacy is highly variable. Pre-existing intratumoral heterogeneity (ITH) has been proven to contribute to the poor treatment response and the resistance to targeted therapies. In this work, we investigated whether the variant allele frequencies (VAFs) of ALK fusions can help assess ITH and predict targeted therapy efficacy. Through the application of next-generation sequencing (NGS), 7.2% (326/4548) of patients were detected to be ALK positive. On the basis of the adjusted VAF (adjVAF, VAF normalization for tumor purity) of four different threshold values (adjVAF < 50%, 40%, 30%, or 20%), the association of ALK subclonality with crizotinib efficacy was assessed. Nonetheless, no statistical association was observed between median progression-free survival (PFS) and ALK subclonality assessed by adjVAF, and a poor correlation of adjVAF with PFS was found among the 85 patients who received first-line crizotinib. Results suggest that the ALK VAF determined by hybrid capture-based NGS is probably unreliable for ITH assessment and targeted therapy efficacy prediction in NSCLC.

关键词： ALK fusion     next-generation sequencing     fluorescence in situ hybridization     immunohistochemistry     variant allele frequency     intratumoral heterogeneity     targeted therapy    

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Remote calibration system for frequency based on in-place benchmark

Xiaobin HONG, Guixiong LIU, Zhuokui WU, Xipeng DU,

《机械工程前沿（英文）》 2010年 第5卷 第3期   页码 316-321 doi: 10.1007/s11465-010-0021-1

摘要： According to the deficiencies of remote calibration mode based on material object reference, a new model of a remote calibration system for frequency based on in-place benchmark is introduced, which is made of a calibration subsystem on the spot and a remote management subsystem. The key technology of some key problems for the remote calibration system is particularly discussed, including the time and frequency benchmark receiving module based on global positioning system (GPS), frequency comparison based on a phase method, frequency division based on dual high-frequency phase locked loop (PLL), and remote calibration based on the web. The results show that the system possesses some characteristics, such as high precision, good versatility, and no limitation of time and place.

关键词： remote calibration     in-place benchmark     frequency comparison     global position system (GPS)    

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Research progress in pathogenic genes of hereditary non-syndromic mid-frequency deafness

null

《医学前沿（英文）》 2016年 第10卷 第2期   页码 137-142 doi: 10.1007/s11684-016-0449-8

摘要：

Hearing impairment is considered as the most prevalent impairment worldwide. Almost 600 million people in the world suffer from mild or moderate hearing impairment, an estimated 10% of the human population. Genetic factors play an important role in the pathogenesis of this disorder. Hereditary hearing loss is divided into syndromic hearing loss (associated with other anomalies) and non-syndromic hearing loss (not associated with other anomalies). Approximately 80% of genetic deafness is non-syndromic. On the basis of the frequency of hearing loss, hereditary non-syndromic hearing loss can be divided into high-, mid-, low-, and total-frequency hearing loss. An audiometric finding of mid-frequency sensorineural hearing loss, or a “bowl-shaped” audiogram, is uncommon. Up to now, merely 7 loci have been linked to mid-frequency hearing loss. Only four genetic mid-frequency deafness genes, namely, DFNA10 (EYA4), DFNA8/12 (TECTA), DFNA13 (COL11A2), DFNA44 (CCDC50), have been reported to date. This review summarizes the research progress of the four genes to draw attention to mid-frequency deafness genes.

关键词： hereditary non-syndromic hearing loss     mid-frequency hearing loss     deafness genes    

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标题 作者 时间 类型 操作

Frequency-controlable sine signal based on PWM and its implementation on FPGA

Lianzhen HUANG, Jiangang LI, Dongjun ZHANG

期刊论文

Modeling and analysis of controllable output property of cantilever-beam inertial sensors based on magnetic

Guixiong LIU, Peiqiang ZHANG, Chen XU

期刊论文

A chemical etching route to controllable fabrication of TiO

Weixin ZHANG, Jie XING, Zeheng YANG, Mei KONG, Hongxu YAO

期刊论文

Size-controllable synthesis of monodispersed nitrogen-doped carbon nanospheres from polydopamine for

期刊论文

二维可控细胞自动机伪随机序列发生方法研究

朱保平,马骞,刘凤玉

期刊论文

A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

期刊论文

Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

期刊论文

Fuel variability effect on flickering frequency of diffusion flames

Jizhao LI, Yang ZHANG

期刊论文

Capacity limitation of nuclear units in grid based on analysis of frequency regulation

Yiping DAI, Pan JIANG, Lin GAO, Weimin KAN, Xiaoqing XIAO, Ge JIN

期刊论文

Oscillation frequency of simplified arterial tubes

Hui AN, Fan HE, Lingxia XING, Xiaoyang LI

期刊论文

Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

期刊论文

Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer

Lili CHEN, Wu ZHOU

期刊论文

Potential unreliability of ALK variant allele frequency in the efficacy prediction of targeted therapy

期刊论文

Remote calibration system for frequency based on in-place benchmark

Xiaobin HONG, Guixiong LIU, Zhuokui WU, Xipeng DU,

期刊论文

Research progress in pathogenic genes of hereditary non-syndromic mid-frequency deafness

null

期刊论文