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高速电镀锡机组卷取机电机变基频的参数设计与验证
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作者 刘俊华 罗茜 +1 位作者 张超 娄亚军 《制造业自动化》 北大核心 2023年第10期211-215,共5页
卷取机作为带钢生产线的末端设备,主要负责钢卷的卷取功能,为了保证带材的卷取质量,在卷取过程中,卷取机需始终保持卷取张力的恒定。随着矢量变频技术的发展,变频电机在卷取机上的应用越发广泛,使用变频电机可以提高生产效率,降低能耗,... 卷取机作为带钢生产线的末端设备,主要负责钢卷的卷取功能,为了保证带材的卷取质量,在卷取过程中,卷取机需始终保持卷取张力的恒定。随着矢量变频技术的发展,变频电机在卷取机上的应用越发广泛,使用变频电机可以提高生产效率,降低能耗,同时响应国家绿色环保政策,因此对卷取机电机变基频参数的设计至关重要。结合我公司电镀锡机组生产线,通过改变卷取机电机基频参数,经计算结果对比分析得出,额定基频(50Hz)电机功率远大于变基频(17Hz)电机的功率,因此选择变基频(17Hz)电机能够充分发挥电机性能,提高电机利用率,同时降低设备装机容量,减少工厂的一次性投资,能够取得较好的经济效益。 展开更多
关键词 卷取机 变基频 电机 恒功率 节能降耗
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融合CNN和Transformer编码器的变声语音鉴别与还原 被引量:1
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作者 魏春雨 孙蒙 +1 位作者 刘伟 张星昱 《信息技术与网络安全》 2022年第1期47-54,共8页
语音变声伪装会导致人耳感知和声纹识别出现错误,从而达到隐匿说话人真实身份的目的。为削弱变声语音的影响,提出一种融合卷积神经网络(Convolutional Neural Networks,CNN)和Transformer编码器的模型,提取变声语音的局部特征和全局特... 语音变声伪装会导致人耳感知和声纹识别出现错误,从而达到隐匿说话人真实身份的目的。为削弱变声语音的影响,提出一种融合卷积神经网络(Convolutional Neural Networks,CNN)和Transformer编码器的模型,提取变声语音的局部特征和全局特征用于判别变声因子,并根据变声因子的数值实施变声语音还原。在中英文真实场景录音数据集上验证了所提方法的有效性,对变声因子判别实现了95%以上的准确率。利用所提出的方法,在黑箱条件下对某型商用硬件变声器输出的语音进行鉴别与还原,取得了较好的效果。 展开更多
关键词 基频 语音鉴伪 声还原 时频特征
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Transcription-coupled repair pathway in UVC-induced SupF gene mutation in Tet-on 293 cell line
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作者 Li Jin Song Bo +4 位作者 Chen Zhiwen Zeng Yijun Zhou Huchuan Wei Quanfang Yang Jin 《Journal of Medical Colleges of PLA(China)》 CAS 2008年第2期76-80,共5页
Objective: To explore the role of transcription-coupled repair (TCR) pathway in the UVC-induced SupF gene mutation in Tet-on 293 cell line, we designed and constructed a Tet-responsive plasmid DNA pTCR-C1, and util... Objective: To explore the role of transcription-coupled repair (TCR) pathway in the UVC-induced SupF gene mutation in Tet-on 293 cell line, we designed and constructed a Tet-responsive plasmid DNA pTCR-C1, and utilized this pTCR-C 1 plasmid to obtain the mutation frequency of SupF reporter gene induced by UVC in Tet-on 293 cell line. Methods: SupF gene was cloned into a Tet-responsive plamid pBI-L, which include a bidirectional Tet-responsive promoter, and was named pTCR-C1. The pTCR-C1 plasmid was transfected into Tet-on 293 cell line, and the mutation frequency of SupF reporter gene was detected in the presence and absence of DOX. Results: The pTCR-C1 plasmid was identified with the methods of restriction digestion and DNA sequencing. The mutation frequency of SupF reporter gene in the presence of DOX was higher than in the absence of DOX. Conclusion: The TCR pathway takes part in the UVC-induced SupF gene mutation in Tet-on 293 cell line. 展开更多
关键词 Transcription-coupled repair SupF gene TET-ON Mutation frequency
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Frequency of primary iron overload and HFE gene mutations (C282Y,H63D and S65C) in chronic liver disease patients in north India 被引量:5
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作者 Barjinderjit Kaur Dhillon Reena Das +5 位作者 Gurjeewan Garewal Yogesh Chawla RK Dhiman Ashim Das Ajay Duseja GR Chandak 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第21期2956-2959,共4页
AIM:To identify the frequency of iron overload and study the three mutations in the HFE gene (C282Y,H63D,and S65C) in patients with chronic liver disorders (CLD) and controls. METHODS:To identify patients with iron ov... AIM:To identify the frequency of iron overload and study the three mutations in the HFE gene (C282Y,H63D,and S65C) in patients with chronic liver disorders (CLD) and controls. METHODS:To identify patients with iron overload (transferrin saturation > 45% in females and > 50% in males and serum ferritin > 1000 ng/mL) we evaluated 236 patients with CLD,including 59 with non-alcoholic steatohepatitis (NASH),22 with alcoholic liver disease (ALD),19 of cirrhosis due to viruses (HBV,HCV),and 136 with cryptogenic cirrhosis. Mutations of the HFE gene were analyzed by PCR-RE. hundred controls were screened for iron status and the mutations. RESULTS:Seventeen patients with CLD showed evidence of iron overload. Fifteen cases of iron overload had cryptogenic cirrhosis and two had ALD. None of the controls showed iron overload. We did not find any individual with 282Y or 65C either in the cases or in the controls. The prevalence of H63D heterozygosity was 12% in normal individuals,14.8% in 236 patients (16.9% in NASH,13.6% in ALD,26.3% in viral and 12.5% in cryptogenic cirrhosis) and the overall prevalence was 13.98%. Only two of the 17 patients with primary iron overload were heterozygous for H63D. One patient with NASH and one normal individual who were homozygous for H63D showed no iron overload.CONCLUSION:Primary iron overload in Indians is nonHFE type,which is different from that in Europeans and further molecular studies are required to determine the defect in various iron regulatory genes. 展开更多
关键词 HFE gene mutations C282Y H63D S65C Population genetics
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Genotypes and polymorphisms of mutant CCR5-△32,CCR2-64I and SDF1-3'A HIV-1 resistance alleles in indigenous Han Chinese 被引量:1
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作者 王福生 金磊 +8 位作者 雷周云 施红 洪卫国 徐东平 蒋建东 汪悦 张冰 刘明旭 李跃旗 《Chinese Medical Journal》 SCIE CAS CSCD 2001年第11期42-46,105-106,共7页
Objective To evaluate the frequencies and polymorphisms of CCR5-△32,CCR2-641 and SDF1-3'A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin.Methods This cohort was comp... Objective To evaluate the frequencies and polymorphisms of CCR5-△32,CCR2-641 and SDF1-3'A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin.Methods This cohort was comprised of 1251 subjects(915 men and 336 women)aged 15 -80 years and none was HIV-1 positive.Genotyping of allelic CCR5-△32,CCR2-641 and SDF1-3' A variants was performed using PCR or PCR/RFLP assay,and further confirmed by direct DNA sequencing.Results Our finding shows that the△32 deletion mutation in the CCR5 gene does occur in this population and can be inherited in a Mendelian fashion in indigenous Han Chinese at a very low frequency of 0.00119(n= 1254).The frequencies of mutant CCR2-641 and SDF1-3'A alleles were 0.20023(n = 1251)and 0.2873(n = 893),in this population,which are higher than those found in American Caucasians.Furthermore the polymorphisms of CCR2-641 and SDF1-3' A alleles in the Han Chinese population were different from those in American Caucasians.Statistical analysis showed that the genotype distribution of CCR5-△32,CCR2-641 and SDF1-3' A alleles was in equilibrium according to the Hardy-Weinberg equation.Conclusion The CCR5-△32 mutation may not be a major resistant factor against HIV-1 infection in indigenous Han Chinese.The significance of higher frequencies of CCR2-641 and SDF1-3' A alleles (0.20023 and 0.2791)in the Han population remains to be clarified in HIV-1-positive carriers and AIDS patients. 展开更多
关键词 HIV-1· chemokine receptor 5 (CCR5) · polymorphism ·allelic frequency· mutation
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DICER1 mutations in twelve Chinese patients with pleuropulmonary blastoma 被引量:5
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作者 Siyu Cai Xisi Wang +3 位作者 Wen Zhao Libing Fu Xiaoli Ma Xiaoxia Peng 《Science China(Life Sciences)》 SCIE CAS CSCD 2017年第7期714-720,共7页
Our aim is to examine the impact of DICER1 mutations on the pathogenesis of pleuropulmonary blastoma(PPB) by evaluating the mutation frequency and investigating the family history of Chinese patients with PPB. The fam... Our aim is to examine the impact of DICER1 mutations on the pathogenesis of pleuropulmonary blastoma(PPB) by evaluating the mutation frequency and investigating the family history of Chinese patients with PPB. The family histories of 12 children with PPB recruited consecutively were surveyed. Blood samples from patients and their first-degree relatives were tested for DICER1 mutations. Whole-genome sequencing of blood samples and formalin-fixed and paraffin-embedded(FFPE) tumor tissue was performed in one family with twins. Twelve patients with PPB included six type II and six type III cases. Seven of the12 patients harbored DICER1 mutations, six of which were frameshift or nonsense mutations. Another case carried a germline DICER1 mutation affecting the splice site. FFPE sample had a nonsense mutation in TDG and missense mutations in DICER1.In addition, two cases with DICER1 mutations were found to have lung cysts preceding the diagnosis of PPB. Furthermore, one patient had a family history remarkable for thyroid diseases. Our results indicate that the germline mutation frequency in Chinese patients with PPB is similar to the ones reported for patients from USA, UK, and Japan. Moreover, our study strongly suggests that investigating the family history and detecting germline DICER1 mutations might be of benefit to increasing awareness and improving the accuracy of the differential diagnosis of PPB from non-malignant lung cysts. 展开更多
关键词 China DICER1 mutation pleuropulmonary blastoma
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Transfer efficiency optimal control of magnetic resonance coupled system of wireless power transfer based on frequency control 被引量:41
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作者 TAN LinLin HUANG XueLiang +2 位作者 HUANG Hui ZOU YuWei LI Hui 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第6期1428-1434,共7页
In order to suppress the fast decrease of the transfer efficiency of magnetic resonance coupled wireless power transfer system(MRCWPTS) with distance increase,this paper investigates the impact factors of the system t... In order to suppress the fast decrease of the transfer efficiency of magnetic resonance coupled wireless power transfer system(MRCWPTS) with distance increase,this paper investigates the impact factors of the system transfer efficiency and is,then formulates a new efficiency optimal control method based on frequency control.Based upon this control method two optimal control schemes are designed to achieve transfer efficiency control of the system.Simulations and experiments show that the proposed efficiency optimal control method can effectively stabilize the system transfer efficiency in a certain range so as to successfully solve the subtle issue of transfer efficiency variation with distance. 展开更多
关键词 magnetic coupling frequency control efficiency optimal wireless power transfer
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Estimating mean trabecular bone spacing based on the combination of Hilbert transform and fundamental frequency estimation
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作者 李颖 徐峰 +3 位作者 刘成成 许凯亮 他得安 王威琪 《Science Foundation in China》 CAS 2017年第3期57-71,共15页
Ultrasonic backscatter signals from cancellous bone are sensitive to the microstructure of trabecular bone,and thus enable the feasibility to extract microstructural information of trabecular bone.The mean trabecular ... Ultrasonic backscatter signals from cancellous bone are sensitive to the microstructure of trabecular bone,and thus enable the feasibility to extract microstructural information of trabecular bone.The mean trabecular bone spacing(MTBS)is an important parameter for characterizing bone microstructure.This paper proposes an MTBS estimation method based on the combination of Hilbert transform and fundamental frequency estimation(CHF). The CHF was verified with ultrasonic backscatter signals from simulations and in vitro measurements at a central frequency of 5MHz.The CHF method was compared with the simplified inverse filter tracking(SIFT)method,Simons' Quadratic Transformation(QT)method,Singular Spectrum Analysis(SSA)method,and Spectral Autocorrelation(SAC)method.Monte-Carlo simulations were performed by varying the MTBS,signal-to-noise ratio(SNR),standard deviation of regular spacing(SDRS),amplitude ratio of diffuse scattering to regular scattering(Ad)and frequency dependent attenuation(nBUA).The simulation results showed that the CHF method had a better performance in MTBS estimation under almost all the examination conditions except for SNR.The estimation percentage correct(EPC)was greater than 90% when the MTBS was in the range of 0.4to 1.4mm.In the in vitro measurements,the estimated EPC by the CHF method was91.25±7.81%(mean±standard deviation).A significant correlation was observed for the CHF-estimated MTBS and micro-computed tomography(μ-CT)-measured values(R^2=0.75,p<0.01).These results demonstrate that the CHF method is anti-interference for MTBS estimation and can be used to estimate trabecular bone spacing. 展开更多
关键词 Ultrasonic backscatter Mean trabecular bone spacing estimation Hilbert transform and fundamental frequency estimation Cancellous bone microstructure
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Understanding the commonalities and differences in genomic organizations across closely related bacteria from an energy perspective 被引量:1
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作者 MA Qin CHEN Xin +5 位作者 LIU Chao MAO XiZeng ZHANG HanYuan JI Fei WU ChunGuo XU Ying 《Science China(Life Sciences)》 SCIE CAS 2014年第11期1121-1130,共10页
The availability of a large number of sequenced bacterial genomes facilitates in-depth studies about why genes(operons)in a bacterial genome are globally organized the way they are.We have previously discovered that(t... The availability of a large number of sequenced bacterial genomes facilitates in-depth studies about why genes(operons)in a bacterial genome are globally organized the way they are.We have previously discovered that(the relative)transcription-activation frequencies among different biological pathways encoded in a genome have a dominating role in the global arrangement of operons.One complicating factor in such a study is that some operons may be involved in multiple pathways with different activation frequencies.A quantitative model has been developed that captures this information,which tends to be minimized by the current global arrangement of operons in a bacterial(and archaeal)genome compared to possible alternative arrangements.A study is carried out here using this model on a collection of 52 closely related Escherichia coli genomes,which revealed interesting new insights about how bacterial genomes evolve to optimally adapt to their environments through adjusting the(relative)genomic locations of the encoding operons of biological pathways once their utilization and hence transcription activation frequencies change,to maintain the above energy-efficiency property.More specifically we observed that it is the frequencies of the transcription activation of pathways relative to those of the other encoded pathways in an organism as well as the variation in the activation frequencies of a specific pathway across the related genomes that play a key role in the observed commonalities and differences in the genomic organizations of genes(and operons)encoding specific pathways across different genomes. 展开更多
关键词 genomic organization transcription activation frequency pathway modeling comparative genomics analysis
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