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单指向性水听器指向性影响因素的研究 被引量:3
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作者 李书光 张军 胡松青 《石油大学学报(自然科学版)》 CSCD 北大核心 2003年第2期132-133,共2页
对二元相控阵单指向性水听器的指向性影响因素进行了理论分析 ,并对部分影响因素进行了实验验证。结果表明 ,两个基元输出信号的幅值发生变化 ,或者其移相角度发生漂移 ,都会对单指向水听器的性能产生影响。这为单指向性水听器的设计制... 对二元相控阵单指向性水听器的指向性影响因素进行了理论分析 ,并对部分影响因素进行了实验验证。结果表明 ,两个基元输出信号的幅值发生变化 ,或者其移相角度发生漂移 ,都会对单指向水听器的性能产生影响。这为单指向性水听器的设计制作提供了一定的参考依据。 展开更多
关键词 单指向性 水听器 影响因素 基阵 基元 指向函数
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单指向性水听器的研究 被引量:2
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作者 李书光 徐春华 《石油大学学报(自然科学版)》 CSCD 1996年第5期108-110,共3页
对二元基阵经电子移相形成单指向性的原理进行了理论分析。并采用三种形状不同的压电材料作为基阵的基元,制作了三种水听器,实验测定结果与理论结果一致,获得较好的单指向性。
关键词 压电水声器 单指向性 水声换能器
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ES937单指向性宽频电容话筒
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《世界专业音响与灯光》 2004年第4期12-12,共1页
关键词 ES937 收音头 单指向性 宽频电容话筒
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一种实用的管道有源消声器
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作者 孙海燕 沙家正 《南京大学学报(自然科学版)》 CAS CSCD 北大核心 2001年第4期515-521,共7页
为了降低成本 ,推广应用 ,设计了一种实用的管道有源消声器装置 ,其中所用的的单指向次级源由一个专门的移相器和一个功放组成 ,结构简单 ,便于调节 ;同时 ,专门设计了一种新的单指向传声器电路 ,利用普通的驻极体传声器 ,制成单指向性... 为了降低成本 ,推广应用 ,设计了一种实用的管道有源消声器装置 ,其中所用的的单指向次级源由一个专门的移相器和一个功放组成 ,结构简单 ,便于调节 ;同时 ,专门设计了一种新的单指向传声器电路 ,利用普通的驻极体传声器 ,制成单指向性传声器 ,其成本低 ,且单指向性能良好 ;最后分别研制了高频和低频两套管道有源消声器 .实验结果表明 ,整套装置的消声效果好 ,构造简单 ,显著地降低了成本 ,因而有利于在实践中推广使用 . 展开更多
关键词 单指向性 次级源 传声器 移相器 功放 管道有源消声器 设计
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An Introduction to the Theory of C~*-modules
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作者 邓宏钧 刘德权 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第2期72-77,共6页
This paper,combined algebraical structure with analytical system,has studied the part of theory of C~*-modules over A by using the homolgical methods, where A is a commutative C~*-algebra over complex number field C. ... This paper,combined algebraical structure with analytical system,has studied the part of theory of C~*-modules over A by using the homolgical methods, where A is a commutative C~*-algebra over complex number field C. That is to say we have not only defined some relevant new concept,but also obtained some results about them. 展开更多
关键词 commutative C~*-algebra C~*-module C~*-homomorphism
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Polymorphisms of micro RNA target genes IL12B, INSR, CCND1 and IL10 in gastric cancer 被引量:2
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作者 Vytenis Petkevicius Violeta Salteniene +10 位作者 Simonas Juzenas Thomas Wex Alexander Link Marcis Leja Ruta Steponaitiene Jurgita Skieceviciene Limas Kupcinskas Laimas Jonaitis Gediminas Kiudelis Peter Malfertheiner Juozas Kupcinskas 《World Journal of Gastroenterology》 SCIE CAS 2017年第19期3480-3487,共8页
AIM To evaluate associations between mi RNA target genes IL12B,INSR,CCND1 and IL10 polymorphisms and gastric cancer(GC)in European population.METHODS Gene polymorphisms were analyzed in 508 controls and474 GC patients... AIM To evaluate associations between mi RNA target genes IL12B,INSR,CCND1 and IL10 polymorphisms and gastric cancer(GC)in European population.METHODS Gene polymorphisms were analyzed in 508 controls and474 GC patients from 3 tertiary centers in Germany,Lithuania and Latvia.Controls were patients from the out-patient departments,who were referred for upper endoscopy because of dyspeptic symptoms and had no history of previous malignancy.Gastric cancer(GC)patients had histopathological verification of gastric adenocarcinoma.Genomic DNA was extracted using salting out method from peripheral blood mononuclear cells.IL12B T>G(rs1368439),INSR T>C(rs1051690),CCND1 A>C(rs7177)and IL10 T>C(rs3024498)SNPs were genotyped by the real-time polymerase chain reaction.Associations between gene polymorphism and GC were evaluated using multiple logistic regression analysis with adjustment for sex,age and country of birth.RESULTS We observed similar distribution of genotypes and allelic frequencies of all polymorphisms between GC patients and controls except of INSR rs1051690.The frequency of the T allele of INSR gene was significantly higher in GC patients than in controls(23.26%and 19.19%respectively,P=0.028).CT genotype was also more prevalent in patients compared to control group(38.48%and 30.12%respectively,P<0.021).Logistic regression analysis revealed that only one polymorphism(rs1051690 in INSR gene)was associated with increased risk of GC.Carriers of CT genotype had higher odds of GC when compared to CC genotype(OR=1.45,95%PI:1.08-1.95,P=0.01).Similar association was observed in a dominant model for INSR gene,where comparison of TT+CT vs CC genotypes showed an increased risk of GC(OR=1.44,95%PI:1.08-1.90,P=0.01).Other analyzed SNPs were not associated with the presence of GC.CONCLUSION INSR rs1051690 SNP is associated with increased risk of GC,while polymorphisms in IL12B,CCND1 and IL10genes are not linked with the presence of GC. 展开更多
关键词 Gastric cancer MIRNA Target genes Single-nucleotide polymorphisms
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