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基于1/4环状T型结构的源——负载耦合带通滤波器 被引量:1
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作者 张全琪 严曙辉 谭洪舟 《空间电子技术》 2015年第2期1-5,共5页
为了得到小尺寸、低损耗和低成本的射频带通滤波器,文章提出了一种利用1/4环状T型结构和源——负载耦合结构的带通滤波器(BPF)。1/4环状T型结构可以减少滤波器尺寸和方便中心频率的选择以及带宽的设计。同时根据信号多路径传输产生零点... 为了得到小尺寸、低损耗和低成本的射频带通滤波器,文章提出了一种利用1/4环状T型结构和源——负载耦合结构的带通滤波器(BPF)。1/4环状T型结构可以减少滤波器尺寸和方便中心频率的选择以及带宽的设计。同时根据信号多路径传输产生零点原理,在滤波器的输入和输出端之间加入可控耦合元件,因此采用源——负载耦合结构,从而增加传输零点,提高滤波器的阻带抑制性。文中最后设计和制作了一个插入损耗为0.16d B、回波损耗为-18d B、相对带宽为14%、中心频率为2.4GHz的小型滤波器,并对其进行了测试,测试结果与仿真结果吻合良好,说明这种设计方法是有效的。 展开更多
关键词 带通滤波器(BPF) 1/4环状T型结构 源-负载耦合结构 阻带抑制性
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SYNTHESIS OF 1H,1'H BIS(BENZ-△~4-IMIDAZOLINE)2,2'-SPIRO-TITANIUM DICHLORIDE
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作者 Wei Rongbao Liang Ya +1 位作者 Wu Jinguo Xue Qifeng 《Chinese Journal of Reactive Polymers》 1996年第1期7-11,共5页
New model compound 1H, 1' H-Bis (benz-△ ̄4-imidazoline) 2,2'-spiro-titanium dichloride was prepared and the structure of the compound was determined by 1R, us and elementary analysis.
关键词 H 1' H-Bis (benz-△ ̄4-imidazoline) 2 2'-spiro-titanium dichloride o-Phenylene diamine Titanium tetrachloride.
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X-ray Structure of 1- (3' -Phenyl-4' -morpholinyl-2' 5' - dithiole-1' - ylidene)-3, 4-biscarboethoxy-2-thionaphthalene
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作者 ZQU Jian-Ping ZENG Run-Sheng +2 位作者 SHEN Pei-Ying LIU Xian-Jun LU Zhong-E(Department of Chemistry, Suzhou University, Suzhou 215006) 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1998年第4期268-272,共5页
The title compound (C28H27NO5S3, Mr= 553. 69) was prepared bythe reaction of a-thiobenzoylthioformmorholine with diethyl acetylene dicarboxylate.The crystal is monoclinic, space group P21/n with a= 9. 160(3), b= 17. 7... The title compound (C28H27NO5S3, Mr= 553. 69) was prepared bythe reaction of a-thiobenzoylthioformmorholine with diethyl acetylene dicarboxylate.The crystal is monoclinic, space group P21/n with a= 9. 160(3), b= 17. 726(3), c=16. 602(3) A ; β= 100. 375(13)°; V=2651. 4(10) A3, Z=4, Dc= 1. 387 g/cm3, μ(MoKa) =0. 319 mm-1, F(000) =1160, R=0. 0428, wR(F2) =0. 0910 for 2438 observed reflections (I>2(I)). X-ray analysis reveals that interatomic distances for C(5)-C(6), C(13)-C(14) and C(21)-C(22) are 1. 331(4), 1. 351(4), 1. 344(4)A respectively, which show that they are normal C=C double bonds. All S-C bondlengths are similar to typical S-C single bonds (1. 75 - 1. 78 A ). The five-membered ring A (C(5) -C(6) -S(2)-C(13) -S(1) ) (Fig. 1) and six-membered ringB (C(14) -C(15) -C(20) -C(21)-C(22)-S(3) ) (Fig. 1) adopt the flat twist conformation. Furthermore, the morpholine ring adopts chair conformtion. 展开更多
关键词 X-ray crystallography 1-(3' -pbenyl-4' -morpholinyl-2' 5' -dithiole-1
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结构力学教学中几个问题的探讨
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作者 闫志红 《西北水力发电》 2007年第4期130-132,共3页
通过分析,对铰化法规则的应用作了补充;并针对力法中利用对称性取1/4结构分析时,属于自由度为零的可变体系的情况,采取了增加约束的方法及位移法进行计算。
关键词 铰化法 链杆 直接的独立的约束 对称性 1/4结构
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Synthesis and Crystal Structure of Carvedilol
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作者 CHEN Wei-Min XU Ji-Hong ( Institute of Pharmaceutical Sciences, the First Military Medical University,Guangzhou, 5l05l5) +3 位作者 ZENG Long-Mei ( Department of Chemistry, Zhongshan University ,Guangzhou 51O275) YU Kai-Bei ( Chengdu Institue of Analysis 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1998年第5期325-328,共4页
The crystal structure of the title compound carvedilol, C24H25N2O4(Mr= 406. 47), has determined by single-crystal X-ray diffraction. The crystal is mono-clinic with space group P21/c, a=9. 094(l), b= l2. 754(1), c= 18... The crystal structure of the title compound carvedilol, C24H25N2O4(Mr= 406. 47), has determined by single-crystal X-ray diffraction. The crystal is mono-clinic with space group P21/c, a=9. 094(l), b= l2. 754(1), c= 18. 330(2) A, β=97. 36(1 )°, V= 2l08. 5(4) A 3, Z= 4, D.= l. 280 g/cm3, F(000) = 864, μ=O. O88mm-1 and final R= O. O368, wR(F2) = 0.0787 for reflections (I>2σ(I) ). X-ray anal-ysis reveals that the crystal is composed of a pair of enantiomer, and there are hydrogenbonds O(3) -H(3O) -N(l ) between the two enantimers. There are two planes in themolecule. 展开更多
关键词 CARVEDILOL SYNTHESIS crystal structure
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