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老年腹部手术患者BIS监测下异丙酚闭环与开环靶控输注模式的麻醉效果比较
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作者 姚朋 张丹 《临床心身疾病杂志》 CAS 2024年第3期51-55,共5页
目的探讨脑电双频指数(BIS)监测下异丙酚闭环与开环靶控输注在老年腹部手术患者中的麻醉效果。方法将76例老年腹部手术患者按照随机数字表法分为对照组38例[采用异丙酚开环靶控输注(OLTCI)]和研究组38例[采用异丙酚闭环靶控输注(CLTCI)... 目的探讨脑电双频指数(BIS)监测下异丙酚闭环与开环靶控输注在老年腹部手术患者中的麻醉效果。方法将76例老年腹部手术患者按照随机数字表法分为对照组38例[采用异丙酚开环靶控输注(OLTCI)]和研究组38例[采用异丙酚闭环靶控输注(CLTCI)]。比较两组患者的麻醉效果、麻醉药物使用情况、不同时间阶段血流动力学指标以及手术相关指标。结果在麻醉诱导阶段和麻醉维持阶段,研究组患者麻醉满意时间占比高于对照组,麻醉过深时间占比低于对照组,且麻醉维持阶段的麻醉过浅时间占比低于对照组(P<0.05或0.01)。研究组患者异丙酚诱导总量少于对照组,每小时泵调整次数多于对照组(P<0.01)。两组患者意识消失、插管即刻、插管后1 min时的心率(HR)均慢于麻醉诱导前,但研究组患者意识消失、插管即刻、插管后1 min时的HR均快于对照组(P<0.05或0.01)。研究组患者诱导阶段各时期的平均动脉压(MAP)水平无明显变化(P>0.05)。对照组患者意识消失、插管即刻、插管后1 min时的MAP水平均低于麻醉诱导前,且插管即刻、插管后1 min时的MAP水平低于研究组(P<0.05或0.01)。两组患者手术时间、麻醉时间、拔管时间、苏醒时间以及恶心、呕吐发生率等手术相关指标比较,差异无统计学意义(P>0.05)。结论对老年腹部手术患者行BIS监测下异丙酚CLTCI时,可按照BIS的数值及时调整异丙酚用量,避免了血流动力学指标的大幅度波动,可减少麻醉药物的用量,值得临床大力推广。 展开更多
关键词 脑电双频指数 异丙酚 闭环靶控输注 开环靶控输注 老年 腹部手术
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Hydrothermal Syntheses,Crystal Structures,and Characterization of Two Zinc(Ⅱ)Complexes Containing Flexible Bis(benzimidazole)Ligands 被引量:2
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作者 刘晓兵 张泽婷 +3 位作者 王艳彦 刘蕊 赵永 崔广华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第11期1745-1753,共9页
Two zinc(II) complexes, namely, [Zn(L1)Cl2]2 (1) and {[Zn(L2)(tbta)]·3H2O}n (2) (L1 = 1,3-bis(2-methylbenzimidazol-1-ylmethyl)benzene, H2tbta = tetrabromoterephthalic acid, L2 = 1,3-bis(2-methylbe... Two zinc(II) complexes, namely, [Zn(L1)Cl2]2 (1) and {[Zn(L2)(tbta)]·3H2O}n (2) (L1 = 1,3-bis(2-methylbenzimidazol-1-ylmethyl)benzene, H2tbta = tetrabromoterephthalic acid, L2 = 1,3-bis(2-methylbenzimidazol-1-yl)-2-propanol) have been successfully obtained under hydrothermal conditions. Complex 1 displays binuclear structure which is further extended into a 1D supramolecular chain through π–π stacking. Complex 2 features 2D (4,4) network based on L2/tbta2– double linker. The thermal stability, fluorescence properties and catalytic activities of two complexes for degradation of Methyl orange in a Fenton-like process were discussed. 展开更多
关键词 bis(benzimidazole) catalytic property crystal structure fluorescence property zinc(Ⅱ) complex
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Engineering of oxygen vacancy and bismuth cluster assisted ultrathin Bi_(12)O_(17)Cl_(2)nanosheets with efficient and selective photoreduction of CO_(2)to CO
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作者 Meili Guan Ni Lu +7 位作者 Xuan Zhang Qiuwan Wang Jian Bao Guiye Chen Hao Yu Huaming Li Jiexiang Xia Xuezhong Gong 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期1-11,共11页
The photocatalytic conversion of CO_(2)into solar‐powered fuels is viewed as a forward‐looking strategy to address energy scarcity and global warming.This work demonstrated the selective photoreduction of CO_(2)to C... The photocatalytic conversion of CO_(2)into solar‐powered fuels is viewed as a forward‐looking strategy to address energy scarcity and global warming.This work demonstrated the selective photoreduction of CO_(2)to CO using ultrathin Bi_(12)O_(17)Cl_(2)nanosheets decorated with hydrothermally synthesized bismuth clusters and oxygen vacancies(OVs).The characterizations revealed that the coexistences of OVs and Bi clusters generated in situ contributed to the high efficiency of CO_(2)–CO conversion(64.3μmol g^(−1)h^(−1))and perfect selectivity.The OVs on the facet(001)of the ultrathin Bi_(12)O_(17)Cl_(2)nanosheets serve as sites for CO_(2)adsorption and activation sites,capturing photoexcited electrons and prolonging light absorption due to defect states.In addition,the Bi‐cluster generated in situ offers the ability to trap holes and the surface plasmonic resonance effect.This study offers great potential for the construction of semiconductor hybrids as multiphotocatalysts,capable of being used for the elimination and conversion of CO_(2)in terms of energy and environment. 展开更多
关键词 bi cluster bi_(12)O_(17)Cl_(2)nanosheet oxygen vacancy photocatalytic CO_(2)reduction
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早期BIS和凝血功能监测对心肺复苏患者预后的价值分析
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作者 杨陆 高永艳 《中国科技期刊数据库 医药》 2024年第1期0156-0159,共4页
探究对心肺复苏患者应用早期BIS和凝血功能监测的预后价值分析。方法 选取2022年6月至2023年6月在我院接受过心肺复苏患者60例,对预后良好组与预后不良组患者的数据进行分析,预后良好组在经过了BIS和凝血功能监测之后,其CQI指标以及BIS... 探究对心肺复苏患者应用早期BIS和凝血功能监测的预后价值分析。方法 选取2022年6月至2023年6月在我院接受过心肺复苏患者60例,对预后良好组与预后不良组患者的数据进行分析,预后良好组在经过了BIS和凝血功能监测之后,其CQI指标以及BIS等方面的指标得到了明显改善,两组患者之间的数据差异十分显著(P<0.05)。预后良好组的CPR持续时间、入院APACHE评分以及GCS评分方面的临床特征水平均得到改善(P<0.05),具有统计学意义;患者的ROSC时间上并未出现显著变化(P>0.05),不具有统计学意义。结论 对心肺复苏患者进行早期BIS和凝血功能监测,能在一定程度上有效改善患者的相关指证数据,对患者的预后有着较高的价值。因此,BIS和凝血功能监测值得在临床上进行推广。 展开更多
关键词 早期bis 凝血功能监测 心肺复苏患者 预后价值
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A 2D Wavy Parquet Architecture Based on the Biphenyl-3,3',4,4'-tetracarboxylic Acid and Bis(2-benzimidazole)alkanes Ligands 被引量:5
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作者 冯国栋 姜娈 +4 位作者 陈强 杨得锁 王敏娟 李宗孝 罗小林 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第1期45-50,共6页
A double-T-shaped ligand (H4BPTC) and bis(2-benzimidazole)alkanes as the spacers have been firstly used to direct the assembly of a 2D coordination polymer with wavy parquet network topology, [Zn(BPTC)0.5(H2C2... A double-T-shaped ligand (H4BPTC) and bis(2-benzimidazole)alkanes as the spacers have been firstly used to direct the assembly of a 2D coordination polymer with wavy parquet network topology, [Zn(BPTC)0.5(H2C2EIm)(H2O)]n (1, C24H18ZnN4O5, Mr = 507.79, H4BPTC = biphenyl-3,3',4,4'-tetracarboxylic acid, H2C2EIm = 2,2'-(1,2-ethanediyl)-bis(1H-benzi- midazole), which was determined by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/n with a = 1.1844(5), b = 1.4019(5), c = 1.4026(5) nm, β = 108.359(5)°, V = 2.2104(15) nm3, Z = 4, Dc = 1.526 g/cm3, μ(MoKα) = 1.156 mm-1, F(000) = 1040, S = 1.038, the final R = 0.0427 and wR = 0.0793 for 3834 reflections with I 2σ(I). The compound units are linked through BPTC ligands into a wavilness parquet 2D layer and further connected into a 3D framework via π-π packing interactions between the adjacent H2C2EIm ligands and weak N-H…O hydrogen bonding between uncoordinated carboxylate and the nitrogen atoms of H2C2EIm as well as the free water molecules. 展开更多
关键词 synthesis crystal structure zinc(II) bis(2-benzimidazoles) double-T-shaped ligand
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Flexible Bis(benzimidazole)-based Ligands Directed the Structure Characteristics of Coordination Polymers Based on Diphenic Acid Co-ligands:Syntheses, Structures and Properties 被引量:1
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作者 屠长征 杨玉亭 +2 位作者 许丽丽 晏帮领 汪帆 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第1期155-164,5,共11页
Two new coordination polymers [Cu_2(bbim)(dpa)_2(C_2H_5OH)_2](1), [Co(dpa)_2(bbbm)](2)(H_2dpa = diphenic acid, bbim = 1,1?-(1,6-hexanediyl)bis-1H-benzimidazole, bbbm = 1,1?-(1,4-butanediyl)bis-1 H-benzimidazole) const... Two new coordination polymers [Cu_2(bbim)(dpa)_2(C_2H_5OH)_2](1), [Co(dpa)_2(bbbm)](2)(H_2dpa = diphenic acid, bbim = 1,1?-(1,6-hexanediyl)bis-1H-benzimidazole, bbbm = 1,1?-(1,4-butanediyl)bis-1 H-benzimidazole) constructed from bis(benzimidazole)-based ligands with different lengths and diphenic acid co-ligand have been synthesized under solvothermal conditions.Complex 1 possesses Cu-dpa helical chains. The adjacent chains are connected by the bbim ligands into two-dimensional(2D) 3-connected(63) topology. Differently, the layer structure of 2 was consisted by one-dimensional chains containing alternated 8-and 18-membered rings. Furthermore,the thermal stability and fluorescence property for all crystalline materials have been investigated. 展开更多
关键词 coordination polymer crystal structure diphenic acid bis(benzimidazole)-based LIGANDS fluorescence
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Synthesis, Crystal Structure and Catalytic Properties of a New 2D Nickel(II) Coordination Polymer Based on Flexible Bis(benzimidazole) 被引量:1
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作者 杨瑞 葛明 +1 位作者 VAN HECKE Kristof 崔广华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第12期1819-1825,共7页
A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The... A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/c with a = 9.4760(3), b = 24.0408(8), c = 16.5871(5) A, β = 99.832(3)°, V = 3723.2(2) A3, Z = 4, Dc = 1.348 g/cm3, F(000) = 1576, the final R = 0.0486 and w R = 0.0936 for 2938 observed reflections with I 】 2σ(I) for the complex. Structural analysis shows that the coordination polymer possesses a 2D(4,4) layer structure which is composed of Ni(II) centers bridged by L ligand with two kinds of conformations and further assembled into a 3D supramolecular network via π-π stacking interactions. In addition, the fluorescence and catalytic properties, for the degradation of Congo red, of the complex were investigated. 展开更多
关键词 bis(benzimidazole) catalytic property crystal structure Ni(II) complex
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SYNTHESIS, CHARACTERIZATION, METAL-UPTAKE BEHAVIOR OF BIS(BENZIMIDAZOLE) RESIN SUPPORTED ON EPOXIDE POLYMER 被引量:1
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作者 束家有 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2006年第4期395-401,共7页
The new chelate resins, abbreviated as PNBMZs and PBBMZs based on epoxide polymer, were synthesized by polycondensation of N,N-diglycidyl-4-glycidyloxyaniline or 1,4-bis(2,3-epoxypropyl)benzene with the primary amin... The new chelate resins, abbreviated as PNBMZs and PBBMZs based on epoxide polymer, were synthesized by polycondensation of N,N-diglycidyl-4-glycidyloxyaniline or 1,4-bis(2,3-epoxypropyl)benzene with the primary amine group of 1,3-bis(benzimidazol-2yl)propylamine (BBPAH). The ion exchangers contain 2.71-3.23 mmol of the ligand contents per gram of the resin. Batch extraction capacities were determined for the metal chloride salts in buffer solutions in the pH range from -1 to 6.0. The chelate resins were very selective for Cu^2+, Zn^2+, Cd^2+ in the presence of other divalent transition metal ions. The maximum uptake capacities of PNBMZ (synthetic molar ratio = 1:1.5) under non-competitive condition were found to be 0.94 mmol/g for Cu^2+ at pH = 2, 1.3 mmol/g for Cd^2+ at pH = 1 and 1.75 mmol/g for Zn^2+ at pH = -1 respectively. While in the case of PBBMZ, it was 1.39 mmol/g for Cd〉 at pH = 1. The metal-uptake behaviors for both of them showed strong pH dependence, and their extraction capacities increase with decreasing pH. The uptake of Cu^2+ by the resin PNBMZs at pH = 1 was found to be rather fast with t1/2 = 18 min. Metal-uptake experiments under competitive conditions also confirm that the chelate resins have a high selectivity for Cu^2+, Zn^2+, Cd^2+ and the contrary pH dependence. 展开更多
关键词 Chelate resin benzimidazole Matrix of epoxide polymer-type Metal uptake.
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Synthesis,Crystal Structure and in vitro Anticancer Studies of 1,2-Bis-benzimidazole-phenyl Copper(Ⅱ) Complex 被引量:5
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作者 林娟娟 蒙法艳 李雪华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第1期41-48,共8页
One new benzimidazole derivative copper(II) complex 1(C10H6Cu N2, Mr = 217.71) has been synthesized and characterized by FT-IR and X-ray single-crystal diffraction. It crystallizes in orthorhombic, space group Pbc... One new benzimidazole derivative copper(II) complex 1(C10H6Cu N2, Mr = 217.71) has been synthesized and characterized by FT-IR and X-ray single-crystal diffraction. It crystallizes in orthorhombic, space group Pbcn with a = 17.417(2), b = 8.9963(8), c = 11.3432(9) ?, V = 1777.3(3) ?3, Z = 8, μ(Mo Kα) = 2.403, F(000) = 872, Dc = 1.627 g/cm3. The final R = 0.0598 for 1153 observed reflections with I 〉 2σ(I) and w R = 0.17 for all data. The in vitro anti-cancer activities of 1, Cu Cl2 and the benzimidazole ligand L were investigated using human cervical(Hela) and hepatocellular carcinoma(Hep-G2) cancer cell lines. The copper(II) complex can greatly inhibit the cell proliferation and show stronger cytotoxic activities against the tested cancer cell lines than both the ligand and copper(II) salt. 展开更多
关键词 1 2-bis-benzimidazole-phenyl copper(II) X-ray anti-cancer in vitro
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Synthesis and Crystal Structure of catena-Poly[bis-(benzimidazole)cobalt(II) μ-Phthalato]
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作者 薛宇虹 张骊 徐端钧 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第9期1043-1045,共3页
The title polymeric complex [Co(C8H4O4)(C7H6N2)2]n has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group C2/c with a=7.7865(12), b... The title polymeric complex [Co(C8H4O4)(C7H6N2)2]n has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group C2/c with a=7.7865(12), b=20.4215(18), c=13.4880(14)A°,β=103.298(2)°, V=2087.3(4)A°^3, Mr=459.32, Z=4, Dc=1.462 g/cm^3,μ=0.859 mm^-1, F(000)=940, R=0.0636 and wR=0.1639 for 1278 observed reflections (I〉2σ(I)). The complex assumes a distorted tetrahedral coordination geometry, formed by two phthalate anions and two benzimidazoles (bzim). The phthalate anions bridge the neighboring Co(Ⅱ) atoms to form the polymeric chains. The centroid distance of 3.471(3)A° between the parallel bzim rings of adjacent polymeric chains suggests the existence of π-π stacking. 展开更多
关键词 polymeric Co(Ⅱ) complex benzimidazole crystal structure π-π stacking
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Cadmium(Ⅱ) Nitrite Complex Based on the Bis(2-benzimidazole) and Aromatic Carboxylate Ligands
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作者 姜娈 冯国栋 +3 位作者 陈强 杨得锁 李宗孝 罗小林 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第4期529-534,共6页
A new cadmium(Ⅱ) nitrite complex Cd2(H2C3PIm)2(BDC)(NO2)2(1,H2C3PIm = 2,2'-(1,3-propanediyl)bis(1H-benzimidazole),H2BDC = 1,4-benzenedicarboxylic acid) has been synthesized by solvothermal reaction in ... A new cadmium(Ⅱ) nitrite complex Cd2(H2C3PIm)2(BDC)(NO2)2(1,H2C3PIm = 2,2'-(1,3-propanediyl)bis(1H-benzimidazole),H2BDC = 1,4-benzenedicarboxylic acid) has been synthesized by solvothermal reaction in formamide,and its structure(C42H36Cd2N10O8,Mr = 1033.61) was determined by single-crystal X-ray diffraction analysis.The crystal belongs to the monoclinic system,space group P21/n with a = 0.9859(5),b = 0.8936(5),c = 2.3188(5) nm,β = 97.576(5)°,V = 2.025(16) nm3,Z = 2,Dc = 1.695 g/cm3,μ(MoKα) = 1.118 mm-1,F(000) = 1036,S = 1.017,the final R = 0.0304 and wR = 0.0752 for 3761 reflections with I 〉 2σ(I).The centrosymmetric complex 1 contains a dimer in which two distorted octahedral Cd(II) centers are bridged by BDC ligand and chelated by H2C3PIm.The units of the complex are linked via weak N-H···O hydrogen bonds between the nitrito and the BDC ligands,leading to the formation of a 1D zigzag chain along the b axis.The π-π packing interactions contribute to the formation of a three-dimensional supramolecular architecture.The complex exhibits strong photoluminescence at room temperature. 展开更多
关键词 solvothermal reaction crystal structure cadmium(Ⅱ) bis(2-benzimidazoles) nitrite
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离子化合物[2,6-bis(Benzimidazol-2-yl)pyridineH_2]^(2+)·[SbCl_5]^(2-)的合成、晶体结构及荧光性质 被引量:2
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作者 郭应臣 卓立宏 +3 位作者 乔占平 黄群增 孙汝中 闫家伟 《无机化学学报》 SCIE CAS CSCD 北大核心 2008年第1期15-20,共6页
利用邻苯二胺、2,6-吡啶二甲酸与三氯化锑在盐酸溶液中经水热反应,合成了一种新的离子型化合物[2,6-bis(Benzimidazol-2-yl)pyridineH2]2+.[SbCl5]2-。通过化学分析、元素分析、热重分析、红外光谱及荧光光谱对结构和性质进行了表征,用X... 利用邻苯二胺、2,6-吡啶二甲酸与三氯化锑在盐酸溶液中经水热反应,合成了一种新的离子型化合物[2,6-bis(Benzimidazol-2-yl)pyridineH2]2+.[SbCl5]2-。通过化学分析、元素分析、热重分析、红外光谱及荧光光谱对结构和性质进行了表征,用X-射线单晶衍射测定了该化合物的晶体结构。化合物的晶体属三斜晶系,P1空间群。Sb3+与其周围5个氯离子配位,构成一个畸变四方锥构型[SbCl5]2-配位结构,2个配阴离子[SbCl5]2-之间通过Sb(1)…Cl(1)ii次级键形成四元环状结构,并与2,6-二(苯并咪唑-2′)吡啶两价阳离子,通过离子键及氢键形成三维网状离子化合物晶体。该化合物具有很好的荧光特性。 展开更多
关键词 2 6-二(苯并咪唑-2′)吡啶 离子化合物 水热合成 晶体结构 荧光光谱
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A New Efficient Synthesis of Bisphenol A Diether Bis-imidazoles and Bis-benzimidazoles
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作者 Cheng He ZHOU Jun WEI +2 位作者 Zhong Jun LI Ru Gang XIE Meng Shen CAI( Department of Bioorganic Chemistry, State Key Laboratory of Natural and Biomimetic Drugs,School of Pharmaceutical Sciences, Beijing Medical University, Beding 100083 Depotment of Chemistry 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第10期917-918,共2页
A new efficient synthesis of bisphenol A diether bis-imidazoles and bis-benzimidazoles by bromoalkylation and imidazolylation or benzimidazolylation two-step reactions from commercial bisphenol A, imidazole, 2-methyli... A new efficient synthesis of bisphenol A diether bis-imidazoles and bis-benzimidazoles by bromoalkylation and imidazolylation or benzimidazolylation two-step reactions from commercial bisphenol A, imidazole, 2-methylimidazole and benzimidazole is reported. 展开更多
关键词 bisphenol A imidazole benzimidazole ether synthesis
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ABPBI/SPEEK高温质子交换复合膜的制备与表征
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作者 张琪 陆婕妤 +1 位作者 钟璟 郭向前 《现代化工》 CAS CSCD 北大核心 2024年第2期91-96,共6页
采用溶剂蒸发法制备聚(2,5-苯并咪唑)/磺化聚醚醚酮(ABPBI/SPEEK)高温质子交换复合膜。考察了SPEEK的掺入对ABPBI/SPEEK质子交换复合膜的结构及性能的影响。结果表明,ABPBI膜和ABPBI/SPEEK复合膜在高温下的热稳定性能良好;随着SPEEK的掺... 采用溶剂蒸发法制备聚(2,5-苯并咪唑)/磺化聚醚醚酮(ABPBI/SPEEK)高温质子交换复合膜。考察了SPEEK的掺入对ABPBI/SPEEK质子交换复合膜的结构及性能的影响。结果表明,ABPBI膜和ABPBI/SPEEK复合膜在高温下的热稳定性能良好;随着SPEEK的掺入,ABPBI/SPEEK复合膜有更好的氧化稳定性和机械性能,ABPBI/SPEEK(20%)复合膜在芬顿试剂中96 h后的质量损失为0.84%,其拉伸强度为120.51 MPa,相较于Nafion 117膜明显提高;ABPBI/SPEEK(20%)复合膜的酸掺杂率为186.68%,该膜在160℃、0%RH时的质子电导率为3.4 mS/cm,约为ABPBI膜的1.78倍。 展开更多
关键词 聚(2 5-苯并咪唑) 磺化聚醚醚酮 质子交换膜 高温 质子电导率
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放电等离子体烧结BaTiO_(3-x)Bi(Ni_(0.5)Zr_(0.5))O_(3)陶瓷的介电和阻抗性能
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作者 肖长江 马金明 张群飞 《材料工程》 EI CAS CSCD 北大核心 2024年第5期203-211,共9页
采用传统固相反应法合成BaTiO_(3-x)Bi(Ni_(0.5)Zr_(0.5))O_(3)粉体和放电等离子体烧结技术制备BaTiO_(3-x)Bi(Ni_(0.5)Zr_(0.5))O_(3)陶瓷,研究陶瓷的晶体结构、微观形貌、介电和阻抗性能。结果表明:BaTiO_(3)-0.10Bi(Ni_(0.5)Zr_(0.5)... 采用传统固相反应法合成BaTiO_(3-x)Bi(Ni_(0.5)Zr_(0.5))O_(3)粉体和放电等离子体烧结技术制备BaTiO_(3-x)Bi(Ni_(0.5)Zr_(0.5))O_(3)陶瓷,研究陶瓷的晶体结构、微观形貌、介电和阻抗性能。结果表明:BaTiO_(3)-0.10Bi(Ni_(0.5)Zr_(0.5))O_(3)陶瓷具有钙钛矿型,晶体结构为赝立方相,晶粒尺寸约为0.64μm,密度为5.81 g/cm^(3),最大介电常数为7149,且随频率升高相变温度向高温移动。在1 kHz下,BaTiO_(3)-0.10Bi(Ni_(0.5)Zr_(0.5))O_(3)陶瓷的ln(1/ε-1/ε_(m))与ln(T-T_(m))的拟合曲线斜率为1.61,在-41~169℃内,Δε/ε_(25℃)≤±15%,表明样品有良好的温度稳定性。此外,随温度和频率的升高,材料的阻抗降低,在50℃下,当频率为100 Hz时,电阻为2.33×10~6Ω,离子电导率为10^(-8)S/cm。 展开更多
关键词 BaTiO_(3-x)bi(Ni_(0.5)Zr_(0.5))O_(3) 放电等离子体烧结 赝立方相 介电性能 弛豫特性 阻抗
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融合改进Bi-RRT和DWA算法的无人机动态路径规划
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作者 罗毅 陈新洲 《电光与控制》 CSCD 北大核心 2024年第5期77-82,共6页
为解决无人机在复杂环境中的避障问题,提出一种融合改进Bi-RRT和DWA的无人机动态路径规划算法。通过设置启发式函数、动态步长和安全距离改进Bi-RRT算法,提升全局路径的搜索效率和安全性;之后,修剪路径中的冗余路段并对修剪后的路径进... 为解决无人机在复杂环境中的避障问题,提出一种融合改进Bi-RRT和DWA的无人机动态路径规划算法。通过设置启发式函数、动态步长和安全距离改进Bi-RRT算法,提升全局路径的搜索效率和安全性;之后,修剪路径中的冗余路段并对修剪后的路径进行插值与平滑操作获得全局最优路径;对DWA修正障碍物距离评价函数并引入目标点距离评价函数,提升局部预测轨迹评分的准确性;然后,实时输出速度指令控制无人机跟踪全局最优路径并实现局部动态避障。仿真实验表明,改进Bi-RRT算法生成的路径更短更平滑、安全性更高且规划时间更少;在同时存在动、静态障碍物的复杂环境中,所提融合算法能控制无人机精准地跟踪全局最优路径并高效地完成局部动态避障。 展开更多
关键词 无人机 路径规划 bi-RRT算法 DWA 融合算法
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基于BO-BiGRU-Attention短期电力负荷预测
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作者 包广斌 张瑞 +2 位作者 彭璐 李明 赵怀森 《计算机技术与发展》 2024年第6期201-206,共6页
电力系统的可靠供应对于工业、商业和居民的生活至关重要。为了满足电力需求并维持电力系统的稳定运行,提高短期电力负荷预测的准确性和可靠性尤为关键;针对负荷数据存在复杂的非线性特性,该文提出一种基于贝叶斯优化算法的双向门控循... 电力系统的可靠供应对于工业、商业和居民的生活至关重要。为了满足电力需求并维持电力系统的稳定运行,提高短期电力负荷预测的准确性和可靠性尤为关键;针对负荷数据存在复杂的非线性特性,该文提出一种基于贝叶斯优化算法的双向门控循环单元和注意力机制(BO-BiGRU-Attention)的混合预测模型对短期电力负荷进行精准预测。首先,使用Min-Max Normalization方法对负荷数据进行归一化处理。其次,利用BiGRU网络捕获序列中的长期依赖关系和上下文信息,结合注意力机制,通过在输入序列的不同部分给予不同的权重,从而突出关键特征。最后,针对BiGRU-Attention模型的超参数难以选取最优解的问题,引入贝叶斯优化算法对BiGRU-Attention模型的超参数进行寻优,完成短期电力负荷的预测。采用印度北部某地区的电力负荷数据进行预测分析,仿真结果表明,BO-BiGRU-Attention网络表现优于其他模型,各误差评价指标最小,其中MAE、RMSE和MAPE分别为56.67,73.49和1.16%,预测精度达到了99.47%。 展开更多
关键词 电力系统 负荷预测 贝叶斯优化算法 双向门控循坏单元 注意力机制
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基于DKF-Bi-LSTM的阀控式铅酸电池SOC在线估计方法
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作者 李练兵 刘艳杰 +3 位作者 王海良 李思佳 李秉宇 杜旭浩 《中国测试》 CAS 北大核心 2024年第2期28-37,共10页
精准估计阀控式铅酸蓄电池的荷电状态(SOC)对变电站直流系统的可靠性和安全性有着重要的作用,为提高SOC估算精度,提出一种基于DKF-Bi-LSTM的铅酸蓄电池SOC在线估计方法,基于二级结构的双卡尔曼滤波算法,分别进行模型估计和状态估计。通... 精准估计阀控式铅酸蓄电池的荷电状态(SOC)对变电站直流系统的可靠性和安全性有着重要的作用,为提高SOC估算精度,提出一种基于DKF-Bi-LSTM的铅酸蓄电池SOC在线估计方法,基于二级结构的双卡尔曼滤波算法,分别进行模型估计和状态估计。通过卡尔曼滤波算法对模型参数进行动态跟踪,进而基于扩展卡尔曼滤波算法在线估算电池SOC值。将在线估算结果、电流、电压、温度值作为Bi-LSTM神经网络的输入,电池SOC预测值作为网络输出,实现对电池SOC的在线估计。经测试发现,与DKF和Bi-LSTM算法相比,DKF-Bi-LSTM算法的SOC预测均方根误差更小,其SOC在线估计方法具有更高的准确性。 展开更多
关键词 阀控式铅酸电池 荷电状态 等效电路模型 卡尔曼滤波 扩展卡尔曼滤波 双向长短时记忆神经网络
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基于聚类的HPO-BILSTM光伏功率短期预测
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作者 周育才 肖添 +2 位作者 谢七月 付强 钟敏 《太阳能学报》 EI CAS CSCD 北大核心 2024年第4期512-518,共7页
考虑到光伏发电功率在不同天气类型下的波动性和不确定性,对此提出一种基于模糊C均值聚类算法(FCM)和猎食者优化算法(HPO)优化双向长短期记忆网络(BILSTM)的光伏发电短期功率预测模型。首先对光伏发电数据进行处理和分析,再进行主成分分... 考虑到光伏发电功率在不同天气类型下的波动性和不确定性,对此提出一种基于模糊C均值聚类算法(FCM)和猎食者优化算法(HPO)优化双向长短期记忆网络(BILSTM)的光伏发电短期功率预测模型。首先对光伏发电数据进行处理和分析,再进行主成分分析(PCA)降维和FCM聚类算法将数据按天气类型分为阴、晴、雨;最后通过HPO筛选得出BILSTM神经网络的最佳超参数,避免因超参数设置不佳对实验带来的影响,进一步提高实验的准确性和模型的泛化能力。最后通过预测和对比实验进行分析,验证所提方法的优越性。 展开更多
关键词 光伏发电 双向长短期记忆网络 功率预测 降维 聚类 优化算法
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乳腺超声BI-RADS 4类在乳腺癌患者良恶性鉴别中的应用
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作者 周彩虹 唐珊 《影像研究与医学应用》 2024年第3期29-31,34,共4页
目的:探讨乳腺超声BI-RADS 4类在乳腺癌患者良恶性鉴别中的应用价值。方法:回顾性分析2023年1月—10月在盐城市妇幼保健院治疗的50例乳腺影像报告和数据系统(BI-RADS)4类乳腺结节患者的临床资料,均实施乳腺超声检查,以病理检查结果为金... 目的:探讨乳腺超声BI-RADS 4类在乳腺癌患者良恶性鉴别中的应用价值。方法:回顾性分析2023年1月—10月在盐城市妇幼保健院治疗的50例乳腺影像报告和数据系统(BI-RADS)4类乳腺结节患者的临床资料,均实施乳腺超声检查,以病理检查结果为金标准,分析乳腺超声对乳腺结节良恶性的诊断效能,对比良恶性结节的超声征象。结果:病理结果显示,恶性14例,良性36例;乳腺超声检查显示,恶性15例,良性35例,乳腺超声检查的灵敏度为85.71%、特异度为91.67%、准确率为90.00%,Kappa值=0.849,与病理检查结果一致性良好;恶性结节与良性结节在年龄、单发或多发、内部回声、后方回声方面差异无统计学意义(P>0.05),但恶性结节直径大于良性结节,且形态、边缘、高回声声晕、微钙化、汇聚征、弹性评分、血流分布等与良性结节相比差异有统计学意义(P<0.05)。结论:乳腺超声BI-RADS 4类在乳腺良恶性鉴别中的应用效果显著,良恶性病灶具有不同的超声影像特征,能提高对乳腺癌的诊断效能。 展开更多
关键词 bi-RADS 4类 乳腺结节 良恶性 超声
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