A new flexible double betaine L （L = 1,4-bis（pyridinio-4-carboxylato-N-methyl）benzene, C20H16N2O4） and its cadmium（Ⅱ） complex [Cd（H2O）aL（NO3）]NO3.H2O 1 were synthesized. Complex 1 was obtained by self-assem...A new flexible double betaine L （L = 1,4-bis（pyridinio-4-carboxylato-N-methyl）benzene, C20H16N2O4） and its cadmium（Ⅱ） complex [Cd（H2O）aL（NO3）]NO3.H2O 1 were synthesized. Complex 1 was obtained by self-assembly reaction of [Cd（NO3）2]-4H2O and L in hot water,and its crystal structure was determined by single-crystal X-ray diffraction analysis. Crystallographic data for complex 1： C20H24CdN4O14.H2O, Mr = 674.85, monoclinic, space group P21/c, a =13.7854（3）, b = 14.2820（3）, c = 14.9188（4） ,A°, β = 116.418（1）°, V = 2630.5（1）A°^3, Z = 4, Dc= 1.704g/cm^3,/J（MoKα） = 0.911 mm^-1, F（000） = 1368, the final R = 0.0315 and wR = 0.0768 for 3637 observed reflections with I 〉 2σ（I）. In complex 1, L acts as a monodentate ligand to link a Cd（Ⅱ） ion in a novel coordination mode of double betaines. The mononuclear [Cd（H2O）aL（NO3）] units are connected through intermolecular hydrogen bonds and π-π stacking reactions to generate a 3D network.展开更多
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
AIM To examine usefulness of virtual biopsy using endocytoscopy by comparing the in vivo endocytoscopic and histopathological images of gastric cancers.METHODS Endocytoscopy was performed in 30 patients with early gas...AIM To examine usefulness of virtual biopsy using endocytoscopy by comparing the in vivo endocytoscopic and histopathological images of gastric cancers.METHODS Endocytoscopy was performed in 30 patients with early gastric cancer. Of these, 26 patients showed well differentiated adenocarcinomas, while 4 patients showed poorly differentiated adenocarcinomas(including one signet ring cell carcinoma). Cancerous and non-cancerous areas were observed after double staining with 0.05% crystal violet and 0.1% methylene blue. The endocytoscopic images obtained were evaluated by an expert endoscopist and an expert pathologist without knowledge of patient clinical data, and endocytoscopic and histopathological diagnoses were compared.RESULTS The endocytoscopic images of the cancerous area were assessed as evaluable in 25(83.3%) and 27(90%) patients by endoscopist A and pathologist B, respectively, and those of the non-cancerous area as evaluable in 28(93.3%) and 23(76.7%) patients by the endoscopist and pathologist, respectively. The sensitivity, specificity, and diagnostic accuracy of gastric cancer diagnosis using evaluable endocytoscopic images were 88.0% and 92.9%, and 90.6% by endoscopist A, and 88.9% and 91.3%, and 90.0% by pathologist B, respectively. Evaluation of the diagnostic concordance rate between the endoscopist and the pathologist by inter-observer agreement calculation revealed no significant difference between the two observers. The inter-observer agreement(κ-value) for endocytoscopic diagnosis was 0.745. CONCLUSION Endocytoscopy is useful for the differentiation of cancerous from non-cancerous gastric mucosa, making it a promising tool for virtual biopsy.展开更多
To achieve real-time monitoring of humidity in various applications,we prepared facile and ultra-thin CoAl layered double hydroxide(CoAl LDH)nanosheets to engineer quartz crystal microbalances(QCM).The characteristics...To achieve real-time monitoring of humidity in various applications,we prepared facile and ultra-thin CoAl layered double hydroxide(CoAl LDH)nanosheets to engineer quartz crystal microbalances(QCM).The characteristics of CoAl LDH were investigated by transmission electron microscopy(TEM),X-ray diffraction(XRD),X-ray photoelectric spectroscopy(XPS),Brunauer–Emmett–Telle(BET),atomic force microscopy(AFM)and zeta potential.Due to their large specific surface area and abundant hydroxyl groups,CoAl LDH nanosheets exhibit good humidity sensing performance.In a range of 11.3%and 97.6%relative humidity(RH),the sensor behaved an ultrahigh sensitivity(127.8 Hz/%RH),fast response(9.1 s)and recovery time(3.1 s),low hysteresis(3.1%RH),good linearity(R^(2)=0.9993),stability and selectivity.Besides,the sensor can recover the initial response frequency after being wetted by deionized water,revealing superior self-recovery ability under high humidity.Based on in-situ Fourier transform infrared spectroscopy(FT-IR),the adsorption mechanism of CoAl LDH toward water molecules was explored.The QCM sensor can distinguish different respiratory states of people and wetting degree of fingers,as well as monitor the humidity in vegetable packaging,suggesting excellent properties and a promising application in humidity sensing.展开更多
N-doped porous carbon has been extensively investigated for broad electrochemical applications.The performance is significantly impacted by the electrochemical double layer(EDL),which is material dependent and hard to...N-doped porous carbon has been extensively investigated for broad electrochemical applications.The performance is significantly impacted by the electrochemical double layer(EDL),which is material dependent and hard to characterize.Limited understanding of doping-derived EDL structure hinders insight into the structure-performance relations and the rational design of high-performance materials.Thus,we analyzed the mass and chemical composition variation of EDL within electrochemical operation by electrochemical quartz crystal microbalance,in-situ X-ray photoelectron spectroscopy,and time-offlight secondary ion mass spectrometry.We found that N-doping triggers specifically adsorbed propylene carbonate solvent in the inner Helmholtz plane(IHP),which prevents ion rearrangement and enhances the migration of cations.However,this specific adsorption accelerated solvent decomposition,rendering rapid performance degradation in practical devices.This work reveals that the surface chemistry of electrodes can cause specific adsorption of solvents and change the EDL structure,which complements the classical EDL theory and provide guidance for practical applications.展开更多
Lead-free double perovskite halides are emerging optoelectronic materials that are alternatives to leadbased perovskite halides.Recently,single-crystalline double perovskite halides were synthesized,and their intrigui...Lead-free double perovskite halides are emerging optoelectronic materials that are alternatives to leadbased perovskite halides.Recently,single-crystalline double perovskite halides were synthesized,and their intriguing functional properties were demonstrated.Despite such pioneering works,lead-free double perovskite halides with better crystallinity are still in demand for applications to novel optoelectronic devices.Here,we realized highly crystalline Cs2AgBiBr6 single crystals with a well-defined atomic ordering on the microscopic scale.We avoided the formation of Ag vacancies and the subsequent secondary Cs3Bi2Br9 by manipulating the initial chemical environments in hydrothermal synthesis.The suppression of Ag vacancies allows us to reduce the trap density in the as-grown crystals and to enhance the carrier mobility further.Our design strategy is applicable for fabricating other lead-free halide materials with high crystallinity.展开更多
A 1D supramolecular compound [dmbbbi]（1） and a 2D cobalt coordination polymer [Co（dmbbbi）（ox）] 2（2） [dmbbbi=1,1-（1,4-butanediyl）bis（5,6-dimethylbenzimidazole）,ox=oxalate],C48H52Co2N8O8,were obtained under ...A 1D supramolecular compound [dmbbbi]（1） and a 2D cobalt coordination polymer [Co（dmbbbi）（ox）] 2（2） [dmbbbi=1,1-（1,4-butanediyl）bis（5,6-dimethylbenzimidazole）,ox=oxalate],C48H52Co2N8O8,were obtained under hydrothermal conditions by tuning the molar ratio of the reactants.The crystal structure analysis reveals that in compound 1,the adjacent dmbbbi molecules connect with each other via hydrogen bonds to form a 1D supramolecular chain.In compound 2,two crystallographically independent Co2＋ ions show the same six-coordination mode.Each Co2＋ ion is coordinated by four oxygen atoms from two ox anions and two nitrogen atoms from two cis-dmbbbi ligands.The adjacent Co2＋ ions are bridged by ox anions to generate an infinite 1D zigzag chain,which is extended by pairs of dmbbbi ligands to form a 2D honeycomb-like（6,3） network.Moreover,the thermal stability and the electrochemical property of compound 2 were studied.展开更多
Reaction of HgCl2 and double betaine ligands in water at about 80 ℃ yielded two new Hg（Ⅱ） complexes,[Hg（L1）Cl2]·H2O 1 and [Hg2（L2）Cl4]·3HgCl2 2（L1 = 1,3-bis（pyridinio-4-carboxylato）-propane,L2 = 1...Reaction of HgCl2 and double betaine ligands in water at about 80 ℃ yielded two new Hg（Ⅱ） complexes,[Hg（L1）Cl2]·H2O 1 and [Hg2（L2）Cl4]·3HgCl2 2（L1 = 1,3-bis（pyridinio-4-carboxylato）-propane,L2 = 1,4-bis（pyridinio-4-carboxylato）-1,4-dimenthylbenzene）.Their struc-tures have been characterized by single-crystal X-ray diffraction techniques.The structure of 1 contains 1-D chains,in which the adjacent Hg（Ⅱ） atoms are bridged by L1 ligands in a syn-syn bis-monodentate mode.The chains are further connected through face-to-face π-π stacking interactions between pyridine rings to generate an infinite double-chain network.In 2,two Hg（Ⅱ） atoms are joined by L2 ligands in the same coordination mode as 1 to form an isolated dinuclear structure.The thermal stabilities of both complexes have also been investigated.展开更多
We report a double Q-switched 946 nm laser with a magnesium-oxide-doped LiNbO3 （MgO：LN） electro-optic （EO） crystal and a monolayer molybdenum diselenide （MoSe2） saturable absorber （SA）. A pulsed laser diode s...We report a double Q-switched 946 nm laser with a magnesium-oxide-doped LiNbO3 （MgO：LN） electro-optic （EO） crystal and a monolayer molybdenum diselenide （MoSe2） saturable absorber （SA）. A pulsed laser diode side-pumped long neodymium-doped yttrium aluminum garnet rod （φ3×65 mm） is used as the gain medium. Large pulse energy up to 3.15 mJ and peak power up to 346 kW are generated at the repetition rate of 550 Hz, corresponding to the beam quality factors of Mx^2=3.849, My^2=3.868. Monolayer MoSe2 nanosheets applied in the experiment would be a promising SA for a passive Q-switching operation.展开更多
By hydrothermal synthesis, a manganese（H） tetracarboxylate [Mn（2,2′-bipyridi- ne）（btec）0.5（HEO）]En （H4btec = 1,2,4,5-benzenetetracarboxylic acid） was obtained and characterized by single-crystal X-ray diffr...By hydrothermal synthesis, a manganese（H） tetracarboxylate [Mn（2,2′-bipyridi- ne）（btec）0.5（HEO）]En （H4btec = 1,2,4,5-benzenetetracarboxylic acid） was obtained and characterized by single-crystal X-ray diffraction, IR, elemental analysis and thermogravimetric analysis. It crystallizes in triclinic, space group P1, with a = 7.721（4）, b = 8.905（5）, c = 10.712（6）A, a = 80.899（8）, β = 70.371（8）, y = 78.201（8）°, Z = 2, V= 675.8（7）A3, Mr= 354.20, De= 1.741 g/cm^3,μ = 1.007 mm^-1, F（000） = 360, S = 0.956, （△/σ）max = 0.000, the final R = 0.0490 and wR = 0.1262. This compound presents an infinite 1D polymer featuring a double-chain structure. The Mn（Ⅱ） ion is five-coordinated. The four carboxylate groups of btec4- are all deprotonated and coordinated to four Mn atoms in a monodentate fashion, forming a 1D double chain structure with a cavity. Such chains are interconnected by π-π stacking interactions into 2D layers which are further interlinked into a supramolecular structure by hydrogen bonds.展开更多
A novel double 1：11 series arsenotungstate, [Cu^I（phen）2]5H6[Sm（AsW11O39）2]·6H2O （phen=1, 10-phenanthroline） was synthesized by the hydrothermal method and characterized by elemental analysis, 1R spectra, ...A novel double 1：11 series arsenotungstate, [Cu^I（phen）2]5H6[Sm（AsW11O39）2]·6H2O （phen=1, 10-phenanthroline） was synthesized by the hydrothermal method and characterized by elemental analysis, 1R spectra, and single-crystal X-ray diffraction. The title compound was monoclinic, space group P2 1/c, a=3.75710（2） nm, b=1.39776（8） nm, c=-3.33735（18） nm, β=96.967（10）°, V=17.3969（17） nm^3, Z=4. Single crystal X-ray structural analyses revealed that the dimeric polyanion, [SmAs2W22O78]^1-, consisted of one central Sm^3＋ ion and two tetradentate heteropoly ligands [ASW11O39]^7-. The Sm^3＋ ion and two tetradentate defective [AsW11O39]^7- anions were joined together by the sharing of four oxygen atoms from each heteropoly ligand. The bond valence sum （BVS） calculations of the title compound suggested that all four Cu atoms were in the ＋1 oxidation sate.展开更多
基金This work was supported by the NSF for Distinguished Young Scientist of China (20425104) and the NSF of Fujian Province (2005I017, A0420002)
文摘A new flexible double betaine L （L = 1,4-bis（pyridinio-4-carboxylato-N-methyl）benzene, C20H16N2O4） and its cadmium（Ⅱ） complex [Cd（H2O）aL（NO3）]NO3.H2O 1 were synthesized. Complex 1 was obtained by self-assembly reaction of [Cd（NO3）2]-4H2O and L in hot water,and its crystal structure was determined by single-crystal X-ray diffraction analysis. Crystallographic data for complex 1： C20H24CdN4O14.H2O, Mr = 674.85, monoclinic, space group P21/c, a =13.7854（3）, b = 14.2820（3）, c = 14.9188（4） ,A°, β = 116.418（1）°, V = 2630.5（1）A°^3, Z = 4, Dc= 1.704g/cm^3,/J（MoKα） = 0.911 mm^-1, F（000） = 1368, the final R = 0.0315 and wR = 0.0768 for 3637 observed reflections with I 〉 2σ（I）. In complex 1, L acts as a monodentate ligand to link a Cd（Ⅱ） ion in a novel coordination mode of double betaines. The mononuclear [Cd（H2O）aL（NO3）] units are connected through intermolecular hydrogen bonds and π-π stacking reactions to generate a 3D network.
基金supported by the research grant of Phytochemistry Key Laboratory of Shaanxi Province(No.11JS006,11JS007)the Scientific Research Fund of shaanxi Provincial Education Department(No.11JK0603)
文摘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.
文摘AIM To examine usefulness of virtual biopsy using endocytoscopy by comparing the in vivo endocytoscopic and histopathological images of gastric cancers.METHODS Endocytoscopy was performed in 30 patients with early gastric cancer. Of these, 26 patients showed well differentiated adenocarcinomas, while 4 patients showed poorly differentiated adenocarcinomas(including one signet ring cell carcinoma). Cancerous and non-cancerous areas were observed after double staining with 0.05% crystal violet and 0.1% methylene blue. The endocytoscopic images obtained were evaluated by an expert endoscopist and an expert pathologist without knowledge of patient clinical data, and endocytoscopic and histopathological diagnoses were compared.RESULTS The endocytoscopic images of the cancerous area were assessed as evaluable in 25(83.3%) and 27(90%) patients by endoscopist A and pathologist B, respectively, and those of the non-cancerous area as evaluable in 28(93.3%) and 23(76.7%) patients by the endoscopist and pathologist, respectively. The sensitivity, specificity, and diagnostic accuracy of gastric cancer diagnosis using evaluable endocytoscopic images were 88.0% and 92.9%, and 90.6% by endoscopist A, and 88.9% and 91.3%, and 90.0% by pathologist B, respectively. Evaluation of the diagnostic concordance rate between the endoscopist and the pathologist by inter-observer agreement calculation revealed no significant difference between the two observers. The inter-observer agreement(κ-value) for endocytoscopic diagnosis was 0.745. CONCLUSION Endocytoscopy is useful for the differentiation of cancerous from non-cancerous gastric mucosa, making it a promising tool for virtual biopsy.
基金supported by the Shanghai Natural Science Foundation(No.21ZR1427500)the Agricultural Project of Shanghai Science and Technology Innovation Action Plan(No.19391901600).
文摘To achieve real-time monitoring of humidity in various applications,we prepared facile and ultra-thin CoAl layered double hydroxide(CoAl LDH)nanosheets to engineer quartz crystal microbalances(QCM).The characteristics of CoAl LDH were investigated by transmission electron microscopy(TEM),X-ray diffraction(XRD),X-ray photoelectric spectroscopy(XPS),Brunauer–Emmett–Telle(BET),atomic force microscopy(AFM)and zeta potential.Due to their large specific surface area and abundant hydroxyl groups,CoAl LDH nanosheets exhibit good humidity sensing performance.In a range of 11.3%and 97.6%relative humidity(RH),the sensor behaved an ultrahigh sensitivity(127.8 Hz/%RH),fast response(9.1 s)and recovery time(3.1 s),low hysteresis(3.1%RH),good linearity(R^(2)=0.9993),stability and selectivity.Besides,the sensor can recover the initial response frequency after being wetted by deionized water,revealing superior self-recovery ability under high humidity.Based on in-situ Fourier transform infrared spectroscopy(FT-IR),the adsorption mechanism of CoAl LDH toward water molecules was explored.The QCM sensor can distinguish different respiratory states of people and wetting degree of fingers,as well as monitor the humidity in vegetable packaging,suggesting excellent properties and a promising application in humidity sensing.
基金the National Science Foundation for Excellent Young Scholars of China(21922815)the National Natural Science Foundation of China(22179139)+2 种基金the National Key Research and Development Program of China(2020YFB1505800)the Youth Innovation Promotion Association of CAS(2019178)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of the CAS(XDA21000000)。
文摘N-doped porous carbon has been extensively investigated for broad electrochemical applications.The performance is significantly impacted by the electrochemical double layer(EDL),which is material dependent and hard to characterize.Limited understanding of doping-derived EDL structure hinders insight into the structure-performance relations and the rational design of high-performance materials.Thus,we analyzed the mass and chemical composition variation of EDL within electrochemical operation by electrochemical quartz crystal microbalance,in-situ X-ray photoelectron spectroscopy,and time-offlight secondary ion mass spectrometry.We found that N-doping triggers specifically adsorbed propylene carbonate solvent in the inner Helmholtz plane(IHP),which prevents ion rearrangement and enhances the migration of cations.However,this specific adsorption accelerated solvent decomposition,rendering rapid performance degradation in practical devices.This work reveals that the surface chemistry of electrodes can cause specific adsorption of solvents and change the EDL structure,which complements the classical EDL theory and provide guidance for practical applications.
基金the National Research Foundation of Korea(NRF)grants funded by the Ministry of Science and ICT(NRF-2020R1F1A1057220)the Ministry of Education(NRF-2019R1A6A1A11053838)+4 种基金C.W.A acknowledges the support by Basic Science Research Program through the NRF funded the Ministry of Science and ICT(NRF-2018R1A2B6009210)Y.H.H.acknowledges the support by the NRF of Korea(NRF-2019R1I1A3A01063856)H.Y.J.acknowledges the support from Creative Materials Discovery Program(NRF-2016M3D1A1900035)Y.-H.S.acknowledges the support by Basic Science Research Programthrough the NRF funded the Ministry of Science and ICT(NRF-2018R1A2B6005159)Experiments at PLS-II were supported in part by MSICT and POSTECH.
文摘Lead-free double perovskite halides are emerging optoelectronic materials that are alternatives to leadbased perovskite halides.Recently,single-crystalline double perovskite halides were synthesized,and their intriguing functional properties were demonstrated.Despite such pioneering works,lead-free double perovskite halides with better crystallinity are still in demand for applications to novel optoelectronic devices.Here,we realized highly crystalline Cs2AgBiBr6 single crystals with a well-defined atomic ordering on the microscopic scale.We avoided the formation of Ag vacancies and the subsequent secondary Cs3Bi2Br9 by manipulating the initial chemical environments in hydrothermal synthesis.The suppression of Ag vacancies allows us to reduce the trap density in the as-grown crystals and to enhance the carrier mobility further.Our design strategy is applicable for fabricating other lead-free halide materials with high crystallinity.
基金Supported by the National Natural Science Foundation of China(No.21171025)the Natural Science Foundation of Liaoning Province,China(Nos.201102003 and 2009402007)
文摘A 1D supramolecular compound [dmbbbi]（1） and a 2D cobalt coordination polymer [Co（dmbbbi）（ox）] 2（2） [dmbbbi=1,1-（1,4-butanediyl）bis（5,6-dimethylbenzimidazole）,ox=oxalate],C48H52Co2N8O8,were obtained under hydrothermal conditions by tuning the molar ratio of the reactants.The crystal structure analysis reveals that in compound 1,the adjacent dmbbbi molecules connect with each other via hydrogen bonds to form a 1D supramolecular chain.In compound 2,two crystallographically independent Co2＋ ions show the same six-coordination mode.Each Co2＋ ion is coordinated by four oxygen atoms from two ox anions and two nitrogen atoms from two cis-dmbbbi ligands.The adjacent Co2＋ ions are bridged by ox anions to generate an infinite 1D zigzag chain,which is extended by pairs of dmbbbi ligands to form a 2D honeycomb-like（6,3） network.Moreover,the thermal stability and the electrochemical property of compound 2 were studied.
基金financially supported by the National Natural Science Foundation of China (20871115)Fujian Provincial Key Laboratory of Nanomaterials (NM10-06)
文摘Reaction of HgCl2 and double betaine ligands in water at about 80 ℃ yielded two new Hg（Ⅱ） complexes,[Hg（L1）Cl2]·H2O 1 and [Hg2（L2）Cl4]·3HgCl2 2（L1 = 1,3-bis（pyridinio-4-carboxylato）-propane,L2 = 1,4-bis（pyridinio-4-carboxylato）-1,4-dimenthylbenzene）.Their struc-tures have been characterized by single-crystal X-ray diffraction techniques.The structure of 1 contains 1-D chains,in which the adjacent Hg（Ⅱ） atoms are bridged by L1 ligands in a syn-syn bis-monodentate mode.The chains are further connected through face-to-face π-π stacking interactions between pyridine rings to generate an infinite double-chain network.In 2,two Hg（Ⅱ） atoms are joined by L2 ligands in the same coordination mode as 1 to form an isolated dinuclear structure.The thermal stabilities of both complexes have also been investigated.
基金supported by the National Natural Science Foundation of China(No.61205114)the Science & Technology Coordinator Innovation Plan Project of the Shaanxi Province(No.2011KTCL01-06)the Key Laboratory Project of Shaanxi(No.2010JS112)
文摘We report a double Q-switched 946 nm laser with a magnesium-oxide-doped LiNbO3 （MgO：LN） electro-optic （EO） crystal and a monolayer molybdenum diselenide （MoSe2） saturable absorber （SA）. A pulsed laser diode side-pumped long neodymium-doped yttrium aluminum garnet rod （φ3×65 mm） is used as the gain medium. Large pulse energy up to 3.15 mJ and peak power up to 346 kW are generated at the repetition rate of 550 Hz, corresponding to the beam quality factors of Mx^2=3.849, My^2=3.868. Monolayer MoSe2 nanosheets applied in the experiment would be a promising SA for a passive Q-switching operation.
基金This work was supported by Jiangxi provincial department of education’s item of Science and Technology (No. [2007]316)
文摘By hydrothermal synthesis, a manganese（H） tetracarboxylate [Mn（2,2′-bipyridi- ne）（btec）0.5（HEO）]En （H4btec = 1,2,4,5-benzenetetracarboxylic acid） was obtained and characterized by single-crystal X-ray diffraction, IR, elemental analysis and thermogravimetric analysis. It crystallizes in triclinic, space group P1, with a = 7.721（4）, b = 8.905（5）, c = 10.712（6）A, a = 80.899（8）, β = 70.371（8）, y = 78.201（8）°, Z = 2, V= 675.8（7）A3, Mr= 354.20, De= 1.741 g/cm^3,μ = 1.007 mm^-1, F（000） = 360, S = 0.956, （△/σ）max = 0.000, the final R = 0.0490 and wR = 0.1262. This compound presents an infinite 1D polymer featuring a double-chain structure. The Mn（Ⅱ） ion is five-coordinated. The four carboxylate groups of btec4- are all deprotonated and coordinated to four Mn atoms in a monodentate fashion, forming a 1D double chain structure with a cavity. Such chains are interconnected by π-π stacking interactions into 2D layers which are further interlinked into a supramolecular structure by hydrogen bonds.
基金the Natural Science Foundation of Henan Province (0611011900)
文摘A novel double 1：11 series arsenotungstate, [Cu^I（phen）2]5H6[Sm（AsW11O39）2]·6H2O （phen=1, 10-phenanthroline） was synthesized by the hydrothermal method and characterized by elemental analysis, 1R spectra, and single-crystal X-ray diffraction. The title compound was monoclinic, space group P2 1/c, a=3.75710（2） nm, b=1.39776（8） nm, c=-3.33735（18） nm, β=96.967（10）°, V=17.3969（17） nm^3, Z=4. Single crystal X-ray structural analyses revealed that the dimeric polyanion, [SmAs2W22O78]^1-, consisted of one central Sm^3＋ ion and two tetradentate heteropoly ligands [ASW11O39]^7-. The Sm^3＋ ion and two tetradentate defective [AsW11O39]^7- anions were joined together by the sharing of four oxygen atoms from each heteropoly ligand. The bond valence sum （BVS） calculations of the title compound suggested that all four Cu atoms were in the ＋1 oxidation sate.
