检索结果-南通市图书馆

Science china Chemistry 2025年

作者： Qingyu Niu Yingxiang Ye Lingna Su Xu He Zhiqiang Li Yu Liu School of Chemical Engineering and Technology Hebei University of Technology Fujian Provincial Key Laboratory of Polymer Materials College of Chemistry and Materials Science Fujian Normal University Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Nankai University College of Chemistry State Key Laboratory of Elemento-Organic Chemistry Nankai University

It is a great challenge to modulate purely organic fluorescence-phosphorescence dual emission in aqueous solution because the excited singlet and triplet states are in competition with each other. Herein, we report a crystalline 1:2 host-guest formed by selfassembly of 4-(4-bromophenyl)-pyridinium derivatives and cucurbit[8]uril, in which a rigid environment rich in weak interactions is directly demonstrated. Due to the inhibition of non-radiative transition and stabilization of triplet exciton in the crystalline environment, the crystalline inclusion complex exhibits ultralong room-temperature phosphorescence lifetime of 3.21 ms with an room-temperature phosphorescence(RTP) quantum yield up to 16.29%. Interestingly, the crystalline 1:2 hostguest complex demonstrates the ability of rapid identification and sensitive fluorescence-phosphorescence ratiometric detection behavior toward phenethylamine, a drug analogue, with a limit of detection as low as 27.5 nM. We believe that this study will undoubtedly broaden the utilizing scopes of RTP and offer a novel avenue for psychoactive substances monitoring.

关键词：

A Laser Imaging-LDV Coupling Measurement of Single Bubble Forming and Rising in Shear-thinning Fluid

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2014年第3期23卷 233-238页

作者： FAN Wenyuan YIN XiaoHong School of Chemistry and Chemical Engineering Tianjin University of Technology

The shape evolution of bubble formed in carboxymethylcellulose(CMC) aqueous solution was real-time observed using laser image technique. The flow fields of liquid around growing and rising bubble were measured by laser Doppler velocimetry(LDV), and the liquid mean velocity and its contour curves were obtained. The results show that bubble grows as spherical shape because of the dominant role of surface tension in the early period, and then is stretched gradually as a teardrop shape due to the common effect of buoyancy and shear-thinning of fluid. The axial mean velocity of liquid phase takes on Gaussian distribution with the symmetrical axis passing through orifice center. However, the radial mean velocity increases first and then decreases with the increase of the distance from measured point to the symmetrical axis above. Further, the axial component along symmetrical axis decreases initially and increases with the rise of height, as well as its corresponding contour map diverging gradually. The radial component, yet, decreases steadily with the rise of height, and the maximum value deviates towards the two sides until disappear, as it contour shape of butterfly's "front wing".

关键词： shear-thinning fluid bubble formation laser Doppler velocimetry flow field

Nearly transform-limited optical pulse from a passively mode-locked laser diode

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2004年第1期2卷 36-38页

作者：杜荣建向望华张贵忠 College of Precision Instrument and Opto-Electronics Engineering Key Laboratory of Opto-Electronics Information Technical Science EMC Tianjin University Tianjin 300072 Department of Opto-Electronic Information and Electronic Engineering Tianjin Institute of Technology Tianjin 300191 College of Precision Instrument and Opto-Electronics Engineering Key Laboratory of Opto-Electronics Information Technical Science EMC Tianjin University Tianjin 300072

An optical ultra-short pulse train with a duration of 2.9 ps was successfully generated from a passively mode-locked laser diode. The time-bandwidth product was 0.43, and it was very close to the transform-limited value of a Gaussian waveform. The highest peak power of 10 mW in an InP-based passively mode-locked laser has been achieved. The laser is promisng as an optical source for an ultra-high-speed bit rate transmission system, especially for the optical time division multiplexing (OTDM) system.

关键词： mode Nearly transform-limited optical pulse from a passively mode-locked laser diode SHG

Synthesis of Thieno[3,4-b]pyrazine-based Alternating Conjugated Polymers via Direct Arylation for Near-infrared OLED Applications

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2022年第2期40卷 138-146页

作者： Ze-Wang He Qiang Zhang Chen-Xi Li Hong-Ting Han Yan Lu School of Materials Science&Engineering Tianjin Key Laboratory for Photoelectric Materials and DevicesKey Laboratory of Display Materials&Photoelectric DevicesMinistry of EducationTianjin University of TechnologyTianjin 300384China College of Chemistry Nankai UniversityTianjin 300071China

Three alternating conjugated polymers,namely PFTP,PCz TP,and PSi TP,which combine a thieno[3,4-b]pyrazine(TP)unit with different benzene-based donor units such as 9,9-dioctylfluorene,9-heptadecyl-9H-carbazole and 5,5-dioctyl-5H-dibenzo[b,d]silole,were synthesized in good yield(>85%)and high molecular weight up to Mn=5.82×10^(4) via direct arylation polymerization(DAr P).All the resultant polymers exhibit moderate bandgap of about 1.80 e V and strong deep red/near-infrared emitting in the solid *** them,the PSi TP-based electroluminescence(EL)devices with an architecture of ITO/PEDOT:PSS/PTAA/emitting layer/TPBi/Li F/Al give the best performance with a maximum luminance of 2543 cd/m^(2) at 478 m A/cm^(2).This work expands the application scope of high-performance conjugated polymers which can be synthesized by DAr P.

关键词： Thieno[3 4-b]pyrazine Alternating D-A structure Direct arylation polymerization Conjugated polymer Organic light-emitting diodes

Syntheses and Crystal Structures of Two Cadmium(Ⅱ) Compounds Linked by N,N-Bis(3-pyridylmethyl)amine

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2013年第1期32卷 89-95页

作者：王思思崔志华王修光高东昭孙亚秋张国英许艳艳 Key Laboratory of Inorganic-organic Hybrid Functional Material Chemistry (tianjin Normal University) Ministry of Education tianjin Key Laboratory of Structure and Performance for Functional Molecule College of Chemistry Tianjin Normal University

Two cadmium（Ⅱ） compounds linked by a flexible dipyridyl ligand {[Cd2（Hbpma） Cl5（H2O）]·2H2O}n 1 and [Cd（Hbpma）Cl（H2O）2]2·2SO4·3H2O 2 （bpma = N,N-bis（3-pyridylmethyl）amine） have been synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 crystallizes in triclinic, space group P with a = 9.5612（6）, b = 11.3401（7）, c = 11.5069（12）, α = 112.8540（10）, β = 106.5330（10）, γ = 101.6680（10）°, V = 1030.77（14）3, C12H20Cd2Cl5N3O3, Mr = 656.36, Z = 2, Dc = 2.115 g/cm3, μ（MoKα） = 2.727 mm–1, F（000） = 636, S = 1.059, the final R = 0.0319 and wR = 0.0822 for 3443 observed reflections （I 2σ（I））. For complex 2, it belongs to triclinic, space group P with a = 10.9487（4）, b = 11.4197（4）, c = 15.4288（5）, α = 94.7470（10）, β = 104.1000（10）, γ = 104.42°, V = 1790.76（11）3, C24H42Cd2Cl2N6O15S2, Mr = 1014.46, Z = 2, Dc = 1.881 g/cm3, μ（MoKα） = 1.529 mm–1, F（000） = 1020, S = 1.050, the final R = 0.0178 and wR = 0.0451 for 6026 observed reflections （I 2σ（I））. Complex 1 is found to have tetranuclear Cd（Ⅱ） clusters which are bridged by the protonated bpma ligands leading to one-dimensional coordination polymers, whereas complex 2 consists of binuclear Cd（Ⅱ） structures linked by the protonated bpma ligands. Both complexes are assembled into three-dimensional supramolecular structures through hydrogen bonding interactions.

关键词： cadmium(Ⅱ) complex flexible dipyridyl ligand crystal structure

A Novel Binuclear Cu(Ⅱ) Complex with Nitroxide Radicals Exhibiting Ferromagnetic Interactions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2012年第1期31卷 39-44页

作者：刘尚远陈毅雯高东昭 tianjin Key Laboratory of Structure and Performance for Functional Molecule College of ChemistryTianjin Normal University

A new binuclear Cu（Ⅱ） complex with nitronyl nitroxide radicals [Cu（NIT3Py）2Cl2]2（NIT3Py = 2-（3＇-pyridinyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide） has been synthesized and structurally characterized by X-ray diffraction *** crystallizes in monoclinic,space group C2/c with a = 38.483（4）,b = 7.2450（8）,c = 27.559（3） ,β = 134.0180（10）°,V = 5525.6（10） 3,C48H64Cl4Cu2N12O8,Mr = 1206.00,Z = 4,Dc = 1.450 g/cm3,μ（MoKα） = 1.025 mm-1,F（000） = 2504,S = 1.066,the final R = 0.0471 and wR = 0.1121 for 3286 observed reflections（I 2σ（I））.The title complex consists of centrosymmetric dinuclear units [Cu（NIT3Py）2Cl2]2,in which the copper ions are square-pyramidally coordinated by two pyridyl nitrogen atoms of two radical ligands and three chlorine anions,two of which bridge the copper *** magnetic measurements show ferromagnetic interactions between the copper ions and the radical ligands.

关键词： Cu(Ⅱ) complex nitroxide radical crystal structure ferromagnetic interaction

Laser-rewritable room temperature phosphorescence based on in-situ polymerized tartaric acid

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2024年第9期67卷 3029-3038页

作者： Tuo-Yu Zhou Tai-Wen Li Hai-Fu Zhang Rui-Lin Chai Qian Zhao Penglin Zhang Guang-Yue Li Qian-Wen Wang Chang Li Yu Shu Zhi Fan Sheng-Hua Li College of Chemical Engineering and Materials Science College of SciencesTianjin University of Science&TechnologyTianjin 300457China College of Chemical Engineering North China University of Science and TechnologyTangshan 063210China tianjin Key Laboratory of Multiplexed Identification for Port Hazardous Chemicals Tianjin University of Science&TechnologyTianjin 300457China

Organic room temperature phosphorescence(RTP)materials have potential applications in information technology and ***,the precise control of the afterglow in reversible manners remains challenging for organic ***,we report a kind of organic RTP material fabricated by simple heating mixtures of tartaric acid(TA)and aromatic acids,which can switch their phosphorescence by *** mixtures show tunable phosphorescence from indigo to orange with phosphorescence efficiency of up to 53.99% due to locking different organic luminogens by the TA-formed matrix through the noncovalent *** afterglow of those materials lasts a few seconds and disappears by water fumigation,which can be repeated in response to wet/heat *** drop-casting those materials on glass slides,a laser-repatternable phosphorescence is achieved by facile laser direct writing and quenched by water *** results open the opportunity for the design of smart stimuli-responsive phosphorescence materials from sustainable natural products.

关键词： room temperature phosphorescence tunable afterglows tartaric acid laser direct writing stimuli-response

Synthesis,Crystal Structure and Magnetic Property of a New Cd(Ⅱ) Complex with Four Nitronyl Nitroxide Radicals

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2011年第6期30卷 853-857页

作者：崔志华魏海霞高东昭孙亚秋张国英许艳艳 tianjin Key Laboratory of Structure and Performance for Functional Molecule College of ChemistryTianjin Normal University

A new Cd（Ⅱ） complex with four nitronyl nitroxide radicals [Cd（NIT4Py）4Cl2]（NIT4Py = 2-（4＇-pyridinyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide） has been synthesized and structurally characterized by X-ray diffraction *** crystallizes in triclinic,space group P1 with a = 7.2441（4）,b = 13.6964（8）,c = 13.7354（8） ,α = 89.8610（10）,β = 77.9180（10）,γ = 87.2250（10）°,V = 1331.01（13） 3,C48H64CdCl2N12O8,Mr = 1120.41,Z = 1,Dc = 1.398 g/cm3,μ（MoKα） = 0.573 mm-1,F（000） = 582,S = 1.043,the final R = 0.0257 and wR = 0.0641 for 4333 observed reflections（I 〉2σ（I））.The title complex exists in the mononuclear-metal structures,in which each Cd（Ⅱ） ion adopts a distorted octahedral geometry and is coordinated by two Cl-anions and four pyridyl-N atoms from four NIT4Py *** magnetic measurements show weak antiferromagnetic interactions between the nitroxide radicals.

关键词： Cd(Ⅱ) complex nitronyl nitroxide radical crystal structure antiferromagnetic interaction

Y-shaped beam splitter by graded structure design in a photonic crystal

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2012年第11期57卷 1241-1245页

作者： REN Kun REN XiaoBin Key Laboratory of Opto-electronics Information Technology(tianjin University) Ministry of EducationCollege of Precision Instrument and Opto-electronics EngineeringTianjin UniversityTianjin 300072China College of Science Tianjin University of Science&TechnologyTianjin 300222China

We propose a method to bend a self-collimated beam in a photonic crystal. The beam bending relies on the gradual variation of the constitutive parameters of the photonic crystal. A new Y-shaped beam splitter is designed with a composite structure constructed using two graded photonic crystals. We demonstrate that the incident beam is divided into two output beams by the designed splitter. The power ratio of the two beams can be adjusted easily by changing the location of the input beam.

关键词：光子晶体结构设计 Y型准直光束复合结构输出光束梁弯曲分束器

Exergy analysis of operation process of district heating systems

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2017年第7期24卷 1663-1670页

作者： JIE Peng-fei KONG Xiang-fei LI Jing School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China School of Energy and Environmental Engineering Hebei University of TechnologyTianjin 300401China china Environmental Resources Technology Co. LtdBeijing 100012China

The nature of the exergy consumption of district heating(DH) systems can not be explained clearly using the first law of *** analysis method was used.A case study based on a DH system in Inner Mongolia,china,was carried *** impact of operating parameters and design parameters on the energy quality of circulating water and exergy losses of DH systems during heat distribution was *** show that the energy quality of circulating water and exergy losses of DH systems during heat distribution could be reduced by decreasing the indoor temperature or increasing radiator *** with other factors,the outdoor temperature and indoor temperature have a greater impact on the energy quality of circulating water,exergy losses of circulating water,and total exergy losses during heat *** the outdoor temperature varied by 10.00%,the average variation rates of such parameters were 85.12%,90.02%,and 64.60%,*** the outdoor temperature was 273.00 K and indoor temperature varied by 50.00%,the average variation rates of such parameters were 83.88%,99.34% and 32.87%,*** can be observed that the energy quality and exergy losses of DH systems can be reduced in the operation process.

关键词： energy quality coefficient exergy loss rate design parameters operating parameters energy conservation measures