In this theoretical study,we investigate the generation of second harmonics(SH)during the interaction of a laser beam with a metallic nanoparticle(MNP)trimer.Utilizing a classical electrodynamics framework,we explore ...In this theoretical study,we investigate the generation of second harmonics(SH)during the interaction of a laser beam with a metallic nanoparticle(MNP)trimer.Utilizing a classical electrodynamics framework,we explore the nonlinear interactions between the laser beam fields and nanoparticles(NPs),accounting for dipole-dipole interactions among the particles.Analytical expressions are derived to quantify the impact of these interactions on SH radiation power for two distinct polarizations of the laser beam.Our findings indicate that when the laser electric field is aligned parallel to the trimer's symmetry axis,there is a significant enhancement in SH radiation power compared to a single non-interacting NP,accompanied by a red-shift in the plasmon resonance peak.Conversely,when the laser electric field is perpendicular to the trimer axis,the SH radiation power from each NP decreases,and the plasmon resonance peak experiences a blue-shift.Additionally,we examine the influence of particle size and interparticle separation on SH generation.These results provide valuable insights into the role of interparticle interactions in enhancing nonlinear optical processes in NP assemblies,with potential implications for the design of nanophotonic devices.展开更多
Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of pro...Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe_(2)O_(3)-doped NiSO_(4)/Al_(2)O_(3) catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst demonstrates an enhanced reaction rate(48.5 mmol_(C3)/(g_(cat).·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO_(4)/Al_(2)O_(3) catalyst(C9:~24.1%).The incorporation of Fe_(2)O_(3) modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts.展开更多
One new A - type proanthocyanidin trimer, lindetannin trimer, was isolated from the stems of Lindera aggregata (Sims) Kosterm.. Its structure was elucidated by spectral and chemical methods.
The electronic states of the smallest boron cluster B_(3)with excitation energies up to 5 e V are systematically investigated.Geometries and spectroscopic constants for the low-lying electronic states were calculated ...The electronic states of the smallest boron cluster B_(3)with excitation energies up to 5 e V are systematically investigated.Geometries and spectroscopic constants for the low-lying electronic states were calculated using the multireference configuration interaction method with Davidson correction(MRCI+Q).The nondegenerate 1^(2)B_(2)and 2^(2)A_(1)states are arising from the degenerate~2E~′state in D_(3h)symmetry,this is also the case for 2^(2)B_(2)and 3~2A_(1).Furthermore,vertical excitation energies,oscillator strengths,main configurations,and transitions of the excited state of B_(3)were determined.Notably,the theoretically predicted wavelengths for the X^(2)A_(1)→2^(2)A_(1)and X^(2)A_(1)→2^(2)B_(2)electronic transitions(728 nm and 457 nm,respectively)exhibit excellent agreements with experimental absorption bands observed at 736 nm and 458 nm.These theoretical findings provide critical insights into the electronic structure and geometric configuration of the B_(3)cluster.展开更多
From an aqueous extract of“tian ma”(the steamed and dried rhizomes of Gastrodia elata),ten new compounds gastrodiben-zins A−D(1−4)and gastrotribenzins A−F(5−10),along with known analogues(11−20),having structure fea...From an aqueous extract of“tian ma”(the steamed and dried rhizomes of Gastrodia elata),ten new compounds gastrodiben-zins A−D(1−4)and gastrotribenzins A−F(5−10),along with known analogues(11−20),having structure features coupling between two and three p-hydroxybenzyl-derived units via carbon-and/or ether-bonds,were isolated and characterized by spectroscopic data analysis.Meanwhile,the new compounds 5a,6a,8a,22,and 23,as well as the known derivatives 13a,14a,15,17−21,24,25,and p-hydroxybenzyl aldehyde were isolated and identified from a refluxed aqueous solution of p-hydroxybenzyl alcohol.Methylation of 5a and 6a in methanol and ethylation of 6a,8a,13a,and 14a in ethanol produced 5 and 6 and 7,8,13,and 14,respectively.using ultra-performance liquid chromatography high-resolution electrospray ioniza-tion mass spectrometry(UPLC-HRESIMS)analysis of the refluxed solutions of p-hydroxybenzyl alcohol and the refluxed extracts of the fresh G.elata rhizome and“tian ma”extracts indicated consistent production and variation of the dimeric and trimeric derivatives of p-hydroxybenzyl alcohol upon extracting solvents and refluxing time.In various assays,the dimeric and trimeric derivatives showed more potent activities than p-hydroxybenzyl alcohol itself and gastrodin,which are the main known active constituents of“tian ma”.These results revealed for the first time that the more effective dimers and trimers can be produced through condensation of the co-occurring p-hydroxybenzyl alcohol during processing and decocting of the G.elata rhizomes,demonstrating insights into medicinal chemistry behind application protocols of traditional Chinese medicines.展开更多
A trimeric porous coordination framework [Ni_3(TPTC)(IN)_2(μ_2-H_2O)_2(CH_3OH)_2)]n· x(solvents)(1, TPTC = terphenyl-3,3?,5,5??-tetracarboxylic acid, IN = isonicotinic acid) was synthesized and characterized by ...A trimeric porous coordination framework [Ni_3(TPTC)(IN)_2(μ_2-H_2O)_2(CH_3OH)_2)]n· x(solvents)(1, TPTC = terphenyl-3,3?,5,5??-tetracarboxylic acid, IN = isonicotinic acid) was synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, single-crystal and powder X-ray diffraction. It crystallizes in monoclinic space group C2/c with a = 33739(12), b = 14.820(5), c = 13.568(5) ?, β = 97.388(6)o, V = 6728(4) ?3, Z = 4, Mr = 965.35, Dc = 0.953 g·cm^(-3), F(000) = 1955.5, μ = 0.881 mm^(–1), GOOF = 1.072, the final R = 0.0859 and w R = 0.2424 for 5284 observed reflections with I > 2σ(I). The structure of 1 is constructed from the linkage of trinuclear {Ni_3} second building units through TPTC and IN spacers, forming a 4,8-connected network of Schl?fli symbol {32.42.52}{34.46.58.68.72}. The CO2 uptake values for 1 are 97.9 m^2·g^(-1) at 273 K and 66.2 m^2·g^(-1) at 298 K, while its N_2 adsorption values are 8.5 m^2·g^(-1) at 273 K and 4.9 m^2·g^(-1) at 298 K, respectively. These results show that 1 has high CO_2/N_2 adsorption selectivity at ambient conditions.展开更多
The trimeric phenylenevinylene with the symmetrical chiral end-groups （ChTPV） was synthesized. The liquid crystalline and luminescent properties of the ChTPV have been studied by differential scanning calorimetry （...The trimeric phenylenevinylene with the symmetrical chiral end-groups （ChTPV） was synthesized. The liquid crystalline and luminescent properties of the ChTPV have been studied by differential scanning calorimetry （DSC）, polarized optical microscopy （POM）, absorption and photoluminescence spectra. The results indicated that the ChTPV exhibits mesophase over a wide temperature range and a typical optical texture of smectic phase. In contrast with the spectra of the solution, that of the film showed blue-shift in maximal absorption and red-shift in maximal emission due to H-type aggregation with parallel alignment of the TPV transition dipole moment.展开更多
HDI trimer was firstly used to improve the mechanical properties of hydroxyl-terminated unsaturated polyester （UP）. Mechanical properties measurements performed on the cured materials demonstrate a distinct improvem...HDI trimer was firstly used to improve the mechanical properties of hydroxyl-terminated unsaturated polyester （UP）. Mechanical properties measurements performed on the cured materials demonstrate a distinct improvement in intensity and toughness in the presence of HDI trimer and shows the change trends of increase and then decrease. The morphological analysis of the fracture surfaces shows that the micro-phase separated structures appear in modified UPR systems and changed from dendritric, dimple and to cystiform structures with the increase of HDI trimer content. The presence of the cystiform structures made the modified UPR systems present the best properties.展开更多
A novel oxamide-bridged trimeric tetranuclear complex 1 incorporating a macro- cyclic oxamide of formula {[(CuL)3Mn](ClO4)2}3 (macrocyclic oxamide L = 2,3-dioxo-5,6,14,15- dibenzo-1,4,8,12-tetraazacyclopentadeca-7,12-...A novel oxamide-bridged trimeric tetranuclear complex 1 incorporating a macro- cyclic oxamide of formula {[(CuL)3Mn](ClO4)2}3 (macrocyclic oxamide L = 2,3-dioxo-5,6,14,15- dibenzo-1,4,8,12-tetraazacyclopentadeca-7,12-diene) was prepared and structurally characterized. The compound [(CuL)3Mn](ClO4)2 crystallizes in the trigonal system, space group P 3 with a = 22.434(17), b = 22.434(17), c = 18.82(2) ?, α = β = 90, γ = 120o, V = 8203(13) ?3, Z = 6, Dc = 1.751g/cm3, μ(MoKα) = 1.557, F(000) = 4392, the final R = 0.083 and wR = 0.1727 for 9604 obser- ved reflections with I > 2σ(I). The single-crystal X-ray analysis shows that 1 is a trimeric complex. There are three similar constitutes, dissimilar conformations and asymmetrically independent ‘building-block’ [(CuL)3Mn] in one crystal cell of the title complex 1.展开更多
ω -Bromopropylporphyrin ether synthesized from the raction of 1,3-dibromopropane as the bridge-linked reagent and 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (H_2MHTPP) as the matrix reacts with 5,15-di(4- hydrox...ω -Bromopropylporphyrin ether synthesized from the raction of 1,3-dibromopropane as the bridge-linked reagent and 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (H_2MHTPP) as the matrix reacts with 5,15-di(4- hydroxyphenyl)-10,20-diphenyl porphyrin( trans -H_2DHDPP) to give the title nanometer porphyrin trimer. The characterization was carried out by means of elemental analyses,UV-Vis,IR, 1H NMR and XRD.展开更多
Hexafluoropropylene oxide trimer acid(HFPO-TA), an emerging replacement of perfluorooctanoic acid(PFOA), has recently been reported to be a potential environmental contaminant.Due to the similar structure to PFOA, HFP...Hexafluoropropylene oxide trimer acid(HFPO-TA), an emerging replacement of perfluorooctanoic acid(PFOA), has recently been reported to be a potential environmental contaminant.Due to the similar structure to PFOA, HFPO-TA may cause comparable adverse effects on human health. Therefore, evaluating the toxic profiles of HFPO-TA has become an urgent task.In this study, we investigated the cytotoxicity and hepatoxicity of HFPO-TA using human embryonic stem cell(h ESC)-based assays. Results showed that HFPO-TA reduced h ESCs’ viability in a dose dependent manner, and the calculated IC50 for 24, 48 and 72 hr were 222.8,167.4, and 80.6 μmol/L, respectively. Significant intracellular ROS accumulation and mitochondrion membrane potential reduction were detected with HFPO-TA exposure, and increased apoptotic/necrotic cells were also observed in high dose of HFPO-TA treated group.Moreover, HFPO-TA at noncytotoxic concentrations also significantly impaired the functions of induced hepatocytes by diminishing cell glycogen storage ability and deregulating specific functional genes. Transcriptome sequencing analysis identified a set of hepatic associated biological processes responding to HFPO-TA exposure. PPAR was the most significantly enriched pathway. Genes including FGA, FGB, FGG, AHSG, HRG, ITIH2, ALB were characterized as hub genes by cyto Hubba plug-in. These data indicated that HFPO-TA is a potential hepatotoxicant, and may not be a safe replacement for PFOA.展开更多
A nanometer porphyrin trimer was firstly synthesized with 1 ,3-dibromopropane as a bridge-linked agent and the fluorescence property and thermostability were studied. The results show that the fluorescence property an...A nanometer porphyrin trimer was firstly synthesized with 1 ,3-dibromopropane as a bridge-linked agent and the fluorescence property and thermostability were studied. The results show that the fluorescence property and thermostability of the trimer are different from those of monoporphyrin. The effects of the molecule structure on the optical property and the thermostability were also studied in detail.展开更多
A viscoelastic system formed by the solutions of di（2-hydroxyl-dimethylene ether）-α,ω, y-triple （ dimethyloctadecylammonium chlorine ） （ 18-4 （ OH ） -18-4 （ OH ） -18 ） is proposed to solve the problems of ...A viscoelastic system formed by the solutions of di（2-hydroxyl-dimethylene ether）-α,ω, y-triple （ dimethyloctadecylammonium chlorine ） （ 18-4 （ OH ） -18-4 （ OH ） -18 ） is proposed to solve the problems of poor temperature and shear resistances of clean fracturing fluid. The apparent viscosity of 18-4（ OH）-18-4（ OH）-18 solution affected by inorganic salt, hydrotropic salt and their mixtures is investigated using steady state measurements. Meanwhile, the temperature and shear resistances of systems of 18-4（ OH）-18-4（ OH）-18 and several common single-chain surfactants are compared. The rheological experiments show that, the coexistence of NaSal and NaC1 makes it easier for the system to promote micellar growth yielding wormlike micelles than single NaSal or NaC1. The apparent vis- cosity of 18-4（OH） -18-4（OH） -18 solution maintains over 87. 5 mPa-s above 100 22. The results indi- cate that there exists a synergistic effect in solutions of 18-4 （ OH ） -18-4 （ OH ） -18 trimeric surfactant展开更多
We study exciton transfer dynamics in a trimer system by investigating excitation transfer probability （ETP）. We calculate ETP in the zero-temperature limit and theoretically predict the environment-assisted quantum...We study exciton transfer dynamics in a trimer system by investigating excitation transfer probability （ETP）. We calculate ETP in the zero-temperature limit and theoretically predict the environment-assisted quantum critical effect, in which ETP exhibits a sudden change at the critical point of quantum phase transition for the trimer. In particular, we find that the steady-state ETP can be observed in the presence of the environment interaction.展开更多
The Bose-Hubbard model with an effective off-site three-body tunneling,characterized by jumps towards one another,between one atom on a site and a pair atoms on the neighborhood site,is studied systematically on a one...The Bose-Hubbard model with an effective off-site three-body tunneling,characterized by jumps towards one another,between one atom on a site and a pair atoms on the neighborhood site,is studied systematically on a one-dimensional（1D） lattice,by using the density matrix renormalization group method.The off-site trimer superfluid,condensing at momentum k = 0,emerges in the softcore Bose-Hubbard model but it disappears in the hardcore Bose-Hubbard model.Our results numerically verify that the off-site trimer superfluid phase derived in the momentum space from[Phys.Rev.A81,011601（R）（2010）]is stable in the thermodynamic limit.The off-site trimer superfluid phase,the partially off-site trimer superfluid phase and the Mott insulator phase are found,as well as interesting phase transitions,such as the continuous or first-order phase transition from the trimer superfluid phase to the Mott insulator phase.Our results are helpful in realizing this novel off-site trimer superfluid phase by cold atom experiments.展开更多
文摘In this theoretical study,we investigate the generation of second harmonics(SH)during the interaction of a laser beam with a metallic nanoparticle(MNP)trimer.Utilizing a classical electrodynamics framework,we explore the nonlinear interactions between the laser beam fields and nanoparticles(NPs),accounting for dipole-dipole interactions among the particles.Analytical expressions are derived to quantify the impact of these interactions on SH radiation power for two distinct polarizations of the laser beam.Our findings indicate that when the laser electric field is aligned parallel to the trimer's symmetry axis,there is a significant enhancement in SH radiation power compared to a single non-interacting NP,accompanied by a red-shift in the plasmon resonance peak.Conversely,when the laser electric field is perpendicular to the trimer axis,the SH radiation power from each NP decreases,and the plasmon resonance peak experiences a blue-shift.Additionally,we examine the influence of particle size and interparticle separation on SH generation.These results provide valuable insights into the role of interparticle interactions in enhancing nonlinear optical processes in NP assemblies,with potential implications for the design of nanophotonic devices.
文摘Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe_(2)O_(3)-doped NiSO_(4)/Al_(2)O_(3) catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst demonstrates an enhanced reaction rate(48.5 mmol_(C3)/(g_(cat).·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO_(4)/Al_(2)O_(3) catalyst(C9:~24.1%).The incorporation of Fe_(2)O_(3) modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts.
文摘One new A - type proanthocyanidin trimer, lindetannin trimer, was isolated from the stems of Lindera aggregata (Sims) Kosterm.. Its structure was elucidated by spectral and chemical methods.
基金Project supported by the National Natural Science Foundation of China(Grant No.12274178)。
文摘The electronic states of the smallest boron cluster B_(3)with excitation energies up to 5 e V are systematically investigated.Geometries and spectroscopic constants for the low-lying electronic states were calculated using the multireference configuration interaction method with Davidson correction(MRCI+Q).The nondegenerate 1^(2)B_(2)and 2^(2)A_(1)states are arising from the degenerate~2E~′state in D_(3h)symmetry,this is also the case for 2^(2)B_(2)and 3~2A_(1).Furthermore,vertical excitation energies,oscillator strengths,main configurations,and transitions of the excited state of B_(3)were determined.Notably,the theoretically predicted wavelengths for the X^(2)A_(1)→2^(2)A_(1)and X^(2)A_(1)→2^(2)B_(2)electronic transitions(728 nm and 457 nm,respectively)exhibit excellent agreements with experimental absorption bands observed at 736 nm and 458 nm.These theoretical findings provide critical insights into the electronic structure and geometric configuration of the B_(3)cluster.
基金support from the National Natural Sciences Foundation of China(NNSFCGrant Nos.81730093,81630094,and 81502942)+1 种基金CAMS Innovation Fund for Medical Science of China(2017-I2M-3-010 and 2016-I2M-1-004)the Drug Innovation Major Project(2018ZX09711001-001,China)is acknowledged is acknowledged.
文摘From an aqueous extract of“tian ma”(the steamed and dried rhizomes of Gastrodia elata),ten new compounds gastrodiben-zins A−D(1−4)and gastrotribenzins A−F(5−10),along with known analogues(11−20),having structure features coupling between two and three p-hydroxybenzyl-derived units via carbon-and/or ether-bonds,were isolated and characterized by spectroscopic data analysis.Meanwhile,the new compounds 5a,6a,8a,22,and 23,as well as the known derivatives 13a,14a,15,17−21,24,25,and p-hydroxybenzyl aldehyde were isolated and identified from a refluxed aqueous solution of p-hydroxybenzyl alcohol.Methylation of 5a and 6a in methanol and ethylation of 6a,8a,13a,and 14a in ethanol produced 5 and 6 and 7,8,13,and 14,respectively.using ultra-performance liquid chromatography high-resolution electrospray ioniza-tion mass spectrometry(UPLC-HRESIMS)analysis of the refluxed solutions of p-hydroxybenzyl alcohol and the refluxed extracts of the fresh G.elata rhizome and“tian ma”extracts indicated consistent production and variation of the dimeric and trimeric derivatives of p-hydroxybenzyl alcohol upon extracting solvents and refluxing time.In various assays,the dimeric and trimeric derivatives showed more potent activities than p-hydroxybenzyl alcohol itself and gastrodin,which are the main known active constituents of“tian ma”.These results revealed for the first time that the more effective dimers and trimers can be produced through condensation of the co-occurring p-hydroxybenzyl alcohol during processing and decocting of the G.elata rhizomes,demonstrating insights into medicinal chemistry behind application protocols of traditional Chinese medicines.
基金supported by the National Science Foundation of Fujian Province(No.2017J01039)
文摘A trimeric porous coordination framework [Ni_3(TPTC)(IN)_2(μ_2-H_2O)_2(CH_3OH)_2)]n· x(solvents)(1, TPTC = terphenyl-3,3?,5,5??-tetracarboxylic acid, IN = isonicotinic acid) was synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, single-crystal and powder X-ray diffraction. It crystallizes in monoclinic space group C2/c with a = 33739(12), b = 14.820(5), c = 13.568(5) ?, β = 97.388(6)o, V = 6728(4) ?3, Z = 4, Mr = 965.35, Dc = 0.953 g·cm^(-3), F(000) = 1955.5, μ = 0.881 mm^(–1), GOOF = 1.072, the final R = 0.0859 and w R = 0.2424 for 5284 observed reflections with I > 2σ(I). The structure of 1 is constructed from the linkage of trinuclear {Ni_3} second building units through TPTC and IN spacers, forming a 4,8-connected network of Schl?fli symbol {32.42.52}{34.46.58.68.72}. The CO2 uptake values for 1 are 97.9 m^2·g^(-1) at 273 K and 66.2 m^2·g^(-1) at 298 K, while its N_2 adsorption values are 8.5 m^2·g^(-1) at 273 K and 4.9 m^2·g^(-1) at 298 K, respectively. These results show that 1 has high CO_2/N_2 adsorption selectivity at ambient conditions.
基金supported by the National Science Foundation(No.20674005)the major project of Ministry Education of the People's Republic of China(No.104187).
文摘The trimeric phenylenevinylene with the symmetrical chiral end-groups （ChTPV） was synthesized. The liquid crystalline and luminescent properties of the ChTPV have been studied by differential scanning calorimetry （DSC）, polarized optical microscopy （POM）, absorption and photoluminescence spectra. The results indicated that the ChTPV exhibits mesophase over a wide temperature range and a typical optical texture of smectic phase. In contrast with the spectra of the solution, that of the film showed blue-shift in maximal absorption and red-shift in maximal emission due to H-type aggregation with parallel alignment of the TPV transition dipole moment.
基金Funded by the Hubei Provincial Natural Science Fundation of China(No.2006ABA321)
文摘HDI trimer was firstly used to improve the mechanical properties of hydroxyl-terminated unsaturated polyester （UP）. Mechanical properties measurements performed on the cured materials demonstrate a distinct improvement in intensity and toughness in the presence of HDI trimer and shows the change trends of increase and then decrease. The morphological analysis of the fracture surfaces shows that the micro-phase separated structures appear in modified UPR systems and changed from dendritric, dimple and to cystiform structures with the increase of HDI trimer content. The presence of the cystiform structures made the modified UPR systems present the best properties.
基金This project was supported by the National Natural Science Foundation of China (No. 20331010) and Natural Science Foundation of Tianjing (No. 033602011)
文摘A novel oxamide-bridged trimeric tetranuclear complex 1 incorporating a macro- cyclic oxamide of formula {[(CuL)3Mn](ClO4)2}3 (macrocyclic oxamide L = 2,3-dioxo-5,6,14,15- dibenzo-1,4,8,12-tetraazacyclopentadeca-7,12-diene) was prepared and structurally characterized. The compound [(CuL)3Mn](ClO4)2 crystallizes in the trigonal system, space group P 3 with a = 22.434(17), b = 22.434(17), c = 18.82(2) ?, α = β = 90, γ = 120o, V = 8203(13) ?3, Z = 6, Dc = 1.751g/cm3, μ(MoKα) = 1.557, F(000) = 4392, the final R = 0.083 and wR = 0.1727 for 9604 obser- ved reflections with I > 2σ(I). The single-crystal X-ray analysis shows that 1 is a trimeric complex. There are three similar constitutes, dissimilar conformations and asymmetrically independent ‘building-block’ [(CuL)3Mn] in one crystal cell of the title complex 1.
文摘ω -Bromopropylporphyrin ether synthesized from the raction of 1,3-dibromopropane as the bridge-linked reagent and 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (H_2MHTPP) as the matrix reacts with 5,15-di(4- hydroxyphenyl)-10,20-diphenyl porphyrin( trans -H_2DHDPP) to give the title nanometer porphyrin trimer. The characterization was carried out by means of elemental analyses,UV-Vis,IR, 1H NMR and XRD.
基金supported by the Advanced Talents Incubation Program of Hebei University(No.050001-521000981349)the National Natural Science Foundation of China(No.81472744)。
文摘Hexafluoropropylene oxide trimer acid(HFPO-TA), an emerging replacement of perfluorooctanoic acid(PFOA), has recently been reported to be a potential environmental contaminant.Due to the similar structure to PFOA, HFPO-TA may cause comparable adverse effects on human health. Therefore, evaluating the toxic profiles of HFPO-TA has become an urgent task.In this study, we investigated the cytotoxicity and hepatoxicity of HFPO-TA using human embryonic stem cell(h ESC)-based assays. Results showed that HFPO-TA reduced h ESCs’ viability in a dose dependent manner, and the calculated IC50 for 24, 48 and 72 hr were 222.8,167.4, and 80.6 μmol/L, respectively. Significant intracellular ROS accumulation and mitochondrion membrane potential reduction were detected with HFPO-TA exposure, and increased apoptotic/necrotic cells were also observed in high dose of HFPO-TA treated group.Moreover, HFPO-TA at noncytotoxic concentrations also significantly impaired the functions of induced hepatocytes by diminishing cell glycogen storage ability and deregulating specific functional genes. Transcriptome sequencing analysis identified a set of hepatic associated biological processes responding to HFPO-TA exposure. PPAR was the most significantly enriched pathway. Genes including FGA, FGB, FGG, AHSG, HRG, ITIH2, ALB were characterized as hub genes by cyto Hubba plug-in. These data indicated that HFPO-TA is a potential hepatotoxicant, and may not be a safe replacement for PFOA.
文摘A nanometer porphyrin trimer was firstly synthesized with 1 ,3-dibromopropane as a bridge-linked agent and the fluorescence property and thermostability were studied. The results show that the fluorescence property and thermostability of the trimer are different from those of monoporphyrin. The effects of the molecule structure on the optical property and the thermostability were also studied in detail.
文摘A viscoelastic system formed by the solutions of di（2-hydroxyl-dimethylene ether）-α,ω, y-triple （ dimethyloctadecylammonium chlorine ） （ 18-4 （ OH ） -18-4 （ OH ） -18 ） is proposed to solve the problems of poor temperature and shear resistances of clean fracturing fluid. The apparent viscosity of 18-4（ OH）-18-4（ OH）-18 solution affected by inorganic salt, hydrotropic salt and their mixtures is investigated using steady state measurements. Meanwhile, the temperature and shear resistances of systems of 18-4（ OH）-18-4（ OH）-18 and several common single-chain surfactants are compared. The rheological experiments show that, the coexistence of NaSal and NaC1 makes it easier for the system to promote micellar growth yielding wormlike micelles than single NaSal or NaC1. The apparent vis- cosity of 18-4（OH） -18-4（OH） -18 solution maintains over 87. 5 mPa-s above 100 22. The results indi- cate that there exists a synergistic effect in solutions of 18-4 （ OH ） -18-4 （ OH ） -18 trimeric surfactant
基金Project supported by the National Natural Science Foundation of China (Grant No. 11075050)the National Basic Research Program of China (Grant No. 2013CB921804)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT0964)the Hunan Provincial National Science Foundation, China (Grant No. 11JJ7001)
文摘We study exciton transfer dynamics in a trimer system by investigating excitation transfer probability （ETP）. We calculate ETP in the zero-temperature limit and theoretically predict the environment-assisted quantum critical effect, in which ETP exhibits a sudden change at the critical point of quantum phase transition for the trimer. In particular, we find that the steady-state ETP can be observed in the presence of the environment interaction.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11305113)the Project GDW201400042 for the“High End Foreign Experts Program”
文摘The Bose-Hubbard model with an effective off-site three-body tunneling,characterized by jumps towards one another,between one atom on a site and a pair atoms on the neighborhood site,is studied systematically on a one-dimensional（1D） lattice,by using the density matrix renormalization group method.The off-site trimer superfluid,condensing at momentum k = 0,emerges in the softcore Bose-Hubbard model but it disappears in the hardcore Bose-Hubbard model.Our results numerically verify that the off-site trimer superfluid phase derived in the momentum space from[Phys.Rev.A81,011601（R）（2010）]is stable in the thermodynamic limit.The off-site trimer superfluid phase,the partially off-site trimer superfluid phase and the Mott insulator phase are found,as well as interesting phase transitions,such as the continuous or first-order phase transition from the trimer superfluid phase to the Mott insulator phase.Our results are helpful in realizing this novel off-site trimer superfluid phase by cold atom experiments.
