A benzotriazole-containing derivative was synthesized via the Mannich reaction.The structure was characterized by NMR spectroscopy.By utilizing computational chemistry and molecular simulation,the calculation and mapp...A benzotriazole-containing derivative was synthesized via the Mannich reaction.The structure was characterized by NMR spectroscopy.By utilizing computational chemistry and molecular simulation,the calculation and mapping of atomic charge and frontier molecular orbitals with complex structure of the borate were carried out.The acid number of BTBE(nitrogen-containing heterocyclic borate)was determined by the standard test method for acid number and the open observation method.The results showed that BTBE had a low initial acid number,because the acid number was changed only after 72 hours of hydrolysis,and it was negative after the hydrolysis reached 120 hours.The extreme-pressure friction resistance of BTBE and other four base oils was also determined.For 5 kinds of base oils,the friction experiment was carried out under a load of 30 kgf,and the BTBE showed a lowest wear scar diameter(0.365 mm)along with a highest maximum non-seizure load.The results showed that the EP friction resistance of BTBE was stronger than that of other four base oils under the same test conditions.The results of hydrolysis performance showed that the synthesized nitrogencontaining heterocyclic borate had a high resistance to hydrolysis,while demonstrating broad application prospects.展开更多
The prediction of new fluorooxoborates as ultraviolet(UV)/deep ultraviolet(DUV)opto-electronic functional materials from a largely unexplored chemical space is a challenging task.It has been suggested that the anionic...The prediction of new fluorooxoborates as ultraviolet(UV)/deep ultraviolet(DUV)opto-electronic functional materials from a largely unexplored chemical space is a challenging task.It has been suggested that the anionic frameworks formed by B–O and B–O–F units significantly determine the physical properties of fluorooxoborates.Therefore,the rational design of anionic frameworks could facilitate the materials discovery process.Herein,we propose that a candidate anionic framework can be efficiently derived from an existing one by slightly altering its oxygen content.Following this idea,we hypothesized the existence of a 1D[B_(3)O_(5)F]_(∞)chain from the wellknown 2D[B_(6)O_(9)F_(2_)]_(∞)layer.Accordingly,seven CaB_(3)O_(5)F structures with the expected anionic framework were successfully predicted.First-principles calculations show that all these structures have potential in the UV/DUV birefringent or nonlinear optical(NLO)material field,indicating that the 1D[B_(3)O_(5)F]_(∞)chain is indeed a promising anionic framework for achieving UV/DUV birefringent and NLO performance.展开更多
The Li metal battery with ultrahigh-nickel cathode(LiNi_(x)M_(1-x)O_(2),M=Mn,Co,and x≥0.9)under high-voltage is regarded as one of the most promising approaches to fulfill the ambitious target of 400 Wh/kg.However,th...The Li metal battery with ultrahigh-nickel cathode(LiNi_(x)M_(1-x)O_(2),M=Mn,Co,and x≥0.9)under high-voltage is regarded as one of the most promising approaches to fulfill the ambitious target of 400 Wh/kg.However,the practical application is impeded by the instability of electrode/electrolyte interface and Ni-rich cathode itself.Herein we proposed an electron-defect electrolyte additive trimethyl borate(TMB)which is paired with the commercial carbonate electrolyte to construct highly conductive fluorine-and boron-rich cathode electrolyte interface(CEI)on LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90)surface and solid electrolyte interphase(SEI)on lithium metal surface.The modified CEI effectively mitigates the structural transformation from layered to disordered rock-salt phase,and consequently alleviate the dissolution of transition metal ions(TMs)and its“cross-talk”effect,while the enhanced SEI enables stable lithium plating/striping and thus demonstrated good compatibility between electrolyte and lithium metal anode.As a result,the common electrolyte with 1 wt%TMB enables 4.7 V NCM90/Li cell cycle stably over 100 cycles with 70%capacity retention.This work highlights the significance of the electron-defect boron compounds for designing desirable interfacial chemistries to achieve high performance NCM90/Li battery under high voltage operation.展开更多
Tribological properties of 150SN mineral oil and lubricating oils containing triethanolamine borate(TBE)with and without electromagnetic field impact were evaluated on a modified four-ball tribo-tester.The characteris...Tribological properties of 150SN mineral oil and lubricating oils containing triethanolamine borate(TBE)with and without electromagnetic field impact were evaluated on a modified four-ball tribo-tester.The characteristics of the worn surfaces were studied by scanning electronic microscopy(SEM),energy dispersive spectrometry(EDS)and X-ray photoelectron spectroscopy(XPS).Moreover,the tribological mechanisms are discussed from the viewpoint of physical effect and chemical effect.The results indicated that the friction coefficients and wear scar diameters(WSDs)lubricated by 150SN mineral oil under electromagnetic field were higher than those without electromagnetism impact.The WSDs of steel balls lubricated by TBE-doped oils under electromagnetic field were smaller than those obtained from non-electromagnetic field,but the friction coefficients were higher than those under non-electromagnetic field.A protective coating consists of wear particles could be formed on the frictional surface due to the physical effect of electromagnetic field on wear debris.The electromagnetic field could facilitate the interaction of elemental boron and nitrogen in TBE with metal interfaces,and contributes to forming tribo-chemical reaction film to reduce friction and wear.展开更多
Tris(trimethylsilyl)borate(TMSB) has been intensively studied to improve the performances of lithiumion batteries. However, it is still an interesting issue needed to be resolved for the research on the Li^(+) solvati...Tris(trimethylsilyl)borate(TMSB) has been intensively studied to improve the performances of lithiumion batteries. However, it is still an interesting issue needed to be resolved for the research on the Li^(+) solvation structure affected by TMSB additive. Herein, the electrochemical tests, quantum chemistry calculations, potential-resolved in-situ electrochemical impedance spectroscopy measurements and surface analyses were used to explore the effects of Li^(+) solvation structure with TMSB additive on the formation of the cathode electrolyte interface(CEI) film in LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/Li half cells. The results reveal that the TMSB additive is easy to complex with Li^(+) ion, thus weaken the intermolecular force between Li^(+) ions and ethylene carbonate solvent, which is benefit for the cycle performance. Besides, the changed Li^(+) solvation structure results in a thin and dense CEI film containing compounds with Si–O and B–O bonds which is favorable to the transfer of Li^(+) ions. As a result, the performances of the LNCM811/Li half cells are effectively improved. This research provides a new idea to construct a high-performance CEI film by adjusting the Li^(+) solvation structures.展开更多
Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, ...Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, TEM, EDS, FTIR and XRD, respectively. Moreover, the friction and wear properties of OA/La BO_3·H_2O as a lubricant additive in rapeseed oil were evaluated on a four-ball tribotester. The tribochemical characteristics of worn surfaces were investigated by SEM and XPS. The results showed that the hydrophobic OA/La BO_3·H_2O nanosheets exhibited their morphology with a diameter in the range of 100 nm to 300 nm and a thickness of about 25 nm, and displayed excellent dispersing stability in rapeseed oil. In the meantime, the rapeseed oil doped with OA/La BO_3·H_2O nanosheets markedly decreased the friction and wear of steel balls, and the optimal friction-reducing and antiwear ability of rapeseed oil was obtained at an OA/La BO_3·H_2O content of 1.0%. The outstanding tribological performance of OA/La BO_3·H_2O in rapeseed oil was attributed to the formation of a composite boundary lubrication film mainly composed of lubricious tribochemical species of B_2O_3, La_2O_3 and Fe_2O_3, and deposits of OA/La BO_3·H_2O nanosheets as well as the adsorbates of rapeseed oil on rubbed surfaces.展开更多
Adenosine triphosphate(ATP)borate ester as a new boron agent for boron neutron capture therapy was tested.It was synthesized via a dehydration reaction induced by heating adenosine triphosphate disodium with boric aci...Adenosine triphosphate(ATP)borate ester as a new boron agent for boron neutron capture therapy was tested.It was synthesized via a dehydration reaction induced by heating adenosine triphosphate disodium with boric acid.Next,ATP borate ester pretreatments were assessed to study their effects on cell sensitization from exposure to thermal neutron irradiation emitted by a nuclear reactor.Using cell viability assays(CCK8),survival rates of A549 cells pretreated with or without boroncontaining agents,including ATP borate ester and 4-dihydroxyborylphenylalanine(BPA),were measured.One week after feeding an ATP borate ester solution to tumorbearing nude mice,elemental B content values of tumor muscle and blood were measured using inductively coupled plasma mass spectrometry(ICP-MS).Meanwhile,other tumor tissue samples were placed in a culture medium,subjected to a 3-min neutron irradiation exposure,and then fixed in formalin 24 h later for the terminaldeoxynucleotidyl transferase(TDT)-mediated d UTP nick end labeling(TUNEL)immunohistochemical staining analysis.Results showed that A549 cell irradiation sensitization(irradiation dose of 0.33 Gy)varied with pretreatment.Sensitization values of the ATP borate ester pretreatment group were 1.3–14.1 with boron agent concentrations of 0.3–4.5 mM.Within 1.1–3.4 mM,ATP borate ester showed significantly higher sensitization values than BPA.Meanwhile,TUNEL results demonstrated that apoptosis rates of tumor tissue cells exposed to irradiation after ATP borate ester pretreatment significantly exceeded the corresponding rates for BPA-pretreated cells.In animal experiments,although the distribution ratio of ATP borate ester(tumor tissue/normal muscle,T/N)of 1.2 was not significantly different compared with that of BPA(1.3),the total ATP borate ester concentration in the tumor tissue(0.79±0.05μg/g)significantly exceeded that of BPA(0.58±0.05μg/g).Thus,compared with BPA,the greater enrichment of ATP borate ester in tumor tissues permits preferential targeting toward tumor cells for radiation sensitization.Therefore,ATP borate ester is superior to BPA for use in boron neutron capture therapy.展开更多
Cadmium dizinc diborate （CdZn2B2O6） single crystals have been grown for the first time. The crystal structure of CdZn2B2O6 is the same as that of the Cd3Zn3B4O12. The x-ray diffraction, infrared and Raman spectra, d...Cadmium dizinc diborate （CdZn2B2O6） single crystals have been grown for the first time. The crystal structure of CdZn2B2O6 is the same as that of the Cd3Zn3B4O12. The x-ray diffraction, infrared and Raman spectra, differential scanning calorimetry analysis and density indicate that the physical and chemical properties of both crystals are very similar. Especially, the nonlinear optical coefficients of CdZn2B2O6 and Cd3Zn3B4O12 crystals are 2.6 and 2.4 times as large as that of KH2PO4 crystal respectively. Chemical etching experiments indicated that these crystals are very stable in neutral solution and not hygroscopic in air at room temperature.展开更多
Global economic and pollution concerns are having a major impact on how modern engine oils are being formulated.Modern engine oil specifications mandate reduced levels of phosphorus and sulfur to protect the efficacy ...Global economic and pollution concerns are having a major impact on how modern engine oils are being formulated.Modern engine oil specifications mandate reduced levels of phosphorus and sulfur to protect the efficacy of pollution control devices.In addition,modern engine oil must also be more fuel efficient than earlier generations to reduce greenhouse gas emissions and the impact of high priced gasoline and diesel fuel to the consumer.At the same time,oxidation,wear,and corrosion performance of the oil must not be compromised.Multifunctional additives are useful formulation tools that help formulators meet these tough new challenges.One such additive is the organo-borate ester/amide.Originally conceived as an organic friction modifier,this patented technology is really a multifunctional additive that addresses the global economic and pollution concerns.With the addition of boron,this unique commercial organic friction modifier also imparts antioxidancy,antiwear and anticorrosion properties to engine oil.In addition,the organo-borate ester/amide is compatible with pollution control devices because it does not contain sulfur or phosphorus.Work is on going to uncover additional beneficial properties of this chemistry.展开更多
Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatal...Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.展开更多
The dislocations in lithium tetraborate crystal have been investigated by means of synchrotron radiation white beam topography in BSRL(Beijing Synchrotron Radiation Laboratory).The Burgers'vectors of these disloca...The dislocations in lithium tetraborate crystal have been investigated by means of synchrotron radiation white beam topography in BSRL(Beijing Synchrotron Radiation Laboratory).The Burgers'vectors of these dislocations are determined by their vanishing conditions.Both screw and edge dislocations exist in the specimen.展开更多
A new compound with the stone cheinical composition as Li3AlB2O6 but with a different x-ray powder diffraction pattern as reported before was synthesized and studied experimentally by M. He, Chen X Let al （J. Solid S...A new compound with the stone cheinical composition as Li3AlB2O6 but with a different x-ray powder diffraction pattern as reported before was synthesized and studied experimentally by M. He, Chen X Let al （J. Solid State Chem. 163, 369 （2002））, but there lacks first principles study on the structure of it. Using conjugant gradient （CG） molecule dynamics （MD） simulation with a full relaxation of the atomic positions and of the shape and size of the cell, the structure of Li3AlB2O6 is studied from first principles. For the density functional, the local density approximation （LDA） and the generalized gradient approximation （GGA） forms are used respectively. Both the LDA and GGA results support the experimental structure of M. He et al. The result of MD simulation using GGA agrees with the experimental result much better. The energy bands are also studied, the band gap given by LDA and GGA are 5.65 eV, 5.34eV, respectively.展开更多
The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1 wt% TMSB can dramati...The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1 wt% TMSB can dramatically reduce the capacity fading that occurs during cycling at room temperature (RT) and elevated temperature (60 degrees C). After 150 cycles at 1 C rate (1 C= 278 mAh/g), the capacity retention of Li/LiCo1/3Ni1/3Mn1/3O2 is up to near 72% in the electrolyte with TMSB added, while it is only about 35% in the baseline electrolyte. The electrochemical behaviors, the surface chemistry and structure of Li/LiCo1/3Ni1/3Mn1/3O2 cathode are characterized with charge/discharge test, linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), thermal gravimetric analyses (TGA), scanning electron microscope (SEM) and transmission electron microscopy (TEM). These analysis results reveal that the addition of TMSB is able to protectively modify the electrode CEI film in a manner that suppresses electrolyte decomposition and degradation of electrode surface structure, even though at both a higher voltage of 4.7 V and an elevated temperature of 60 degrees C. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
A novel lubricating oil additive dodecoxyl barium borate was synthesized. The product was characterized by FTIR, elemental analysis, thermo-gravimetric analysis （TGA）, and scanning electron microscopy （SEM）. Four-...A novel lubricating oil additive dodecoxyl barium borate was synthesized. The product was characterized by FTIR, elemental analysis, thermo-gravimetric analysis （TGA）, and scanning electron microscopy （SEM）. Four-ball tests showed that the addition of a certain concentration of the additive to rapeseed oil could effectively increase both the load-carrying capacity （PB value）, resistance to wear, and friction-reducing abilities. SEM observations confirmed that the additive could result in a reduced diameter of the wear scar.展开更多
Overbased complex sulphonates containing two metals -- sodium and magnesium -- were prepared by using overbased magnesium sulphonate as the starting material. Borated overbased complex sulphonate containing two metals...Overbased complex sulphonates containing two metals -- sodium and magnesium -- were prepared by using overbased magnesium sulphonate as the starting material. Borated overbased complex sulphonate containing two metals was synthesized by reaction of boric acid with the corresponding sulphonate. The total base number （TBN） of overbased complex sulphonates decreased compared with that of magnesium sulphonate, while TBN of borated overbased complex sulphonate further decreased. The detergency, anti-oxidation and extreme pressure performances of overbased complex sulphonates were improved compared with those of overbased magnesium sulphonate; the anti-oxidation and extreme pressure performances of borated overbased complex sulphonates were further improved whereas its detergency was reduced.展开更多
The Raman spectrum of rhombohedral NdAl 3 (BO 3) 4 (NAB) is recorded and interpreted. A factor group analysis of the NAB space group shows that there are 21A 1 and 59E Raman active modes. A discussion of ...The Raman spectrum of rhombohedral NdAl 3 (BO 3) 4 (NAB) is recorded and interpreted. A factor group analysis of the NAB space group shows that there are 21A 1 and 59E Raman active modes. A discussion of the assignment of the individual Raman lines is given. The splitting predicted by factor group for the internal modes of (BO 3) 3+ anion are observed and interpreted.展开更多
Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/...Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/2,is obviously altered with different silicon/aluminum ratios.The Judd-Ofelt parameters of the Er3+ ions are adopted to explain the intensity change in the NIR fluorescence,and the Raman scattering intensity versus the amount of Al and/or Si components are discussed.The spectra of the three samples are quite similar in the peak positions,but different in intensity.The maximal phonon density of state for the samples is calculated from the Raman spectra and is correlated to the NIR luminescence efficiency.展开更多
文摘A benzotriazole-containing derivative was synthesized via the Mannich reaction.The structure was characterized by NMR spectroscopy.By utilizing computational chemistry and molecular simulation,the calculation and mapping of atomic charge and frontier molecular orbitals with complex structure of the borate were carried out.The acid number of BTBE(nitrogen-containing heterocyclic borate)was determined by the standard test method for acid number and the open observation method.The results showed that BTBE had a low initial acid number,because the acid number was changed only after 72 hours of hydrolysis,and it was negative after the hydrolysis reached 120 hours.The extreme-pressure friction resistance of BTBE and other four base oils was also determined.For 5 kinds of base oils,the friction experiment was carried out under a load of 30 kgf,and the BTBE showed a lowest wear scar diameter(0.365 mm)along with a highest maximum non-seizure load.The results showed that the EP friction resistance of BTBE was stronger than that of other four base oils under the same test conditions.The results of hydrolysis performance showed that the synthesized nitrogencontaining heterocyclic borate had a high resistance to hydrolysis,while demonstrating broad application prospects.
基金supported by the National Natural Science Foundation of China(Grant No.52403305)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0880000)+1 种基金Tianchi Talent Program of Xinjiang Uygur Autonomous Region(Grant No.2024000068)Postdoctoral Fellow-ship Program(Grade C)(Grant No.GZC20232959)。
文摘The prediction of new fluorooxoborates as ultraviolet(UV)/deep ultraviolet(DUV)opto-electronic functional materials from a largely unexplored chemical space is a challenging task.It has been suggested that the anionic frameworks formed by B–O and B–O–F units significantly determine the physical properties of fluorooxoborates.Therefore,the rational design of anionic frameworks could facilitate the materials discovery process.Herein,we propose that a candidate anionic framework can be efficiently derived from an existing one by slightly altering its oxygen content.Following this idea,we hypothesized the existence of a 1D[B_(3)O_(5)F]_(∞)chain from the wellknown 2D[B_(6)O_(9)F_(2_)]_(∞)layer.Accordingly,seven CaB_(3)O_(5)F structures with the expected anionic framework were successfully predicted.First-principles calculations show that all these structures have potential in the UV/DUV birefringent or nonlinear optical(NLO)material field,indicating that the 1D[B_(3)O_(5)F]_(∞)chain is indeed a promising anionic framework for achieving UV/DUV birefringent and NLO performance.
基金financially supported by the National Key Research and Development Program of China(2022YFE0206300)the National Natural Science Foundation of China(U21A2081,22075074,22209047)+1 种基金the Natural Science Foundation of Hunan Province(2022JJ40140)the Hunan Provincial Department of Education Outstanding Youth Project(22B0864,23B0037)。
文摘The Li metal battery with ultrahigh-nickel cathode(LiNi_(x)M_(1-x)O_(2),M=Mn,Co,and x≥0.9)under high-voltage is regarded as one of the most promising approaches to fulfill the ambitious target of 400 Wh/kg.However,the practical application is impeded by the instability of electrode/electrolyte interface and Ni-rich cathode itself.Herein we proposed an electron-defect electrolyte additive trimethyl borate(TMB)which is paired with the commercial carbonate electrolyte to construct highly conductive fluorine-and boron-rich cathode electrolyte interface(CEI)on LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90)surface and solid electrolyte interphase(SEI)on lithium metal surface.The modified CEI effectively mitigates the structural transformation from layered to disordered rock-salt phase,and consequently alleviate the dissolution of transition metal ions(TMs)and its“cross-talk”effect,while the enhanced SEI enables stable lithium plating/striping and thus demonstrated good compatibility between electrolyte and lithium metal anode.As a result,the common electrolyte with 1 wt%TMB enables 4.7 V NCM90/Li cell cycle stably over 100 cycles with 70%capacity retention.This work highlights the significance of the electron-defect boron compounds for designing desirable interfacial chemistries to achieve high performance NCM90/Li battery under high voltage operation.
基金financial support provided by the Basic Science and Frontier Technology Research Project of Chongqing (CSTC, 2017jcyjAX0058)
文摘Tribological properties of 150SN mineral oil and lubricating oils containing triethanolamine borate(TBE)with and without electromagnetic field impact were evaluated on a modified four-ball tribo-tester.The characteristics of the worn surfaces were studied by scanning electronic microscopy(SEM),energy dispersive spectrometry(EDS)and X-ray photoelectron spectroscopy(XPS).Moreover,the tribological mechanisms are discussed from the viewpoint of physical effect and chemical effect.The results indicated that the friction coefficients and wear scar diameters(WSDs)lubricated by 150SN mineral oil under electromagnetic field were higher than those without electromagnetism impact.The WSDs of steel balls lubricated by TBE-doped oils under electromagnetic field were smaller than those obtained from non-electromagnetic field,but the friction coefficients were higher than those under non-electromagnetic field.A protective coating consists of wear particles could be formed on the frictional surface due to the physical effect of electromagnetic field on wear debris.The electromagnetic field could facilitate the interaction of elemental boron and nitrogen in TBE with metal interfaces,and contributes to forming tribo-chemical reaction film to reduce friction and wear.
基金supported by the National Natural Science Foundation of China(51962019)the Natural Science Foundation of Gansu Province(20JR5RA469)+1 种基金the Education Department of Gansu Province:"Star of Innovation"Project for Outstanding Graduate Students(2021CXZX-455)the Lanzhou University of Technology Hongliu First-class Discipline Construction Program。
文摘Tris(trimethylsilyl)borate(TMSB) has been intensively studied to improve the performances of lithiumion batteries. However, it is still an interesting issue needed to be resolved for the research on the Li^(+) solvation structure affected by TMSB additive. Herein, the electrochemical tests, quantum chemistry calculations, potential-resolved in-situ electrochemical impedance spectroscopy measurements and surface analyses were used to explore the effects of Li^(+) solvation structure with TMSB additive on the formation of the cathode electrolyte interface(CEI) film in LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/Li half cells. The results reveal that the TMSB additive is easy to complex with Li^(+) ion, thus weaken the intermolecular force between Li^(+) ions and ethylene carbonate solvent, which is benefit for the cycle performance. Besides, the changed Li^(+) solvation structure results in a thin and dense CEI film containing compounds with Si–O and B–O bonds which is favorable to the transfer of Li^(+) ions. As a result, the performances of the LNCM811/Li half cells are effectively improved. This research provides a new idea to construct a high-performance CEI film by adjusting the Li^(+) solvation structures.
基金the financial support of the National Natural Science Foundation of China(Project 50975282)
文摘Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, TEM, EDS, FTIR and XRD, respectively. Moreover, the friction and wear properties of OA/La BO_3·H_2O as a lubricant additive in rapeseed oil were evaluated on a four-ball tribotester. The tribochemical characteristics of worn surfaces were investigated by SEM and XPS. The results showed that the hydrophobic OA/La BO_3·H_2O nanosheets exhibited their morphology with a diameter in the range of 100 nm to 300 nm and a thickness of about 25 nm, and displayed excellent dispersing stability in rapeseed oil. In the meantime, the rapeseed oil doped with OA/La BO_3·H_2O nanosheets markedly decreased the friction and wear of steel balls, and the optimal friction-reducing and antiwear ability of rapeseed oil was obtained at an OA/La BO_3·H_2O content of 1.0%. The outstanding tribological performance of OA/La BO_3·H_2O in rapeseed oil was attributed to the formation of a composite boundary lubrication film mainly composed of lubricious tribochemical species of B_2O_3, La_2O_3 and Fe_2O_3, and deposits of OA/La BO_3·H_2O nanosheets as well as the adsorbates of rapeseed oil on rubbed surfaces.
基金supported by the project,‘‘Research on the targeted treatment of malignant tumors with Base 20180199 New Transmembrane Antibody’’(No.JCYJ20180507182217748)the National Natural Science Foundation of China(No.11375117)
文摘Adenosine triphosphate(ATP)borate ester as a new boron agent for boron neutron capture therapy was tested.It was synthesized via a dehydration reaction induced by heating adenosine triphosphate disodium with boric acid.Next,ATP borate ester pretreatments were assessed to study their effects on cell sensitization from exposure to thermal neutron irradiation emitted by a nuclear reactor.Using cell viability assays(CCK8),survival rates of A549 cells pretreated with or without boroncontaining agents,including ATP borate ester and 4-dihydroxyborylphenylalanine(BPA),were measured.One week after feeding an ATP borate ester solution to tumorbearing nude mice,elemental B content values of tumor muscle and blood were measured using inductively coupled plasma mass spectrometry(ICP-MS).Meanwhile,other tumor tissue samples were placed in a culture medium,subjected to a 3-min neutron irradiation exposure,and then fixed in formalin 24 h later for the terminaldeoxynucleotidyl transferase(TDT)-mediated d UTP nick end labeling(TUNEL)immunohistochemical staining analysis.Results showed that A549 cell irradiation sensitization(irradiation dose of 0.33 Gy)varied with pretreatment.Sensitization values of the ATP borate ester pretreatment group were 1.3–14.1 with boron agent concentrations of 0.3–4.5 mM.Within 1.1–3.4 mM,ATP borate ester showed significantly higher sensitization values than BPA.Meanwhile,TUNEL results demonstrated that apoptosis rates of tumor tissue cells exposed to irradiation after ATP borate ester pretreatment significantly exceeded the corresponding rates for BPA-pretreated cells.In animal experiments,although the distribution ratio of ATP borate ester(tumor tissue/normal muscle,T/N)of 1.2 was not significantly different compared with that of BPA(1.3),the total ATP borate ester concentration in the tumor tissue(0.79±0.05μg/g)significantly exceeded that of BPA(0.58±0.05μg/g).Thus,compared with BPA,the greater enrichment of ATP borate ester in tumor tissues permits preferential targeting toward tumor cells for radiation sensitization.Therefore,ATP borate ester is superior to BPA for use in boron neutron capture therapy.
基金Supported by the National Natural Science Foundation of China under Grant No 50590402.
文摘Cadmium dizinc diborate （CdZn2B2O6） single crystals have been grown for the first time. The crystal structure of CdZn2B2O6 is the same as that of the Cd3Zn3B4O12. The x-ray diffraction, infrared and Raman spectra, differential scanning calorimetry analysis and density indicate that the physical and chemical properties of both crystals are very similar. Especially, the nonlinear optical coefficients of CdZn2B2O6 and Cd3Zn3B4O12 crystals are 2.6 and 2.4 times as large as that of KH2PO4 crystal respectively. Chemical etching experiments indicated that these crystals are very stable in neutral solution and not hygroscopic in air at room temperature.
文摘Global economic and pollution concerns are having a major impact on how modern engine oils are being formulated.Modern engine oil specifications mandate reduced levels of phosphorus and sulfur to protect the efficacy of pollution control devices.In addition,modern engine oil must also be more fuel efficient than earlier generations to reduce greenhouse gas emissions and the impact of high priced gasoline and diesel fuel to the consumer.At the same time,oxidation,wear,and corrosion performance of the oil must not be compromised.Multifunctional additives are useful formulation tools that help formulators meet these tough new challenges.One such additive is the organo-borate ester/amide.Originally conceived as an organic friction modifier,this patented technology is really a multifunctional additive that addresses the global economic and pollution concerns.With the addition of boron,this unique commercial organic friction modifier also imparts antioxidancy,antiwear and anticorrosion properties to engine oil.In addition,the organo-borate ester/amide is compatible with pollution control devices because it does not contain sulfur or phosphorus.Work is on going to uncover additional beneficial properties of this chemistry.
基金Financially supported by the National Natural Science Foundation of China(51872115,52101256,51932003)China Postdoctoral Science Foundation Project(2020M680043)+1 种基金Science and Technology Research Project of the Department of Education of Jilin Province(JJKH20211083KJ)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH)。
文摘Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.
文摘The dislocations in lithium tetraborate crystal have been investigated by means of synchrotron radiation white beam topography in BSRL(Beijing Synchrotron Radiation Laboratory).The Burgers'vectors of these dislocations are determined by their vanishing conditions.Both screw and edge dislocations exist in the specimen.
基金Project supported by the National Natural Science Foundation of China and CAEP （Grant No NSAF.10376021）.
文摘A new compound with the stone cheinical composition as Li3AlB2O6 but with a different x-ray powder diffraction pattern as reported before was synthesized and studied experimentally by M. He, Chen X Let al （J. Solid State Chem. 163, 369 （2002））, but there lacks first principles study on the structure of it. Using conjugant gradient （CG） molecule dynamics （MD） simulation with a full relaxation of the atomic positions and of the shape and size of the cell, the structure of Li3AlB2O6 is studied from first principles. For the density functional, the local density approximation （LDA） and the generalized gradient approximation （GGA） forms are used respectively. Both the LDA and GGA results support the experimental structure of M. He et al. The result of MD simulation using GGA agrees with the experimental result much better. The energy bands are also studied, the band gap given by LDA and GGA are 5.65 eV, 5.34eV, respectively.
文摘The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1 wt% TMSB can dramatically reduce the capacity fading that occurs during cycling at room temperature (RT) and elevated temperature (60 degrees C). After 150 cycles at 1 C rate (1 C= 278 mAh/g), the capacity retention of Li/LiCo1/3Ni1/3Mn1/3O2 is up to near 72% in the electrolyte with TMSB added, while it is only about 35% in the baseline electrolyte. The electrochemical behaviors, the surface chemistry and structure of Li/LiCo1/3Ni1/3Mn1/3O2 cathode are characterized with charge/discharge test, linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), thermal gravimetric analyses (TGA), scanning electron microscope (SEM) and transmission electron microscopy (TEM). These analysis results reveal that the addition of TMSB is able to protectively modify the electrode CEI film in a manner that suppresses electrolyte decomposition and degradation of electrode surface structure, even though at both a higher voltage of 4.7 V and an elevated temperature of 60 degrees C. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
文摘A novel lubricating oil additive dodecoxyl barium borate was synthesized. The product was characterized by FTIR, elemental analysis, thermo-gravimetric analysis （TGA）, and scanning electron microscopy （SEM）. Four-ball tests showed that the addition of a certain concentration of the additive to rapeseed oil could effectively increase both the load-carrying capacity （PB value）, resistance to wear, and friction-reducing abilities. SEM observations confirmed that the additive could result in a reduced diameter of the wear scar.
文摘Overbased complex sulphonates containing two metals -- sodium and magnesium -- were prepared by using overbased magnesium sulphonate as the starting material. Borated overbased complex sulphonate containing two metals was synthesized by reaction of boric acid with the corresponding sulphonate. The total base number （TBN） of overbased complex sulphonates decreased compared with that of magnesium sulphonate, while TBN of borated overbased complex sulphonate further decreased. The detergency, anti-oxidation and extreme pressure performances of overbased complex sulphonates were improved compared with those of overbased magnesium sulphonate; the anti-oxidation and extreme pressure performances of borated overbased complex sulphonates were further improved whereas its detergency was reduced.
文摘The Raman spectrum of rhombohedral NdAl 3 (BO 3) 4 (NAB) is recorded and interpreted. A factor group analysis of the NAB space group shows that there are 21A 1 and 59E Raman active modes. A discussion of the assignment of the individual Raman lines is given. The splitting predicted by factor group for the internal modes of (BO 3) 3+ anion are observed and interpreted.
基金Project supported by the Natural Science Foundation of Tianjin (Grant Nos. 09JCYBJC01400 and 11JCYBJC00300)the Natural Science Foundation of the Tianjin Education Committee (Grant No. 20071207)Tianjin Key Subject for Materials Physics and Chemistry
文摘Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/2,is obviously altered with different silicon/aluminum ratios.The Judd-Ofelt parameters of the Er3+ ions are adopted to explain the intensity change in the NIR fluorescence,and the Raman scattering intensity versus the amount of Al and/or Si components are discussed.The spectra of the three samples are quite similar in the peak positions,but different in intensity.The maximal phonon density of state for the samples is calculated from the Raman spectra and is correlated to the NIR luminescence efficiency.
