Rapid development of solid-state lighting technology requires new materials with highly efficient and stable luminescence,and especially relies on blue light pumped red phosphors for improved light quality.Herein,we d...Rapid development of solid-state lighting technology requires new materials with highly efficient and stable luminescence,and especially relies on blue light pumped red phosphors for improved light quality.Herein,we discovered an unprecedented red-emitting Mg_(2)AI_(4)Si_(5)0_(18):Eu^(2+)composite phosphor(λex=450 nm,λem=620 nm)via the crystallization of MgO-AI_(2)O_(3)-Sio_(2) aluminosilicate glass.Combined experimental measurement and first-principles calculations verify that Eu^(2+)dopants insert at the vacant channel of Mg_(2)AI_(4)Si_(5)0_(18)crystal with six-fold coordination responsible for the peculiar red emission.Importantly,the resulting phosphor exhibits high internal/external quantum efficiency of 94.5/70.6%,and stable emission against thermal quenching,which reaches industry production.The maximum luminous flux and luminous efficiency of the constructed laser driven red emitting device reaches as high as 274 Im and 54lm W^(-1),respectively.The combinations of extraordinary optical properties coupled with economically favorable and innovative preparation method indicate,that the Mg_(2)AI_(4)Si_(5)0_(18):Eu^(2+)composite phosphor will provide a significant step towards the development of high-power solid-state lighting.展开更多
Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,ne...Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,next-generation Cr^(3+)-free NIR-emitting phosphors with high efficiency and tunable optical properties are highly desired to enrich the types of NIR luminescent materials for different application fields.Here,we report the Fe^(3+)-activated Sr2−yCay(InSb)1−zSn_(2)zO_(6)phosphors that exhibit unprecedented long-wavelength NIR emission.The overall emission tuning from 885 to 1005 nm with broadened full-width at half maximum from 108 to 146 nm was realized through a crystallographic site engineering strategy.The NIR emission was significantly enhanced after complete Ca^(2+)incorporation owing to the substitution-induced lower symmetry of the Fe^(3+)sites.The Ca_(2)InSbO_(6):Fe^(3+)phosphor peaking at 935 nm showed an ultra-high internal quantum efficiency of 87%.The as-synthesized emission-tunable phosphors demonstrated great potential for NIR spectroscopy detection.This work initiates the development of efficient Fe^(3+)-activated broadband NIR-emitting phosphors and opens up a new avenue for designing NIR-emitting phosphor materials.展开更多
We propose a simple method for the efficient and rapid synthesis of one-dimensional hematite(α-Fe_(2)O_(3))nanostructures based on electrical resistive heating of iron wire under ambient conditions.Typically,1-5μm l...We propose a simple method for the efficient and rapid synthesis of one-dimensional hematite(α-Fe_(2)O_(3))nanostructures based on electrical resistive heating of iron wire under ambient conditions.Typically,1-5μm longα-Fe_(2)O_(3)nanowires were synthesized on a time scale of seconds at temperatures of around 700℃.The morphology,structure,and mechanism of formation of the nanowires were studied by scanning and transmission electron microscopies,energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and Raman techniques.A nanowire growth mechanism based on diffusion of iron ions to the surface through grain boundaries and to the growing wire tip through stacking fault defects and due to surface diffusion is proposed.展开更多
Purpose: To evaluate the effect of balanced hypocaloric diet therapy on the anthropometric and basic metabolic indicators in obese women with infertility. Methods: The follow up interventional clinical study included ...Purpose: To evaluate the effect of balanced hypocaloric diet therapy on the anthropometric and basic metabolic indicators in obese women with infertility. Methods: The follow up interventional clinical study included 23 infertile women in reproductive age with grade I gluteofemoral obesity. All patients have prescribed a balanced hypocaloric diet (1200 kcal/day), underwent exercise and behavioral therapy. Before and after 12-month treatment, an anthropometric study was conducted, determining the level of metabolic and hormonal indicators. Results: The total final number of study participants was 20 patients. A decrease in body weight was achieved in 87% of patients from 4 to 24 kg, on the average, by 10.58 ± 5.70 kg, there was also a decrease in BMI from 32.53 ± 1.40 to 28.55 ± 2.50 kg/m2 (p 0.001). The decrease in body weight was accompanied by a statistically significant decrease in leptin levels (p 0.001), E1 (p = 0.049), E2 (p = 0.032), fasting glucose (p 0.001), HOMA-IR (p = 0.002), cholesterol (p < 0.001), TG (p = 0.004), LDL-C (p = 0.001), atherogenic index of plasma (p <0.001) and an increase in progesterone levels (p = 0.030). Ovulatory menstrual cycles were resumed in all women (p = 0.007) and pregnancy occurred within a year in 1 patient. Conclusion: The implementation of a hypocaloric diet for 12 months in infertile women with first-degree obesity helps to normalize metabolic and hormonal indicators, reduces body weight and restores ovulatory menstrual cycle in all patients.展开更多
A double holmium-silver sulfate was obtained for the first time.The temperature intervals for the formation and stability of the compound were determined by differential scanning calorimetry.The crystal structure of A...A double holmium-silver sulfate was obtained for the first time.The temperature intervals for the formation and stability of the compound were determined by differential scanning calorimetry.The crystal structure of AgHo(SO_(4))_(2)was determined by Rietveld method.The X-ray diffraction(XRD)analysis showed that the compound crystallizes in the monoclinic syngony,space group P2_1/m,with the unit cell parameters a=4.71751(4)A,b=6.84940(6)A and c=9.89528(9)A,β=95.1466(4)·,V=318.448(5)A^(3),Z=2,R_B=1.55%,T=303 K.Two types of sulfate tetrahedra were found in the structure,which significantly affected the spectral properties in the infrared range.In the temperature range of 143-703 K,a negative thermal expansion along the b direction accompanied by a positive thermal expansion along the a and c directions was observed.It was established that negative thermal expansion is the result of the deformation of sulfate tetrahedra,which is affected by the movement of holmium and silver atoms.The excitation in the blue spectral range(457.9 nm)produces a luminescence in light blue(489 nm),green(545 nm)and red(654 nm)spectral ranges,and the latter two were of comparable intensity that is favorable for WLED sources.The observed luminescent band distribution is ascribed to the specific crystal field at Ho^(3+)ion sites rather than a variation of radiationless probability.展开更多
Structural model of C100H79O7NS coal organic mass was obtained within density functional theory in the localized orbital basis set using the B3LYP hybrid functional. The model was compared with the known experimental ...Structural model of C100H79O7NS coal organic mass was obtained within density functional theory in the localized orbital basis set using the B3LYP hybrid functional. The model was compared with the known experimental data for coal of different grades and its sorption properties were studied with respect to CH4, CO2 and H2O. It has been shown that macromolecule of coal organic mass has bulk structure with a pore inside it. Interaction between coal and CH4 molecules consists of typical physical adsorption with oligomer formation on the pore border, physical adsorption with elements of chemical adsorption was also observed between coal and H2O molecules. Interaction between coal and H2O molecules included both physical and chemical adsorbion.展开更多
It was supposed that lung and breast cancer risks significantly increased when the levels of serum immunoglobulins A antibodies against benzo[a]pyrene and estradiol increased together, but did not separately. However,...It was supposed that lung and breast cancer risks significantly increased when the levels of serum immunoglobulins A antibodies against benzo[a]pyrene and estradiol increased together, but did not separately. However, the cancer risks dramatically decreased when the levels of immunoglobulins A against progesterone elevated separately or together with immunoglobulins A against benzo[a]pyrene and estradiol. So, immunoglobulins A against benzo[a]pyrene and immunoglobulins A against estradiol acted as co-initiator and co-promoter in developing cancer scenario, but immunoglobulins A against progesterone acted along or conjointly with immunoglobulins A against benzo[a]pyrene and estradiol as strongly inhibitor in human carcinogenesis. Also it was suggested the precise mechanism of carcinogenesis modulation using anti-idiotypic antibodies against estradiol and progesterone through their membrane steroid receptors.展开更多
Methane and carbon dioxide hydrates are one of the possible forms in which these gases exist in natural coal(for more detailed discussion see Refs [1,2]). In this work, the decomposition of carbon dioxide hydrate in f...Methane and carbon dioxide hydrates are one of the possible forms in which these gases exist in natural coal(for more detailed discussion see Refs [1,2]). In this work, the decomposition of carbon dioxide hydrate in five samples of natural coal differing from each other in metamorphism degree was investigated experimentally. Carbon dioxide hydrate dispersed in coals was synthesized from water adsorbed in these coals. During a linear temperature rise in an autoclave with the coal + hydrate sample the hydrate decomposition manifests itself as a step of increase in gas pressure, accompanied by a decrease/stabilization of the temperature of coal sample. The dependencies of the amount of hydrate formed on initial coal humidity and on gas pressure during hydrate formation were studied. It was demonstrated that each coal sample is characterized by its own humidity threshold below which hydrate formation in natural coal is impossible. With an increase in gas pressure, the amount of water transformed into hydrate increases. For the studied coal samples, the decomposition of carbon dioxide hydrates proceeds within a definite temperature and pressure range, and this range is close to the curve of phase equilibrium for bulk hydrate.展开更多
This paper discusses the problem of assessing the negative after-effects of low doses of ionising radiation exposure in humans. Radon and its decay daughter products are the most widespread source of such irradiation....This paper discusses the problem of assessing the negative after-effects of low doses of ionising radiation exposure in humans. Radon and its decay daughter products are the most widespread source of such irradiation. Miners (in both uranium and non-uranium mines) as well as laypeople in domestic life may be exposed to radon, making the problem of assessing the cytogenetic effects of exposure extremely crucial. One of the more promising test systems to assess the effect of radon is the cytokinesis-block micronucleus assay (CBMN) on peripheral blood lymphocytes, which has a number of advantages over other cytogenetic techniques. Recent progress and future prospects of this cytogenetic method are discussed here.展开更多
基金the National Natural Science Foundations of China(Grant Nos.51972118,51961145101,51722202 and 11974022)the Guangzhou Science&Technology Project(202007020005)+1 种基金the Fundamental Research Funds for the Central Universities(D2190980)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137).
文摘Rapid development of solid-state lighting technology requires new materials with highly efficient and stable luminescence,and especially relies on blue light pumped red phosphors for improved light quality.Herein,we discovered an unprecedented red-emitting Mg_(2)AI_(4)Si_(5)0_(18):Eu^(2+)composite phosphor(λex=450 nm,λem=620 nm)via the crystallization of MgO-AI_(2)O_(3)-Sio_(2) aluminosilicate glass.Combined experimental measurement and first-principles calculations verify that Eu^(2+)dopants insert at the vacant channel of Mg_(2)AI_(4)Si_(5)0_(18)crystal with six-fold coordination responsible for the peculiar red emission.Importantly,the resulting phosphor exhibits high internal/external quantum efficiency of 94.5/70.6%,and stable emission against thermal quenching,which reaches industry production.The maximum luminous flux and luminous efficiency of the constructed laser driven red emitting device reaches as high as 274 Im and 54lm W^(-1),respectively.The combinations of extraordinary optical properties coupled with economically favorable and innovative preparation method indicate,that the Mg_(2)AI_(4)Si_(5)0_(18):Eu^(2+)composite phosphor will provide a significant step towards the development of high-power solid-state lighting.
基金financially supported by the National Natural Science Foundation of China(NSFC Nos.51720105015,51932009,51929201,52072349)the Projects for Science and Technology Development Plan of Jilin Province(20210402046GH)the Natural Science Foundation of Zhejiang Province(LR22E020004).
文摘Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,next-generation Cr^(3+)-free NIR-emitting phosphors with high efficiency and tunable optical properties are highly desired to enrich the types of NIR luminescent materials for different application fields.Here,we report the Fe^(3+)-activated Sr2−yCay(InSb)1−zSn_(2)zO_(6)phosphors that exhibit unprecedented long-wavelength NIR emission.The overall emission tuning from 885 to 1005 nm with broadened full-width at half maximum from 108 to 146 nm was realized through a crystallographic site engineering strategy.The NIR emission was significantly enhanced after complete Ca^(2+)incorporation owing to the substitution-induced lower symmetry of the Fe^(3+)sites.The Ca_(2)InSbO_(6):Fe^(3+)phosphor peaking at 935 nm showed an ultra-high internal quantum efficiency of 87%.The as-synthesized emission-tunable phosphors demonstrated great potential for NIR spectroscopy detection.This work initiates the development of efficient Fe^(3+)-activated broadband NIR-emitting phosphors and opens up a new avenue for designing NIR-emitting phosphor materials.
基金supported by the National Key Research and Development Program of China(2021YFE0105700)the National Natural Science Foundations of China(51972118)+3 种基金the Natural Science Foundation of Shandong Province(ZR2021ZD10 and ZR2018JL016)Guangzhou Science&Technology Project(202007020005)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137)funded by Russian Foundation for Basic Research(19-52-80003)。
基金the Academy of Finland(project numbers 128445 and 128495)P.R.M.acknowledges Finnish National Graduate School in Nanoscience(NGS-NANO)S.D.S.thanks the European Commission for financial support through a Marie Curie Individual Fellowship(MIF1-CT-2005-022110).
文摘We propose a simple method for the efficient and rapid synthesis of one-dimensional hematite(α-Fe_(2)O_(3))nanostructures based on electrical resistive heating of iron wire under ambient conditions.Typically,1-5μm longα-Fe_(2)O_(3)nanowires were synthesized on a time scale of seconds at temperatures of around 700℃.The morphology,structure,and mechanism of formation of the nanowires were studied by scanning and transmission electron microscopies,energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and Raman techniques.A nanowire growth mechanism based on diffusion of iron ions to the surface through grain boundaries and to the growing wire tip through stacking fault defects and due to surface diffusion is proposed.
文摘Purpose: To evaluate the effect of balanced hypocaloric diet therapy on the anthropometric and basic metabolic indicators in obese women with infertility. Methods: The follow up interventional clinical study included 23 infertile women in reproductive age with grade I gluteofemoral obesity. All patients have prescribed a balanced hypocaloric diet (1200 kcal/day), underwent exercise and behavioral therapy. Before and after 12-month treatment, an anthropometric study was conducted, determining the level of metabolic and hormonal indicators. Results: The total final number of study participants was 20 patients. A decrease in body weight was achieved in 87% of patients from 4 to 24 kg, on the average, by 10.58 ± 5.70 kg, there was also a decrease in BMI from 32.53 ± 1.40 to 28.55 ± 2.50 kg/m2 (p 0.001). The decrease in body weight was accompanied by a statistically significant decrease in leptin levels (p 0.001), E1 (p = 0.049), E2 (p = 0.032), fasting glucose (p 0.001), HOMA-IR (p = 0.002), cholesterol (p < 0.001), TG (p = 0.004), LDL-C (p = 0.001), atherogenic index of plasma (p <0.001) and an increase in progesterone levels (p = 0.030). Ovulatory menstrual cycles were resumed in all women (p = 0.007) and pregnancy occurred within a year in 1 patient. Conclusion: The implementation of a hypocaloric diet for 12 months in infertile women with first-degree obesity helps to normalize metabolic and hormonal indicators, reduces body weight and restores ovulatory menstrual cycle in all patients.
基金the Russian Foundation for Basic Research(Nos.18-02-00754 and 18-32-20011)the National Scientific Foundations of China(No.11974360)+1 种基金the Russian Science Foundation(No.19-42-02003,in the part of conceptualization)Basic Project of the Ministry of Science of the Russian Federation in part of XRD,luminescent and Raman studies。
文摘A double holmium-silver sulfate was obtained for the first time.The temperature intervals for the formation and stability of the compound were determined by differential scanning calorimetry.The crystal structure of AgHo(SO_(4))_(2)was determined by Rietveld method.The X-ray diffraction(XRD)analysis showed that the compound crystallizes in the monoclinic syngony,space group P2_1/m,with the unit cell parameters a=4.71751(4)A,b=6.84940(6)A and c=9.89528(9)A,β=95.1466(4)·,V=318.448(5)A^(3),Z=2,R_B=1.55%,T=303 K.Two types of sulfate tetrahedra were found in the structure,which significantly affected the spectral properties in the infrared range.In the temperature range of 143-703 K,a negative thermal expansion along the b direction accompanied by a positive thermal expansion along the a and c directions was observed.It was established that negative thermal expansion is the result of the deformation of sulfate tetrahedra,which is affected by the movement of holmium and silver atoms.The excitation in the blue spectral range(457.9 nm)produces a luminescence in light blue(489 nm),green(545 nm)and red(654 nm)spectral ranges,and the latter two were of comparable intensity that is favorable for WLED sources.The observed luminescent band distribution is ascribed to the specific crystal field at Ho^(3+)ion sites rather than a variation of radiationless probability.
文摘Structural model of C100H79O7NS coal organic mass was obtained within density functional theory in the localized orbital basis set using the B3LYP hybrid functional. The model was compared with the known experimental data for coal of different grades and its sorption properties were studied with respect to CH4, CO2 and H2O. It has been shown that macromolecule of coal organic mass has bulk structure with a pore inside it. Interaction between coal and CH4 molecules consists of typical physical adsorption with oligomer formation on the pore border, physical adsorption with elements of chemical adsorption was also observed between coal and H2O molecules. Interaction between coal and H2O molecules included both physical and chemical adsorbion.
文摘It was supposed that lung and breast cancer risks significantly increased when the levels of serum immunoglobulins A antibodies against benzo[a]pyrene and estradiol increased together, but did not separately. However, the cancer risks dramatically decreased when the levels of immunoglobulins A against progesterone elevated separately or together with immunoglobulins A against benzo[a]pyrene and estradiol. So, immunoglobulins A against benzo[a]pyrene and immunoglobulins A against estradiol acted as co-initiator and co-promoter in developing cancer scenario, but immunoglobulins A against progesterone acted along or conjointly with immunoglobulins A against benzo[a]pyrene and estradiol as strongly inhibitor in human carcinogenesis. Also it was suggested the precise mechanism of carcinogenesis modulation using anti-idiotypic antibodies against estradiol and progesterone through their membrane steroid receptors.
基金supported by the project №18 "Study of the physicochemical properties of hydrate-containing rocks for the development of remote sensing methods and the characteristics of natural accumulations of gas hydrates" of the Integrated Basic Research Program of the Siberian Branch of the Russian Academy of Sciences.
文摘Methane and carbon dioxide hydrates are one of the possible forms in which these gases exist in natural coal(for more detailed discussion see Refs [1,2]). In this work, the decomposition of carbon dioxide hydrate in five samples of natural coal differing from each other in metamorphism degree was investigated experimentally. Carbon dioxide hydrate dispersed in coals was synthesized from water adsorbed in these coals. During a linear temperature rise in an autoclave with the coal + hydrate sample the hydrate decomposition manifests itself as a step of increase in gas pressure, accompanied by a decrease/stabilization of the temperature of coal sample. The dependencies of the amount of hydrate formed on initial coal humidity and on gas pressure during hydrate formation were studied. It was demonstrated that each coal sample is characterized by its own humidity threshold below which hydrate formation in natural coal is impossible. With an increase in gas pressure, the amount of water transformed into hydrate increases. For the studied coal samples, the decomposition of carbon dioxide hydrates proceeds within a definite temperature and pressure range, and this range is close to the curve of phase equilibrium for bulk hydrate.
文摘This paper discusses the problem of assessing the negative after-effects of low doses of ionising radiation exposure in humans. Radon and its decay daughter products are the most widespread source of such irradiation. Miners (in both uranium and non-uranium mines) as well as laypeople in domestic life may be exposed to radon, making the problem of assessing the cytogenetic effects of exposure extremely crucial. One of the more promising test systems to assess the effect of radon is the cytokinesis-block micronucleus assay (CBMN) on peripheral blood lymphocytes, which has a number of advantages over other cytogenetic techniques. Recent progress and future prospects of this cytogenetic method are discussed here.
