To study the effect of Green plum citron double strain fermentation filtrate(DSF)on the proliferation rate of HaCaT keratinocytes by CCK8 assay.The effect of DSF on the mRNA transcription levels of filagolin(FLG),lori...To study the effect of Green plum citron double strain fermentation filtrate(DSF)on the proliferation rate of HaCaT keratinocytes by CCK8 assay.The effect of DSF on the mRNA transcription levels of filagolin(FLG),loricrin(LOR),and occludin 1(CLD1)in HaCaT cells in sodium dodecyl sulfate(SLS)model was investigated by qPCR.The effect of DSF on the content of TNF-αin the supernatant of HaCaT cells in the model was investigated by Elisa.The results showed that DSF had no toxicity to HaCaT cells,but it could increase the mRNA transcription levels of FLG,LOR and CLD1 in HaCaT cells in the model,and reduce the content of TNF-αin the supernatant of HaCaT cells in the model.DSF had a certain effect on skin care of strengthening skin barrier.展开更多
In order to develop green good, reduce the use of chemical fertilizer and pesticide, realize "double reduction" and synergism, improve safety and quality of products, protect the ecological environment and promote t...In order to develop green good, reduce the use of chemical fertilizer and pesticide, realize "double reduction" and synergism, improve safety and quality of products, protect the ecological environment and promote the healthy and steady development of strawberry industry, the goals and key technology of fertilizer-pesticide "double reduction" and synergism for greenhouse strawberry are summed up in this paper targeting at the current situation of strawberry production and combined with the new technology achievements at home and abroad. The key technology includes six items: healthy seedling cultivating technique, soil improvement and continuous cropping obstacle treatment technique, agricultural ecological prevention tech- nique, physicochemical trap of pest control technique, biological control technique and low residual risk chemical control technique.展开更多
Central region coarse grains and centerline segregation are common defects in aluminum ingots fabricated by direct chill(DC)casting.A double cooling field was introduced into the DC casting process to reduce these def...Central region coarse grains and centerline segregation are common defects in aluminum ingots fabricated by direct chill(DC)casting.A double cooling field was introduced into the DC casting process to reduce these defects,whereby the external cooling was supplied by the mold and water jets,and intercooling was achieved by inserting a rod of the same alloy into the molten pool along the central axis of the ingot.Rather than forming a good metallurgical interface during solid-liquid compound casting,in the present work,the purpose of inserting the rod is to enforce internal cooling and consequently decrease the sump depth.Moreover,the insertion provides more nucleation sites with the unmoltenα-Al particles.The structure and the macrosegregation of 2024 Al alloy ingots prepared by DC casting with and without the inserts were investigated.Results show that when the inserting position is 50 mm above the upper edge of the graphite ring,significant grain refinement in the central region of the ingot and a reduced centerline segregation are achieved.展开更多
In order to solve the problem of using new nozzle is proposed in fire rescue robot. middle or low water pressure to form fine water mist, a Existing water mist nozzles are basically used for high pressure and in large...In order to solve the problem of using new nozzle is proposed in fire rescue robot. middle or low water pressure to form fine water mist, a Existing water mist nozzles are basically used for high pressure and in large size, complex structure and poor low pressure atomization effect in comparison with requirement of snake-like fire rescue robots. On the basis of comprehensive typical spray noz- zles, a direct spiral double helix converging nozzle (DSDHCN) is proposed, which has the advanta- ges of small volume, light weight, simple structure, and convenient installation. To make the spray nozzle have good performance, and meet the requirements of more efficient fire extinguishing, a nu- merical study is carried out to analyze the internal and external full flow field of nozzle. A gas-liquid two-phase flow is applied to simulate the external full flow field of nozzle with VOF model in fluent software. The simulation results show the real situation of water flow out of the atomization nozzle and the water jet trajectory. Some simulations about middle or low water pressure direct spiral double he- lix converging optimized nozzle have been done in 30bar pressure. The simulation results show that the optimized nozzle structure not only makes the spray droplets have a good cone angle, but also have a sufficient axial velocity,which proves the structure rationality of the proposed optimized nozzle.展开更多
Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based ...Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based on in-situ investigations and theoretical studies,we have summarized typical forms of destruction and identified high stress and unrestricted support at both sides of junction arch as its main causes.In this study,we also presented double-directional control bolt support technology for a large Y-type span intersection,applied to deep intersection engineering in the Jiahe Coal Mine,which has proved effective.展开更多
The unified analysis of omni-directional wheeled mobile manipulator(OWMM) through the dimensionally nonhomogeneous Jacobian matrix may lead to unreliable results. The existing researches focus on the integrated perfor...The unified analysis of omni-directional wheeled mobile manipulator(OWMM) through the dimensionally nonhomogeneous Jacobian matrix may lead to unreliable results. The existing researches focus on the integrated performance evaluation of OWMM, without taking the influence of velocity difference into consideration. This paper presents a new approach to formulate the dimensionally homogeneous Jacobian matrix and a new index for OWMM. First, the universal transformational matrix of the link coordinate frame is derived based on double quaternion. The degree of locomotion of a mobile platform and the degrees of manipulation of a manipulator are treated equally as the joints of a redundant composite robot. Then the integrated modeling of OWMM is established, and the non-dimensional Jacobian matrix is obtained from the above matrix. Next, by examining the concept of directional manipulability, a new index is proposed to evaluate the directional manipulability of OWMM along the specified task direction. Furthermore, for the same task and the time of simulation, the kinematic performance of the fixed base operation of the manipulator and the operation of OWMM are analyzed by numerical simulation. The results suggest that the proposed approach is equivalent to the method of traditional kinematic modeling, with the error of numerical solution being 10-7 , and the varying frequency of DMTR is higher than that of the condition number. This indicates that DMTR is more effective to reflect the variation of the task direction. The proposed method can be used to analyze the manipulating capability of OWMM, and has a simple structure and generality in the unified analysis of OWMM.展开更多
Single(SA) and double(DA) Auger decay including cascade and direct processes are investigated for Hg 4 f^(-1) with multiconfiguration Dirac–Fock method and two-step approaches, i.e., knockout and shakeoff mecha...Single(SA) and double(DA) Auger decay including cascade and direct processes are investigated for Hg 4 f^(-1) with multiconfiguration Dirac–Fock method and two-step approaches, i.e., knockout and shakeoff mechanisms. Due to the computational effort, only the major transitions are considered to describe the SA and DA decays for the Hg+ions with complex electronic configurations. In order to estimate the Auger transition energies and amplitudes, the reference configuration sets producing the configuration state functions are carefully chosen for balancing electron correlations among the successive singly, doubly and triply ionized mercury. The Auger rates and electron spectra, DA probabilities as well as the populations of the final Hg^(3+)states are obtained. Our results well explain the recent experimental data about the 4 f hole states of Hg[Palaudoux J et al., Phys. Rev. A 91 012513(2015)], and could provide guidance for further studies on complex atoms.Particularly for the DA decay, the contributions of the direct processes, which are neglected in their calculations, are found to be important, accounting for as high as about 38% and 34% of the total DA decays for the 4 f(7/2)^(-1) and 4 f(5/2)^(-1), respectively.展开更多
1.Challenges circular methane energy systems In recent decades,methane-based energy systems have rapidly gained traction across the globe because of the increasing availability of low-cost methane production capacity....1.Challenges circular methane energy systems In recent decades,methane-based energy systems have rapidly gained traction across the globe because of the increasing availability of low-cost methane production capacity.However,fossil methane production and combustion lead to large greenhouse gas emissions,contributing to climate change[1].展开更多
A laser diode (LD) pumped Q switched high efficient intracavity frequency doubled Nd ∶YAG laser is reported here. The authors have designed an optical coupler and pointed out that the key to increasing harmonic conve...A laser diode (LD) pumped Q switched high efficient intracavity frequency doubled Nd ∶YAG laser is reported here. The authors have designed an optical coupler and pointed out that the key to increasing harmonic conversion efficiency is to decrease the loss of fundamental wave. In the experiments, a fundamental mode output laser was acquired. When the pumping power was 12 W, 2.6 W average output power at 1 064 nm with AO Q switch was obtained. 2.1 W average output power at 532 nm was obtained with intracavity frequency doubling, and the highest second harmonic conversion efficiency was 82 0 0.展开更多
Layered double hydroxides(LDHs)have received extensive attention in many fields such as catalysis,environmental management and medical applications.Typically,expensive soluble metal salts are commonly used as the star...Layered double hydroxides(LDHs)have received extensive attention in many fields such as catalysis,environmental management and medical applications.Typically,expensive soluble metal salts are commonly used as the starting materials for the synthesis of LDHs.Here,we report a novel synthesis route for Mg/Al-LDH by using inexpensive basic magnesium carbonate as the starting material.X-ray diffraction(XRD)and solid-state nuclear magnetic resonance(ssNMR)data show that LDHs with rich defects are formed rapidly at room temperature and good crystallinity can be obtained after further hydrothermal treatment.These results provide a simple,rapid and green preparation method for LDHs.展开更多
Shenzhen has extensive green construction experience as one of China’s new green development pilot cities.Shenzhen has experienced substantial economic growth as a result of the reform and opening up,but it has also ...Shenzhen has extensive green construction experience as one of China’s new green development pilot cities.Shenzhen has experienced substantial economic growth as a result of the reform and opening up,but it has also had to face the burden of urbanization problems and difficulties.This article looks at the history of green construction in Shenzhen and how the spirit of the city influenced it.The work then divides the procedure into two phases and examines the issues that arise.Suggestions for achieving the“Double Carbon”aim in the building industry are sought through this effort.展开更多
Through cation exchanging of montmorillonite, mixed hydroxy Fe Al pillared montmorillonites with large basal spacing were synthesized. The application of these mixed hydroxy Fe Al pillared montmorillonites as adsorben...Through cation exchanging of montmorillonite, mixed hydroxy Fe Al pillared montmorillonites with large basal spacing were synthesized. The application of these mixed hydroxy Fe Al pillared montmorillonites as adsorbents in the areas of environmental protection and pollution control was investigated. Adsorption of Direct Green B, an organic dye, on OH—Fe—, OH—Al—, OH—Fe—Al— pillared montmorillonites was studied. Results showed that these pillared montmorillonites had much better adsorption properties than traditional Na organo montmorillonite. It was also found that pH of the solutions had great effect on the performance of these hydroxy metal pillared montmorillonites in treating the wastewater containing Direct Green B.展开更多
Zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the environment.It is a growing trend to ...Zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the environment.It is a growing trend to develop an eco‐friendly and nuisanceless OSDA for zeolite synthesis.Herein,choline is employed as a non‐toxic and green OSDA to synthesize high silica Y zeolite with SiO2/Al2O3 ratios of 6.5–6.8.The prepared Y zeolite samples exhibited outstanding(hydro)thermal stability at ultrahigh temperature owing to the higher SiO2/Al2O3 ratio.The XRF,SEM,29Si‐NMR and 13Na+results suggested that choline plays a structure‐directing role in the synthesis of Y zeolite,while the feed molar fraction of Na+is a crucial determinant for the framework SiO2/Al2O3 ratio and the crystal morphology.展开更多
B cells lymphoma is one of the most challenging extrahepatic manifestations of hepatitis C virus(HCV). Recently, a new kind of B-cell lymphoma, named doublehit B(DHL), was characterized with an aggressive clinical cou...B cells lymphoma is one of the most challenging extrahepatic manifestations of hepatitis C virus(HCV). Recently, a new kind of B-cell lymphoma, named doublehit B(DHL), was characterized with an aggressive clinical course whereas a potential association with HCV was not investigated. The new antiviral direct agents(DAAs) against HCV are effective and curative in the majority of HCV infections. We report the first case, to our knowledge, of DHL and HCV-infection successfully treated by new DAAs. According to our experience, a DHL must be suspected in case of HCV-related lymphoma, and an early diagnosis could direct towards a different hematological management because a worse prognosis might be expected. A possible effect of DAAs on DHL regression should be investigated, but eradicating HCV would avoid life-threatening reactivation of viral hepatitis during pharmacological immunosuppression in oncohaematological diseases.展开更多
The inverse problem of wave equation is the importance of study not only in seismic prospecting but also in applied mathematics. With the development of the research, the inverse methods of 1 - D wave equations have b...The inverse problem of wave equation is the importance of study not only in seismic prospecting but also in applied mathematics. With the development of the research, the inverse methods of 1 - D wave equations have been trending towards the multiple parameters inversion . We have obtained an inverse method with double -parameter, in which medium density and wave velocity can be derived simultaneously. In this paper, to increase the inverse accuracy, the method is improved as follows. Firstly, the formula in which the Green Function is omitted are derived and used. Secondly, the regularizing method is reasonable used by choosing the stable function. With the new method, we may derive elastic parameter and medium density or medium density and wave velocity. Thus, lithology parameters for seismic prospecting may be obtained.After comparing the derived values from the new method with that from previous method, we obtain the new method through which substantially improve the derived accuracy . The new method has been applied to real depths inversion for sedimentary strata and volcanic rock strata in Chaoyanggou Terrace of Songliao Basin in eastern China. According to the inverse results,the gas - bearing beds are determlned.展开更多
In SSRF, the design of 1st crystal cooling geometry of double crystal monochromator with sagittal focus is mainly reported by China. Our simulation indicates that the broadening of the full width at half maximum of th...In SSRF, the design of 1st crystal cooling geometry of double crystal monochromator with sagittal focus is mainly reported by China. Our simulation indicates that the broadening of the full width at half maximum of the rocking curve of the double crystal monochromator induced by the heat load is about 3.7 μrad, and is in agreement with the experimental value of 5 μrad. Our scheme showed that the photon flux is reliably linear with electron current of the storage ring, which is extracted from the monochromator.展开更多
To achieve the electric field strength and the induced currents in equivalence in susceptibility tests with the high-level field radiation above 400 MHz,a double differential-mode(DM) current injection method based on...To achieve the electric field strength and the induced currents in equivalence in susceptibility tests with the high-level field radiation above 400 MHz,a double differential-mode(DM) current injection method based on directional couplers is proposed.Two cascaded symmetrical directional couplers compose a coupling device to inject the DM currents.When the coupling device is used,two devices are necessary to achieve the equivalence between radiation and injection,i.e.the equivalence between the injected voltages and the field strength,which is linear,regardless of the characteristics of the equipment under test(EUT).The results are verified by experiments using typical coaxial cables and nonlinear devices,where the equivalence between the nonlinear EUT responses induced by radiation and injection at both ends is achieved by using two coupling devices.At a frequency up to 1.75 GHz,the maximal experimental error is only 3.39%.The experimental results confirm the accuracy of the proposed method even both the EUTs work in the nonlinear region.The proposed method is applicable for radiated susceptibility(RS) testing of interconnected systems in the microwave frequency band.展开更多
A method of determining bifurcation directions at a double eigenvalue is presented by combining the finite element method with the perturbation method. By using the present method, the buckled states of rectangular pl...A method of determining bifurcation directions at a double eigenvalue is presented by combining the finite element method with the perturbation method. By using the present method, the buckled states of rectangular plates at a double eigenvalue are numerically analyzed. The results show that this method is effective.展开更多
The electrical characteristics of a double-gate armchair silicene nanoribbon field-effect-transistor (DG ASiNR FET) are thoroughly investigated by using a ballistic quantum transport model based on non-equilibrium G...The electrical characteristics of a double-gate armchair silicene nanoribbon field-effect-transistor (DG ASiNR FET) are thoroughly investigated by using a ballistic quantum transport model based on non-equilibrium Green's function (NEGF) approach self-consistently coupled with a three-dimensional (3D) Poisson equation. We evaluate the influence of variation in uniaxial tensile strain, ribbon temperature and oxide thickness on the on-off current ratio, subthreshold swing, transconductance and the delay time of a 12-nm-length ultranarrow ASiNR FET. A novel two-parameter strain mag- nitude and temperature-dependent model is presented for designing an optimized device possessing balanced amelioration of all the electrical parameters. We demonstrate that employing HfO2 as the gate insulator can be a favorable choice and simultaneous use of it with proper combination of temperature and strain magnitude can achieve better device performance. Furthermore, a general model power (GMP) is derived which explicitly provides the electron effective mass as a function of the bandgap of a hydrogen passivated ASiNR under strain.展开更多
A theoretical study of resonant tunneling is carried out for an inverse parabolic double-barrier structure subjected to an external electric field. Tunneling transmission coefficient and density of states are analyzed...A theoretical study of resonant tunneling is carried out for an inverse parabolic double-barrier structure subjected to an external electric field. Tunneling transmission coefficient and density of states are analyzed by using the non-equilibrium Green's function approach based on the finite difference method. It is found that the resonant peak of the transmission coefficient, being unity for a symmetrical case, reduces under the applied electric field and depends strongly on the variation of the structure parameters.展开更多
文摘To study the effect of Green plum citron double strain fermentation filtrate(DSF)on the proliferation rate of HaCaT keratinocytes by CCK8 assay.The effect of DSF on the mRNA transcription levels of filagolin(FLG),loricrin(LOR),and occludin 1(CLD1)in HaCaT cells in sodium dodecyl sulfate(SLS)model was investigated by qPCR.The effect of DSF on the content of TNF-αin the supernatant of HaCaT cells in the model was investigated by Elisa.The results showed that DSF had no toxicity to HaCaT cells,but it could increase the mRNA transcription levels of FLG,LOR and CLD1 in HaCaT cells in the model,and reduce the content of TNF-αin the supernatant of HaCaT cells in the model.DSF had a certain effect on skin care of strengthening skin barrier.
基金Supported by Demonstration and Promotion Project of Shanghai Municipal Committee of Agriculture[HNKT(2015)2-7]Jiangsu Agricultural"Three New Engineering"Project[SXGC(2017)208]Jiangsu Agricultural Science and Technology Innovation Fund[CX(15)1029]~~
文摘In order to develop green good, reduce the use of chemical fertilizer and pesticide, realize "double reduction" and synergism, improve safety and quality of products, protect the ecological environment and promote the healthy and steady development of strawberry industry, the goals and key technology of fertilizer-pesticide "double reduction" and synergism for greenhouse strawberry are summed up in this paper targeting at the current situation of strawberry production and combined with the new technology achievements at home and abroad. The key technology includes six items: healthy seedling cultivating technique, soil improvement and continuous cropping obstacle treatment technique, agricultural ecological prevention tech- nique, physicochemical trap of pest control technique, biological control technique and low residual risk chemical control technique.
基金financially supported by the Natural Science Foundation of Liaoning Province(Nos.2019-ZD-0002,2019KF-0503)the Fundamental Research Funds for the Central Universities(Nos.N2002025,N2109006)the National Natural Science Foundation of China(No.51674078)。
文摘Central region coarse grains and centerline segregation are common defects in aluminum ingots fabricated by direct chill(DC)casting.A double cooling field was introduced into the DC casting process to reduce these defects,whereby the external cooling was supplied by the mold and water jets,and intercooling was achieved by inserting a rod of the same alloy into the molten pool along the central axis of the ingot.Rather than forming a good metallurgical interface during solid-liquid compound casting,in the present work,the purpose of inserting the rod is to enforce internal cooling and consequently decrease the sump depth.Moreover,the insertion provides more nucleation sites with the unmoltenα-Al particles.The structure and the macrosegregation of 2024 Al alloy ingots prepared by DC casting with and without the inserts were investigated.Results show that when the inserting position is 50 mm above the upper edge of the graphite ring,significant grain refinement in the central region of the ingot and a reduced centerline segregation are achieved.
基金Supported by the National Natural Science Foundation of China(No.61105086)Self-Planned Task(SKLRS-2010-MS-12)of State Key Laboratory of Robotics and System(HIT)Hubei Province Natural Science Foundation(No.2010CDB03405)
文摘In order to solve the problem of using new nozzle is proposed in fire rescue robot. middle or low water pressure to form fine water mist, a Existing water mist nozzles are basically used for high pressure and in large size, complex structure and poor low pressure atomization effect in comparison with requirement of snake-like fire rescue robots. On the basis of comprehensive typical spray noz- zles, a direct spiral double helix converging nozzle (DSDHCN) is proposed, which has the advanta- ges of small volume, light weight, simple structure, and convenient installation. To make the spray nozzle have good performance, and meet the requirements of more efficient fire extinguishing, a nu- merical study is carried out to analyze the internal and external full flow field of nozzle. A gas-liquid two-phase flow is applied to simulate the external full flow field of nozzle with VOF model in fluent software. The simulation results show the real situation of water flow out of the atomization nozzle and the water jet trajectory. Some simulations about middle or low water pressure direct spiral double he- lix converging optimized nozzle have been done in 30bar pressure. The simulation results show that the optimized nozzle structure not only makes the spray droplets have a good cone angle, but also have a sufficient axial velocity,which proves the structure rationality of the proposed optimized nozzle.
基金supported by the National Basic Research Program of China (No.2006CB202200)the Major Program of the National Natural Science Foundation of China (No.50490270)the Innovative Team Development Project of the Ministry of Education of China (No.IRT0656)
文摘Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based on in-situ investigations and theoretical studies,we have summarized typical forms of destruction and identified high stress and unrestricted support at both sides of junction arch as its main causes.In this study,we also presented double-directional control bolt support technology for a large Y-type span intersection,applied to deep intersection engineering in the Jiahe Coal Mine,which has proved effective.
基金supported by National Natural Science Foundation of China (Grant No. 51075005)
文摘The unified analysis of omni-directional wheeled mobile manipulator(OWMM) through the dimensionally nonhomogeneous Jacobian matrix may lead to unreliable results. The existing researches focus on the integrated performance evaluation of OWMM, without taking the influence of velocity difference into consideration. This paper presents a new approach to formulate the dimensionally homogeneous Jacobian matrix and a new index for OWMM. First, the universal transformational matrix of the link coordinate frame is derived based on double quaternion. The degree of locomotion of a mobile platform and the degrees of manipulation of a manipulator are treated equally as the joints of a redundant composite robot. Then the integrated modeling of OWMM is established, and the non-dimensional Jacobian matrix is obtained from the above matrix. Next, by examining the concept of directional manipulability, a new index is proposed to evaluate the directional manipulability of OWMM along the specified task direction. Furthermore, for the same task and the time of simulation, the kinematic performance of the fixed base operation of the manipulator and the operation of OWMM are analyzed by numerical simulation. The results suggest that the proposed approach is equivalent to the method of traditional kinematic modeling, with the error of numerical solution being 10-7 , and the varying frequency of DMTR is higher than that of the condition number. This indicates that DMTR is more effective to reflect the variation of the task direction. The proposed method can be used to analyze the manipulating capability of OWMM, and has a simple structure and generality in the unified analysis of OWMM.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0402300)the National Natural Science Foundation of China(Grant Nos.11774344 and 11474033)+1 种基金the Joint Foundation of the National Natural Science Foundationthe China Academy of Engineering Physics(Grant No.U1330117)
文摘Single(SA) and double(DA) Auger decay including cascade and direct processes are investigated for Hg 4 f^(-1) with multiconfiguration Dirac–Fock method and two-step approaches, i.e., knockout and shakeoff mechanisms. Due to the computational effort, only the major transitions are considered to describe the SA and DA decays for the Hg+ions with complex electronic configurations. In order to estimate the Auger transition energies and amplitudes, the reference configuration sets producing the configuration state functions are carefully chosen for balancing electron correlations among the successive singly, doubly and triply ionized mercury. The Auger rates and electron spectra, DA probabilities as well as the populations of the final Hg^(3+)states are obtained. Our results well explain the recent experimental data about the 4 f hole states of Hg[Palaudoux J et al., Phys. Rev. A 91 012513(2015)], and could provide guidance for further studies on complex atoms.Particularly for the DA decay, the contributions of the direct processes, which are neglected in their calculations, are found to be important, accounting for as high as about 38% and 34% of the total DA decays for the 4 f(7/2)^(-1) and 4 f(5/2)^(-1), respectively.
基金funding from the European Research Council (ERC)under grant agreement no.834134 (WATUSO)VLAIO for Moonshot funding (ARCLATH,No.HBC.2019.0110 and ARCLATH2,No.HBC.2021.0254)+3 种基金supported by the Flemish Government as an international research infrastructure (I001321N)infrastructure support by Department EWI via the Hermes Fund (AH.2016.134)the Hercules Foundation (AKUL/13/21)FWO Vlaanderen for an FWO-SB fellowship。
文摘1.Challenges circular methane energy systems In recent decades,methane-based energy systems have rapidly gained traction across the globe because of the increasing availability of low-cost methane production capacity.However,fossil methane production and combustion lead to large greenhouse gas emissions,contributing to climate change[1].
文摘A laser diode (LD) pumped Q switched high efficient intracavity frequency doubled Nd ∶YAG laser is reported here. The authors have designed an optical coupler and pointed out that the key to increasing harmonic conversion efficiency is to decrease the loss of fundamental wave. In the experiments, a fundamental mode output laser was acquired. When the pumping power was 12 W, 2.6 W average output power at 1 064 nm with AO Q switch was obtained. 2.1 W average output power at 532 nm was obtained with intracavity frequency doubling, and the highest second harmonic conversion efficiency was 82 0 0.
基金supported by National Key R&D Program of China(2021YFA1502803)the National Natural Science Foundation of China(NSFC)(21972066 and 91745202)+3 种基金NSFC-Royal Society Joint Program(21661130149)Luming Peng thanks the Royal Society and Newton Fund for a Royal Society-Newton Advanced Fellowshipsupported by the Research Funds for the Frontiers Science Center for Critical Earth Material Cycling,Nanjing Universitya Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Layered double hydroxides(LDHs)have received extensive attention in many fields such as catalysis,environmental management and medical applications.Typically,expensive soluble metal salts are commonly used as the starting materials for the synthesis of LDHs.Here,we report a novel synthesis route for Mg/Al-LDH by using inexpensive basic magnesium carbonate as the starting material.X-ray diffraction(XRD)and solid-state nuclear magnetic resonance(ssNMR)data show that LDHs with rich defects are formed rapidly at room temperature and good crystallinity can be obtained after further hydrothermal treatment.These results provide a simple,rapid and green preparation method for LDHs.
文摘Shenzhen has extensive green construction experience as one of China’s new green development pilot cities.Shenzhen has experienced substantial economic growth as a result of the reform and opening up,but it has also had to face the burden of urbanization problems and difficulties.This article looks at the history of green construction in Shenzhen and how the spirit of the city influenced it.The work then divides the procedure into two phases and examines the issues that arise.Suggestions for achieving the“Double Carbon”aim in the building industry are sought through this effort.
文摘Through cation exchanging of montmorillonite, mixed hydroxy Fe Al pillared montmorillonites with large basal spacing were synthesized. The application of these mixed hydroxy Fe Al pillared montmorillonites as adsorbents in the areas of environmental protection and pollution control was investigated. Adsorption of Direct Green B, an organic dye, on OH—Fe—, OH—Al—, OH—Fe—Al— pillared montmorillonites was studied. Results showed that these pillared montmorillonites had much better adsorption properties than traditional Na organo montmorillonite. It was also found that pH of the solutions had great effect on the performance of these hydroxy metal pillared montmorillonites in treating the wastewater containing Direct Green B.
基金supported by the National Natural Science Foundation of China(Grant No.21802136)~~
文摘Zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the environment.It is a growing trend to develop an eco‐friendly and nuisanceless OSDA for zeolite synthesis.Herein,choline is employed as a non‐toxic and green OSDA to synthesize high silica Y zeolite with SiO2/Al2O3 ratios of 6.5–6.8.The prepared Y zeolite samples exhibited outstanding(hydro)thermal stability at ultrahigh temperature owing to the higher SiO2/Al2O3 ratio.The XRF,SEM,29Si‐NMR and 13Na+results suggested that choline plays a structure‐directing role in the synthesis of Y zeolite,while the feed molar fraction of Na+is a crucial determinant for the framework SiO2/Al2O3 ratio and the crystal morphology.
文摘B cells lymphoma is one of the most challenging extrahepatic manifestations of hepatitis C virus(HCV). Recently, a new kind of B-cell lymphoma, named doublehit B(DHL), was characterized with an aggressive clinical course whereas a potential association with HCV was not investigated. The new antiviral direct agents(DAAs) against HCV are effective and curative in the majority of HCV infections. We report the first case, to our knowledge, of DHL and HCV-infection successfully treated by new DAAs. According to our experience, a DHL must be suspected in case of HCV-related lymphoma, and an early diagnosis could direct towards a different hematological management because a worse prognosis might be expected. A possible effect of DAAs on DHL regression should be investigated, but eradicating HCV would avoid life-threatening reactivation of viral hepatitis during pharmacological immunosuppression in oncohaematological diseases.
文摘The inverse problem of wave equation is the importance of study not only in seismic prospecting but also in applied mathematics. With the development of the research, the inverse methods of 1 - D wave equations have been trending towards the multiple parameters inversion . We have obtained an inverse method with double -parameter, in which medium density and wave velocity can be derived simultaneously. In this paper, to increase the inverse accuracy, the method is improved as follows. Firstly, the formula in which the Green Function is omitted are derived and used. Secondly, the regularizing method is reasonable used by choosing the stable function. With the new method, we may derive elastic parameter and medium density or medium density and wave velocity. Thus, lithology parameters for seismic prospecting may be obtained.After comparing the derived values from the new method with that from previous method, we obtain the new method through which substantially improve the derived accuracy . The new method has been applied to real depths inversion for sedimentary strata and volcanic rock strata in Chaoyanggou Terrace of Songliao Basin in eastern China. According to the inverse results,the gas - bearing beds are determlned.
基金Supported by cooling research of double crystal monochromator used by synchrotron radiation(10205024)
文摘In SSRF, the design of 1st crystal cooling geometry of double crystal monochromator with sagittal focus is mainly reported by China. Our simulation indicates that the broadening of the full width at half maximum of the rocking curve of the double crystal monochromator induced by the heat load is about 3.7 μrad, and is in agreement with the experimental value of 5 μrad. Our scheme showed that the photon flux is reliably linear with electron current of the storage ring, which is extracted from the monochromator.
基金supported by National Basic Research Program of China(973 Program)
文摘To achieve the electric field strength and the induced currents in equivalence in susceptibility tests with the high-level field radiation above 400 MHz,a double differential-mode(DM) current injection method based on directional couplers is proposed.Two cascaded symmetrical directional couplers compose a coupling device to inject the DM currents.When the coupling device is used,two devices are necessary to achieve the equivalence between radiation and injection,i.e.the equivalence between the injected voltages and the field strength,which is linear,regardless of the characteristics of the equipment under test(EUT).The results are verified by experiments using typical coaxial cables and nonlinear devices,where the equivalence between the nonlinear EUT responses induced by radiation and injection at both ends is achieved by using two coupling devices.At a frequency up to 1.75 GHz,the maximal experimental error is only 3.39%.The experimental results confirm the accuracy of the proposed method even both the EUTs work in the nonlinear region.The proposed method is applicable for radiated susceptibility(RS) testing of interconnected systems in the microwave frequency band.
基金The Project supported by the NationalGansu Province Natural Science Foundation of China
文摘A method of determining bifurcation directions at a double eigenvalue is presented by combining the finite element method with the perturbation method. By using the present method, the buckled states of rectangular plates at a double eigenvalue are numerically analyzed. The results show that this method is effective.
文摘The electrical characteristics of a double-gate armchair silicene nanoribbon field-effect-transistor (DG ASiNR FET) are thoroughly investigated by using a ballistic quantum transport model based on non-equilibrium Green's function (NEGF) approach self-consistently coupled with a three-dimensional (3D) Poisson equation. We evaluate the influence of variation in uniaxial tensile strain, ribbon temperature and oxide thickness on the on-off current ratio, subthreshold swing, transconductance and the delay time of a 12-nm-length ultranarrow ASiNR FET. A novel two-parameter strain mag- nitude and temperature-dependent model is presented for designing an optimized device possessing balanced amelioration of all the electrical parameters. We demonstrate that employing HfO2 as the gate insulator can be a favorable choice and simultaneous use of it with proper combination of temperature and strain magnitude can achieve better device performance. Furthermore, a general model power (GMP) is derived which explicitly provides the electron effective mass as a function of the bandgap of a hydrogen passivated ASiNR under strain.
文摘A theoretical study of resonant tunneling is carried out for an inverse parabolic double-barrier structure subjected to an external electric field. Tunneling transmission coefficient and density of states are analyzed by using the non-equilibrium Green's function approach based on the finite difference method. It is found that the resonant peak of the transmission coefficient, being unity for a symmetrical case, reduces under the applied electric field and depends strongly on the variation of the structure parameters.