Deuterated potassium dihydrogen phosphate damage performance at 351 nm is studied on a large-aperture laser system. Bulk and rear-surface damage are initiated under the 3ω fluences of 6.T J/cm2 and 33/cm2, and show d...Deuterated potassium dihydrogen phosphate damage performance at 351 nm is studied on a large-aperture laser system. Bulk and rear-surface damage are initiated under the 3ω fluences of 6.T J/cm2 and 33/cm2, and show different growth characteristics under multiple laser irradiations with the fluence of 6 J/cm2. The size and number of bulk damage keep unchanged once initiated. However, surface damage size also does not grow, while surface damage number increases linearly with laser shots. Different damage thresholds and growth behaviors suggest different formations of bulk and surface damage precursors. The cause of surface damage is supposed to be near-surface absorbing particles buried under the sol-gel coating.展开更多
The simulations of three-dimensional particle dynamics show that when irradiated by an ultrashort intense laser pulse, the deuterated methane cluster expands and the majority of deuterons overrun the more slowly expan...The simulations of three-dimensional particle dynamics show that when irradiated by an ultrashort intense laser pulse, the deuterated methane cluster expands and the majority of deuterons overrun the more slowly expanding carbon ions, resulting in the creation of two separated subelusters. The enhanced deuteron kinetic energy and a narrow peak around the energy maximum in the deuteron energy distribution make a considerable contribution to the efficiency of nuclear fusion compared with the ease of homonuelear deuterium clusters. With the intense laser irradiation, the nuclear fusion yield increases with the increase of the cluster size, so that deuterated heteronuelear clusters with larger sizes are required to achieve a greater neutron yield.展开更多
By using a simplified Coulomb explosion model, the laser-driven Coulomb explosion processes of three deuterated alkane clusters, i.e., deuterated methane(CD4)N, ethane(C2D6)N and propane(C3D8)N clusters are simu...By using a simplified Coulomb explosion model, the laser-driven Coulomb explosion processes of three deuterated alkane clusters, i.e., deuterated methane(CD4)N, ethane(C2D6)N and propane(C3D8)N clusters are simulated numerically.The overrun phenomenon that the deuterons overtake the carbon ions inside the expanding clusters, as well as the dependence of the energetic deuterons and fusion neutron yield on cluster size, is discussed in detail. Researches show that the average kinetic energy of deuterons and neutron yield generated in the Coulomb explosion of(C2D6)N cluster are higher than those of(CD4)N cluster with the same size, in qualitative agreement with the reported conclusions from the experiments of(C2 H6)N and(CH4)N clusters. It is indicated that(C2D6)N clusters are superior to(CD4)N clusters as a target for the laser-induced nuclear fusion reaction to achieve a higher neutron yield. In addition, by comparing the relevant data of(C3D8)N cluster with those of(C2D6)N cluster with the same size, it is theoretically concluded that(C3D8)N clusters with a larger competitive parameter might be a potential candidate for improving neutron generation. This will provide a theoretical basis for target selection in developing experimental schemes on laser-driven nuclear fusion in the future.展开更多
Conductivity measurements of deuterated ammonium dihydrogen phosphate (DADP) crystals with different deuterated degrees are described. The conductivities increase with the deuterium content, and the value of the a-d...Conductivity measurements of deuterated ammonium dihydrogen phosphate (DADP) crystals with different deuterated degrees are described. The conductivities increase with the deuterium content, and the value of the a-direction is larger than that of the e-direction. Compared with DKDP crystals, DADP crystals have larger conductivities, which is partly due to the existence of A defects. The ac conductivity over the temperature range 25-170℃has shown a knee in the curve ofln(σT) versus T-1. The conductivity activation energy calculated by the slope of the high temperature region decreases with the deuterium content. The previously reported phase transition is not seen.展开更多
Plinabulin,a potent microtubule-targeting agent,is derived from marine natural diketopiperazine ‘phenylahistin'.To develop novel plinabulin analogue that could display better pharmacokinetic properties and less s...Plinabulin,a potent microtubule-targeting agent,is derived from marine natural diketopiperazine ‘phenylahistin'.To develop novel plinabulin analogue that could display better pharmacokinetic properties and less side effects,deuterated plinabulin 9 was synthesized and evaluated in vitro and in vivo.In comparison with plinabulin,in vivo pharmacokinetic studies indicated that the deuterated derivative 9 could alter blood circulation behavior obviously,which was proved by increased area under the plasma concentration-time curve(AUC_(0–∞)),reduced clearance(CL),and prolonged total body mean residence time(MRT).The derivative 9 also has higher inhibition rates against Bx PC-3,Jurkat and A-431 tumor cell lines as compared with its prototype plinabulin.Therefore,the deuterated compound 9 might be developed as a potential agent for different cancer treatments.展开更多
In this paper,a highly deuterated potassium dihydrogen phosphate(DKDP)crystal with sizes up to 318 mm×312 mm×265 mm was grown by the rapid-growth method.The synthesis tank device was specially designed to sy...In this paper,a highly deuterated potassium dihydrogen phosphate(DKDP)crystal with sizes up to 318 mm×312 mm×265 mm was grown by the rapid-growth method.The synthesis tank device was specially designed to synthesize a higher deuterium concentration and high-purity DKDP solution.The deuterium content of the as-grown crystal,which was 97.9%,was determined by two methods,including infrared(IR)spectroscopy and thermo-gravimetric analysis(TGA)measurements.The performances of the 97.9%DKDP crystal,including transmission,absorption coefficient,and laserinduced damage threshold(LIDT)were measured.The results indicate that,in the near-infrared band,the transmission of the 97.9%DKDP crystal is higher than that of KDP and 70%DKDP crystals,and the absorption coefficient is lower.The LIDT of the crystal reached 23.2 J·cm^-2(R-on-1,1064 nm,3 ns),which meets the engineering requirements for use in optical applications.展开更多
Deuterated ethylene is an important building block for manufacturing various deuterated polyolefins and chemicals.However,low-cost and large-scale production of deuterated ethylene still remain a great challenge.Herei...Deuterated ethylene is an important building block for manufacturing various deuterated polyolefins and chemicals.However,low-cost and large-scale production of deuterated ethylene still remain a great challenge.Herein,with D_(2)O as the D source,we first propose an electrocatalytic deuteration strategy for continuous production of deuterated ethylene from acetylene under ambient conditions.Specially,Ag nanoparticles exhibit a very high deuterated ethylene Faradic efficiency of up to 99.3%at-0.6 V vs.reversible hydrogen electrode.Meanwhile,Ag nanoparticles achieve a deuterated ethylene production rate of 3.72×10^(3)mmol h^(-1)g^(-1)cat and an excellent long-term stability with deuterated ethylene Faradaic efficiencies of~95%in a two-electrode flow cell,which substantially outperform state-of-the-art values for previously reported deuterated alkenes.In-situ electrochemical Infrared absorption and Raman spectroscopies reveal superior acetylene absorption and formation of deuterated ethylene on Ag nanoparticles.This efficient electrocatalytic deuteration strategy opens a new window for continuous and economic production of deuterated alkenes.展开更多
The interaction of intense,ultrashort laser pulses with ordered nanostructure arrays offers a path to the efficient creation of ultra-high-energy density(UHED)matter and the generation of high-energy particles with co...The interaction of intense,ultrashort laser pulses with ordered nanostructure arrays offers a path to the efficient creation of ultra-high-energy density(UHED)matter and the generation of high-energy particles with compact lasers.Irradiation of deuterated nanowires arrays results in a near-solid density environment with extremely high temperatures and large electromagnetic fields in which deuterons are accelerated to multi-megaelectronvolt energies,resulting in deuterium–deuterium(D–D)fusion.Here we focus on the method of fabrication and the characteristics of ordered arrays of deuterated polyethylene nanowires.The irradiation of these array targets with femtosecond pulses of relativistic intensity and joule-level energy creates a micro-scale fusion environment that produced 2×10^(6)neutrons per joule,an increase of about 500 times with respect to flat solid CD2 targets irradiated with the same laser pulses.Irradiation with 8 J laser pulses was measured to generate up to 1.2×10^(7)D–D fusion neutrons per shot.展开更多
Resorcinol/formaldehyde(RF)foam resin is an attractive material as a low-density target in high-power laser–plasma experiments because of its fine network structure,transparency in the visible region,and low-Z elemen...Resorcinol/formaldehyde(RF)foam resin is an attractive material as a low-density target in high-power laser–plasma experiments because of its fine network structure,transparency in the visible region,and low-Z element(hydrogen,carbon,and oxygen)composition.In this study,we developed disk-shaped RF foam and deuterated RF foam targets with 40–200μm thickness and approximately 100 mg/cm^(3) density having a network structure from 100 nm to a few micrometers cell size.By deuteration,the polymerization rate was drastically slowed down owing to kinetic isotope effects.These targets were used in high-power laser experiments where a megaelectronvolt proton beam was successfully generated.展开更多
Tandem water electrolysis for the transformation of universal feedstock to value-added chemicals integrated with hydrogen generation and in situ utilization is a promising approach to address the economic challenges o...Tandem water electrolysis for the transformation of universal feedstock to value-added chemicals integrated with hydrogen generation and in situ utilization is a promising approach to address the economic challenges of electrochemical hydrogen evolution and storage.Herein,we present the controllable electrocatalytic deuteration of halides using inexpensive and reusable heavy water(D2 O)as a D-source for the preparation of valuable D-labelled chemicals and pharmaceuticals under mild conditions.This electrochemical deuteration method with high efficiency and selectivity furnishes a series of D-labelled chemicals and pharmaceuticals in high yields with excellent D-incorporation.The reaction efficiency and selectivity,that is,the precise substitution of deuterium atoms at different halogen positions,can be tuned by varying the applied voltages.The results show the great potential of green and economical electrocatalytic methods for producing value-added fine chemicals in addition to hydrogen evolution.展开更多
A new,stable and scalable reagent for deuteriodifluoromethylthiolation(deuterated N-difluoromethylthiophthalimide,PhthSCF_(2)D)has been developed.This reagent can be applied for the photocatalytic radical deuteriodifl...A new,stable and scalable reagent for deuteriodifluoromethylthiolation(deuterated N-difluoromethylthiophthalimide,PhthSCF_(2)D)has been developed.This reagent can be applied for the photocatalytic radical deuteriodifluoromethylthiolation of various olefins and aldehydes(30 examples).Meanwhile,it can achieve the electrophilic deuteriodifluoromethylthiolation of a series of electrophilic substrates including electron-rich arenes,aryl/vinylboronicacids,alkynes,amines,thiols andβ-ketoesters(22 examples).Some complex molecules can also be applied in both radical and electrophilic deuteriodifluoromethylthiolation using PhthSCF_(2)D as the reagent.展开更多
The alkylation mechanism catalyzed by an ionic liquid (as a Lewis acid) may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear....The alkylation mechanism catalyzed by an ionic liquid (as a Lewis acid) may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene (C 6 D 6) with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] +H + and [AlHCl 3 ] + +[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] + is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] + which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.展开更多
Transverse stimulated Raman scattering (TSRS) gain coefficient in a large aperture 65% deu terated potassium dihydrogen phosphate (DKDP) is measured at 351 nm. The measurement involves the use of an optical fiber ...Transverse stimulated Raman scattering (TSRS) gain coefficient in a large aperture 65% deu terated potassium dihydrogen phosphate (DKDP) is measured at 351 nm. The measurement involves the use of an optical fiber sensor system to detect Raman scattering light in the DKDP crystal. A Raman scattering gain coefficient of 0. 109 cm/GW is obtained and will be used to set upper limit of the DKDP crystals in our laser fa cility to avoid the TSRS induced energy loss and laser damage. The effect of bulk damage on growth behavior of TSRS is also examined and it is found that bulk damage has little impact on the TSRS growth. Thus the influ ence of bulk damage on the measurement of TSRS gain coefficient can be ignored.展开更多
A room-temperature electrochemical strategy for hydrogenation(deuteration)and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode is developed,which includes the hydrogenation of quinoxalin...A room-temperature electrochemical strategy for hydrogenation(deuteration)and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode is developed,which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80%Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99%yield and selectivity.The in situ generated active hydrogen atom(H^(*))is plausibly involved in the hydrogenation of quinoxaline,where a consecutive hydrogen radical coupled electron transfer pathway is proposed.Notably,the MoNi_(4)alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV,owing to its superior water dissociation ability to provide H^(*)in alkaline media.In situ Raman tests indicate that the Ni^(Ⅱ)/Ni^(Ⅲ)redox couple can promote the dehydrogenation process,representing a promising anodic alternative to low-value oxygen evolution.Impressively,electrocatalytic deuteration is easily achieved with up to 99%deuteration ratios using D2O.This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.展开更多
Infrared spectrum is a general quantitation method which can be used to determine the concentration of a certain component in mixture.We proposed that it could also be used to determine the coreactant level of a react...Infrared spectrum is a general quantitation method which can be used to determine the concentration of a certain component in mixture.We proposed that it could also be used to determine the coreactant level of a reactive system.A two-part polyurethane film was used as a model system.The results showed that the height ratio of ring mode signal in urea and C—O signal in polyester polyol can be used to calculate the ratio of the two reactants.The assignments of the peaks were studied by in-situ reaction monitoring with moisture level changes and deuteration methods.The applicable conditions of this calibration curves were also discussed.展开更多
A series of deuterated ammonium dihydrogen phosphate(DADP) crystals were grown and their structures were investigated by using powder neutron diffraction method. In the entire composition range, the deuterated level i...A series of deuterated ammonium dihydrogen phosphate(DADP) crystals were grown and their structures were investigated by using powder neutron diffraction method. In the entire composition range, the deuterated level in the crystals is lower compared with the aqueous growth solution. The deuterium segregation coefficient in the crystals decreases with increasing deuterium content of the solution. The deuterium content in the NH_4^+ group is higher than that in H_2PO_4^- group.In addition, the variations of lattice parameters are shown here.展开更多
The deuterodifluoromethyl group CF_(2)D combines the structural features of CF_(3) and CD_(3) groups,finding wide applications in diverse pharmaceutical entities.In this work,the electrochemical monodeuterodefluorinat...The deuterodifluoromethyl group CF_(2)D combines the structural features of CF_(3) and CD_(3) groups,finding wide applications in diverse pharmaceutical entities.In this work,the electrochemical monodeuterodefluorination of Ar-CF_(3) to Ar-CF_(2)D is achieved with an unreported deuterium atom transfer-coupled electron transfer pathway using D_(2)O as the only D source for the first time.A series of Ar-CF_(3) substances,including commercial pharmaceuticals,were converted to corresponding CF_(2)D products in up to 91% yield and 97% D-incorporation.A variety of functional groups,including pyridine,pyrrole,furan,thiophene,borate,thio ether,amine,amide,sulfonamide,and halide,are well tolerated in this protocol.t-BuOLi was an essential reagent to achieve chemoselective mono-defluorination.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61505187
文摘Deuterated potassium dihydrogen phosphate damage performance at 351 nm is studied on a large-aperture laser system. Bulk and rear-surface damage are initiated under the 3ω fluences of 6.T J/cm2 and 33/cm2, and show different growth characteristics under multiple laser irradiations with the fluence of 6 J/cm2. The size and number of bulk damage keep unchanged once initiated. However, surface damage size also does not grow, while surface damage number increases linearly with laser shots. Different damage thresholds and growth behaviors suggest different formations of bulk and surface damage precursors. The cause of surface damage is supposed to be near-surface absorbing particles buried under the sol-gel coating.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10535070 and 10674145)the National Basic Research Program of China (Grant No 2006CB806000)the Shanghai Supercomputer Center (SSC)
文摘The simulations of three-dimensional particle dynamics show that when irradiated by an ultrashort intense laser pulse, the deuterated methane cluster expands and the majority of deuterons overrun the more slowly expanding carbon ions, resulting in the creation of two separated subelusters. The enhanced deuteron kinetic energy and a narrow peak around the energy maximum in the deuteron energy distribution make a considerable contribution to the efficiency of nuclear fusion compared with the ease of homonuelear deuterium clusters. With the intense laser irradiation, the nuclear fusion yield increases with the increase of the cluster size, so that deuterated heteronuelear clusters with larger sizes are required to achieve a greater neutron yield.
基金supported by the National Natural Science Foundation of China(Grant No.11005080)
文摘By using a simplified Coulomb explosion model, the laser-driven Coulomb explosion processes of three deuterated alkane clusters, i.e., deuterated methane(CD4)N, ethane(C2D6)N and propane(C3D8)N clusters are simulated numerically.The overrun phenomenon that the deuterons overtake the carbon ions inside the expanding clusters, as well as the dependence of the energetic deuterons and fusion neutron yield on cluster size, is discussed in detail. Researches show that the average kinetic energy of deuterons and neutron yield generated in the Coulomb explosion of(C2D6)N cluster are higher than those of(CD4)N cluster with the same size, in qualitative agreement with the reported conclusions from the experiments of(C2 H6)N and(CH4)N clusters. It is indicated that(C2D6)N clusters are superior to(CD4)N clusters as a target for the laser-induced nuclear fusion reaction to achieve a higher neutron yield. In addition, by comparing the relevant data of(C3D8)N cluster with those of(C2D6)N cluster with the same size, it is theoretically concluded that(C3D8)N clusters with a larger competitive parameter might be a potential candidate for improving neutron generation. This will provide a theoretical basis for target selection in developing experimental schemes on laser-driven nuclear fusion in the future.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51323002 and 51402173the Independent Innovation Foundation of Shandong University under Grant No 2012JC016+1 种基金the Natural Science Foundation for Distinguished Young Scholar of Shandong Province under Grant No JQ201218the Project of Key Laboratory of Neutron Physics of China Academy Of Engineering Physics under Grant No 2014BB07
文摘Conductivity measurements of deuterated ammonium dihydrogen phosphate (DADP) crystals with different deuterated degrees are described. The conductivities increase with the deuterium content, and the value of the a-direction is larger than that of the e-direction. Compared with DKDP crystals, DADP crystals have larger conductivities, which is partly due to the existence of A defects. The ac conductivity over the temperature range 25-170℃has shown a knee in the curve ofln(σT) versus T-1. The conductivity activation energy calculated by the slope of the high temperature region decreases with the deuterium content. The previously reported phase transition is not seen.
基金supported by‘Zhufeng Scholar Program’of Ocean University of China(No.841412016)‘Major Projects of Independent Innovation’of Qingdao(15-4-13-zdzx-hy)‘Outstanding Talents Plan’of Qingdao(15-10-3-15-(34)-zch)to Dr.Wenbao Li
文摘Plinabulin,a potent microtubule-targeting agent,is derived from marine natural diketopiperazine ‘phenylahistin'.To develop novel plinabulin analogue that could display better pharmacokinetic properties and less side effects,deuterated plinabulin 9 was synthesized and evaluated in vitro and in vivo.In comparison with plinabulin,in vivo pharmacokinetic studies indicated that the deuterated derivative 9 could alter blood circulation behavior obviously,which was proved by increased area under the plasma concentration-time curve(AUC_(0–∞)),reduced clearance(CL),and prolonged total body mean residence time(MRT).The derivative 9 also has higher inhibition rates against Bx PC-3,Jurkat and A-431 tumor cell lines as compared with its prototype plinabulin.Therefore,the deuterated compound 9 might be developed as a potential agent for different cancer treatments.
基金supported by the State High Technology Program for Inertial Confinement Fusion
文摘In this paper,a highly deuterated potassium dihydrogen phosphate(DKDP)crystal with sizes up to 318 mm×312 mm×265 mm was grown by the rapid-growth method.The synthesis tank device was specially designed to synthesize a higher deuterium concentration and high-purity DKDP solution.The deuterium content of the as-grown crystal,which was 97.9%,was determined by two methods,including infrared(IR)spectroscopy and thermo-gravimetric analysis(TGA)measurements.The performances of the 97.9%DKDP crystal,including transmission,absorption coefficient,and laserinduced damage threshold(LIDT)were measured.The results indicate that,in the near-infrared band,the transmission of the 97.9%DKDP crystal is higher than that of KDP and 70%DKDP crystals,and the absorption coefficient is lower.The LIDT of the crystal reached 23.2 J·cm^-2(R-on-1,1064 nm,3 ns),which meets the engineering requirements for use in optical applications.
基金supported by the Natural Science Foundation of Shaanxi Province(No.2020JQ-141)the National Natural Science Foundation of China(No.22005245)+1 种基金the Synergy Innovation Foundation of the University and Enterprise for Graduate Students in Northwestern Polytechnical University(No.CX2021037)the National Key Research and Development Program of China(No.SQ2021YFE010191)。
文摘Deuterated ethylene is an important building block for manufacturing various deuterated polyolefins and chemicals.However,low-cost and large-scale production of deuterated ethylene still remain a great challenge.Herein,with D_(2)O as the D source,we first propose an electrocatalytic deuteration strategy for continuous production of deuterated ethylene from acetylene under ambient conditions.Specially,Ag nanoparticles exhibit a very high deuterated ethylene Faradic efficiency of up to 99.3%at-0.6 V vs.reversible hydrogen electrode.Meanwhile,Ag nanoparticles achieve a deuterated ethylene production rate of 3.72×10^(3)mmol h^(-1)g^(-1)cat and an excellent long-term stability with deuterated ethylene Faradaic efficiencies of~95%in a two-electrode flow cell,which substantially outperform state-of-the-art values for previously reported deuterated alkenes.In-situ electrochemical Infrared absorption and Raman spectroscopies reveal superior acetylene absorption and formation of deuterated ethylene on Ag nanoparticles.This efficient electrocatalytic deuteration strategy opens a new window for continuous and economic production of deuterated alkenes.
基金the Air Force Office of Scientific Research under award number FA9550-17-1-0278The experiments were conducted at Colorado State University’s ALEPH petawatt-class laser facility supported by LaserNet US with grant DE-SC0019076 from the US Department of Energy,Office of Science,Fusion Energy Sciences.
文摘The interaction of intense,ultrashort laser pulses with ordered nanostructure arrays offers a path to the efficient creation of ultra-high-energy density(UHED)matter and the generation of high-energy particles with compact lasers.Irradiation of deuterated nanowires arrays results in a near-solid density environment with extremely high temperatures and large electromagnetic fields in which deuterons are accelerated to multi-megaelectronvolt energies,resulting in deuterium–deuterium(D–D)fusion.Here we focus on the method of fabrication and the characteristics of ordered arrays of deuterated polyethylene nanowires.The irradiation of these array targets with femtosecond pulses of relativistic intensity and joule-level energy creates a micro-scale fusion environment that produced 2×10^(6)neutrons per joule,an increase of about 500 times with respect to flat solid CD2 targets irradiated with the same laser pulses.Irradiation with 8 J laser pulses was measured to generate up to 1.2×10^(7)D–D fusion neutrons per shot.
基金the Collaboration Research Program between the National Institute for Fusion Science and the Institute of Laser Engineering at Osaka University(NIFS12KUGK057).
文摘Resorcinol/formaldehyde(RF)foam resin is an attractive material as a low-density target in high-power laser–plasma experiments because of its fine network structure,transparency in the visible region,and low-Z element(hydrogen,carbon,and oxygen)composition.In this study,we developed disk-shaped RF foam and deuterated RF foam targets with 40–200μm thickness and approximately 100 mg/cm^(3) density having a network structure from 100 nm to a few micrometers cell size.By deuteration,the polymerization rate was drastically slowed down owing to kinetic isotope effects.These targets were used in high-power laser experiments where a megaelectronvolt proton beam was successfully generated.
基金supported by the National Natural Science Foundation of China(21972094,21902105)the National Postdoctoral Program for Innovative Talents(BX20180203)+4 种基金China Postdoctoral Science Foundation(2018M643176)Guangdong Special Support ProgramPengcheng Scholar programShenzhen Peacock Plan(KQJSCX20170727100802505 and KQTD2016053112042971)Foundation for Distinguished Young Talents in Higher Education of Guangdong(2018KQNCX221)。
文摘Tandem water electrolysis for the transformation of universal feedstock to value-added chemicals integrated with hydrogen generation and in situ utilization is a promising approach to address the economic challenges of electrochemical hydrogen evolution and storage.Herein,we present the controllable electrocatalytic deuteration of halides using inexpensive and reusable heavy water(D2 O)as a D-source for the preparation of valuable D-labelled chemicals and pharmaceuticals under mild conditions.This electrochemical deuteration method with high efficiency and selectivity furnishes a series of D-labelled chemicals and pharmaceuticals in high yields with excellent D-incorporation.The reaction efficiency and selectivity,that is,the precise substitution of deuterium atoms at different halogen positions,can be tuned by varying the applied voltages.The results show the great potential of green and economical electrocatalytic methods for producing value-added fine chemicals in addition to hydrogen evolution.
基金the National Natural Science Foundation of China (Nos. 21776138, 22078161)the Fundamental Research Funds for the Central Universities (Nos. 30920021124, 30918011314)+3 种基金the Natural Science Foundation of Jiangsu Province (No. BK20180476)the Postdoctoral Science Foundation Funded Project (No. 2019M661848)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Center for Advanced Materials and Technology in Nanjing University of Science and Technology for their financial support
文摘A new,stable and scalable reagent for deuteriodifluoromethylthiolation(deuterated N-difluoromethylthiophthalimide,PhthSCF_(2)D)has been developed.This reagent can be applied for the photocatalytic radical deuteriodifluoromethylthiolation of various olefins and aldehydes(30 examples).Meanwhile,it can achieve the electrophilic deuteriodifluoromethylthiolation of a series of electrophilic substrates including electron-rich arenes,aryl/vinylboronicacids,alkynes,amines,thiols andβ-ketoesters(22 examples).Some complex molecules can also be applied in both radical and electrophilic deuteriodifluoromethylthiolation using PhthSCF_(2)D as the reagent.
基金financial support from the National Natural Science Foundation of China (NSFC,2052010)
文摘The alkylation mechanism catalyzed by an ionic liquid (as a Lewis acid) may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene (C 6 D 6) with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] +H + and [AlHCl 3 ] + +[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] + is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] + which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.
文摘Transverse stimulated Raman scattering (TSRS) gain coefficient in a large aperture 65% deu terated potassium dihydrogen phosphate (DKDP) is measured at 351 nm. The measurement involves the use of an optical fiber sensor system to detect Raman scattering light in the DKDP crystal. A Raman scattering gain coefficient of 0. 109 cm/GW is obtained and will be used to set upper limit of the DKDP crystals in our laser fa cility to avoid the TSRS induced energy loss and laser damage. The effect of bulk damage on growth behavior of TSRS is also examined and it is found that bulk damage has little impact on the TSRS growth. Thus the influ ence of bulk damage on the measurement of TSRS gain coefficient can be ignored.
文摘A room-temperature electrochemical strategy for hydrogenation(deuteration)and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode is developed,which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80%Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99%yield and selectivity.The in situ generated active hydrogen atom(H^(*))is plausibly involved in the hydrogenation of quinoxaline,where a consecutive hydrogen radical coupled electron transfer pathway is proposed.Notably,the MoNi_(4)alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV,owing to its superior water dissociation ability to provide H^(*)in alkaline media.In situ Raman tests indicate that the Ni^(Ⅱ)/Ni^(Ⅲ)redox couple can promote the dehydrogenation process,representing a promising anodic alternative to low-value oxygen evolution.Impressively,electrocatalytic deuteration is easily achieved with up to 99%deuteration ratios using D2O.This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.
文摘Infrared spectrum is a general quantitation method which can be used to determine the concentration of a certain component in mixture.We proposed that it could also be used to determine the coreactant level of a reactive system.A two-part polyurethane film was used as a model system.The results showed that the height ratio of ring mode signal in urea and C—O signal in polyester polyol can be used to calculate the ratio of the two reactants.The assignments of the peaks were studied by in-situ reaction monitoring with moisture level changes and deuteration methods.The applicable conditions of this calibration curves were also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant No.51402173)Shandong Provincial Natural Science Joint Foundation with Universities and Scientific Research Institution,China(Grant No.ZR2017LEM006)+1 种基金the Neutron Physics Laboratory,China Academy of Engineering Physics(Grant No.2014BB07)the Fundamental Research Funds for Central Universities,China(Grant No.FRF-TP-15-099A1)
文摘A series of deuterated ammonium dihydrogen phosphate(DADP) crystals were grown and their structures were investigated by using powder neutron diffraction method. In the entire composition range, the deuterated level in the crystals is lower compared with the aqueous growth solution. The deuterium segregation coefficient in the crystals decreases with increasing deuterium content of the solution. The deuterium content in the NH_4^+ group is higher than that in H_2PO_4^- group.In addition, the variations of lattice parameters are shown here.
基金supported by the National Science Foundation of China(grant nos.22071105 and 22031008)the QingLan Project of Jiangsu Education Department.
文摘The deuterodifluoromethyl group CF_(2)D combines the structural features of CF_(3) and CD_(3) groups,finding wide applications in diverse pharmaceutical entities.In this work,the electrochemical monodeuterodefluorination of Ar-CF_(3) to Ar-CF_(2)D is achieved with an unreported deuterium atom transfer-coupled electron transfer pathway using D_(2)O as the only D source for the first time.A series of Ar-CF_(3) substances,including commercial pharmaceuticals,were converted to corresponding CF_(2)D products in up to 91% yield and 97% D-incorporation.A variety of functional groups,including pyridine,pyrrole,furan,thiophene,borate,thio ether,amine,amide,sulfonamide,and halide,are well tolerated in this protocol.t-BuOLi was an essential reagent to achieve chemoselective mono-defluorination.