Heavy metal(HM)pollution is a serious environment problem.Recovering HM from industrial wastewater by efficient adsorbents is a sustainable method due to recycling HM and acquiring reusable water.However,popular effic...Heavy metal(HM)pollution is a serious environment problem.Recovering HM from industrial wastewater by efficient adsorbents is a sustainable method due to recycling HM and acquiring reusable water.However,popular efficient adsorbents are usually expensive or non-reusable.In this paper,methods of efficient HM recycling and water reuse from industrial wastewater were developed using efficient adsorbents,new polyphenylene sulfide derivatives,which are recyclable and stable in an acidic,alkaline or oxidative aqueous solution.Moreover,they can efficiently and quickly adsorb HM ions.The maximum adsorption capacities of these adsorbents for HM ions are at the range from 51.3-184.2 mg·g^(-1).The adsorption equilibrium times of them for HM ions are at the range from 10 to 80 min.Therefore,this paper suggests sustainable methods of HM recovery and water reuse from industrial wastewater.展开更多
Geophysical methods are often used to aid in exploration for safe and abundant groundwater. In particular resistivity and seismic refraction methods are helpful in determining depth to bedrock and zones of saturation ...Geophysical methods are often used to aid in exploration for safe and abundant groundwater. In particular resistivity and seismic refraction methods are helpful in determining depth to bedrock and zones of saturation in the subsurface. However the expense of these instruments ($5000 to $20,000) has resulted in their limited use in developing countries. This paper describes how to construct these devices for less than $250 each. The instruments are small, light and robust and are as useful for groundwater exploration as the commercial models for shallow aquifers (less than 35 m deep) where wells can be hand dug, augured or drilled with small portable drill rigs. Data interpretation can be accomplished quickly in the field with free software implemented on a laptop computer. A suite of geophysical instruments and software can therefore be assembled for less than $850. This paper gives the design for these instruments and essential information needed to use them. It is hoped that these inexpensive geophysical instruments can be widely distributed among drillers and aid workers in developing countries, improving the success rate of water wells.展开更多
An inexpensive material, i.e., tetranuclear zinc(Ⅱ) complex, (Zn40(A/D)6) [AID = 7-azaindolate], was utilized as a cathode buffer in organic photovoltaic (OPV) devices, leading to the improvement of device pe...An inexpensive material, i.e., tetranuclear zinc(Ⅱ) complex, (Zn40(A/D)6) [AID = 7-azaindolate], was utilized as a cathode buffer in organic photovoltaic (OPV) devices, leading to the improvement of device performance. Compared to OPV devices based on a conventional cathode buffer of TPBi (1,3,5-tris(2-N-phenylbenzimidazolyl)benzene), although the freshly prepared devices showed similar performance, when heated to a series of high temperatures under air, the short circuit current and the open circuit voltage of the Zn40(AID)6 devices dropped more slowly, indicating the superiority of using Zn40(AID)6 as a cathode buffer over TPBi in OPV devices.展开更多
Here, we present an optimization of colorimetric determination of hydrogen peroxide content in plants using potassium iodide. Our method is based on a one step buffer (extraction and reaction) for the determination of...Here, we present an optimization of colorimetric determination of hydrogen peroxide content in plants using potassium iodide. Our method is based on a one step buffer (extraction and reaction) for the determination of H2O2 in different plant tissues and overcomes interference of soluble antioxidant and color background. A particular attention is paid to buffer pH shown to be tissue dependent. With this inexpensive microplate method, it is possible to analyze 12 experimental samples in about 45 min all in triplicates, with blanks, controls and standard curve.展开更多
Redundant array of inexpensive disk (RAID)10 is known as the most reliable disk array architecture to tolerate up to half of total disk failures, but failure of two disks in the same mirror set still results in data...Redundant array of inexpensive disk (RAID)10 is known as the most reliable disk array architecture to tolerate up to half of total disk failures, but failure of two disks in the same mirror set still results in data loss. In this paper, we propose a new disk array architecture, mirroring and parity protected RAID (MP-RAID), which combines both mirroring and parity techniques to further improve reliability of disk arrays. The main idea behind MP-RAID is to protect the data by both mirroring and parity techniques: keep two copies of data in the same mirror set and update the parity block in the log disk within the same parity groups. Reliability analysis shows that the reliability of MP-RAID, in terms of mean time to data loss (MTTDL), is much better than RAID10 and RAID5.展开更多
The earth is an enormous open system and the gas-releasing phenomenon of the crust is the major means of exchange of matters and energy at different crustal depth.Therefore,a powerful gas-releasing channel is actually...The earth is an enormous open system and the gas-releasing phenomenon of the crust is the major means of exchange of matters and energy at different crustal depth.Therefore,a powerful gas-releasing channel is actually a "window" to understand the subterranean physical and chemical variations as well as stress-strain changes.The releasing places,quantities and ways obtained by systematically observing and recording can reveal the pressure variation and opening state of channels in the crust,and furthermore provide important information for earthquake prediction,tectonic activity and monitoring of volcanic activity.The fracture-gas measurement has been applied widely to earthquake sciences and has played an important role.The authors introduced systematically the application situation and preliminary achievements in China,and pointed out that though this technique is at the beginning stage and not very sophisticated but its capacities for being easy-carrying,fast-operating and inexpensive,makes for a展开更多
1.Make charts and graphs of your weight loss and eating behavior.Fillthem out every day.2.Don’t let anyone 'love' you with food.3.Select your weight goal.Write it here.Now post this note whereyou’ll see it e...1.Make charts and graphs of your weight loss and eating behavior.Fillthem out every day.2.Don’t let anyone 'love' you with food.3.Select your weight goal.Write it here.Now post this note whereyou’ll see it every day.4.Always set a new goal before you reach the old one.Goals move展开更多
有了日新月异的科技手段,面对不一样的劳动大军,企业管理者该如何应对?与时俱进不能停留在口头上,要付诸行动,才不会被时代淘汰。Carrots for the Millennials让Y世代尝到甜头H o s t:W h y i n a n environment like ours,where there...有了日新月异的科技手段,面对不一样的劳动大军,企业管理者该如何应对?与时俱进不能停留在口头上,要付诸行动,才不会被时代淘汰。Carrots for the Millennials让Y世代尝到甜头H o s t:W h y i n a n environment like ours,where there’s high unemployment,do these kids get to call the shots?Nadira Hira(Journalist,展开更多
Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized,and the thermally activated delayed fluorescence(TADF)property was investigated.Compared to unsubstituted carbazole dendrimers,dendrimer...Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized,and the thermally activated delayed fluorescence(TADF)property was investigated.Compared to unsubstituted carbazole dendrimers,dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields(PLQY)in neat films.Phenylfluorene(PF)-substituted dendrimers showed the highest PLQY of 81%,a smallΔEst of 0.06 eV,and the fastest reverse intersystem crossing(RISC)rate of∼1×10^(5 )s^(−1) compared to other dendrimers.Phosphorescence measurements of dendrimers and dendrons(fragments)indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons(^(3)LE)to that of phenylfluorene-substituted dendrimers(^(1)CT,^(3)CT)contributes to RISC promotion and improves TADF efficiency.Terminal modification fine-tunes the energy level and suppresses intermolecular interactions,and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.展开更多
In this work, we designed and synthesized a novel spirocyclic compound functionalized spiro[fluorene-9,9'- xanthene] with carbazole group (2-carbazolyl-spiro[fluorene-9,9'-xanthene], SFX-Cz) via Friedel-Crafts and...In this work, we designed and synthesized a novel spirocyclic compound functionalized spiro[fluorene-9,9'- xanthene] with carbazole group (2-carbazolyl-spiro[fluorene-9,9'-xanthene], SFX-Cz) via Friedel-Crafts and Ullmann reaction, which is expected to own high thermal and morphological stability, and good carrier injection/ transporting properties due to the excellent hole transporting characteristics of carbazole and cruciform structure of spiro[fluorene-9,9'-xanthene]. The carbazole end-capped spiro[fluorene-9,9'-xanthene] SFX-Cz based PhOLEDs with Flrpic as phosphor emitter have been researched by varying dopant concentration, which exhibit the maximum EQEs of 8.9%, 7.4%, 9.1%, and 4.7% with the doping increasing from 10% to 50%. The higher performance PhOLEDs are independent on concentration variation from 10% to 30%, which suggests the bulky steric hindrance of SFX-Cz might be a potential canditate for high performance and inexpensive device with simplified process.展开更多
We combined lightweight and mechanically flexible printed transistors and actuators with a paper unmanned aerial vehicle(UAV)glider prototype to demonstrate electrically controlled glide path modification in a lightwe...We combined lightweight and mechanically flexible printed transistors and actuators with a paper unmanned aerial vehicle(UAV)glider prototype to demonstrate electrically controlled glide path modification in a lightweight,disposable UAV system.The integration of lightweight and mechanically flexible electronics that is offered by printed electronics is uniquely attractive in this regard because it enables flight control in an inexpensive,disposable,and easily integrated system.Here,we demonstrate electroactive polymer(EAP)actuators that are directly printed into paper that act as steering elements for low cost,lightweight paper UAVs.We drive these actuators by using ion gel-gated organic thin film transistors(OTFTs)that are ideally suited as drive transistors for these actuators in terms of drive current and frequency requirements.By using a printing-based fabrication process on a paper glider,we are able to deliver an attractive path to the realization of inexpensive UAVs for ubiquitous sensing and monitoring flight applications.展开更多
This report described a free-enzyme, convenient and inexpensive genotyping biosensor capable of detecting single nucleotide polymorphism at normal temperature based on the combination of toeholdmediated strand displac...This report described a free-enzyme, convenient and inexpensive genotyping biosensor capable of detecting single nucleotide polymorphism at normal temperature based on the combination of toeholdmediated strand displacement reaction(toehold-SDR) and microbead-capture technique. The biosensor consists of a pre-hybridized strand formed by a reporter probe and a capture probe. In the presence of a mutant sequence, there is no toehold-mediated strand displacement and the reporter probe cannot be released from the pre-hybridized strand. Microbeads capture the fluorescent pre-hybridized strand through biotin–streptavidin interaction, so microbeads give out significant fluorescence signal, while there is no fluorescence in the solution. However, in the presence of a matched target, the strand displacement is effectively initiated and the reporter probe is released from pre-hybridized strand. After adding microbeads, the solution produces bright fluorescence, while microbeads have no obvious signal.Genotypes are identified conveniently according to the fluorescence intensity of the solution. The method provides a simple and inexpensive strategy to detect point mutation. Moreover, this biosensor shows the linear relationship in the range of 1–40 nmol/L and reaches a detection limit of 0.3 nmol/L.? 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.Published by Elsevier B.V. All rights reserved.展开更多
Cucurbituril has a high symmetry and rigid structure.When cucurbit[6]uril(CB[6]) was nitrolyzed with the mixed solution of acetic anhydride in fuming nitric acid,nitroform(NF) was generated.NF also can be obtained...Cucurbituril has a high symmetry and rigid structure.When cucurbit[6]uril(CB[6]) was nitrolyzed with the mixed solution of acetic anhydride in fuming nitric acid,nitroform(NF) was generated.NF also can be obtained by the nitration of both CB[5,7,8].This nitration procedure provides a lower risk,inexpensive,new preparation of nitroform,and the reaction condition of this new method is very mild.展开更多
In the present letter, an efficient, clean and one-pot synthesis of 2-substituted benzimidazole and 1,2-disubstituted benzimidazole derivatives has been explored by reacting o-phenylenediamine with aromatic aldehydes ...In the present letter, an efficient, clean and one-pot synthesis of 2-substituted benzimidazole and 1,2-disubstituted benzimidazole derivatives has been explored by reacting o-phenylenediamine with aromatic aldehydes using bismuth nitrate as a catalyst in ethanol at ambient temperature. This methodology avails with faster reactions, excellent yield, mild reaction conditions, use of inexpensive and non-toxic catalyst compared to literature reported hitherto.展开更多
A portable dual-channel digital/analogue hybrid lock-in amplifier(LIA) is developed,and its amplitude detection error is less than 10% when the signal-to-noise ratio(SNR) is larger than-12 d B.Then,a differential ...A portable dual-channel digital/analogue hybrid lock-in amplifier(LIA) is developed,and its amplitude detection error is less than 10% when the signal-to-noise ratio(SNR) is larger than-12 d B.Then,a differential mid-infrared methane(CH4) detection device is experimentally demonstrated based on a wideband incandescence wire-source and a multi-pass spherical reflector.The experiments are carried out to obtain the sensing performance of the device.With the absorption length of only ~4.8 cm,the limit of detection(Lo D) is about 71.43 mg/m3,and the detection range is from 0 mg/m3 to 5.00×104 mg/m3.As the concentration gets larger than 714.30 mg/m3,the relative detection error falls into the range of-5%—+5%.Two seven-hour-measurements are done on the CH4 samples with concentrations of 1.43×103 mg/m3 and 4.29×103 mg/m3,respectively,and the results show that the maximum relative error is less than 5%.Because of the cost effective incandescence wire-source,the small-size and inexpensive dual-channel LIA,and the small-size absorption pool and reflector,the developed device shows potential applications of CH4 detection in coal mine production and environmental protection.展开更多
With the support by the National Natural Science Foundation of China and'Hundred Talents Program'of the Chinese Academy of Sciences(CAS),the research team led by Prof.Dou Xincun(窦新存)at Xinjiang Technical In...With the support by the National Natural Science Foundation of China and'Hundred Talents Program'of the Chinese Academy of Sciences(CAS),the research team led by Prof.Dou Xincun(窦新存)at Xinjiang Technical Institute of Physics&Chemistry,CAS,developed a chemiresistive sensory array for展开更多
A novel and facile synthesis of 4-arylquinolin-2(1H)-ones without metal catalysis has been developed.This reaction involved cyclization/elimination steps and was performed under metal-free conditions using inexpensi...A novel and facile synthesis of 4-arylquinolin-2(1H)-ones without metal catalysis has been developed.This reaction involved cyclization/elimination steps and was performed under metal-free conditions using inexpensive reagents such as NaI, selectfluor and KOH.展开更多
基金supported by National Natural Science Foundation of China(21473092)Industry-University-Research Cooperation Project of Jiangsu Province(BY2021600)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_0985 and SJCX21_0375)。
文摘Heavy metal(HM)pollution is a serious environment problem.Recovering HM from industrial wastewater by efficient adsorbents is a sustainable method due to recycling HM and acquiring reusable water.However,popular efficient adsorbents are usually expensive or non-reusable.In this paper,methods of efficient HM recycling and water reuse from industrial wastewater were developed using efficient adsorbents,new polyphenylene sulfide derivatives,which are recyclable and stable in an acidic,alkaline or oxidative aqueous solution.Moreover,they can efficiently and quickly adsorb HM ions.The maximum adsorption capacities of these adsorbents for HM ions are at the range from 51.3-184.2 mg·g^(-1).The adsorption equilibrium times of them for HM ions are at the range from 10 to 80 min.Therefore,this paper suggests sustainable methods of HM recovery and water reuse from industrial wastewater.
文摘Geophysical methods are often used to aid in exploration for safe and abundant groundwater. In particular resistivity and seismic refraction methods are helpful in determining depth to bedrock and zones of saturation in the subsurface. However the expense of these instruments ($5000 to $20,000) has resulted in their limited use in developing countries. This paper describes how to construct these devices for less than $250 each. The instruments are small, light and robust and are as useful for groundwater exploration as the commercial models for shallow aquifers (less than 35 m deep) where wells can be hand dug, augured or drilled with small portable drill rigs. Data interpretation can be accomplished quickly in the field with free software implemented on a laptop computer. A suite of geophysical instruments and software can therefore be assembled for less than $850. This paper gives the design for these instruments and essential information needed to use them. It is hoped that these inexpensive geophysical instruments can be widely distributed among drillers and aid workers in developing countries, improving the success rate of water wells.
基金supported by the National Natural Science Foundation of China(20974046,61077021,61076016)New Century Excellent Talents funding from Ministry of Education in China(NCET-08-0697)National Basic Research Program of China(973 Program,2009CB930600)
文摘An inexpensive material, i.e., tetranuclear zinc(Ⅱ) complex, (Zn40(A/D)6) [AID = 7-azaindolate], was utilized as a cathode buffer in organic photovoltaic (OPV) devices, leading to the improvement of device performance. Compared to OPV devices based on a conventional cathode buffer of TPBi (1,3,5-tris(2-N-phenylbenzimidazolyl)benzene), although the freshly prepared devices showed similar performance, when heated to a series of high temperatures under air, the short circuit current and the open circuit voltage of the Zn40(AID)6 devices dropped more slowly, indicating the superiority of using Zn40(AID)6 as a cathode buffer over TPBi in OPV devices.
文摘Here, we present an optimization of colorimetric determination of hydrogen peroxide content in plants using potassium iodide. Our method is based on a one step buffer (extraction and reaction) for the determination of H2O2 in different plant tissues and overcomes interference of soluble antioxidant and color background. A particular attention is paid to buffer pH shown to be tissue dependent. With this inexpensive microplate method, it is possible to analyze 12 experimental samples in about 45 min all in triplicates, with blanks, controls and standard curve.
基金Project supported by the National Basic Research Program of China (Grant No.2004CB318201)the National High-Technology Research and Development Program of China (Grant No.2008AA01A401)the Changjiang Innovative Group of Ministry of Education of China (Grant No.IRT0725)
文摘Redundant array of inexpensive disk (RAID)10 is known as the most reliable disk array architecture to tolerate up to half of total disk failures, but failure of two disks in the same mirror set still results in data loss. In this paper, we propose a new disk array architecture, mirroring and parity protected RAID (MP-RAID), which combines both mirroring and parity techniques to further improve reliability of disk arrays. The main idea behind MP-RAID is to protect the data by both mirroring and parity techniques: keep two copies of data in the same mirror set and update the parity block in the log disk within the same parity groups. Reliability analysis shows that the reliability of MP-RAID, in terms of mean time to data loss (MTTDL), is much better than RAID10 and RAID5.
文摘The earth is an enormous open system and the gas-releasing phenomenon of the crust is the major means of exchange of matters and energy at different crustal depth.Therefore,a powerful gas-releasing channel is actually a "window" to understand the subterranean physical and chemical variations as well as stress-strain changes.The releasing places,quantities and ways obtained by systematically observing and recording can reveal the pressure variation and opening state of channels in the crust,and furthermore provide important information for earthquake prediction,tectonic activity and monitoring of volcanic activity.The fracture-gas measurement has been applied widely to earthquake sciences and has played an important role.The authors introduced systematically the application situation and preliminary achievements in China,and pointed out that though this technique is at the beginning stage and not very sophisticated but its capacities for being easy-carrying,fast-operating and inexpensive,makes for a
文摘1.Make charts and graphs of your weight loss and eating behavior.Fillthem out every day.2.Don’t let anyone 'love' you with food.3.Select your weight goal.Write it here.Now post this note whereyou’ll see it every day.4.Always set a new goal before you reach the old one.Goals move
文摘有了日新月异的科技手段,面对不一样的劳动大军,企业管理者该如何应对?与时俱进不能停留在口头上,要付诸行动,才不会被时代淘汰。Carrots for the Millennials让Y世代尝到甜头H o s t:W h y i n a n environment like ours,where there’s high unemployment,do these kids get to call the shots?Nadira Hira(Journalist,
基金Ministry of Education,Culture,Sports,Science and Technology,Grant/Award Number:ARIM/JPMXP1222JI0040Japan Society for the Promotion of Science,Grant/Award Numbers:KAKENHI/JP20KK0316,KAKENHI/JP21H05405,KAKENHI/JP22H02055,KAKENHI/JP23H02026,KAKENHI/JP23H03966,KAKENHI/JP20H02801。
文摘Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized,and the thermally activated delayed fluorescence(TADF)property was investigated.Compared to unsubstituted carbazole dendrimers,dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields(PLQY)in neat films.Phenylfluorene(PF)-substituted dendrimers showed the highest PLQY of 81%,a smallΔEst of 0.06 eV,and the fastest reverse intersystem crossing(RISC)rate of∼1×10^(5 )s^(−1) compared to other dendrimers.Phosphorescence measurements of dendrimers and dendrons(fragments)indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons(^(3)LE)to that of phenylfluorene-substituted dendrimers(^(1)CT,^(3)CT)contributes to RISC promotion and improves TADF efficiency.Terminal modification fine-tunes the energy level and suppresses intermolecular interactions,and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.
文摘In this work, we designed and synthesized a novel spirocyclic compound functionalized spiro[fluorene-9,9'- xanthene] with carbazole group (2-carbazolyl-spiro[fluorene-9,9'-xanthene], SFX-Cz) via Friedel-Crafts and Ullmann reaction, which is expected to own high thermal and morphological stability, and good carrier injection/ transporting properties due to the excellent hole transporting characteristics of carbazole and cruciform structure of spiro[fluorene-9,9'-xanthene]. The carbazole end-capped spiro[fluorene-9,9'-xanthene] SFX-Cz based PhOLEDs with Flrpic as phosphor emitter have been researched by varying dopant concentration, which exhibit the maximum EQEs of 8.9%, 7.4%, 9.1%, and 4.7% with the doping increasing from 10% to 50%. The higher performance PhOLEDs are independent on concentration variation from 10% to 30%, which suggests the bulky steric hindrance of SFX-Cz might be a potential canditate for high performance and inexpensive device with simplified process.
文摘We combined lightweight and mechanically flexible printed transistors and actuators with a paper unmanned aerial vehicle(UAV)glider prototype to demonstrate electrically controlled glide path modification in a lightweight,disposable UAV system.The integration of lightweight and mechanically flexible electronics that is offered by printed electronics is uniquely attractive in this regard because it enables flight control in an inexpensive,disposable,and easily integrated system.Here,we demonstrate electroactive polymer(EAP)actuators that are directly printed into paper that act as steering elements for low cost,lightweight paper UAVs.We drive these actuators by using ion gel-gated organic thin film transistors(OTFTs)that are ideally suited as drive transistors for these actuators in terms of drive current and frequency requirements.By using a printing-based fabrication process on a paper glider,we are able to deliver an attractive path to the realization of inexpensive UAVs for ubiquitous sensing and monitoring flight applications.
基金supported by National Natural Science Foundation of China(No.21275043)National Basic Research Program of China under Grants(No.2009CB421601)
文摘This report described a free-enzyme, convenient and inexpensive genotyping biosensor capable of detecting single nucleotide polymorphism at normal temperature based on the combination of toeholdmediated strand displacement reaction(toehold-SDR) and microbead-capture technique. The biosensor consists of a pre-hybridized strand formed by a reporter probe and a capture probe. In the presence of a mutant sequence, there is no toehold-mediated strand displacement and the reporter probe cannot be released from the pre-hybridized strand. Microbeads capture the fluorescent pre-hybridized strand through biotin–streptavidin interaction, so microbeads give out significant fluorescence signal, while there is no fluorescence in the solution. However, in the presence of a matched target, the strand displacement is effectively initiated and the reporter probe is released from pre-hybridized strand. After adding microbeads, the solution produces bright fluorescence, while microbeads have no obvious signal.Genotypes are identified conveniently according to the fluorescence intensity of the solution. The method provides a simple and inexpensive strategy to detect point mutation. Moreover, this biosensor shows the linear relationship in the range of 1–40 nmol/L and reaches a detection limit of 0.3 nmol/L.? 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.Published by Elsevier B.V. All rights reserved.
基金supported by the grant of Beijing Institute of Technology
文摘Cucurbituril has a high symmetry and rigid structure.When cucurbit[6]uril(CB[6]) was nitrolyzed with the mixed solution of acetic anhydride in fuming nitric acid,nitroform(NF) was generated.NF also can be obtained by the nitration of both CB[5,7,8].This nitration procedure provides a lower risk,inexpensive,new preparation of nitroform,and the reaction condition of this new method is very mild.
基金UGC,New Delhi,India for financial assistance under UGC-Major Research Project[No.41-302/2012(SR)]SAIF,Panjab University,Chandigarh for NMR analysis
文摘In the present letter, an efficient, clean and one-pot synthesis of 2-substituted benzimidazole and 1,2-disubstituted benzimidazole derivatives has been explored by reacting o-phenylenediamine with aromatic aldehydes using bismuth nitrate as a catalyst in ethanol at ambient temperature. This methodology avails with faster reactions, excellent yield, mild reaction conditions, use of inexpensive and non-toxic catalyst compared to literature reported hitherto.
基金supported by the National Natural Science Foundation of China(No.61307124)the Changchun Municipal Science and Technology Bureau(No.14KG022)the Education Department of Jilin Province in China
文摘A portable dual-channel digital/analogue hybrid lock-in amplifier(LIA) is developed,and its amplitude detection error is less than 10% when the signal-to-noise ratio(SNR) is larger than-12 d B.Then,a differential mid-infrared methane(CH4) detection device is experimentally demonstrated based on a wideband incandescence wire-source and a multi-pass spherical reflector.The experiments are carried out to obtain the sensing performance of the device.With the absorption length of only ~4.8 cm,the limit of detection(Lo D) is about 71.43 mg/m3,and the detection range is from 0 mg/m3 to 5.00×104 mg/m3.As the concentration gets larger than 714.30 mg/m3,the relative detection error falls into the range of-5%—+5%.Two seven-hour-measurements are done on the CH4 samples with concentrations of 1.43×103 mg/m3 and 4.29×103 mg/m3,respectively,and the results show that the maximum relative error is less than 5%.Because of the cost effective incandescence wire-source,the small-size and inexpensive dual-channel LIA,and the small-size absorption pool and reflector,the developed device shows potential applications of CH4 detection in coal mine production and environmental protection.
文摘With the support by the National Natural Science Foundation of China and'Hundred Talents Program'of the Chinese Academy of Sciences(CAS),the research team led by Prof.Dou Xincun(窦新存)at Xinjiang Technical Institute of Physics&Chemistry,CAS,developed a chemiresistive sensory array for
基金financially supported by the National Natural Science Foundation of China(Nos.21302042 and 21172055)the Program for Innovative Research Team from Zhengzhou(No.131P-CXTD605)the Plan for Scientific Innovation Talent of Henan University of Technology(No.171147)
文摘A novel and facile synthesis of 4-arylquinolin-2(1H)-ones without metal catalysis has been developed.This reaction involved cyclization/elimination steps and was performed under metal-free conditions using inexpensive reagents such as NaI, selectfluor and KOH.