Based on Internet technology,modern wireless communication technology and new sensor technology,an intelligent protection and monitoring system of lightning disaster was established to collect lightning current(lightn...Based on Internet technology,modern wireless communication technology and new sensor technology,an intelligent protection and monitoring system of lightning disaster was established to collect lightning current(lightning intensity,frequency and time),induced lightning current and leakage current of surge protector(SPD),earthing resistance,working voltage,temperature and humidity in the lightning environment and other data in real time.Through the online analysis of visual data and automatic alarm beyond the preset value of cloud platform,it can realize the intelligent online monitoring and management of lightning protection devices,providing scientific and reliable lightning protection technical support for lightning protection and disaster reduction,and ensuring the smooth development and efficient management of lightning protection safety work.展开更多
The ternary transitional metal oxide NiCo_2O_4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability i...The ternary transitional metal oxide NiCo_2O_4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo_2O_4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt,and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized productwas tested as an anode material in a sodium ion battery,was found to exhibit a high reversible specific capacity of 511 m Ahg^(-1) at 100 m Ag^(-1), and deliver high capacity retention after 100 cycles.展开更多
A homogeneous better-dispersed ultrathin nanosheets(ca. 5 nm) of cobalt-nickel layered double hydroxides(LDH) supported on nickel foam scaffold was synthesized using controllable electrodeposition approach for high ef...A homogeneous better-dispersed ultrathin nanosheets(ca. 5 nm) of cobalt-nickel layered double hydroxides(LDH) supported on nickel foam scaffold was synthesized using controllable electrodeposition approach for high efficiency electrode materials of new supercapacitor. The morphology and electrochemical performances of the samples can be controlled by adjusting the precursor ratio, i.e., Ni(OAc)_2/Co(NO_3)_2 molar ratio in the electrodeposition approach. With the increase of this molar ratio, the electrochemical performances give a volcano trend. When the optimized molar ratio is 0.64/0.36, the hybrid delivered a high specific capacitance of 1587.5 F g^(-1) at a current density of 0.5 A g^(-1), with good rate capability(1155 F g^(-1) was retained even at 10 A g^(-1)) and a robust recycle stability(remaining 91.5% after 1000 cycles at 5 A g^(-1)). The good performance could be attributed to the enlarged interlayer spacing, ultrathin nanosheets and synergistic effects between Co(OH)_2 and Ni(OH)_2. Furthermore, an asymmetric supercapacitor with a high energy density of 34.5 Wh kg^(-1) at 425 W kg^(-1) and excellent cycling stability of 85.4% after 5000 charge-discharge cycles at 2 A g^(-1) was fabricated. We believe that this fantabulous new electrode material would have encouraging applications in electrochemical energy storage and a wide readership.展开更多
染色体靶向切割和标签化(clevage under target and tagment,CUT&Tag)技术利用Tn5转座酶与Protein A/G的融合蛋白,引导Tn5酶至与靶蛋白结合的抗体附近,对靶蛋白结合的附近染色质区域进行切割,随后通过标签化处理对片段化染色质进行...染色体靶向切割和标签化(clevage under target and tagment,CUT&Tag)技术利用Tn5转座酶与Protein A/G的融合蛋白,引导Tn5酶至与靶蛋白结合的抗体附近,对靶蛋白结合的附近染色质区域进行切割,随后通过标签化处理对片段化染色质进行文库制备,并利用高通量测序技术获取特定位点或蛋白质结合位置的染色质信息。CUT&Tag技术在蛋白质和DNA相互作用的研究领域起到了重大作用,不仅可以了解组蛋白修饰发生的位置,而且可以明确转录因子结合的区域。相较于传统的染色质免疫沉淀高通量测序(chromatin immunoprecipitation-sequencing,ChIP-seq)技术,CUT&Tag技术具有信噪比高、可重复性好、实验周期短、细胞投入量低等优点,在早期胚胎发育、干细胞、肿瘤以及表观遗传学等研究领域体现出巨大优势。本文将针对CUT&Tag在代谢组织细胞(以小鼠原代胰岛细胞为例)的具体操作步骤进行描述,以提供一种研究代谢细胞的表观遗传学方法。展开更多
Biomass-derived carbon materials(B-d-CMs)are considered as a group of very promising electrode materials for electrochemical energy storage(EES)by virtue of their naturally diverse and intricate microarchitectures,ext...Biomass-derived carbon materials(B-d-CMs)are considered as a group of very promising electrode materials for electrochemical energy storage(EES)by virtue of their naturally diverse and intricate microarchitectures,extensive and low-cost source,environmental friendliness,and feasibility to be produced in a large scale.However,the practical application of raw B-d-CMs in EES is limited by their relatively rare storage sites and low diffusion kinetics.In recent years,various strategies from structural design to material composite manipulation have been explored to overcome these problems.In this review,a controllable design of B-d-CM structures boosting their storage sites and diffusion kinetics for EES devices including SIBs,Li-S batteries,and supercapacitors is systematically summarized from the aspects of effects of pseudographic structure,hierarchical pore structure,surface functional groups,and heteroatom doping of B-d-CMs,as well as the composite structure of B-d-CMs,aiming to provide guidance for further rational design of the B-d-CMs for high-performance EES devices.Besides,the contemporary challenges and perspectives on B-d-CMs and their composites are also proposed for further practical application of B-d-CMs for EES devices.展开更多
Potassium-ion batteries(PIBs)are attracted tremendous interest for large-scale energy storage systems(ESSs)owing to their economic merits.However,the main challenges of the PIBs are sluggish K-ion diffusion and large ...Potassium-ion batteries(PIBs)are attracted tremendous interest for large-scale energy storage systems(ESSs)owing to their economic merits.However,the main challenges of the PIBs are sluggish K-ion diffusion and large volume variations in the potassium repeated intercalation/deintercalation.Herein,mesoporous carbon nanosheet-assembled flowers(abbreviated as F-C)are designed as an original anode for superior-performance PIBs.Specifically,the F-C anode exhibits a high K-storage capacity(e.g.,381 mAh/g at 50 mA/g during the 2^(nd)cycle),excellent rate performance(e.g.,101 mAh/g at 2.0 A/g)and superior long cycle capability.Such excellent K-ion storage property is largely benefited from the large surface area(~141 m^(2)/g)and reasonable pore volume(0.465 cm^(3)/g),which not only stimulates rapid Kions diffusion and relieves the huge volume strain,but also exposes extensive active sites for K-ion capacitive storage.展开更多
After the formation of the World Trade Organization(WTO)in 1995,most countries gradually reduced their import tariffs to a fairly low level.However,the reduced tariffs could not he simply read as a reduction in trade ...After the formation of the World Trade Organization(WTO)in 1995,most countries gradually reduced their import tariffs to a fairly low level.However,the reduced tariffs could not he simply read as a reduction in trade barriers.Indeed,many suspect that countries tend to use more non-tariff measures(NTMs),substituting them for tariff barriers,to protect their domestic economies.This paper uses newly compiled and detailed Chinese NTM data,together with highly disaggregated firm import data and manufacturing firm operational data,to investigate the impact of China s import-related NTMs on firm imports.The main empirical results show that,as in the case of tariff barriers,China s trade policy NTMs mainly inhibit firms'intermediate imports.In contrast,China s public policy NTMs significantly improve the intensive and extensive margins of firm s intermediate imports and raise the prices and quality of imported inputs.The greater the extent to which a firm engages in processing trade,the larger is the promoting effect of public policy NTMs on the firm s import margins far intermediate inputs,and the greater is the restricting ejfect on the prices and the quality of the firm's imported inputs.展开更多
文摘Based on Internet technology,modern wireless communication technology and new sensor technology,an intelligent protection and monitoring system of lightning disaster was established to collect lightning current(lightning intensity,frequency and time),induced lightning current and leakage current of surge protector(SPD),earthing resistance,working voltage,temperature and humidity in the lightning environment and other data in real time.Through the online analysis of visual data and automatic alarm beyond the preset value of cloud platform,it can realize the intelligent online monitoring and management of lightning protection devices,providing scientific and reliable lightning protection technical support for lightning protection and disaster reduction,and ensuring the smooth development and efficient management of lightning protection safety work.
基金financially supported by the Science Foundation of Sichuan Province(Grant No.2016FZ0070)the Natural Science Foundation of China(NSFC,201476145)the technical support for Materials Characterization from The Analytical and Testing Center of Sichuan University
文摘The ternary transitional metal oxide NiCo_2O_4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo_2O_4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt,and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized productwas tested as an anode material in a sodium ion battery,was found to exhibit a high reversible specific capacity of 511 m Ahg^(-1) at 100 m Ag^(-1), and deliver high capacity retention after 100 cycles.
基金supported by the National Natural Science Foundation of China (21476145)
文摘A homogeneous better-dispersed ultrathin nanosheets(ca. 5 nm) of cobalt-nickel layered double hydroxides(LDH) supported on nickel foam scaffold was synthesized using controllable electrodeposition approach for high efficiency electrode materials of new supercapacitor. The morphology and electrochemical performances of the samples can be controlled by adjusting the precursor ratio, i.e., Ni(OAc)_2/Co(NO_3)_2 molar ratio in the electrodeposition approach. With the increase of this molar ratio, the electrochemical performances give a volcano trend. When the optimized molar ratio is 0.64/0.36, the hybrid delivered a high specific capacitance of 1587.5 F g^(-1) at a current density of 0.5 A g^(-1), with good rate capability(1155 F g^(-1) was retained even at 10 A g^(-1)) and a robust recycle stability(remaining 91.5% after 1000 cycles at 5 A g^(-1)). The good performance could be attributed to the enlarged interlayer spacing, ultrathin nanosheets and synergistic effects between Co(OH)_2 and Ni(OH)_2. Furthermore, an asymmetric supercapacitor with a high energy density of 34.5 Wh kg^(-1) at 425 W kg^(-1) and excellent cycling stability of 85.4% after 5000 charge-discharge cycles at 2 A g^(-1) was fabricated. We believe that this fantabulous new electrode material would have encouraging applications in electrochemical energy storage and a wide readership.
文摘染色体靶向切割和标签化(clevage under target and tagment,CUT&Tag)技术利用Tn5转座酶与Protein A/G的融合蛋白,引导Tn5酶至与靶蛋白结合的抗体附近,对靶蛋白结合的附近染色质区域进行切割,随后通过标签化处理对片段化染色质进行文库制备,并利用高通量测序技术获取特定位点或蛋白质结合位置的染色质信息。CUT&Tag技术在蛋白质和DNA相互作用的研究领域起到了重大作用,不仅可以了解组蛋白修饰发生的位置,而且可以明确转录因子结合的区域。相较于传统的染色质免疫沉淀高通量测序(chromatin immunoprecipitation-sequencing,ChIP-seq)技术,CUT&Tag技术具有信噪比高、可重复性好、实验周期短、细胞投入量低等优点,在早期胚胎发育、干细胞、肿瘤以及表观遗传学等研究领域体现出巨大优势。本文将针对CUT&Tag在代谢组织细胞(以小鼠原代胰岛细胞为例)的具体操作步骤进行描述,以提供一种研究代谢细胞的表观遗传学方法。
基金This work was financially supported by the National Natural Science Foundation of China(No.51872139)the China Scholarship Council(No.201808610232)+2 种基金the NSF of Jiangsu Province(BK20170045)the Recruitment Program of Global Experts(1211019)the“Six Talent Peak”Project of Jiangsu Province(XCL-043).
文摘Biomass-derived carbon materials(B-d-CMs)are considered as a group of very promising electrode materials for electrochemical energy storage(EES)by virtue of their naturally diverse and intricate microarchitectures,extensive and low-cost source,environmental friendliness,and feasibility to be produced in a large scale.However,the practical application of raw B-d-CMs in EES is limited by their relatively rare storage sites and low diffusion kinetics.In recent years,various strategies from structural design to material composite manipulation have been explored to overcome these problems.In this review,a controllable design of B-d-CM structures boosting their storage sites and diffusion kinetics for EES devices including SIBs,Li-S batteries,and supercapacitors is systematically summarized from the aspects of effects of pseudographic structure,hierarchical pore structure,surface functional groups,and heteroatom doping of B-d-CMs,as well as the composite structure of B-d-CMs,aiming to provide guidance for further rational design of the B-d-CMs for high-performance EES devices.Besides,the contemporary challenges and perspectives on B-d-CMs and their composites are also proposed for further practical application of B-d-CMs for EES devices.
基金financially supported by the National Key R&D Research Program of China(No.2018YFB0905400)National Natural Science Foundation of China(Nos.51925207,U1910210,51972067,61801314,51802044,51872277)+3 种基金Guangdong Natural Science Funds for Distinguished Young Scholar(No.2019B151502039)Sichuan Science and Technology Program(No.2019YFH0078)Fundamental Research Funds for the CentralUniversities of China(Nos.WK2060140026 and YJ201703)he DNL Cooperation Fund,CAS(No.DNL180310)。
文摘Potassium-ion batteries(PIBs)are attracted tremendous interest for large-scale energy storage systems(ESSs)owing to their economic merits.However,the main challenges of the PIBs are sluggish K-ion diffusion and large volume variations in the potassium repeated intercalation/deintercalation.Herein,mesoporous carbon nanosheet-assembled flowers(abbreviated as F-C)are designed as an original anode for superior-performance PIBs.Specifically,the F-C anode exhibits a high K-storage capacity(e.g.,381 mAh/g at 50 mA/g during the 2^(nd)cycle),excellent rate performance(e.g.,101 mAh/g at 2.0 A/g)and superior long cycle capability.Such excellent K-ion storage property is largely benefited from the large surface area(~141 m^(2)/g)and reasonable pore volume(0.465 cm^(3)/g),which not only stimulates rapid Kions diffusion and relieves the huge volume strain,but also exposes extensive active sites for K-ion capacitive storage.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(No.71903041)the Humanity and Social Science Youth Foundation(No.17YJC790142)+2 种基金Key Project of Ministry of Education of China(No.16JZD018)the Natural Science Foundation of Guangdong Province(No.2021 Al515012018)the National Social Science Foundation(Nos.21AZD064 and 19BJL074)。
文摘After the formation of the World Trade Organization(WTO)in 1995,most countries gradually reduced their import tariffs to a fairly low level.However,the reduced tariffs could not he simply read as a reduction in trade barriers.Indeed,many suspect that countries tend to use more non-tariff measures(NTMs),substituting them for tariff barriers,to protect their domestic economies.This paper uses newly compiled and detailed Chinese NTM data,together with highly disaggregated firm import data and manufacturing firm operational data,to investigate the impact of China s import-related NTMs on firm imports.The main empirical results show that,as in the case of tariff barriers,China s trade policy NTMs mainly inhibit firms'intermediate imports.In contrast,China s public policy NTMs significantly improve the intensive and extensive margins of firm s intermediate imports and raise the prices and quality of imported inputs.The greater the extent to which a firm engages in processing trade,the larger is the promoting effect of public policy NTMs on the firm s import margins far intermediate inputs,and the greater is the restricting ejfect on the prices and the quality of the firm's imported inputs.
