Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient ...Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient and effective energy conversion and storage. The booming development of nanotechnology affords emerging but effective tools in designing advanced energy material. We reviewed the significant progress and dominated nanostructured energy materials in electrochemical energy conversion and storage devices, including lithium ion batteries, lithium-sulfur batteries, lithium-oxygen batteries, lithium metal batteries, and supercapacitors. The use of nanostructured electrocatalyst for effective electrocatalysis in oxygen reduction and oxygen evolution reactions for fuel cells and metal-air batteries was also included. The challenges in the undesirable side reactions between electrolytes and electrode due to high electrode/electrolyte contact area, low volumetric energy density of electrode owing to low tap density, and uniform production of complex energy materials in working devices should be overcome to fully demonstrate the advanced energy nanostructures for electrochemical energy conversion and storage. The energy chemistry at the interfaces of nanostructured electrode/electrolyte is highly expected to guide the rational design and full demonstration of energy materials in a working device. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
Lithium (Li) metal with an ultrahigh specific theoretical capacity and the lowest reduction potential is strongly considered as a promising anode for high-energy-density batteries. However, uncontrolled lithium dendri...Lithium (Li) metal with an ultrahigh specific theoretical capacity and the lowest reduction potential is strongly considered as a promising anode for high-energy-density batteries. However, uncontrolled lithium dendrites and infinite volume change during repeated plating/stripping cycles hinder its practical applications immensely. Herein, a house-like Li anode (housed Li) was designed to circumvent the above issues. The house matrix was composed of carbon fiber matrix and affords a stable structure to relieve the volume change. An artificial solid electrolyte layer was formed on composite Li metal, just like the roof of a house, which facilitates uniform Li ions diffusion and serves as a physical barrier against electrolyte corrosion. With the combination of solid electrolyte layer and matrix in the composite Li metal anode, both dendrite growth and volume expansion are remarkably inhibited. The housed Li|LiFePO4 batteries exhibited over 95% capacity retention after 500 cycles at 1.0 C in coin cell and 85% capacity retention after 80 cycles at 0.5 C in pouch cell. The rationally combination of solid electrolyte layer protection and housed framework in one Li metal anode sheds fresh insights on the design principle of a safe and long-lifespan Li metal anode for Li metal batteries.展开更多
Lithium metal batteries(LMBs)are highly considered as promising candidates for next-generation energy storage systems.However,routine electrolytes cannot tolerate the high potential at cathodes and low potential at an...Lithium metal batteries(LMBs)are highly considered as promising candidates for next-generation energy storage systems.However,routine electrolytes cannot tolerate the high potential at cathodes and low potential at anodes simultaneously,leading to severe interfacial reactions.Herein,a highly concentrated electrolyte(HCE)region trapped in porous carbon coating layer is adopted to form a stable and highly conductive solid electrolyte interphase(SEI)on Li metal surface.The protected Li metal anode can potentially match the high-voltage cathode in ester electrolytes.Synergistically,this ingenious design promises high-voltage-resistant interfaces at cathodes and stable SEI with abundance of inorganic components at anodes simultaneously in high-voltage LMBs.The feasibility of this interface-regulation strategy is demonstrated in Li|LiFePO_(4) batteries,realizing a lifespan twice as long as the routine cells,with a huge capacity retention enhancement from 46.4%to 88.7%after 100 cycles.This contribution proof-ofconcepts the emerging principles on the formation and regulation of stable electrode/electrolyte interfaces in the cathode and anode simultaneously towards the next-generation high-energy-density batteries.展开更多
The single crystal of cubic perovskite BaFeO3 shows multiple magnetic transitions and external stimulus sensitive magnetism.In this paper,a 5%-Co-doped BaFeO_(3)(i.e.BaFe_(0.95)Co_(0.05)O_(3))single crystal was grown ...The single crystal of cubic perovskite BaFeO3 shows multiple magnetic transitions and external stimulus sensitive magnetism.In this paper,a 5%-Co-doped BaFeO_(3)(i.e.BaFe_(0.95)Co_(0.05)O_(3))single crystal was grown by combining floating zone methods with high-pressure techniques.Such a slight Co doping has little effect on crystal structure,but significantly changes the magnetism from the parent antiferromagnetic ground state to a ferromagnetic one with the Curie temperature TC≈120 K.Compared with the parent BaFeO3 at the induced ferromagnetic state,the saturated magnetic moment of the doped BaFe_(0.95)Co_(0.05)O_(3) increases by about 10%and reaches 3.64μB/f.u.Resistivity and specific heat measurements show that the ferromagnetic ordering favors metallic-like electrical transport behavior for BaFe_(0.95)Co_(0.05)O_(3).The present work indicates that Co-doping is an effective method to tune the magnetic and electric properties for the cubic perovskite phase of BaFeO_(3).展开更多
Through the study of parse wood materials, the fitting empirical equation of tree growth was obtained, a function with tree growth as a variable and time as an independent variable. The mature age of tree growth was o...Through the study of parse wood materials, the fitting empirical equation of tree growth was obtained, a function with tree growth as a variable and time as an independent variable. The mature age of tree growth was obtained through mathematical operations such as function derivation. The obtained expected maturity ages for the actual forests of Robinia pseudoacacia were 36, 46 and 56 a, respectively, which could be the mature ages for commercial forest, protection forest and special-purpose forest. And the application, research directions and precautions of the mature ages were proposed.展开更多
Through the study of parse wood materials, the fitting empirical equation of tree growth was obtained, a function with tree growth as a variable and time as an independent variable. Through mathematical operations suc...Through the study of parse wood materials, the fitting empirical equation of tree growth was obtained, a function with tree growth as a variable and time as an independent variable. Through mathematical operations such as function derivation, the mature age of tree growth was obtained. The obtained maturity age for the actual forest of Pinus thunbergii Parl was 51 a, and the ideal mature age was 66 a. And the application, research directions and precautions of the mature ages were proposed.展开更多
Objective:To observe the clinical efficacy of Shexian bupleurum on insomnia based on evaluation scales and polysomnogram(PSG).Methods:A total of 260 patients suffering from insomnia admitted to the outpatient departme...Objective:To observe the clinical efficacy of Shexian bupleurum on insomnia based on evaluation scales and polysomnogram(PSG).Methods:A total of 260 patients suffering from insomnia admitted to the outpatient department of Handan Central Hospital were included in a randomized,double blind,placebo-controlled trial.The patients were randomly divided into two groups:a control group(receiving placebo,n=150),and an intervention group(receiving Shexian bupleurum treatment,n=110).The clinical trial lasted for 4 weeks.The Pittsburgh Sleep Quality Index(PSQI),Insomnia Severity Index(ISI),Patient Health Questionnaire(PHQ)-9,Generalized Anxiety Disorder(GAD)-7,17 items of Hamilton Depression Scale(HAMD-17),and Hamilton Anxiety Scale(HAMA)were used to evaluate the patients at baseline as well as two weeks and four weeks after treatment;the Treatment Emergent Symptom Scale(TESS)was used to evaluate adverse reactions;polysomnography(PSG)was used to monitor and analyze their sleep characteristics at baseline and four weeks after treatment.Results:The PSQI,ISI,PHQ-9,HAMD-17,and HAMA scores of the intervention group significantly decreased compared to the control group,while the total sleep time,rapid eye movement sleep latency,stage 2 sleep,deep sleep,rapid eye movement sleep,and sleep efficiency of the intervention group significantly increased compared to the control group.The PHQ-9 score of the control group only decreased two weeks after treatment(p<0.05)compared to the intervention group.In addition,there were no obvious adverse events in both the intervention group and the control group.Conclusion:Shexian bupleurum not only improves sleep quality,but also relieves depression and anxiety in patients who suffer from insomnia.展开更多
Bupleurum has been used as traditional medicine in China,Japan,South Korea,and other Asian countries for more than 2,000 years.The crude extracts and pure compounds isolated from Bupleurum have a variety of biological...Bupleurum has been used as traditional medicine in China,Japan,South Korea,and other Asian countries for more than 2,000 years.The crude extracts and pure compounds isolated from Bupleurum have a variety of biological activities,such as anti-inflammatory,anti-cancer,antipyretic,antibacterial,anti-viral,liver protection,neuroprotection,and immune regxilation.The pharmacological effects of Bupleurum have been classified and summarized in this paper by consulting literatures at home and abroad.At the same time,the quality analysis methods of bupleurum,including high-performance liquid chromatography,thin layer chromatography,ultra-high-performance liquid chromatography mass spectrometry,UPLC-QTOF-MS,and so on,are discussed.This paper provides a reference for further research,development,and application of Bupleurum.展开更多
Chlorine(Cl2)is one of the most important chemicals produced by the electrolysis of brine solutions and is a key raw material for many areas of industrial chemistry.For nearly half a century,dimensionally stable anode...Chlorine(Cl2)is one of the most important chemicals produced by the electrolysis of brine solutions and is a key raw material for many areas of industrial chemistry.For nearly half a century,dimensionally stable anode(DSA)made from a mixture of RuO_(2) and TiO_(2) solid oxides coated on Ti substrate has been the most widely used electrode for chlorine evolution reaction(CER).In harsh operating environments,the stability of DSAs remains a major challenge greatly affecting their lifetime.The deactivation of DSAs significantly increases the cost of the chlor-alkali industry due to the corrosion of Ru and the formation of the passivation layer TiO_(2).Therefore,it is urgent to develop catalysts with higher activity and stability,which requires a thorough understanding of the deactivation mechanism of DSA catalysts.This paper reviews existing references on the deactivation mechanisms of DSA catalysts,including both experimental and theoretical studies.Studies on how CER selectivity affects electrode stability are also discussed.Furthermore,studies on the effects of the preparation process,elemental composition,and surface/interface structures on the DSA stability and corresponding improvement strategies are summarized.The development of other non-DSA-type catalysts with comparable stability is also reviewed,and future opportunities in this exciting field are also outlined.展开更多
Sustainable and low-carbon-emission silicon production is currently one of the main focuses for the metallurgical and materials science communities.Electrochemistry,considered a promising strategy,has been explored to...Sustainable and low-carbon-emission silicon production is currently one of the main focuses for the metallurgical and materials science communities.Electrochemistry,considered a promising strategy,has been explored to produce silicon due to prominent advantages:(a)high electricity utilization efficiency;(b)low-cost silica as a raw material;and(c)tunable morphologies and structures,including films,nanowires,and nanotubes.This review begins with a summary of early research on the extraction of silicon by electrochemistry.Emphasis has been placed on the electro-deoxidation and dissolution–electrodeposition of silica in chloride molten salts since the 21st century,including the basic reaction mechanisms,the fabrication of photoactive Si films for solar cells,the design and production of nanoSi and various silicon components for energy conversion,as well as storage applications.Besides,the feasibility of silicon electrodeposition in room-temperature ionic liquids and its unique opportunities are evaluated.On this basis,the challenges and future research directions for silicon electrochemical production strategies are proposed and discussed,which are essential to achieve large-scale sustainable production of silicon by electrochemistry.展开更多
Aim:The transjugular intrahepatic portosystemic shunt(TIPS)procedure has been performed in China for 30 years,but our understanding of the status and difficulties associated with the use of TIPS for portal hypertensio...Aim:The transjugular intrahepatic portosystemic shunt(TIPS)procedure has been performed in China for 30 years,but our understanding of the status and difficulties associated with the use of TIPS for portal hypertension is incomplete.This study aims to investigate the current situation of the use of TIPS for portal hypertension,which should aid the development of TIPS in China.Methods:This study involved a questionnaire survey,initiated by the China Portal Hypertension Alliance(CHESS)to investigate the use of TIPS for portal hypertension in China.Questionnaires were released on the Internet between August 16,2022 and September 16,2022.Detailed information was collected from 545 hospitals contracted by the CHESS in China,which performed TIPS surgery in 2021.Results:The 545 hospitals covers the majority of hospitals in China that conduct TIPS intervention.In the survey,a total of 13,527 TIPS interventions were carried out with 94.1%(498/545)of them had a system of routine follow‐up after TIPS.The majority(42.6%[232/545])believed that the main indication of TIPS was the control of acute bleeding.Overall,48.1%(262/545)carried out early or pre‐emptive TIPS,53.0%(289/545)carried out TIPS for cavernous transformation of the portal vein,and 81.0%(441/545)chose routine embolization of collateral circulation during operation.Most used coils(97.0%[475/490])and biological glue(72.0%[353/490])as embolic materials,and 78.5%(428/545)routinely performed intraoperative portal pressure gradient measurements.When selecting TIPS stents,57.1%(311/545)chose viator‐specific stents,and 57.2%(312/545)chose conventional anticoagulation after TIPS.Conventional anticoagulation after TIPS is over a time interval of 3–6 months(55.4%[173/312]).The limitation of TIPS surgery is mainly its cost(72.3%[394/545])and insufficient understanding of the procedure by doctors in other related departments(77.4%[422/545]).Most of the hospital teams accept the use of domestic instruments in TIPS surgery(92.7%[505/545]).Conclusions:This survey shows that TIPS is an essential part of the treatment of portal hypertension in China.TIPS is widely used in Chinese patients with portal hypertension,and this survey presents a more comprehensive picture of the options and difficulties encountered in the implementation of TIPS.In the future,it is necessary to promote TIPS technology and further standardize surgical indications,routine operations,and instrument application.展开更多
An L-band HTS duplexer with improved performance for communication applications has been developed.This is an improved version of the duplexer previously developed by our group.The duplexer was composed of a T-junctio...An L-band HTS duplexer with improved performance for communication applications has been developed.This is an improved version of the duplexer previously developed by our group.The duplexer was composed of a T-junction and two channels.Each channel has a 10-pole quasi-elliptic function bandpass HTS filter with a bandwidth of 27 MHz,and center frequencies at 1200 MHz and 1260 MHz.To achieve higher performance,especially a good balance between selectivity and flat group delay,the two pairs of transmission zeros from the two filters were reassigned so that one pair is used for high selectivity and the other for flat group delay.To reduce the influence of parasitical coupling,new coupling structures were developed in the simulation process.The duplexer was fabricated on a 2 inch diameter,0.5 mm thick LaAlO3 wafer with a double-sided YBCO film.The measured results showed a very high performance:a mid-band insertion loss of 0.2 dB,a return loss better than-14 dB,a shape factor better than 1.4:1,an out-of-band rejection of better than 70 dB in a wide frequency range up to 3 GHz and excellent isolation(higher than 80 dB) between the two channels.In addition,the frequency band 5 ns group delay variation is over 10.5 MHz(38.7% of 1 dB bandwidth).展开更多
What is already known about this topic?Morbidity and prevalence of several major parasitic diseases have been declining in China.To reduce the disease burden of parasitic diseases and protect public health security,co...What is already known about this topic?Morbidity and prevalence of several major parasitic diseases have been declining in China.To reduce the disease burden of parasitic diseases and protect public health security,conducting accurate diagnoses following timely treatment is important.What is added by this report?In the national competition held in 2019.展开更多
With the accelerated development of electronic devices,micro-supercapacitors(MSCs),as energy storage devices that can charge and discharge quickly,have attracted considerable attention.To improve the rate capability o...With the accelerated development of electronic devices,micro-supercapacitors(MSCs),as energy storage devices that can charge and discharge quickly,have attracted considerable attention.To improve the rate capability of MSCs with consideration of the energy density remains a challenge.We demonstrated a facile method for the preparation of thin films through bottom-up femtosecond pulsed laser deposition.The femtosecond laser irradiated the polyimide film through a transparent substrate to uniformly sputter the electrode material onto the lower surface of the substrate.We successfully deposited porous amorphous carbon,graphene,and carbon quantum dots with controllable properties by temporally shaping the femtosecond laser.The resulting MSC exhibited an ultrahigh frequency response and good performance at scan rates up to 10,000 V s^(-1).The characteristic frequency f_(0) of the MSC was as high as 42,000 Hz,and the relaxation time constant τ_(0) was 0.0238 ms.The MSC reached an impedance phase angle of -82.6° at a frequency of 120 Hz,an ultrahigh power density of more than 30 kW cm^(-3),and an energy density of 0.068 W h cm-3.This method provides a novel perspective for the preparation of ultrahigh frequency filters for future miniaturized portable electronic devices.展开更多
基金supported by the National Key Research and Development Program (no.2016YFA0202500)National Basic Research Program of China (2015CB932500)the Natural Scientific Foundation of China (nos.21306102 and 21422604)
文摘Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient and effective energy conversion and storage. The booming development of nanotechnology affords emerging but effective tools in designing advanced energy material. We reviewed the significant progress and dominated nanostructured energy materials in electrochemical energy conversion and storage devices, including lithium ion batteries, lithium-sulfur batteries, lithium-oxygen batteries, lithium metal batteries, and supercapacitors. The use of nanostructured electrocatalyst for effective electrocatalysis in oxygen reduction and oxygen evolution reactions for fuel cells and metal-air batteries was also included. The challenges in the undesirable side reactions between electrolytes and electrode due to high electrode/electrolyte contact area, low volumetric energy density of electrode owing to low tap density, and uniform production of complex energy materials in working devices should be overcome to fully demonstrate the advanced energy nanostructures for electrochemical energy conversion and storage. The energy chemistry at the interfaces of nanostructured electrode/electrolyte is highly expected to guide the rational design and full demonstration of energy materials in a working device. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金supported by the National Key Research and Development Program (2016YFA0202500, 2015CB932500, and 2016YFA0200102)the National Natural Science Foundation of China (21676160, 21825501, 21805161, and 21808125)China Postdoctoral Science Foundation (2017M620773, 2018M631480, and BX201700125)
文摘Lithium (Li) metal with an ultrahigh specific theoretical capacity and the lowest reduction potential is strongly considered as a promising anode for high-energy-density batteries. However, uncontrolled lithium dendrites and infinite volume change during repeated plating/stripping cycles hinder its practical applications immensely. Herein, a house-like Li anode (housed Li) was designed to circumvent the above issues. The house matrix was composed of carbon fiber matrix and affords a stable structure to relieve the volume change. An artificial solid electrolyte layer was formed on composite Li metal, just like the roof of a house, which facilitates uniform Li ions diffusion and serves as a physical barrier against electrolyte corrosion. With the combination of solid electrolyte layer and matrix in the composite Li metal anode, both dendrite growth and volume expansion are remarkably inhibited. The housed Li|LiFePO4 batteries exhibited over 95% capacity retention after 500 cycles at 1.0 C in coin cell and 85% capacity retention after 80 cycles at 0.5 C in pouch cell. The rationally combination of solid electrolyte layer protection and housed framework in one Li metal anode sheds fresh insights on the design principle of a safe and long-lifespan Li metal anode for Li metal batteries.
基金supported by Beijing Natural Science Foundation(JQ20004)National Natural Science Foundation of China(21805161,21808121,and U1932220)+1 种基金China Post-Doctoral Science Foundation(2020M670155 and 2020T130054)Scientific and Technological Key Project of Shanxi Province(20191102003)。
文摘Lithium metal batteries(LMBs)are highly considered as promising candidates for next-generation energy storage systems.However,routine electrolytes cannot tolerate the high potential at cathodes and low potential at anodes simultaneously,leading to severe interfacial reactions.Herein,a highly concentrated electrolyte(HCE)region trapped in porous carbon coating layer is adopted to form a stable and highly conductive solid electrolyte interphase(SEI)on Li metal surface.The protected Li metal anode can potentially match the high-voltage cathode in ester electrolytes.Synergistically,this ingenious design promises high-voltage-resistant interfaces at cathodes and stable SEI with abundance of inorganic components at anodes simultaneously in high-voltage LMBs.The feasibility of this interface-regulation strategy is demonstrated in Li|LiFePO_(4) batteries,realizing a lifespan twice as long as the routine cells,with a huge capacity retention enhancement from 46.4%to 88.7%after 100 cycles.This contribution proof-ofconcepts the emerging principles on the formation and regulation of stable electrode/electrolyte interfaces in the cathode and anode simultaneously towards the next-generation high-energy-density batteries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11934017 and 11921004)the National Key Research and Development Program of China(Grant Nos.2021YFA1400300,2018YFE0103200,and 2018YFA0305700)+1 种基金the Beijing Natural Science Foundation(Grant No.Z200007)the Fund from the Chinese Academy of Sciences(Grant No.XDB33000000).
文摘The single crystal of cubic perovskite BaFeO3 shows multiple magnetic transitions and external stimulus sensitive magnetism.In this paper,a 5%-Co-doped BaFeO_(3)(i.e.BaFe_(0.95)Co_(0.05)O_(3))single crystal was grown by combining floating zone methods with high-pressure techniques.Such a slight Co doping has little effect on crystal structure,but significantly changes the magnetism from the parent antiferromagnetic ground state to a ferromagnetic one with the Curie temperature TC≈120 K.Compared with the parent BaFeO3 at the induced ferromagnetic state,the saturated magnetic moment of the doped BaFe_(0.95)Co_(0.05)O_(3) increases by about 10%and reaches 3.64μB/f.u.Resistivity and specific heat measurements show that the ferromagnetic ordering favors metallic-like electrical transport behavior for BaFe_(0.95)Co_(0.05)O_(3).The present work indicates that Co-doping is an effective method to tune the magnetic and electric properties for the cubic perovskite phase of BaFeO_(3).
文摘Through the study of parse wood materials, the fitting empirical equation of tree growth was obtained, a function with tree growth as a variable and time as an independent variable. The mature age of tree growth was obtained through mathematical operations such as function derivation. The obtained expected maturity ages for the actual forests of Robinia pseudoacacia were 36, 46 and 56 a, respectively, which could be the mature ages for commercial forest, protection forest and special-purpose forest. And the application, research directions and precautions of the mature ages were proposed.
文摘Through the study of parse wood materials, the fitting empirical equation of tree growth was obtained, a function with tree growth as a variable and time as an independent variable. Through mathematical operations such as function derivation, the mature age of tree growth was obtained. The obtained maturity age for the actual forest of Pinus thunbergii Parl was 51 a, and the ideal mature age was 66 a. And the application, research directions and precautions of the mature ages were proposed.
文摘Objective:To observe the clinical efficacy of Shexian bupleurum on insomnia based on evaluation scales and polysomnogram(PSG).Methods:A total of 260 patients suffering from insomnia admitted to the outpatient department of Handan Central Hospital were included in a randomized,double blind,placebo-controlled trial.The patients were randomly divided into two groups:a control group(receiving placebo,n=150),and an intervention group(receiving Shexian bupleurum treatment,n=110).The clinical trial lasted for 4 weeks.The Pittsburgh Sleep Quality Index(PSQI),Insomnia Severity Index(ISI),Patient Health Questionnaire(PHQ)-9,Generalized Anxiety Disorder(GAD)-7,17 items of Hamilton Depression Scale(HAMD-17),and Hamilton Anxiety Scale(HAMA)were used to evaluate the patients at baseline as well as two weeks and four weeks after treatment;the Treatment Emergent Symptom Scale(TESS)was used to evaluate adverse reactions;polysomnography(PSG)was used to monitor and analyze their sleep characteristics at baseline and four weeks after treatment.Results:The PSQI,ISI,PHQ-9,HAMD-17,and HAMA scores of the intervention group significantly decreased compared to the control group,while the total sleep time,rapid eye movement sleep latency,stage 2 sleep,deep sleep,rapid eye movement sleep,and sleep efficiency of the intervention group significantly increased compared to the control group.The PHQ-9 score of the control group only decreased two weeks after treatment(p<0.05)compared to the intervention group.In addition,there were no obvious adverse events in both the intervention group and the control group.Conclusion:Shexian bupleurum not only improves sleep quality,but also relieves depression and anxiety in patients who suffer from insomnia.
文摘Bupleurum has been used as traditional medicine in China,Japan,South Korea,and other Asian countries for more than 2,000 years.The crude extracts and pure compounds isolated from Bupleurum have a variety of biological activities,such as anti-inflammatory,anti-cancer,antipyretic,antibacterial,anti-viral,liver protection,neuroprotection,and immune regxilation.The pharmacological effects of Bupleurum have been classified and summarized in this paper by consulting literatures at home and abroad.At the same time,the quality analysis methods of bupleurum,including high-performance liquid chromatography,thin layer chromatography,ultra-high-performance liquid chromatography mass spectrometry,UPLC-QTOF-MS,and so on,are discussed.This paper provides a reference for further research,development,and application of Bupleurum.
文摘Chlorine(Cl2)is one of the most important chemicals produced by the electrolysis of brine solutions and is a key raw material for many areas of industrial chemistry.For nearly half a century,dimensionally stable anode(DSA)made from a mixture of RuO_(2) and TiO_(2) solid oxides coated on Ti substrate has been the most widely used electrode for chlorine evolution reaction(CER).In harsh operating environments,the stability of DSAs remains a major challenge greatly affecting their lifetime.The deactivation of DSAs significantly increases the cost of the chlor-alkali industry due to the corrosion of Ru and the formation of the passivation layer TiO_(2).Therefore,it is urgent to develop catalysts with higher activity and stability,which requires a thorough understanding of the deactivation mechanism of DSA catalysts.This paper reviews existing references on the deactivation mechanisms of DSA catalysts,including both experimental and theoretical studies.Studies on how CER selectivity affects electrode stability are also discussed.Furthermore,studies on the effects of the preparation process,elemental composition,and surface/interface structures on the DSA stability and corresponding improvement strategies are summarized.The development of other non-DSA-type catalysts with comparable stability is also reviewed,and future opportunities in this exciting field are also outlined.
基金the National Natural Science Foundation of China(nos.52022054,51974181,5200415,62004044,and 62204048)the National Key Research and Development Program of China(no.2022YFC2906100)+3 种基金the China Postdoctoral Science Foundation(no.2022M712023)the Shanghai Postdoctoral Excellence Program(no.2021159)the Science and Technology Commission of Shanghai Municipality(no.21DZ1208900)the Iron and Steel Joint Research Fund of National Natural Science Foundation and China Baowu Steel Group Corporation Limited(U1860203).
文摘Sustainable and low-carbon-emission silicon production is currently one of the main focuses for the metallurgical and materials science communities.Electrochemistry,considered a promising strategy,has been explored to produce silicon due to prominent advantages:(a)high electricity utilization efficiency;(b)low-cost silica as a raw material;and(c)tunable morphologies and structures,including films,nanowires,and nanotubes.This review begins with a summary of early research on the extraction of silicon by electrochemistry.Emphasis has been placed on the electro-deoxidation and dissolution–electrodeposition of silica in chloride molten salts since the 21st century,including the basic reaction mechanisms,the fabrication of photoactive Si films for solar cells,the design and production of nanoSi and various silicon components for energy conversion,as well as storage applications.Besides,the feasibility of silicon electrodeposition in room-temperature ionic liquids and its unique opportunities are evaluated.On this basis,the challenges and future research directions for silicon electrochemical production strategies are proposed and discussed,which are essential to achieve large-scale sustainable production of silicon by electrochemistry.
文摘Aim:The transjugular intrahepatic portosystemic shunt(TIPS)procedure has been performed in China for 30 years,but our understanding of the status and difficulties associated with the use of TIPS for portal hypertension is incomplete.This study aims to investigate the current situation of the use of TIPS for portal hypertension,which should aid the development of TIPS in China.Methods:This study involved a questionnaire survey,initiated by the China Portal Hypertension Alliance(CHESS)to investigate the use of TIPS for portal hypertension in China.Questionnaires were released on the Internet between August 16,2022 and September 16,2022.Detailed information was collected from 545 hospitals contracted by the CHESS in China,which performed TIPS surgery in 2021.Results:The 545 hospitals covers the majority of hospitals in China that conduct TIPS intervention.In the survey,a total of 13,527 TIPS interventions were carried out with 94.1%(498/545)of them had a system of routine follow‐up after TIPS.The majority(42.6%[232/545])believed that the main indication of TIPS was the control of acute bleeding.Overall,48.1%(262/545)carried out early or pre‐emptive TIPS,53.0%(289/545)carried out TIPS for cavernous transformation of the portal vein,and 81.0%(441/545)chose routine embolization of collateral circulation during operation.Most used coils(97.0%[475/490])and biological glue(72.0%[353/490])as embolic materials,and 78.5%(428/545)routinely performed intraoperative portal pressure gradient measurements.When selecting TIPS stents,57.1%(311/545)chose viator‐specific stents,and 57.2%(312/545)chose conventional anticoagulation after TIPS.Conventional anticoagulation after TIPS is over a time interval of 3–6 months(55.4%[173/312]).The limitation of TIPS surgery is mainly its cost(72.3%[394/545])and insufficient understanding of the procedure by doctors in other related departments(77.4%[422/545]).Most of the hospital teams accept the use of domestic instruments in TIPS surgery(92.7%[505/545]).Conclusions:This survey shows that TIPS is an essential part of the treatment of portal hypertension in China.TIPS is widely used in Chinese patients with portal hypertension,and this survey presents a more comprehensive picture of the options and difficulties encountered in the implementation of TIPS.In the future,it is necessary to promote TIPS technology and further standardize surgical indications,routine operations,and instrument application.
基金supported by the External Cooperation Program of the Chinese Academy of Sciences (GJHZ1007)Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-W16)
文摘An L-band HTS duplexer with improved performance for communication applications has been developed.This is an improved version of the duplexer previously developed by our group.The duplexer was composed of a T-junction and two channels.Each channel has a 10-pole quasi-elliptic function bandpass HTS filter with a bandwidth of 27 MHz,and center frequencies at 1200 MHz and 1260 MHz.To achieve higher performance,especially a good balance between selectivity and flat group delay,the two pairs of transmission zeros from the two filters were reassigned so that one pair is used for high selectivity and the other for flat group delay.To reduce the influence of parasitical coupling,new coupling structures were developed in the simulation process.The duplexer was fabricated on a 2 inch diameter,0.5 mm thick LaAlO3 wafer with a double-sided YBCO film.The measured results showed a very high performance:a mid-band insertion loss of 0.2 dB,a return loss better than-14 dB,a shape factor better than 1.4:1,an out-of-band rejection of better than 70 dB in a wide frequency range up to 3 GHz and excellent isolation(higher than 80 dB) between the two channels.In addition,the frequency band 5 ns group delay variation is over 10.5 MHz(38.7% of 1 dB bandwidth).
基金National Science Foundation of China(Grant No.82073619).
文摘What is already known about this topic?Morbidity and prevalence of several major parasitic diseases have been declining in China.To reduce the disease burden of parasitic diseases and protect public health security,conducting accurate diagnoses following timely treatment is important.What is added by this report?In the national competition held in 2019.
基金supported by the Outstanding Youth Science Foundation of China(51922005)the National Natural Science Foundation of China(51775047 and 52105427)。
文摘With the accelerated development of electronic devices,micro-supercapacitors(MSCs),as energy storage devices that can charge and discharge quickly,have attracted considerable attention.To improve the rate capability of MSCs with consideration of the energy density remains a challenge.We demonstrated a facile method for the preparation of thin films through bottom-up femtosecond pulsed laser deposition.The femtosecond laser irradiated the polyimide film through a transparent substrate to uniformly sputter the electrode material onto the lower surface of the substrate.We successfully deposited porous amorphous carbon,graphene,and carbon quantum dots with controllable properties by temporally shaping the femtosecond laser.The resulting MSC exhibited an ultrahigh frequency response and good performance at scan rates up to 10,000 V s^(-1).The characteristic frequency f_(0) of the MSC was as high as 42,000 Hz,and the relaxation time constant τ_(0) was 0.0238 ms.The MSC reached an impedance phase angle of -82.6° at a frequency of 120 Hz,an ultrahigh power density of more than 30 kW cm^(-3),and an energy density of 0.068 W h cm-3.This method provides a novel perspective for the preparation of ultrahigh frequency filters for future miniaturized portable electronic devices.