Conductive and transparent dipeptide hydrogels are desirable building blocks to prepare soft electronic devices and wearable biosensors due to their excellent biocompatibility,multi-functionality,and physiochemical pr...Conductive and transparent dipeptide hydrogels are desirable building blocks to prepare soft electronic devices and wearable biosensors due to their excellent biocompatibility,multi-functionality,and physiochemical properties similar to those of body tissues.However,the preparation of such hydrogels featuring high conductivity and transparency is a huge challenge because of the hydrophobic feature of conductive additives making the doping process difficult.To overcome this issue,hydrophilic conductive polydopamine(PDA)-doped polypyrrole(PPy)nanoparticles are introduced into the dipeptide hydrogel networks to form conductive nanofibrils in situ to achieve a good level of hydrophilic templating of the hydrogel networks.This tech-nique creates a complete conductive network and allows visible light to pass through.The strategy proposed herein not only endows the dipeptide hydrogel with good conductivity and high transparency,but also provides a great potential application of conductive dipeptide hydrogels for body-adhered signal detection,as evidenced by the experimental data.展开更多
In this work, a facile strategy is proposed to construct stretchable electronics based on agarose hydrogels. The hot agarose solution is casted onto a template with patterned Ag nanowires, endowing agarose hydrogel wi...In this work, a facile strategy is proposed to construct stretchable electronics based on agarose hydrogels. The hot agarose solution is casted onto a template with patterned Ag nanowires, endowing agarose hydrogel with patterned conductive surface. After further heating treatment, Ag nanowires can be embedded into the agarose hydrogel, which improves the stability of Ag pattern and has no obvious e ffect on the conductivity of hydrogels. The agarose hydrogel with patterned Ag nanowires is certi fied to be an e ffective stretchable electrode to record the motion of joints, which has great potential applications in the field of wearable devices.展开更多
Three-dimensional （3D） bioprinting is a computer-assisted technology which precisely controls spatial position of biomaterials, growth factors and living cells, offering unprecedented possibility to bridge the gap b...Three-dimensional （3D） bioprinting is a computer-assisted technology which precisely controls spatial position of biomaterials, growth factors and living cells, offering unprecedented possibility to bridge the gap between structurally mimic tissue constructs and functional tissues or organoids. We briefly focus on diverse bioinks used in the recent progresses of biofabrication and 3D bioprinting of various tissue architectures including blood vessel, bone, cartilage, skin, heart, liver and nerve systems. This paper provides readers a guideline with the conjunction between bioinks and the targeted tissue or organ types in structuration and final functionalization of these tissue analogues. The challenges and perspectives in 3D bioprinting field are also illustrated.展开更多
With rapid economic development,resource and environment problems become more and more prominent. Chongqing Municipality, as a city focusing on industrial development in the past,has serious problem of environmental p...With rapid economic development,resource and environment problems become more and more prominent. Chongqing Municipality, as a city focusing on industrial development in the past,has serious problem of environmental pollution and scarce agricultural resources. At present,it is urgent to find out how to develop circular agriculture and coordinate economic,social,environmental development. On the basis of understanding the intension of circular agriculture,this paper built evaluation indicator system for development of circular agriculture from social and economic development,resource reduction input,resource recycling use,and resource and environment safety. Then,it made an evaluation of circular agricultural development of Chongqing Municipality by AHP approach combined with gray correlation analysis. Finally,it came up with countermeasures,including reducing input of agricultural production materials,strengthening land management,promoting scientific and technological progress,and improving policy systems.展开更多
Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur batteries.However,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kineti...Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur batteries.However,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical performance.In this study,an electrolyte with dual-additives comprising 2-fluoropyridine(2-FP)and lithium difluorobis(oxalato)phosphate(LiDFBOP)was used to improve the performance of Li||SPAN cells.2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte,leading to its prior reduction.A LiF-rich film can be formed on the electrode,effectively improving the stability of the electrolyte-electrode interfaces and prolonging the life.Simultaneously,LiDFBOP could form an electrolyte-electrode interface film containing a large amount of Li_(x)PO_(y)F_(z) species,compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode interface.Hence,an electrode-interface film with good chemical stability and high Li^(+) transport was established by LiF and Li_(x)PO_(y)F_(z)-rich species.The Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5%after 200 cycles at 1.0 C,25℃,comparing to 56.2%capacity retention without additives.Moreover,the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C,comparing to only 813.5 mAh/g using electrolyte without additives.Our results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.展开更多
Silicon is considered as one of the most promising anodes for Li-ion batteries(LIBs), but it is limited for commercial applications by the critical issue of large volume expansion during the lithiation. In this work, ...Silicon is considered as one of the most promising anodes for Li-ion batteries(LIBs), but it is limited for commercial applications by the critical issue of large volume expansion during the lithiation. In this work, the structure of silicon/carbon(Si/C) particles on graphene sheets(Si/C–G) was obtained to solve the issue by using the void space of Si/C particles and graphene. Si/C–G material was from Si/PDA-GO that silicon particles was coated by polydopamine(PDA) and reacted with oxide graphene(GO). The Si/C–G material have good cycling performance as the stability of the structure during the lithiation/dislithiation.The Si/C–G anode materials exhibited high reversible capacity of 1910.5 mA h g^(-1) and 1196.1 mA h g^(-1) after 700 cycles at 357.9 m A g^(-1), and have good rate property of 507.2 mA h g^(-1) at high current density,showing significantly improved commercial viability of silicon electrodes in high-energy-density LIBs.展开更多
The friction and wear behavior of resin/graphite composite has been investigated using a pin-on-disc configuration under dry sliding condition. The results showed that the resin/graphite composite exhibited much bette...The friction and wear behavior of resin/graphite composite has been investigated using a pin-on-disc configuration under dry sliding condition. The results showed that the resin/graphite composite exhibited much better mechanical and tribological properties compared with the unimpregnated graphite. The friction coefficient was reduced by addition of furan resin, which could also prevent the'dusting' wear at loads more than 15 MPa. The steady and lubricated transfer film was easily formed on the counterpart surface due to the interaction of furan resin and wear debris of graphite, which was useful to reduce the wear rate of the resin/graphite composite. The composite is highly promising for mechanical sealing application and can be used at high load for long time sliding.展开更多
In recent years,short peptide self-assembled materials,prepared under the control of the thermolysin catalyst,have been investigated extensively and shown to acquire various morphologies and functions as building bloc...In recent years,short peptide self-assembled materials,prepared under the control of the thermolysin catalyst,have been investigated extensively and shown to acquire various morphologies and functions as building blocks for a wide range of biomaterials and device applications.However,the role played by thermolysin in this enzymatically triggered peptide self-assembly is still ambiguous.Herein,we designed a series of Fmoc-dipeptide amphiphiles to explore the catalytic role of thermolysin.展开更多
基金the Beijing Municipal Natural Science Foundation (No. 7212206)the National Natural Science Foundation of China (Nos. 21774132, 22072155, 22002170, 21571025, and 21601025)Project of Young Science and Technology Star of Dalian (No. 2017RQ156).
文摘Conductive and transparent dipeptide hydrogels are desirable building blocks to prepare soft electronic devices and wearable biosensors due to their excellent biocompatibility,multi-functionality,and physiochemical properties similar to those of body tissues.However,the preparation of such hydrogels featuring high conductivity and transparency is a huge challenge because of the hydrophobic feature of conductive additives making the doping process difficult.To overcome this issue,hydrophilic conductive polydopamine(PDA)-doped polypyrrole(PPy)nanoparticles are introduced into the dipeptide hydrogel networks to form conductive nanofibrils in situ to achieve a good level of hydrophilic templating of the hydrogel networks.This tech-nique creates a complete conductive network and allows visible light to pass through.The strategy proposed herein not only endows the dipeptide hydrogel with good conductivity and high transparency,but also provides a great potential application of conductive dipeptide hydrogels for body-adhered signal detection,as evidenced by the experimental data.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(Project No.21774132,21703253,21877052,31700706)Natural Science Foundation for Distinguished Young Scholars of Jiangsu Province(BK20180030)the Fundamental Research Funds for the Central Universities(JUSRP51712B)and Open Funding Project of the State Key Laboratory of Biochemical Engineering(No.2019KF-02).
文摘In this work, a facile strategy is proposed to construct stretchable electronics based on agarose hydrogels. The hot agarose solution is casted onto a template with patterned Ag nanowires, endowing agarose hydrogel with patterned conductive surface. After further heating treatment, Ag nanowires can be embedded into the agarose hydrogel, which improves the stability of Ag pattern and has no obvious e ffect on the conductivity of hydrogels. The agarose hydrogel with patterned Ag nanowires is certi fied to be an e ffective stretchable electrode to record the motion of joints, which has great potential applications in the field of wearable devices.
基金The authors acknowledge financial support from the National Natural Science Foundation of China （Project No. 21703253, 21774132, 21644007） and the Talent Fund of the Recruit- ment Program of Global Youth Experts.
文摘Three-dimensional （3D） bioprinting is a computer-assisted technology which precisely controls spatial position of biomaterials, growth factors and living cells, offering unprecedented possibility to bridge the gap between structurally mimic tissue constructs and functional tissues or organoids. We briefly focus on diverse bioinks used in the recent progresses of biofabrication and 3D bioprinting of various tissue architectures including blood vessel, bone, cartilage, skin, heart, liver and nerve systems. This paper provides readers a guideline with the conjunction between bioinks and the targeted tissue or organ types in structuration and final functionalization of these tissue analogues. The challenges and perspectives in 3D bioprinting field are also illustrated.
基金Supported by Social Science Planning Project of Chongqing(2011YBGL120)National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2012BAD14B18)Ph.D.Foundation Project of Southwest University(swu1209338)
文摘With rapid economic development,resource and environment problems become more and more prominent. Chongqing Municipality, as a city focusing on industrial development in the past,has serious problem of environmental pollution and scarce agricultural resources. At present,it is urgent to find out how to develop circular agriculture and coordinate economic,social,environmental development. On the basis of understanding the intension of circular agriculture,this paper built evaluation indicator system for development of circular agriculture from social and economic development,resource reduction input,resource recycling use,and resource and environment safety. Then,it made an evaluation of circular agricultural development of Chongqing Municipality by AHP approach combined with gray correlation analysis. Finally,it came up with countermeasures,including reducing input of agricultural production materials,strengthening land management,promoting scientific and technological progress,and improving policy systems.
基金financial support from the National Natural Science Foundation of China(Nos.52072378,22209189)the National Key R&D Program of China(No.2022YFB3803400)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA22010602 and 2022YFB3803400)Shenyang Science and Technology Program(No.22-322-3-19)。
文摘Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur batteries.However,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical performance.In this study,an electrolyte with dual-additives comprising 2-fluoropyridine(2-FP)and lithium difluorobis(oxalato)phosphate(LiDFBOP)was used to improve the performance of Li||SPAN cells.2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte,leading to its prior reduction.A LiF-rich film can be formed on the electrode,effectively improving the stability of the electrolyte-electrode interfaces and prolonging the life.Simultaneously,LiDFBOP could form an electrolyte-electrode interface film containing a large amount of Li_(x)PO_(y)F_(z) species,compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode interface.Hence,an electrode-interface film with good chemical stability and high Li^(+) transport was established by LiF and Li_(x)PO_(y)F_(z)-rich species.The Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5%after 200 cycles at 1.0 C,25℃,comparing to 56.2%capacity retention without additives.Moreover,the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C,comparing to only 813.5 mAh/g using electrolyte without additives.Our results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.
基金financially supported by the National Key R&D Program of China (2021YFA1500800)the National Natural Science Foundation of China (51825204, 52072377, and 52188101)+2 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2020192)the Natural Science Foundation of Liaoning Province (2021MS-014)the financial support from the New Cornerstone Science Foundation through the XPLORER PRIZE
文摘离子液体(ILs)改性固体催化剂是一种构筑高效电催化界面的方法。为了研究ILs阳离子在催化剂中Pt表面对燃料电池中氧还原反应(ORR)性能的影响,本研究自主合成了两种疏水质子型ILs ([EIM][NTf_(2)],[BIM][NTf_(2)])和两种疏水非质子型ILs([EMIM][NTf_(2)],[BMIM][NTf_(2)]),并对商业化Pt/C进行改性。在本研究采用的咪唑类疏水ILs中,质子型ILs改性催化剂的ORR活性均高于非质子型ILs改性催化剂,其中,由1-丁基咪唑双(三氟甲磺酰)亚胺改性后的催化剂([BIM][NTf_(2)]@Pt/C)活性最高。在酸性半电池中ORR半波电位高达0.913 V (vs.RHE),质量活性提升至商业化Pt/C的1.73倍,比活性提升至商业化Pt/C的3倍,同时达到5000圈循环后半波电位仅下降12 mV,性能仍高于商业化Pt/C。进一步材料表征和电化学测试表明,[BIM][NTf_(2)]@Pt/C电催化活性的增强归因于该ILs可增多Pt表面参与反应活性位点、强化Pt表面质子及质量传递,并可有效抑制Pt纳米颗粒溶解,从而起到了增强ORR活性及稳定性的作用。本研究深化了对ILs@Pt界面协同电催化机理的认识,为设计下一代高效燃料电池催化剂提供了理论依据。
基金financial support from National Natural Science Foundation of China(Nos.51525206,51927803,51902316)National Key R&D Program of China(2016YFA0200102 and 2016YFB0100100)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010602)Liaoning Revitalization Talents Program(No.XLYC1908015)。
文摘Silicon is considered as one of the most promising anodes for Li-ion batteries(LIBs), but it is limited for commercial applications by the critical issue of large volume expansion during the lithiation. In this work, the structure of silicon/carbon(Si/C) particles on graphene sheets(Si/C–G) was obtained to solve the issue by using the void space of Si/C particles and graphene. Si/C–G material was from Si/PDA-GO that silicon particles was coated by polydopamine(PDA) and reacted with oxide graphene(GO). The Si/C–G material have good cycling performance as the stability of the structure during the lithiation/dislithiation.The Si/C–G anode materials exhibited high reversible capacity of 1910.5 mA h g^(-1) and 1196.1 mA h g^(-1) after 700 cycles at 357.9 m A g^(-1), and have good rate property of 507.2 mA h g^(-1) at high current density,showing significantly improved commercial viability of silicon electrodes in high-energy-density LIBs.
文摘The friction and wear behavior of resin/graphite composite has been investigated using a pin-on-disc configuration under dry sliding condition. The results showed that the resin/graphite composite exhibited much better mechanical and tribological properties compared with the unimpregnated graphite. The friction coefficient was reduced by addition of furan resin, which could also prevent the'dusting' wear at loads more than 15 MPa. The steady and lubricated transfer film was easily formed on the counterpart surface due to the interaction of furan resin and wear debris of graphite, which was useful to reduce the wear rate of the resin/graphite composite. The composite is highly promising for mechanical sealing application and can be used at high load for long time sliding.
基金support from the National Natural Science Foundation of China(project no.21774132)The computation was performed at ECNU Public Platform for Innovation(001).
文摘In recent years,short peptide self-assembled materials,prepared under the control of the thermolysin catalyst,have been investigated extensively and shown to acquire various morphologies and functions as building blocks for a wide range of biomaterials and device applications.However,the role played by thermolysin in this enzymatically triggered peptide self-assembly is still ambiguous.Herein,we designed a series of Fmoc-dipeptide amphiphiles to explore the catalytic role of thermolysin.
