Indoor heating with an electrical heating cable,which has no harmful emissions to the environment,is an attractive way for radiant floor heating.To improve the heat transfer efficiency,a novel structure of the heating...Indoor heating with an electrical heating cable,which has no harmful emissions to the environment,is an attractive way for radiant floor heating.To improve the heat transfer efficiency,a novel structure of the heating cable was designed by proposing the concept of the aluminum finned sheath.The transient heat transfer model from the embedded heating cables to the floor is established to validate the feasibility of this novel cable.The effects of the fin number and shape on the cable’s temperature and heat flux distribution were analyzed.The results show that,with the specific volume of the sheath,increasing the number of fins can enhance the thermal diffusion capacity of the heating cable and reduce its temperature.Rectangular fins exhibit higher performance for heat dissipation than triangular fins due to their larger surface area.The simulation result shows that the floor temperature above the cable rises from 5°C to 22.5°C after a 2-h heating process,which was validated with experimental results.The results and suggestions can provide reference to guide the design of the heating cable.展开更多
Aerogel fiber has broad applications in thermal insulation,pollution adsorption,biomedicine,energy storage,and aerospace.However,the large-scale and continuous production of aerogel fibers remains a significant challe...Aerogel fiber has broad applications in thermal insulation,pollution adsorption,biomedicine,energy storage,and aerospace.However,the large-scale and continuous production of aerogel fibers remains a significant challenge.Wet spinning technology transforms the static sol-gel process into rapid dynamic gel fiber molding,and is the preferred spinning method for continuous molding and large-scale production of aerogel fibers.This review provides a systematic overview of the production process of wet-spun aerogel fibers and the obstacles it encounters in the forming and drying stages.It also discusses the progress of different spinning strategies in optimizing the structure and properties of aerogel fibers.Recent advances in the properties of aerogel fibers,such as thermal insulation,adsorption,and optical and electromagnetic shielding,which are affected by the structural characteristics of aerogel fibers,are presented.Finally,this review provides a brief conclusion and discusses the technical challenges and future directions for wet-spun aerogel fibers.This review is expected to offer fresh perspectives and innovative strategies for the continuous production of aerogel fibers,the development of high-performance and multifunctional aerogel fibers,and their diverse applications.展开更多
One-dimensional(1D)oxide nanofibers have attracted much attention in recent years but are still hampered by the difficulty in the expansion to 2D or 3D dimensions.Herein,ultrathin CeO_(2)/SiO_(2)nanofibers with intrig...One-dimensional(1D)oxide nanofibers have attracted much attention in recent years but are still hampered by the difficulty in the expansion to 2D or 3D dimensions.Herein,ultrathin CeO_(2)/SiO_(2)nanofibers with intriguing core-sheath structures were simply fabricated by a facile single-spinneret electrospinning method and were subsequently integrated as 2D nanofi-brous mats and 3D sponges.Introducing secondary oxide(i.e.,SiO_(2))could induce a unique fine structure and further inhibit the sintering of CeO_(2)nanocrystals,endowing the resultant dual-oxide nanofibers with high porosity,good flexibility,and enriched oxygen defects.Benefiting from the core-sheath structure and dual-oxide component,the CeO_(2)/SiO_(2)nanofibers could stabilize 2.59 nm-Pt clusters against sintering at 600℃.Once assembled into a 2D mat,the nanofibers could efficiently decrease the soot oxidation temperature by 63℃.Moreover,the core-sheath CeO_(2)/SiO_(2)nanofibers can be readily integrated with graphene nanosheets into a 3D sponge via a gas foaming protocol,showing 218.5 mg/g of adsorption capacity toward Rhodamine B molecules.This work shed lights on the versatile applications of oxide nanofibers toward clean energy ultili-zation and low-carbon development.展开更多
An adequate wide temperature electrolyte for high nickel ternary cathode is urgent to further develop high energy density batteries.Herein,a comprehensive double-salt local high-concentration sulfolane-based electroly...An adequate wide temperature electrolyte for high nickel ternary cathode is urgent to further develop high energy density batteries.Herein,a comprehensive double-salt local high-concentration sulfolane-based electrolyte(DLi)is proposed with specific sheath structure to build stable interface on the LiNi_(0.8)Co_(0.1)Mn_(0.1O2)(NCM811)cathode at wide operating temperature between−60 and 55℃.Lithium perchlorate(LiClO_(4))in combination with high concentration lithium bis-(trifluoromethanesulfonyl)imide(LiTFSI)strengthens the internal interaction between anion and cation in the solvation structure,increasing Li+transference number of the electrolyte to 0.61.Moreover,the structure and component characteristics of the passive interface layer on NCM811 are modulated,decreasing desolvation energy of Li+ions,benefiting Li+transport dynamics especially at low temperature,and also ensuring the interfacial stability at a wide operating temperature range.As a result,the cathode with DLi exhibits excellent high-temperature storage performance and high capacity retention of 80.5%in 100 cycles at 55℃.Meanwhile,the Li||NCM811 cells can deliver high discharge capacity of 160.1,136.1,and 110.3 mAh·g^(−1)under current density of 0.1 C at−20,−40,and−60℃,maintaining 84.5%,71.8%,and 58.2%of the discharge capacity at 30℃,respectively.Moreover,it enables NCM811 cathode to achieve a reversible capacity of 142.8 mAh·g^(−1)in 200 cycles at−20℃and 0.2 C.Our studies shed light on the molecular strategy of wide operational temperature electrolyte for high nickel ternary cathode.展开更多
Self-healing superhydrophobic polyvinylidene fluoride/Fe3O4@polypyrrole （F- PVDF/FeBO4@PPyx） fibers with core-sheath structure were successfully fabricated by electrospinning of a PVDF/Fe3O4 mixture and in situ chem...Self-healing superhydrophobic polyvinylidene fluoride/Fe3O4@polypyrrole （F- PVDF/FeBO4@PPyx） fibers with core-sheath structure were successfully fabricated by electrospinning of a PVDF/Fe3O4 mixture and in situ chemical oxidative polymerization of pyrrole, followed by chemical vapor deposition with fluoroalkyl silane. The F-PVDF/Fe3O4@PPy0.075 fiber film produces a superhydrophobic surface with self-healing behavior, which can repetitively and automatically restore superhydrophobicity when the surface is chemically damaged. Moreover, the maximum refection loss （Ru） of the F-PVDF/Fe304@PPy0.075 fiber film reaches -21.5 dB at 16.8 GHz and the RL below -10 dB is in the frequency range of 10.6-16.5 GHz with a thickness of 2.5 mm. The microwave absorption performance is attributed to the synergetic effect between dielectric loss and magnetic loss originating from PPy, PVDF and Fe3O4. As a consequence, preparing such F-PVDF/Fe3O4@PPyx fibers in this manner provides a simple and effective route to develop multi-functional microwave absorbing materials for practical applications.展开更多
文摘Indoor heating with an electrical heating cable,which has no harmful emissions to the environment,is an attractive way for radiant floor heating.To improve the heat transfer efficiency,a novel structure of the heating cable was designed by proposing the concept of the aluminum finned sheath.The transient heat transfer model from the embedded heating cables to the floor is established to validate the feasibility of this novel cable.The effects of the fin number and shape on the cable’s temperature and heat flux distribution were analyzed.The results show that,with the specific volume of the sheath,increasing the number of fins can enhance the thermal diffusion capacity of the heating cable and reduce its temperature.Rectangular fins exhibit higher performance for heat dissipation than triangular fins due to their larger surface area.The simulation result shows that the floor temperature above the cable rises from 5°C to 22.5°C after a 2-h heating process,which was validated with experimental results.The results and suggestions can provide reference to guide the design of the heating cable.
基金financially by the National Natural Science Foundation of China(52003191)Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20221539)Science and Technology Program of Jiangsu Administration for Market Regulation(KJ2024013)Fuzhou Changle District Major Science and Technology Project:'Leading the Charge with Open Competition'(CLJBGS20220001).
文摘Aerogel fiber has broad applications in thermal insulation,pollution adsorption,biomedicine,energy storage,and aerospace.However,the large-scale and continuous production of aerogel fibers remains a significant challenge.Wet spinning technology transforms the static sol-gel process into rapid dynamic gel fiber molding,and is the preferred spinning method for continuous molding and large-scale production of aerogel fibers.This review provides a systematic overview of the production process of wet-spun aerogel fibers and the obstacles it encounters in the forming and drying stages.It also discusses the progress of different spinning strategies in optimizing the structure and properties of aerogel fibers.Recent advances in the properties of aerogel fibers,such as thermal insulation,adsorption,and optical and electromagnetic shielding,which are affected by the structural characteristics of aerogel fibers,are presented.Finally,this review provides a brief conclusion and discusses the technical challenges and future directions for wet-spun aerogel fibers.This review is expected to offer fresh perspectives and innovative strategies for the continuous production of aerogel fibers,the development of high-performance and multifunctional aerogel fibers,and their diverse applications.
基金This work was financially supported by the Natural Science Foundation of China(21975042)the Project of Six Talents Climax Foundation of Jiangsu(XCL-082)+3 种基金Innovation Platform Project Supported by Jiangsu Province(6907041203)the Young Talent Lifting Project of Jiangsu Science and Technology Associate,the Fundamental Research Funds for the Central Universities,the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_0261)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe open project of State Key Laboratory of Physical Chemistry of Solid Surfaces in Xiamen University.
文摘One-dimensional(1D)oxide nanofibers have attracted much attention in recent years but are still hampered by the difficulty in the expansion to 2D or 3D dimensions.Herein,ultrathin CeO_(2)/SiO_(2)nanofibers with intriguing core-sheath structures were simply fabricated by a facile single-spinneret electrospinning method and were subsequently integrated as 2D nanofi-brous mats and 3D sponges.Introducing secondary oxide(i.e.,SiO_(2))could induce a unique fine structure and further inhibit the sintering of CeO_(2)nanocrystals,endowing the resultant dual-oxide nanofibers with high porosity,good flexibility,and enriched oxygen defects.Benefiting from the core-sheath structure and dual-oxide component,the CeO_(2)/SiO_(2)nanofibers could stabilize 2.59 nm-Pt clusters against sintering at 600℃.Once assembled into a 2D mat,the nanofibers could efficiently decrease the soot oxidation temperature by 63℃.Moreover,the core-sheath CeO_(2)/SiO_(2)nanofibers can be readily integrated with graphene nanosheets into a 3D sponge via a gas foaming protocol,showing 218.5 mg/g of adsorption capacity toward Rhodamine B molecules.This work shed lights on the versatile applications of oxide nanofibers toward clean energy ultili-zation and low-carbon development.
基金supported by the National Natural Science Foundation of China(Nos.52172180 and 51872026)the National Key R&D Program of China(No.2018YFB0104300).
文摘An adequate wide temperature electrolyte for high nickel ternary cathode is urgent to further develop high energy density batteries.Herein,a comprehensive double-salt local high-concentration sulfolane-based electrolyte(DLi)is proposed with specific sheath structure to build stable interface on the LiNi_(0.8)Co_(0.1)Mn_(0.1O2)(NCM811)cathode at wide operating temperature between−60 and 55℃.Lithium perchlorate(LiClO_(4))in combination with high concentration lithium bis-(trifluoromethanesulfonyl)imide(LiTFSI)strengthens the internal interaction between anion and cation in the solvation structure,increasing Li+transference number of the electrolyte to 0.61.Moreover,the structure and component characteristics of the passive interface layer on NCM811 are modulated,decreasing desolvation energy of Li+ions,benefiting Li+transport dynamics especially at low temperature,and also ensuring the interfacial stability at a wide operating temperature range.As a result,the cathode with DLi exhibits excellent high-temperature storage performance and high capacity retention of 80.5%in 100 cycles at 55℃.Meanwhile,the Li||NCM811 cells can deliver high discharge capacity of 160.1,136.1,and 110.3 mAh·g^(−1)under current density of 0.1 C at−20,−40,and−60℃,maintaining 84.5%,71.8%,and 58.2%of the discharge capacity at 30℃,respectively.Moreover,it enables NCM811 cathode to achieve a reversible capacity of 142.8 mAh·g^(−1)in 200 cycles at−20℃and 0.2 C.Our studies shed light on the molecular strategy of wide operational temperature electrolyte for high nickel ternary cathode.
基金The work is supported by the National Natural Sdence Foundation of China （Nos. 51273008, 51473008, and 21103006）, Beijing Natural Science Foundation （No. 2132030） and the National Basic Research Program of China （No. 2012CB933200）.
文摘Self-healing superhydrophobic polyvinylidene fluoride/Fe3O4@polypyrrole （F- PVDF/FeBO4@PPyx） fibers with core-sheath structure were successfully fabricated by electrospinning of a PVDF/Fe3O4 mixture and in situ chemical oxidative polymerization of pyrrole, followed by chemical vapor deposition with fluoroalkyl silane. The F-PVDF/Fe3O4@PPy0.075 fiber film produces a superhydrophobic surface with self-healing behavior, which can repetitively and automatically restore superhydrophobicity when the surface is chemically damaged. Moreover, the maximum refection loss （Ru） of the F-PVDF/Fe304@PPy0.075 fiber film reaches -21.5 dB at 16.8 GHz and the RL below -10 dB is in the frequency range of 10.6-16.5 GHz with a thickness of 2.5 mm. The microwave absorption performance is attributed to the synergetic effect between dielectric loss and magnetic loss originating from PPy, PVDF and Fe3O4. As a consequence, preparing such F-PVDF/Fe3O4@PPyx fibers in this manner provides a simple and effective route to develop multi-functional microwave absorbing materials for practical applications.
