To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and...To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and decrease the energy cost further,we report a new carbon capture approach using a 2-methylimidazole(mIm)aqueous solution.The properties and sorption behaviors of this approach have been experimentally investigated.The results show that the mIm solution has higher CO_(2) absorption capacity under relatively higher equilibrium pressure(>130 kPa)and lower desorption heat than the methyldiethanolamine solution.91.6%sorption capacity of mIm solution can be recovered at 353.15 K and 80 kPa.The selectivity for CO_(2)/N_(2) and CO_(2)/CH_(4) can reach an exceptional 7609 and 4324,respectively.Furthermore,the pilot-scale tests were also performed,and the results demonstrate that more than 98%of CO_(2) in the feed gas could be removed and cyclic absorption capacity can reach 1 mol·L^(-1).This work indicates that mIm is an excellent alternative to alkanolamines for carbon capture in the industry.展开更多
Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-co...Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.展开更多
This paper provides a survey of foreign investment activity in China ＂s high-technology manufacturing industry. In addition, we closely examine the relationship between industrial policy, foreign investment and China...This paper provides a survey of foreign investment activity in China ＂s high-technology manufacturing industry. In addition, we closely examine the relationship between industrial policy, foreign investment and China ＂s high-technology export success using the development of an indigenous integrated circuits industry as a case study. This paper finds that China＇s efforts to raise the productivity and innovative capacity of indigenous enterprises is consistent with rising domestic shares of high-technology assets and profits. Nevertheless, foreign-funded enterprises remain the source of most high-technology manufactured exports, primarily from wholly foreign-owned firms. In sum, despite indigenous development, Chinese high-technology manufacturing and exports remain deeply tied to foreign investment.展开更多
Single-nucleotide variants(SNVs)are crucial in disease development,but their accurate detection is challenging due to their low abundance and interference from wild-type targets.Although nucleic acid analogs like pept...Single-nucleotide variants(SNVs)are crucial in disease development,but their accurate detection is challenging due to their low abundance and interference from wild-type targets.Although nucleic acid analogs like peptide nucleic acids(PNAs)have been used for SNV detection,they often lack programmable sensitivity and specificity due to poorly calculated thermodynamics and kinetics.Here,we present a computational method for calculating the stacking energy of PNA and DNA hybrids,leveraging nearest neighbor parameters.Validation against experimental data from 16 sequences under varied hybridization conditions yielded good agreement using Bland-Altman analysis,with all data points falling within the confidence interval.Our findings indicate that PNA-DNA hybridization is thermodynamically more stable and exhibits kinetics 140-fold faster than DNA-DNA hybridization for identical sequences.Utilizing this computational framework,we designed PNA toehold probes,which were screened via simulations and experiments.This combined approach facilitated the identification of highly sensitive and specific PNA toehold probes for single point mutation detection via strand displacement reaction.Our results demonstrate the successful application of PNA toehold probes for detecting point mutations with high sensitivity and specificity,achieving a selective amplification of approximately 200-fold for variants with a variant allele frequency(VAF)of 0.5%using quantitative polymerase chain reaction.展开更多
A practical fixed-time adaptive fuzzy control strategy is investigated for uncertain nonlinear systems with time-varying asymmetric constraints and input quantization. To overcome the difficulties of designing control...A practical fixed-time adaptive fuzzy control strategy is investigated for uncertain nonlinear systems with time-varying asymmetric constraints and input quantization. To overcome the difficulties of designing controllers under the state constraints, a unified barrier function approach is employed to construct a coordinate transformation that maps the original constrained system to an equivalent unconstrained one, thus relaxing the time-varying asymmetric constraints upon system states and avoiding the feasibility check condition typically required in the traditional barrier Lyapunov function based control approach. Meanwhile, the “explosion of complexity” problem in the traditional backstepping approach arising from repeatedly derivatives of virtual controllers is solved by using the command filter method. It is verified via the fixed-time Lyapunov stability criterion that the system output can track a desired signal within a small error range in a predetermined time, and that all system states remain in the constraint range. Finally, two simulation examples are offered to demonstrate the effectiveness of the proposed strategy.展开更多
基金The financial supports received from National Natural Science Foundation of China (U20B6005, 22178378, and 22127812)
文摘To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and decrease the energy cost further,we report a new carbon capture approach using a 2-methylimidazole(mIm)aqueous solution.The properties and sorption behaviors of this approach have been experimentally investigated.The results show that the mIm solution has higher CO_(2) absorption capacity under relatively higher equilibrium pressure(>130 kPa)and lower desorption heat than the methyldiethanolamine solution.91.6%sorption capacity of mIm solution can be recovered at 353.15 K and 80 kPa.The selectivity for CO_(2)/N_(2) and CO_(2)/CH_(4) can reach an exceptional 7609 and 4324,respectively.Furthermore,the pilot-scale tests were also performed,and the results demonstrate that more than 98%of CO_(2) in the feed gas could be removed and cyclic absorption capacity can reach 1 mol·L^(-1).This work indicates that mIm is an excellent alternative to alkanolamines for carbon capture in the industry.
基金supports received from the National Natural Science Foundation of China (21776301,21636009)are gratefully acknowledged.
文摘Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.
文摘This paper provides a survey of foreign investment activity in China ＂s high-technology manufacturing industry. In addition, we closely examine the relationship between industrial policy, foreign investment and China ＂s high-technology export success using the development of an indigenous integrated circuits industry as a case study. This paper finds that China＇s efforts to raise the productivity and innovative capacity of indigenous enterprises is consistent with rising domestic shares of high-technology assets and profits. Nevertheless, foreign-funded enterprises remain the source of most high-technology manufactured exports, primarily from wholly foreign-owned firms. In sum, despite indigenous development, Chinese high-technology manufacturing and exports remain deeply tied to foreign investment.
基金support from the National Key R&D Program of China(2021YFF1200300)the National Natural Science Foundation of China(Nos.22174094,22274097)+1 种基金the Fundamental Research Funds for the Central Universities(YG2023QNA33)Young Leading Scientists Cultivation Plan supportedby ShanghaiMunicipal Education Commission(ZXWH1082101).
文摘Single-nucleotide variants(SNVs)are crucial in disease development,but their accurate detection is challenging due to their low abundance and interference from wild-type targets.Although nucleic acid analogs like peptide nucleic acids(PNAs)have been used for SNV detection,they often lack programmable sensitivity and specificity due to poorly calculated thermodynamics and kinetics.Here,we present a computational method for calculating the stacking energy of PNA and DNA hybrids,leveraging nearest neighbor parameters.Validation against experimental data from 16 sequences under varied hybridization conditions yielded good agreement using Bland-Altman analysis,with all data points falling within the confidence interval.Our findings indicate that PNA-DNA hybridization is thermodynamically more stable and exhibits kinetics 140-fold faster than DNA-DNA hybridization for identical sequences.Utilizing this computational framework,we designed PNA toehold probes,which were screened via simulations and experiments.This combined approach facilitated the identification of highly sensitive and specific PNA toehold probes for single point mutation detection via strand displacement reaction.Our results demonstrate the successful application of PNA toehold probes for detecting point mutations with high sensitivity and specificity,achieving a selective amplification of approximately 200-fold for variants with a variant allele frequency(VAF)of 0.5%using quantitative polymerase chain reaction.
基金Project supported by Institutional Fund Projects(No.IFPIP:131-611-1443)。
文摘A practical fixed-time adaptive fuzzy control strategy is investigated for uncertain nonlinear systems with time-varying asymmetric constraints and input quantization. To overcome the difficulties of designing controllers under the state constraints, a unified barrier function approach is employed to construct a coordinate transformation that maps the original constrained system to an equivalent unconstrained one, thus relaxing the time-varying asymmetric constraints upon system states and avoiding the feasibility check condition typically required in the traditional barrier Lyapunov function based control approach. Meanwhile, the “explosion of complexity” problem in the traditional backstepping approach arising from repeatedly derivatives of virtual controllers is solved by using the command filter method. It is verified via the fixed-time Lyapunov stability criterion that the system output can track a desired signal within a small error range in a predetermined time, and that all system states remain in the constraint range. Finally, two simulation examples are offered to demonstrate the effectiveness of the proposed strategy.
