Copper is a microelement with important physiological functions in the body.However,the excess copper ion(Cu^(2+))may cause severe health problems,such as hair cell apoptosis and the resultant hearing loss.Therefore,t...Copper is a microelement with important physiological functions in the body.However,the excess copper ion(Cu^(2+))may cause severe health problems,such as hair cell apoptosis and the resultant hearing loss.Therefore,the assay of Cu^(2+)is important.We integrate ionic imprinting technology(IIT)and structurally colored hydrogel beads to prepare chitosan-based ionically imprinted hydrogel beads(IIHBs)as a low-cost and high-specificity platform for Cu^(2+)detection.The IIHBs have a macroporous microstructure,uniform size,vivid structural color,and magnetic responsiveness.When incubated in solution,IIHBs recognize Cu^(2+)and exhibit a reflective peak change,thereby achieving label-free detection.In addition,benefiting from the IIT,the IIHBs display good specificity and selectivity and have an imprinting factor of 19.14 at 100μmol·L^(-1).These features indicated that the developed IIHBs are promising candidates for Cu^(2+)detection,particularly for the prevention of hearing loss.展开更多
In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and exper...In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and experimental data have shown that the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure has a stronger light absorption capacity and larger specific surface area than pure g-C_(3)N_(4) NCs and g-C_(3)N_(4) nanosheets(NSs),and the presence of the co-catalysts 1T'-MoS_(2) can effectively inhibit the photoinduced carrier recombination.As a result,the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure with an optimum 1T'-MoS_(2) loading of 9 wt%displays a hydrogen evolution rate of 1949 mmol h^(-1) g^(-1),162.4,1.2,1.5,1.6 and 1.2 times than pure g-C_(3)N_(4) NCs(12 mmol h^(-1) g^(-1)),Pt/g-C_(3)N_(4) NCs(1615 mmol h^(-1) g^(-1))and Pt/g-C_(3)N_(4) nanosheets(NSs,1297 mmol h^(-1) g^(-1)),1T'-MoS_(2)/g-C_(3)N_(4) nanosheets(1216 mmol h^(-1) g^(-1))and 2H-MoS_(2)/g-C_(3)N_(4) nanocages(1573 mmol h^(-1) g^(-1)),respectively,and exhibits excellent cycle stability.Therefore,1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure is a suitable photocatalyst for green H_(2) production.展开更多
The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The ...The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The photocatalytic reduction of N_(2)is expected to achieve clean and sustainable NH_(3)production by using clean solar energy.To date,the new photocatalysts for photocatalytic reduction of N_(2)to NH_(3)at room temperature and atmospheric pressure have not been fully developed.The major challenge is to achieve high light-absorption efficiency,conversion efficiency,and stability of photocatalysts.Herein,the methods for measuring produced NH_(3)are compared,and the problems related to possible NH_(3)pollution in photocatalytic systems are mentioned to provide accurate ideas for measuring photocatalytic efficiency.The recent progress of nitrogen reduction reaction(NRR)photocatalysts at ambient temperature and pressure is summarized by introducing charge transfer,migration,and separation in photocatalytic NRR,which provides a guidance for the selection of future photocatalyst.More importantly,we introduce the latest research strategies of photocatalysts in detail,which can guide the preparation and design of photocatalysts with high NRR activity.展开更多
2D-layered graphitic carbon nitride(g-C_(3)N_(4))is regarded as a great prospect as a photocatalyst for H_(2)generation.However,g-C_(3)N_(4)’s photocatalytic hydrogen evolution(HER)activity is significantly restricte...2D-layered graphitic carbon nitride(g-C_(3)N_(4))is regarded as a great prospect as a photocatalyst for H_(2)generation.However,g-C_(3)N_(4)’s photocatalytic hydrogen evolution(HER)activity is significantly restricted by the recombination of photocarriers.We find that cobalt sulfide(CoS_(2))as a cocatalyst can promote g-C_(3)N_(4)nanosheets(NSs)to realize very efficient photocatalytic H_(2)generation.The prepared CoS_(2)/g-C_(3)N_(4)hybrids display highly boosted photocatalytic H_(2)generation performance and outstanding cycle stability.The optimized 7%-CoS_(2)/g-C_(3)N_(4)hybrids show a much improved photocatalytic H_(2)generation rate of 36.2μmol-1h-1,which is about 180 times as much as bare g-C_(3)N_(4)(0.2μmol-1h-1).In addition,the apparent quantum efficiency(AQE)of all the samples was computed under light atλ=370 nm,in which the AQE of 7%-CoS_(2)/g-C_(3)N_(4)hybrids is up to 5.72%.The experimental data and the DFT calculation suggest that the CoS_(2)/g-C_(3)N_(4)hybrid’s excellent HER activity is attributable to the lower overpotential and the smaller Co-H bond activation energy for HER.Accordingly,the CoS_(2)cocatalyst loading effectively boosts the photocatalytic performance of g-C_(3)N_(4)for H_(2)evolution.The project promotes fast development of high-efficiency photocatalysts and low-cost for photocatalytic H_(2)generation.展开更多
The large-scale deployment of carbon capture and storage(CCS)is becoming increasingly urgent in the global path toward net zero emissions;however,global CCS deployment is significantly lagging behind its expected cont...The large-scale deployment of carbon capture and storage(CCS)is becoming increasingly urgent in the global path toward net zero emissions;however,global CCS deployment is significantly lagging behind its expected contribution to greenhouse gas emission reduction.Reviewing and learning from the examples and history of successful CCS practices in advanced countries will help other countries,including China,to promote and deploy CCS projects using scientific methods.This paper shows that the establishment of major science and technology CCS infrastructures in advanced countries has become the main source of CCS technological innovation,cost reduction,risk reduction,commercial promotion,and talent training in the development and demonstration of key CCS technologies.Sound development of CCS requires a transition from pilot-scale science and technology infrastructures to large-scale commercial infrastructures,in addition to incentive policies;otherwise,it will be difficult to overcome the technical barriers between small-scale demonstrations and the implementation of million-tonne-scale CCS and ten-million-tonne-scale CCS hubs.Geological CO_(2) storage is the ultimate goal of CCS projects and the driving force of CO_(2) capture.Further improving the accuracy of technologies for the measurement,monitoring,and verification(MMV)of CO_(2) storage capacity,emission reduction,and safety remains a problem for geological storage.CO_(2) storage in saline aquifers can better couple multiple carbon emission sources and is currently a priority direction for development.Reducing the energy consumption of lowconcentration CO_(2) capture and the depletion of chemical absorbents and improving the operational efficiency and stability of post-combustion CO_(2) capture systems have become the key constraints to largescale CCS deployment.Enhanced oil recovery(EOR)is also important in order for countries to maximize fossil fuel extraction instead of importing oil from less environmentally friendly oil-producing countries.展开更多
Hydrogen(H2)production is a latent feasibility of renewable clean energy.The industrial H2 production is obtained from reforming of natural gas,which consumes a large amount of nonrenewable energy and simultaneously p...Hydrogen(H2)production is a latent feasibility of renewable clean energy.The industrial H2 production is obtained from reforming of natural gas,which consumes a large amount of nonrenewable energy and simultaneously produces greenhouse gas carbon dioxide.Electrochemical water splitting is a promising approach for the H2 production,which is sustainable and pollution-free.Therefore,developing efficient and economic technologies for electrochemical water splitting has been an important goal for researchers around the world.The utilization of green energy systems to reduce overall energy consumption is more important for H2 production.Harvesting and converting energy from the environment by different green energy systems for water splitting can efficiently decrease the external power consumption.A variety of green energy systems for efficient producing H2,such as two-electrode electrolysis of water,water splitting driven by photoelectrode devices,solar cells,thermoelectric devices,triboelectric nanogenerator,pyroelectric device or electrochemical water-gas shift device,have been developed recently.In this review,some notable progress made in the different green energy cells for water splitting is discussed in detail.We hoped this review can guide people to pay more attention to the development of green energy system to generate pollution-free H2 energy,which will realize the whole process of H2 production with low cost,pollution-free and energy sustainability conversion.展开更多
This study explored the molecular diversity and biogeography of benthic ciliates in Chinese marginal seas, the Bohai Sea(BHS), North Yellow Sea(NYS) and South Yellow Sea(SYS). From a previous 18S rRNA gene pyrosequenc...This study explored the molecular diversity and biogeography of benthic ciliates in Chinese marginal seas, the Bohai Sea(BHS), North Yellow Sea(NYS) and South Yellow Sea(SYS). From a previous 18S rRNA gene pyrosequencing dataset of the benthic microeukaryotes, we retrieved the sequences affiliated with phylum Ciliophora and analyzed alpha and beta diversities of ciliate communities. We found that BHS had the highest ciliate operational taxonomic unit(OTU) richness than NYS and SYS, whereas the richness was not significantly different between summer and winter. Among all the measured environmental variables, water depth showed consistently the strongest correlations with alpha diversities. Overall, the class Spirotrichea(mostly Choreotrichia and unassigned lineages within the class) dominated the communities in terms of both relative proportion of sequences(77.0%) and OTU richness(66.5%). OTU-level ciliate community structure was significant different among the three basins, but not between the seasons. Structurally, significant differences in relative proportion among the basins were detected for the class Litostomatea, but not for other classes. Partial Mantel tests demonstrated that water depth difference was more important than geographic and environment distances in shaping the community structure of benthic ciliates in the studied area. About 60% OTUs were not assigned at a class or order level and at least 45% OTUs shared a sequence similarity no more than 97% with the described species, indicating a great potential for ciliate species discovery in the offshore sediments. Compared with previous morphology-based surveys, the spatial pattern of ciliate diversity(decreasing from NYS to SYS) is also identified in the present study. Nevertheless, structurally, the dominant class appeared to be Spirotrichea in the sequencing dataset, which differs from previous morphology-based results(dominance of classes Prostomatea and Karyorelictea in biomass). The potential causes for the discrepancies between molecular and morphological findings are also discussed.展开更多
Cauliflower is an important variety of Brassica oleracea and is planted worldwide.Here,the high-quality genome sequence of cauliflower was reported.The assembled cauliflower genome was 584.60 Mb in size,with a contig ...Cauliflower is an important variety of Brassica oleracea and is planted worldwide.Here,the high-quality genome sequence of cauliflower was reported.The assembled cauliflower genome was 584.60 Mb in size,with a contig N50 of 2.11 Mb,and contained 47,772 genes;56.65%of the genome was composed of repetitive sequences.Among these sequences,long terminal repeats(LTRs)were the most abundant(32.71%of the genome),followed by transposable elements(TEs)(12.62%).Comparative genomic analysis confirmed that after an ancient paleohexaploidy(γ)event,cauliflower underwent two whole-genome duplication(WGD)events shared with Arabidopsis and an additional whole-genome triplication(WGT)event shared with other Brassica species.The present cultivated cauliflower diverged from the ancestral B.oleracea species~3.0 million years ago(Mya).The speciation of cauliflower(~2.0 Mya)was later than that of B.oleracea L.var.capitata(approximately 2.6 Mya)and other Brassica species(over 2.0 Mya).Chromosome no.03 of cauliflower shared the most syntenic blocks with the A,B,and C genomes of Brassica species and its eight other chromosomes,implying that chromosome no.03 might be the most ancient one in the cauliflower genome,which was consistent with the chromosome being inherited from the common ancestor of Brassica species.In addition,2,718 specific genes,228 expanded genes,2 contracted genes,and 1,065 positively selected genes in cauliflower were identified and functionally annotated.These findings provide new insights into the genomic diversity of Brassica species and serve as a valuable reference for molecular breeding of cauliflower.展开更多
An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great ...An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great potential for air-coupled applications,mainly because of their low acoustic impedance.In this study,an air-coupled CMUT array is designed as an air parametric array.A hexagonal array is proposed to improve the directivity of the sound generated.A finite element model of the CMUT is established in COMSOL software to facilitate the choice of appropriate structural parameters of the CMUT cell.The CMUT array is then fabricated by a wafer bonding process with high consistency.The performances of the CMUT are tested to verify the accuracy of the finite element analysis.By optimizing the component parameters of the bias-T circuit used for driving the CMUT,DC and AC voltages can be effectively applied to the top and bottom electrodes of the CMUT to provide efficient ultrasound transmission.Finally,the prepared hexagonal array is successfully used to conduct preliminary experiments on its application as an air parametric array.展开更多
Recently, in response to the major challenges in energy development and environmental issues, tremendous efforts are being devoted to developing electrochemical energy storage devices based on green sustainable resour...Recently, in response to the major challenges in energy development and environmental issues, tremendous efforts are being devoted to developing electrochemical energy storage devices based on green sustainable resources. As a class of green materials, nanocellulose(NC) has received extensive attention. In this review, we summarize the research progress of NC derived materials in electrochemical energy storage. Specifically, we first introduce various synthesis methods based on NC and the pretreatment process to increase the conductivity. Then we focus on the specific application of NC in electrochemical energy storage devices. Finally, we summarize the previously reported work and put forward views on the further development of NC in the field of electrochemical energy storage.展开更多
The link of hedgehog (Hh) signaling activation to human cancer and synthesis of a variety of Hh signaling inhibitors raise great expectation that inhibiting Hh signaling may be effective in human cancer treatment. Cyc...The link of hedgehog (Hh) signaling activation to human cancer and synthesis of a variety of Hh signaling inhibitors raise great expectation that inhibiting Hh signaling may be effective in human cancer treatment. Cyclopamine (Cyc), an alkaloid from the Veratrum plant, is a specific natural product inhibitor of the Hh pathway that acts by targeting smoothened (SMO) protein. However, its poor solubility, acid sensitivity, and weak potency relative to other Hh antagonists prevent the clinical development of Cyc as a therapeutic agent. Here, we report properties of cyclopamine tartrate salt (CycT) and its activities in Hh signaling-mediated cancer in vitro and in vivo. Unlike Cyc, CycT is water soluble (5-10 mg/mL). The median lethal dose (LD50) of CycT was 62.5 mg/kg body weight compared to 43.5 mg/kg for Cyc, and the plasma half-life (T1/2) of CycT was not significantly different from that of Cyc. We showed that CycT had a higher inhibitory activity for Hh signaling-dependent motor neuron differentiation than did Cyc (IC50 = 50 nmol/L for CycT vs. 300 nmol/L for Cyc). We also tested the antitumor effectiveness of these Hh inhibitors using two mouse models of basal cell carcinomas (K14cre:Ptch1neo/neo and K14cre:SmoM2YFP). After topical application of CycT or Cyc daily for 21 days, we found that all CycT-treated mice had tumor shrinkage and decreased expression of Hh target genes. Taken together, we found that CycT is an effective inhibitor of Hh signaling-mediated carcinogenesis.展开更多
Red skin is an important quality trait for pear fruits and is determined by the concentration and composition of anthocyanins.The regulatory mechanism underlying anthocyanin accumulation is a popular topic in fruit re...Red skin is an important quality trait for pear fruits and is determined by the concentration and composition of anthocyanins.The regulatory mechanism underlying anthocyanin accumulation is a popular topic in fruit research.Red mutants are ideal materials for studying the molecular mechanism of color diversity in pear.Although several red pear mutants have been cultivated and are in production,no exact locus containing the responsible genetic mutation has been identified.In this study,by combining the bulked segregant analysis with whole-genome sequencing,we identified a 14 nucleotide deletion mutation in the coding region of the PpBBX24 gene from the red pear mutant“Zaosu Red”.We further verified that the deletion was present only in the red mutant of“Zaosu”and in its red offspring,which was different from that which occurred in other red pear fruits.This deletion results in a coding frame shift such that there is an early termination of the PpBBX24 gene and loss of key NLS and VP domains from PpBBX24.The lost domains may reduce or alter the normal function of PpBBX24.In addition,we found that the transcript levels of the PpMYB10 and PpHY5 genes in red samples were significantly higher than those in green samples,whereas the results for the normal-type PpBBX24 gene were the opposite.We ultimately revealed that the 14 nucleotide deletion mutation in the coding region of the PpBBX24 gene is associated with the red skin of the“Zaosu Red”pear.This finding of somatic mutational events will be helpful for breeding new red pear cultivars and for understanding the regulatory mechanisms involved in pear skin pigmentation.展开更多
Tumor cells show acidic conditions compared with normal cells,which further inspires scientist to build nanocarrier responsive to tumor microenvironment(TME)for enhancing tumor therapeutic efficacy.Here,we report a pH...Tumor cells show acidic conditions compared with normal cells,which further inspires scientist to build nanocarrier responsive to tumor microenvironment(TME)for enhancing tumor therapeutic efficacy.Here,we report a pH-sensitive and biocompatible polyprodrug based on dextran-doxorubicin(DOX)prodrug(DOXDT)for enhanced chemotherapy.Highdensity DOX component was covalently decorated on the nanocarrier and the drug molecules could be effectively released in the acidic tumor tissue/cells,improving chemotherapy efficacy.Specifically,a dextran-based copolymer was preliminarily prepared by one-step atom transfer radical polymerization(ATRP);then DOX was conjugated on the copolymer component via pH-responsive hydrazone bond.The structure of DOXDT can be well-controlled.The resulting DOXDT was able to further self-assemble into nanoscale micelles with a hydration diameter of about 32.4 nm,which presented excellent micellar stability.Compared to lipid-based drug delivery system,the DOXDT prodrug showed higher drug load capacity up to 23.6%.In addition,excellent stability and smaller size of the nanocarrier contributed to better tissue permeability and tumor suppressive effects in vivo.Hence,this amphipathic DOXDT prodrug is promising in the development of translational DOX formulations,which would be widely applied in cancer therapy.展开更多
Atomically dispersed metals on N-doped carbon supports(M-N_(xCs)) have great potential applications in various fields.However,a precise understanding of the definitive relationship between the configuration of metal s...Atomically dispersed metals on N-doped carbon supports(M-N_(xCs)) have great potential applications in various fields.However,a precise understanding of the definitive relationship between the configuration of metal single atoms and the dielectric loss properties of M-N_(xCs) at the atomic-level is still lacking.Herein,we report a general approach to synthesize a series of three-dimensional(3D)honeycomb-like M-N_xC(M=Mn,Fe,Co,Cu,or Ni) containing metal single atoms.Experimental results indicate that 3D M-N_(xCs) exhibit a greatly enhanced dielectric loss compared with that of the NC matrix.Theoretical calculations demonstrate that the density of states of the d orbitals near the Fermi level is significantly increased and additional electrical dipoles are induced due to the destruction of the symmetry of the local microstructure,which enhances conductive loss and dipolar polarization loss of 3D M-N_(xCs),respectively.Consequently,these 3D M-N_(xCs) exhibit excellent electromagnetic wave absorption properties,outperforming the most commonly reported absorbers.This study systematically explains the mechanism of dielectric loss at the atomic level for the first time and is of significance to the rational design of high-efficiency electromagnetic wave absorbing materials containing metal single atoms.展开更多
The effects of metal atomic ratio, water content, oxygen content, and calcination temperature on the catalytic performances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic aci...The effects of metal atomic ratio, water content, oxygen content, and calcination temperature on the catalytic performances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid have been investigated and discussed. Among the catalysts studied, it was found that the MoVTeNbO catalyst calcined at a temperature of 600 ℃ showed the best performance in terms of propane conversion and selectivity for acrylic acid under an atmosphere of nitrogen. An effective MoVTeNbO oxide catalyst for propane selective oxidation to acrylic acid was obtained with a combination of a preferred metal atomic ratio （Mo1V0.31Te0.23Nb0.12）. The optimum reaction condition for the selective oxidation of propane was the molar ratio of C3H8 ：O2 ： H2O ： N2 = 4.4： 12.8 ： 15.3 ： 36.9. Under such conditions, the conversion of propane and the maximum yield of acrylic acid reached about 50% and 21%, respectively.展开更多
基金supported by grants from the National Key Research and Development Program of China(2021YFA1101300,2021YFA1101800,and 2020YFA0112503)the National Natural Science Foundation of China(82030029,81970882,92149304,and 22302231)+5 种基金the Science and Technology Department of Sichuan Province(2021YFS0371)the Guangdong Basic and Applied Basic Research Foundation(2023A1515011986)the Shenzhen Fundamental Research Program(JCYJ20190814093401920,JCYJ20210324125608022,JCYJ20190813152616459,and JCYJ20190808120405672)the Futian Healthcare Research Project(FTWS2022013 and FTWS2023080)the Open Research Fund of State Key Laboratory of Genetic Engineering,Fudan University(SKLGE-2104)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23qnpy153)。
文摘Copper is a microelement with important physiological functions in the body.However,the excess copper ion(Cu^(2+))may cause severe health problems,such as hair cell apoptosis and the resultant hearing loss.Therefore,the assay of Cu^(2+)is important.We integrate ionic imprinting technology(IIT)and structurally colored hydrogel beads to prepare chitosan-based ionically imprinted hydrogel beads(IIHBs)as a low-cost and high-specificity platform for Cu^(2+)detection.The IIHBs have a macroporous microstructure,uniform size,vivid structural color,and magnetic responsiveness.When incubated in solution,IIHBs recognize Cu^(2+)and exhibit a reflective peak change,thereby achieving label-free detection.In addition,benefiting from the IIT,the IIHBs display good specificity and selectivity and have an imprinting factor of 19.14 at 100μmol·L^(-1).These features indicated that the developed IIHBs are promising candidates for Cu^(2+)detection,particularly for the prevention of hearing loss.
基金funding from the National Natural Science Foundation of China (No.51872173)Taishan Scholar Foundation of Shandong Province (No.tsqn201812068)+2 种基金Youth Innovation Technology Project of Higher School in Shandong Province (No.2019KJA013)Science and Technology Special Project of Qingdao City (No.20-3-4-3-nsh)the Opening Fund of State Key Laboratory of Heavy Oil Processing (No.SKLOP202002006)。
文摘In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and experimental data have shown that the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure has a stronger light absorption capacity and larger specific surface area than pure g-C_(3)N_(4) NCs and g-C_(3)N_(4) nanosheets(NSs),and the presence of the co-catalysts 1T'-MoS_(2) can effectively inhibit the photoinduced carrier recombination.As a result,the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure with an optimum 1T'-MoS_(2) loading of 9 wt%displays a hydrogen evolution rate of 1949 mmol h^(-1) g^(-1),162.4,1.2,1.5,1.6 and 1.2 times than pure g-C_(3)N_(4) NCs(12 mmol h^(-1) g^(-1)),Pt/g-C_(3)N_(4) NCs(1615 mmol h^(-1) g^(-1))and Pt/g-C_(3)N_(4) nanosheets(NSs,1297 mmol h^(-1) g^(-1)),1T'-MoS_(2)/g-C_(3)N_(4) nanosheets(1216 mmol h^(-1) g^(-1))and 2H-MoS_(2)/g-C_(3)N_(4) nanocages(1573 mmol h^(-1) g^(-1)),respectively,and exhibits excellent cycle stability.Therefore,1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure is a suitable photocatalyst for green H_(2) production.
基金Taishan Scholars Program of Shandong Province,Grant/Award Number:tsqn201812068Higher School Youth Innovation Team of Shandong Province,Grant/Award Number:2019KJA013+1 种基金The Opening Fund of State Key Laboratory of Heavy Oil Processing,Grant/Award Number:SKLOP202002006National Natural Science Foundation of China,Grant/Award Number:51872173。
文摘The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The photocatalytic reduction of N_(2)is expected to achieve clean and sustainable NH_(3)production by using clean solar energy.To date,the new photocatalysts for photocatalytic reduction of N_(2)to NH_(3)at room temperature and atmospheric pressure have not been fully developed.The major challenge is to achieve high light-absorption efficiency,conversion efficiency,and stability of photocatalysts.Herein,the methods for measuring produced NH_(3)are compared,and the problems related to possible NH_(3)pollution in photocatalytic systems are mentioned to provide accurate ideas for measuring photocatalytic efficiency.The recent progress of nitrogen reduction reaction(NRR)photocatalysts at ambient temperature and pressure is summarized by introducing charge transfer,migration,and separation in photocatalytic NRR,which provides a guidance for the selection of future photocatalyst.More importantly,we introduce the latest research strategies of photocatalysts in detail,which can guide the preparation and design of photocatalysts with high NRR activity.
基金funding from the National Natural Science Foundation of China(No.51872173 and 51772176)Taishan Scholar Foundation of Shandong Province(No.tsqn201812068 and tspd20161006)+2 种基金Youth Innovation Technology Project of Higher School in Shandong Province(No.2019KJA013)Science and Technology Special Project of Qingdao City(No.20-3-4-3-nsh)the Opening Fund of State Key Laboratory of Heavy Oil Processing(No.SKLOP202002006)。
文摘2D-layered graphitic carbon nitride(g-C_(3)N_(4))is regarded as a great prospect as a photocatalyst for H_(2)generation.However,g-C_(3)N_(4)’s photocatalytic hydrogen evolution(HER)activity is significantly restricted by the recombination of photocarriers.We find that cobalt sulfide(CoS_(2))as a cocatalyst can promote g-C_(3)N_(4)nanosheets(NSs)to realize very efficient photocatalytic H_(2)generation.The prepared CoS_(2)/g-C_(3)N_(4)hybrids display highly boosted photocatalytic H_(2)generation performance and outstanding cycle stability.The optimized 7%-CoS_(2)/g-C_(3)N_(4)hybrids show a much improved photocatalytic H_(2)generation rate of 36.2μmol-1h-1,which is about 180 times as much as bare g-C_(3)N_(4)(0.2μmol-1h-1).In addition,the apparent quantum efficiency(AQE)of all the samples was computed under light atλ=370 nm,in which the AQE of 7%-CoS_(2)/g-C_(3)N_(4)hybrids is up to 5.72%.The experimental data and the DFT calculation suggest that the CoS_(2)/g-C_(3)N_(4)hybrid’s excellent HER activity is attributable to the lower overpotential and the smaller Co-H bond activation energy for HER.Accordingly,the CoS_(2)cocatalyst loading effectively boosts the photocatalytic performance of g-C_(3)N_(4)for H_(2)evolution.The project promotes fast development of high-efficiency photocatalysts and low-cost for photocatalytic H_(2)generation.
基金Shaanxi Natural Science Foundation(2021JCW-04)of Department of Science and Technology of Shaanxi for Northwest University.
文摘The large-scale deployment of carbon capture and storage(CCS)is becoming increasingly urgent in the global path toward net zero emissions;however,global CCS deployment is significantly lagging behind its expected contribution to greenhouse gas emission reduction.Reviewing and learning from the examples and history of successful CCS practices in advanced countries will help other countries,including China,to promote and deploy CCS projects using scientific methods.This paper shows that the establishment of major science and technology CCS infrastructures in advanced countries has become the main source of CCS technological innovation,cost reduction,risk reduction,commercial promotion,and talent training in the development and demonstration of key CCS technologies.Sound development of CCS requires a transition from pilot-scale science and technology infrastructures to large-scale commercial infrastructures,in addition to incentive policies;otherwise,it will be difficult to overcome the technical barriers between small-scale demonstrations and the implementation of million-tonne-scale CCS and ten-million-tonne-scale CCS hubs.Geological CO_(2) storage is the ultimate goal of CCS projects and the driving force of CO_(2) capture.Further improving the accuracy of technologies for the measurement,monitoring,and verification(MMV)of CO_(2) storage capacity,emission reduction,and safety remains a problem for geological storage.CO_(2) storage in saline aquifers can better couple multiple carbon emission sources and is currently a priority direction for development.Reducing the energy consumption of lowconcentration CO_(2) capture and the depletion of chemical absorbents and improving the operational efficiency and stability of post-combustion CO_(2) capture systems have become the key constraints to largescale CCS deployment.Enhanced oil recovery(EOR)is also important in order for countries to maximize fossil fuel extraction instead of importing oil from less environmentally friendly oil-producing countries.
基金supported by Taishan Scholars Project Special Funds(tsqn201812083)Natural Science Foundation of Shandong Province(ZR2019YQ20,2019JMRH0410)the National Natural Science Foundation of China(51972147)。
文摘Hydrogen(H2)production is a latent feasibility of renewable clean energy.The industrial H2 production is obtained from reforming of natural gas,which consumes a large amount of nonrenewable energy and simultaneously produces greenhouse gas carbon dioxide.Electrochemical water splitting is a promising approach for the H2 production,which is sustainable and pollution-free.Therefore,developing efficient and economic technologies for electrochemical water splitting has been an important goal for researchers around the world.The utilization of green energy systems to reduce overall energy consumption is more important for H2 production.Harvesting and converting energy from the environment by different green energy systems for water splitting can efficiently decrease the external power consumption.A variety of green energy systems for efficient producing H2,such as two-electrode electrolysis of water,water splitting driven by photoelectrode devices,solar cells,thermoelectric devices,triboelectric nanogenerator,pyroelectric device or electrochemical water-gas shift device,have been developed recently.In this review,some notable progress made in the different green energy cells for water splitting is discussed in detail.We hoped this review can guide people to pay more attention to the development of green energy system to generate pollution-free H2 energy,which will realize the whole process of H2 production with low cost,pollution-free and energy sustainability conversion.
基金The National Natural Science Foundation of China under contract Nos 41522604,31572255 and 31301867the Strategic Priority Research Program of CAS under contract No.XDA11020702the CAS Key Research Program of Frontier Sciences under contract No.QYZDB-SSW-DQC013
文摘This study explored the molecular diversity and biogeography of benthic ciliates in Chinese marginal seas, the Bohai Sea(BHS), North Yellow Sea(NYS) and South Yellow Sea(SYS). From a previous 18S rRNA gene pyrosequencing dataset of the benthic microeukaryotes, we retrieved the sequences affiliated with phylum Ciliophora and analyzed alpha and beta diversities of ciliate communities. We found that BHS had the highest ciliate operational taxonomic unit(OTU) richness than NYS and SYS, whereas the richness was not significantly different between summer and winter. Among all the measured environmental variables, water depth showed consistently the strongest correlations with alpha diversities. Overall, the class Spirotrichea(mostly Choreotrichia and unassigned lineages within the class) dominated the communities in terms of both relative proportion of sequences(77.0%) and OTU richness(66.5%). OTU-level ciliate community structure was significant different among the three basins, but not between the seasons. Structurally, significant differences in relative proportion among the basins were detected for the class Litostomatea, but not for other classes. Partial Mantel tests demonstrated that water depth difference was more important than geographic and environment distances in shaping the community structure of benthic ciliates in the studied area. About 60% OTUs were not assigned at a class or order level and at least 45% OTUs shared a sequence similarity no more than 97% with the described species, indicating a great potential for ciliate species discovery in the offshore sediments. Compared with previous morphology-based surveys, the spatial pattern of ciliate diversity(decreasing from NYS to SYS) is also identified in the present study. Nevertheless, structurally, the dominant class appeared to be Spirotrichea in the sequencing dataset, which differs from previous morphology-based results(dominance of classes Prostomatea and Karyorelictea in biomass). The potential causes for the discrepancies between molecular and morphological findings are also discussed.
基金supported by grants from the National Key Research and Development Program of China(2017YFD0101805)the Modern Agro-Industry Technology Research System,China(CARS-23-A-07)+1 种基金the Vegetable Modern Agro-Industry Technology Research System,Tianjin(ITTVRS2017004)the Natural Science Foundation of China(No.31872115).
文摘Cauliflower is an important variety of Brassica oleracea and is planted worldwide.Here,the high-quality genome sequence of cauliflower was reported.The assembled cauliflower genome was 584.60 Mb in size,with a contig N50 of 2.11 Mb,and contained 47,772 genes;56.65%of the genome was composed of repetitive sequences.Among these sequences,long terminal repeats(LTRs)were the most abundant(32.71%of the genome),followed by transposable elements(TEs)(12.62%).Comparative genomic analysis confirmed that after an ancient paleohexaploidy(γ)event,cauliflower underwent two whole-genome duplication(WGD)events shared with Arabidopsis and an additional whole-genome triplication(WGT)event shared with other Brassica species.The present cultivated cauliflower diverged from the ancestral B.oleracea species~3.0 million years ago(Mya).The speciation of cauliflower(~2.0 Mya)was later than that of B.oleracea L.var.capitata(approximately 2.6 Mya)and other Brassica species(over 2.0 Mya).Chromosome no.03 of cauliflower shared the most syntenic blocks with the A,B,and C genomes of Brassica species and its eight other chromosomes,implying that chromosome no.03 might be the most ancient one in the cauliflower genome,which was consistent with the chromosome being inherited from the common ancestor of Brassica species.In addition,2,718 specific genes,228 expanded genes,2 contracted genes,and 1,065 positively selected genes in cauliflower were identified and functionally annotated.These findings provide new insights into the genomic diversity of Brassica species and serve as a valuable reference for molecular breeding of cauliflower.
基金the National Key R&D Program of China(Nos.2017YFA0205103 and 2018YFE020505)the National Natural Science Foundation of China(Nos.81571766 and 61771337)+1 种基金the Natural Science Foundation of Tianjin,China(No.17JCYBJC24400)the“111”Project of China(No.B07014).
文摘An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great potential for air-coupled applications,mainly because of their low acoustic impedance.In this study,an air-coupled CMUT array is designed as an air parametric array.A hexagonal array is proposed to improve the directivity of the sound generated.A finite element model of the CMUT is established in COMSOL software to facilitate the choice of appropriate structural parameters of the CMUT cell.The CMUT array is then fabricated by a wafer bonding process with high consistency.The performances of the CMUT are tested to verify the accuracy of the finite element analysis.By optimizing the component parameters of the bias-T circuit used for driving the CMUT,DC and AC voltages can be effectively applied to the top and bottom electrodes of the CMUT to provide efficient ultrasound transmission.Finally,the prepared hexagonal array is successfully used to conduct preliminary experiments on its application as an air parametric array.
基金financial support by the National Natural Science Foundation of China (grant no. 51808303, 51672143 and 31870535)Outstanding Youth of Natural Science in Shandong Province (JQ201713)Taishan Scholars Program and ARC Discovery Project (No. 170103317)。
文摘Recently, in response to the major challenges in energy development and environmental issues, tremendous efforts are being devoted to developing electrochemical energy storage devices based on green sustainable resources. As a class of green materials, nanocellulose(NC) has received extensive attention. In this review, we summarize the research progress of NC derived materials in electrochemical energy storage. Specifically, we first introduce various synthesis methods based on NC and the pretreatment process to increase the conductivity. Then we focus on the specific application of NC in electrochemical energy storage devices. Finally, we summarize the previously reported work and put forward views on the further development of NC in the field of electrochemical energy storage.
基金supported by a grant from the National Institute of Health, USA (No. R01-CA94160)
文摘The link of hedgehog (Hh) signaling activation to human cancer and synthesis of a variety of Hh signaling inhibitors raise great expectation that inhibiting Hh signaling may be effective in human cancer treatment. Cyclopamine (Cyc), an alkaloid from the Veratrum plant, is a specific natural product inhibitor of the Hh pathway that acts by targeting smoothened (SMO) protein. However, its poor solubility, acid sensitivity, and weak potency relative to other Hh antagonists prevent the clinical development of Cyc as a therapeutic agent. Here, we report properties of cyclopamine tartrate salt (CycT) and its activities in Hh signaling-mediated cancer in vitro and in vivo. Unlike Cyc, CycT is water soluble (5-10 mg/mL). The median lethal dose (LD50) of CycT was 62.5 mg/kg body weight compared to 43.5 mg/kg for Cyc, and the plasma half-life (T1/2) of CycT was not significantly different from that of Cyc. We showed that CycT had a higher inhibitory activity for Hh signaling-dependent motor neuron differentiation than did Cyc (IC50 = 50 nmol/L for CycT vs. 300 nmol/L for Cyc). We also tested the antitumor effectiveness of these Hh inhibitors using two mouse models of basal cell carcinomas (K14cre:Ptch1neo/neo and K14cre:SmoM2YFP). After topical application of CycT or Cyc daily for 21 days, we found that all CycT-treated mice had tumor shrinkage and decreased expression of Hh target genes. Taken together, we found that CycT is an effective inhibitor of Hh signaling-mediated carcinogenesis.
基金the National Key Research and Development Program of China(2018YFD1000102)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2016-RIP)programs for funding this work.
文摘Red skin is an important quality trait for pear fruits and is determined by the concentration and composition of anthocyanins.The regulatory mechanism underlying anthocyanin accumulation is a popular topic in fruit research.Red mutants are ideal materials for studying the molecular mechanism of color diversity in pear.Although several red pear mutants have been cultivated and are in production,no exact locus containing the responsible genetic mutation has been identified.In this study,by combining the bulked segregant analysis with whole-genome sequencing,we identified a 14 nucleotide deletion mutation in the coding region of the PpBBX24 gene from the red pear mutant“Zaosu Red”.We further verified that the deletion was present only in the red mutant of“Zaosu”and in its red offspring,which was different from that which occurred in other red pear fruits.This deletion results in a coding frame shift such that there is an early termination of the PpBBX24 gene and loss of key NLS and VP domains from PpBBX24.The lost domains may reduce or alter the normal function of PpBBX24.In addition,we found that the transcript levels of the PpMYB10 and PpHY5 genes in red samples were significantly higher than those in green samples,whereas the results for the normal-type PpBBX24 gene were the opposite.We ultimately revealed that the 14 nucleotide deletion mutation in the coding region of the PpBBX24 gene is associated with the red skin of the“Zaosu Red”pear.This finding of somatic mutational events will be helpful for breeding new red pear cultivars and for understanding the regulatory mechanisms involved in pear skin pigmentation.
基金supported by Science and Technology Project from the Science Technology and Innovation Committee of Shenzhen Municipality(JCYJ20170817170110940 and JCJY20170307163529489)the Sichuan Science and Technology Program(2018JY0392 and 2018GZYZF0008)+1 种基金Sanming Project of Medicine in Shenzhen(SZSM201512033)Shenzhen Public Service Platform of Molecular Medicine in Pediatric Hematology and Oncology。
文摘Tumor cells show acidic conditions compared with normal cells,which further inspires scientist to build nanocarrier responsive to tumor microenvironment(TME)for enhancing tumor therapeutic efficacy.Here,we report a pH-sensitive and biocompatible polyprodrug based on dextran-doxorubicin(DOX)prodrug(DOXDT)for enhanced chemotherapy.Highdensity DOX component was covalently decorated on the nanocarrier and the drug molecules could be effectively released in the acidic tumor tissue/cells,improving chemotherapy efficacy.Specifically,a dextran-based copolymer was preliminarily prepared by one-step atom transfer radical polymerization(ATRP);then DOX was conjugated on the copolymer component via pH-responsive hydrazone bond.The structure of DOXDT can be well-controlled.The resulting DOXDT was able to further self-assemble into nanoscale micelles with a hydration diameter of about 32.4 nm,which presented excellent micellar stability.Compared to lipid-based drug delivery system,the DOXDT prodrug showed higher drug load capacity up to 23.6%.In addition,excellent stability and smaller size of the nanocarrier contributed to better tissue permeability and tumor suppressive effects in vivo.Hence,this amphipathic DOXDT prodrug is promising in the development of translational DOX formulations,which would be widely applied in cancer therapy.
基金financial supports from the NNSF of China(Grant No.51972077)the Fundamental Research Funds for the Central Universities(Grant No.3072020CF2518,3072020CFT2505+1 种基金3072021CFT2506,3072021CF2523 and 3072021CF2524)Heilongjiang Touyan Innovation Team Program.
文摘Atomically dispersed metals on N-doped carbon supports(M-N_(xCs)) have great potential applications in various fields.However,a precise understanding of the definitive relationship between the configuration of metal single atoms and the dielectric loss properties of M-N_(xCs) at the atomic-level is still lacking.Herein,we report a general approach to synthesize a series of three-dimensional(3D)honeycomb-like M-N_xC(M=Mn,Fe,Co,Cu,or Ni) containing metal single atoms.Experimental results indicate that 3D M-N_(xCs) exhibit a greatly enhanced dielectric loss compared with that of the NC matrix.Theoretical calculations demonstrate that the density of states of the d orbitals near the Fermi level is significantly increased and additional electrical dipoles are induced due to the destruction of the symmetry of the local microstructure,which enhances conductive loss and dipolar polarization loss of 3D M-N_(xCs),respectively.Consequently,these 3D M-N_(xCs) exhibit excellent electromagnetic wave absorption properties,outperforming the most commonly reported absorbers.This study systematically explains the mechanism of dielectric loss at the atomic level for the first time and is of significance to the rational design of high-efficiency electromagnetic wave absorbing materials containing metal single atoms.
文摘The effects of metal atomic ratio, water content, oxygen content, and calcination temperature on the catalytic performances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid have been investigated and discussed. Among the catalysts studied, it was found that the MoVTeNbO catalyst calcined at a temperature of 600 ℃ showed the best performance in terms of propane conversion and selectivity for acrylic acid under an atmosphere of nitrogen. An effective MoVTeNbO oxide catalyst for propane selective oxidation to acrylic acid was obtained with a combination of a preferred metal atomic ratio （Mo1V0.31Te0.23Nb0.12）. The optimum reaction condition for the selective oxidation of propane was the molar ratio of C3H8 ：O2 ： H2O ： N2 = 4.4： 12.8 ： 15.3 ： 36.9. Under such conditions, the conversion of propane and the maximum yield of acrylic acid reached about 50% and 21%, respectively.
