Quality and yield are the primary concerns in kiwifruit breeding,but research on the genetic mechanisms of fruit size,shape,and ascorbic acid(ASA)content is currently very limited,which restricts the development of ki...Quality and yield are the primary concerns in kiwifruit breeding,but research on the genetic mechanisms of fruit size,shape,and ascorbic acid(ASA)content is currently very limited,which restricts the development of kiwifruit molecular breeding.In this study,we obtained a total of 8.88 million highly reliable single nucleotide polymorphism(SNP)markers from 140 individuals from the natural hybrid offspring of Actinidia eriantha cv.‘White’using whole genome resequencing technology.A genome-wide association study was conducted on eight key agronomic traits,including single fruit weight,fruit shape,ASA content,and the number of inflorescences per branch.A total of 59 genetic loci containing potential functional genes were located,and candidate genes related to single fruit weight,fruit length,ASA content,number of inflorescences per branch and other traits were identified within the candidate interval,such as AeWUSCHEL,AeCDK1(cell cycle dependent kinase),AeAO1(ascorbic oxidase)and AeCO1(CONSTANS-like 4).After constructing an RNAi vector for AeAO1 and injecting it into the fruit of cv.‘Midao 31’to interfere with the expression of the AeAO1 gene,the results showed that the activity of ascorbic oxidase in the fruit of‘Midao 31’significantly decreased,while the content of ASA significantly increased.This study provides valuable insights into the genetic basis of variation in A.eriantha fruit traits,which may benefit molecular marker-assisted breeding efforts.展开更多
High-performance Cu/Graphene composite wire synergistically strengthened by nano Cr_(3)C_(2) phase was directly synthesized via hot press sintering followed by severe cold plastic deformation, using liquid paraffin an...High-performance Cu/Graphene composite wire synergistically strengthened by nano Cr_(3)C_(2) phase was directly synthesized via hot press sintering followed by severe cold plastic deformation, using liquid paraffin and CuCr alloy powder as the raw materials. Since graphene is in situ formed under the catalysis of copper powder during the sintering process, the problem that graphene is easy to agglomerate and difficult to disperse uniformly in the copper matrix has been solved. The nano Cr_(3)C_(2)-particles nailed at the interface favor to improve the interface bonding. The Cu/Graphene composite possesses high electrical conductivity, hardness, and plasticity. The composite wire exhibits high electrical conductivity of 96.93% IACS, great tensile strength of 488MPa, and excellent resistance to softening. Even after annealing at 400℃ for 1 h, the tensile strength can still reach 268 MPa with a conductivity of about 99.14% IACS.The wire's temperature coefficient of resistance(TCR) is largely reduced to 0.0035/℃ due to the complex structure,which leads the wire to present low resistivity at higher temperatures. Such Cu/Graphene composite wire with excellent comprehensive performance has a good application prospect in high-power density motors.展开更多
Kiwifruit is an economically and nutritionally important fruit crop with extremely high contents of vitamin C.However,the previously released versions of kiwifruit genomes all have a mass of unanchored or missing regi...Kiwifruit is an economically and nutritionally important fruit crop with extremely high contents of vitamin C.However,the previously released versions of kiwifruit genomes all have a mass of unanchored or missing regions.Here,we report a highly continuous and completely gap-free reference genome of Actinidia chinensis cv.‘Hongyang’,named Hongyang v4.0,which is the first to achieve two de novo haploid-resolved haplotypes,HY4P and HY4A.HY4P and HY4A have a total length of 606.1 and 599.6 Mb,respectively,with almost the entire telomeres and centromeres assembled in each haplotype.In comparison with Hongyang v3.0,the integrity and contiguity of Hongyang v4.0 is markedly improved by filling all unclosed gaps and correcting some misoriented regions,resulting in∼38.6–39.5 Mb extra sequences,which might affect 4263 and 4244 protein-coding genes in HY4P and HY4A,respectively.Furthermore,our gap-free genome assembly provides the first clue for inspecting the structure and function of centromeres.Globally,centromeric regions are characterized by higher-order repeats that mainly consist of a 153-bp conserved centromere-specific monomer(Ach-CEN153)with different copy numbers among chromosomes.Functional enrichment analysis of the genes located within centromeric regions demonstrates that chromosome centromeres may not only play physical roles for linking a pair of sister chromatids,but also have genetic features for participation in the regulation of cell division.The availability of the telomere-to-telomere and gap-free Hongyang v4.0 reference genome lays a solid foundation not only for illustrating genome structure and functional genomics studies but also for facilitating kiwifruit breeding and improvement.展开更多
A high-quality genome is the basis for studies on functional,evolutionary,and comparative genomics.The majority of attention has been paid to the solution of complex chromosome structures and highly repetitive sequenc...A high-quality genome is the basis for studies on functional,evolutionary,and comparative genomics.The majority of attention has been paid to the solution of complex chromosome structures and highly repetitive sequences,along with the emergence of a new‘telomere-to-telomere(T2T)assembly’era.However,the bioinformatic tools for the automatic construction and/or characterization of T2T genome are limited.Here,we developed a user-friendly web toolkit,quarTeT,which currently includes four modules:AssemblyMapper,GapFiller,TeloExplorer,and CentroMiner.First,AssemblyMapper is designed to assemble phased contigs into the chromosome-level genome by referring to a closely related genome.Then,GapFiller would endeavor to fill all unclosed gaps in a given genome with the aid of additional ultra-long sequences.Finally,TeloExplorer and CentroMiner are applied to identify candidate telomere and centromere as well as their localizations on each chromosome.These four modules can be used alone or in combination with each other for T2T genome assembly and characterization.As a case study,by adopting the entire modular functions of quarTeT,we have achieved the Actinidia chinensis genome assembly that is of a quality comparable to the reported genome Hongyang v4.0,which was assembled with the addition of manual handling.Further evaluation of CentroMiner by searching centromeres in Arabidopsis thaliana and Oryza sativa genomes showed that quarTeT is capable of identifying all the centromeric regions that have been previously detected by experimental methods.Collectively,quarTeT is an efficient toolkit for studies of large-scale T2T genomes and can be accessed at http://www.atcgn.com:8080/quarTeT/home.html without registration.展开更多
Layered two dimensional(2D) or quasi-2D perovskites are emerging photovoltaic materials due to their superior environment and structure stability in comparison with their 3D counterparts. The typical 2D perovskites ca...Layered two dimensional(2D) or quasi-2D perovskites are emerging photovoltaic materials due to their superior environment and structure stability in comparison with their 3D counterparts. The typical 2D perovskites can be obtained by cutting 3D perovskites along < 100 > orientation by incorporation of bulky organic spacers, which play a key role in the performance of 2D perovskite solar cells(PSCs). Compared with aliphatic spacers, aromatic spacers with high dielectric constant have the potential to decrease the dielectric and quantum confinement effect of 2D perovskites, promote efficient charge transport and reduce the exciton binding energy, all of which are beneficial for the photovoltaic performance of 2D PSCs. In this review, we aim to provide useful guidelines for the design of aromatic spacers for 2D perovskites. We systematically reviewed the recent progress of aromatic spacers used in 2D PSCs. Finally, we propose the possible design strategies for aromatic spacers that may lead to more efficient and stable 2D PSCs.展开更多
Thoracic spinal stenosis (TSS) is a group of clinical syndromes caused by thoracic spinal cord compression, which always results in severe clinical complications. The incidence of TSS is relatively low compared with l...Thoracic spinal stenosis (TSS) is a group of clinical syndromes caused by thoracic spinal cord compression, which always results in severe clinical complications. The incidence of TSS is relatively low compared with lumbar spinal stenosis, while the incidence of spinal cord injury during thoracic decompression is relatively high. The reported incidence of neurological deficits after thoracic decompression reached 13.9%.Intraoperative neurophysiological monitoring (IONM) can timely provide information regarding the function status of the spinal cord, and help surgeons with appropriate performance during operation. This article illustrates the theoretical basis of applying IONM in thoracic decompression surgery, and elaborates on the relationship between signal changes in IONM and postoperative neurological function recovery of the spinal cord. It also introduces updated information in multimodality IONM, the factors influencing evoked potentials,and remedial measures to improve the prognosis.展开更多
Kiwifruit(Actinidia spp.)plants produce economically important fruits containing abundant,balanced phytonutrients with extraordinarily high vitamin C contents.Since the release of the first kiwifruit reference genome ...Kiwifruit(Actinidia spp.)plants produce economically important fruits containing abundant,balanced phytonutrients with extraordinarily high vitamin C contents.Since the release of the first kiwifruit reference genome sequence in 2013,large volumes of genome and transcriptome data have been rapidly accumulated for a handful of kiwifruit species.To efficiently store,analyze,integrate,and disseminate these large-scale datasets to the research community,we constructed the Kiwifruit Genome Database(KGD;http://kiwifruitgenome.org/).The database currently contains all publicly available genome and gene sequences,gene annotations,biochemical pathways,transcriptome profiles derived from public RNA-Seq datasets,and comparative genomic analysis results such as syntenic blocks and homologous gene pairs between different kiwifruit genome assemblies.A set of user-friendly query interfaces,analysis tools and visualization modules have been implemented in KGD to facilitate translational and applied research in kiwifruit,which include JBrowse,a popular genome browser,and the NCBI BLAST sequence search tool.Other notable tools developed within KGD include a genome synteny viewer and tools for differential gene expression analysis as well as gene ontology(GO)term and pathway enrichment analysis.展开更多
Objective To evaluate the rates of wound healing and limb preservation following angiosome-targeted infrapopliteal endovascular revascularization in the treatment of diabetic limb ischemia. Methods We performed a retr...Objective To evaluate the rates of wound healing and limb preservation following angiosome-targeted infrapopliteal endovascular revascularization in the treatment of diabetic limb ischemia. Methods We performed a retrospective analysis of data gathered from 102 infrapopliteal angioplasty cases(60 males and 42 females; mean age, 72 ± 11 years) with Fontaine IV ischemia(ankle-brachial index, ABI: 0.16 ± 0.06). Forty-seven angioplasties were performed based on the angiosome concept(direct revascularization, DR), while 55 did not incorporate the angiosome concept(indirect revascularization, IR). The curative effects of angioplasty were assessed by postoperative determinations of ABI performed every 3 months during clinical follow-up visits conducted to assess healing of the ischemic wound. Amputation and death events were recorded throughout the study. Results All 102 patients were successfully revascularized without complications, and during a mean follow-up period of 18 ± 11 months, the mean postoperative ABI improved to 0.84 ± 0.10. The postoperative 6 and 12 month healing rates in the DR group were 85.1% and 93.5%, respectively, while the limb-salvage rates were 100% and 93.5%, respectively. The postoperative 6 and 12 month healing rates in the IR group were 60% and 76.4%, respectively, while the limb-salvage rates were 90.1%, and 85.5%, respectively. Conclusion Angiosome-based Infrapopliteal angioplasty was associated with better wound healing and higher rates of limb salvage in cases of critical diabetic foot ischemia. Revascularization should be provided to patients who have undergone indirect perfusion of the ischemic angiosome, as acceptable rates of limb salvage are obtained.展开更多
Fleshy fruit ripening is governed by multiple external and internal cues and accompanied by changes in color,texture,volatiles,and nutritional quality traits.While extended shelf-life and increased phytonutrients are ...Fleshy fruit ripening is governed by multiple external and internal cues and accompanied by changes in color,texture,volatiles,and nutritional quality traits.While extended shelf-life and increased phytonutrients are desired,delaying ripening via genetic or postharvest means can be accompanied by reduced nutritional value.Here we report that the high pigment 1(hp1)mutation at the UV-DAMAGED DNA BINDING PROTEIN 1(DDB1)locus,previously shown to influence carotenoid and additional phytonutrient accumulation via altered light signal transduction,also results in delayed ripening and firmer texture,resulting at least in part from decreased ethylene evolution.Transcriptome analysis revealed multiple ethylene biosynthesis and signaling-associated genes downregulated in hp1.Furthermore,the hp1 mutation impedes softening of the pericarp,placenta,columella as well as the whole fruit,in addition to reduced expression of the FRUITFUL2(FUL2)MADS-box transcription factor and xyloglucan endotransglucosylase/hydrolase 5(XTH5).These results indicate that DDB1 influences a broader range of fruit development and ripening processes than previously thought and present an additional genetic target for increasing fruit quality and shelf-life.展开更多
Objective:This study aimed to evaluate the clinical and angiographic outcomes of aneurysms that were completely or near-completely embolized and ascertain whether complete embolization is important in the stent-assist...Objective:This study aimed to evaluate the clinical and angiographic outcomes of aneurysms that were completely or near-completely embolized and ascertain whether complete embolization is important in the stent-assisted coiling(SAC)of intracranial aneurysms.Methods:This retrospective study enrolled 390 patients(417 aneurysms).Among them,complete(100%)or nearcomplete(>90%)angiographic obliteration of the aneurysms on immediate angiography was accomplished.Baseline characteristics,complications,angiography follow-up results,and clinical outcomes were analyzed.Results:Cumulative adverse events occurred in 30 patients(7.7%),including thromboembolic complications in 17(4.4%),intraoperative rupture in 10(2.6%),and others in 3(0.8%).Statistical analyses revealed an increased intraprocedural rupture rate in the initial completely occluded aneurysms(5.6%compared with 1.0%).The incidence of cumulative adverse events was higher in patients with completely occluded aneurysms(11.1%)than in those with near-completely occluded aneurysms(5.5%).Angiography follow-up was available for 173 aneurysms.Aneurysm occlusion status at follow-up was correlated with stent placement(p?0.000,odds ratio?5.847),size(p?0.000,odds ratio?6.446 for tiny aneurysms;and p?0.001,odds ratio?5.616 for small aneurysms),and initial aneurysm occlusion status(p?0.001,odds ratio?3.436).Complete occlusion at followup was seen in 82.6%of the initial complete occlusion group versus 63.0%of the initial near-complete occlusion group.The incidence of complete occlusion at follow-up was higher in the initial completely occluded aneurysms with SAC(100%)than in the initial completely occluded aneurysms with non-SAC(65.2%).Conclusions:Initial complete treatment may lead to higher complication rates and good clinical outcomes at follow-up.Stent placement may enhance progressive aneurysm occlusion.Initial complete occlusion with SAC can provide durable closure at follow-up.展开更多
Use of CRISPR-Cas9(Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)-CRISPR-associated 9)-mediated genome editing has proliferated for use in numerous plant species to modify gene function and expressi...Use of CRISPR-Cas9(Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)-CRISPR-associated 9)-mediated genome editing has proliferated for use in numerous plant species to modify gene function and expression,usually in the context of either transient or stably inherited genetic alternations.While extremely useful in many applications,modification of some loci yields outcomes detrimental to further experimental evaluation or viability of the target organism.Expression of Cas9 under a promoter conferring gene knockouts in a tissue-specific subset of genomes has been demonstrated in insect and animal models,and recently in Arabidopsis.We developed an in planta GFP(green fluorescent protein)assay system to demonstrate fruit-specific gene editing in tomato using a phosphoenolpyruvate carboxylase 2 gene promoter.We then targeted a SET-domain containing polycomb protein,SlEZ2,previously shown to yield pleiotropic phenotypes when targeted via ^(35)S-driven RNA interference and we were able to characterize fruit phenotypes absent additional developmental perturbations.Tissue-specific gene editing will have applications in assessing function of essential genes otherwise difficult to study via germline modifications and will provide routes to edited genomes in tissues that could not otherwise be recovered when their germline modification perturbs their normal development.展开更多
A forest fire is a severe threat to forest resources and human life, In this paper, we propose a forest-fire detection system that has an artificial neural network algorithm implemented in a wireless sensor network (...A forest fire is a severe threat to forest resources and human life, In this paper, we propose a forest-fire detection system that has an artificial neural network algorithm implemented in a wireless sensor network (WSN). The proposed detection system mitigates the threat of forest fires by provide accurate fire alarm with low maintenance cost. The accuracy is increased by the novel multi- criteria detection, referred to as an alarm decision depends on multiple attributes of a forest fire. The multi-criteria detection is implemented by the artificial neural network algorithm. Meanwhile, we have developed a prototype of the proposed system consisting of the solar batter module, the fire detection module and the user interface module.展开更多
Flowers are an essential organ for sexual reproduction of higher plants.Severe lesions along with flower blight on tea(Camellia sinensis)plants were observed in the experimental tea plantation located in Hefei(China)....Flowers are an essential organ for sexual reproduction of higher plants.Severe lesions along with flower blight on tea(Camellia sinensis)plants were observed in the experimental tea plantation located in Hefei(China).The pathogens isolated from diseased flowers matched the morphological peculiarity of Alternaria alternata.The species characteristics of A.alternata were further confirmed by both pathogenicity tests and multi-gene phylogenetic analyses by using internal transcribed spacer(ITS),glyceraldehyde-3-phosphate dehydrogenase(GAPDH)and betatubulin(TUB).The combined phylogeny analysis using sequences derived from the ITS,GAPDH and TUB showed that the isolated pathogens belong to the genus Alternaria.Pathogenicity tests conducted on healthy tea flowers and leaves manifested typical symptoms of flower blight while weaker symptoms of leaf spot,demonstrating the A.alternata isolates were the causal agents of flower blight disease on tea plants.This fungus is first reported as a pathogen causing flower blight on C.sinensis in this study.展开更多
Discontinuity is critical for strength,deformability,and permeability of rock mass.Set information is one of the essential discontinuity characteristics and is usually accessed by orientation grouping.Traditional meth...Discontinuity is critical for strength,deformability,and permeability of rock mass.Set information is one of the essential discontinuity characteristics and is usually accessed by orientation grouping.Traditional methods of identifying optimal discontinuity set numbers are usually achieved by clustering validity indexes,which mainly relies on the aggregation and dispersion of clusters and leads to the inaccuracy and instability of evaluation.This paper proposes a new method of Fisher mixed evaluation(FME)to identify optimal group numbers of rock mass discontinuity orientation.In FME,orientation distribution is regarded as the superposition of Fisher mixed distributions.Optimal grouping results are identified by considering the fitting accuracy of Fisher mixed distributions,the probability monopoly and central location significance of independent Fisher centers.A Halley-Expectation-Maximization(EM)algorithm is derived to achieve an automatic fitting of Fisher mixed distribution.Three real rock discontinuity models combined with three orientation clustering algorithms are adopted for discontinuity grouping.Four clustering validity indexes are used to automatically identify optimal group numbers for comparison.The results show that FME is more accurate and robust than the other clustering validity indexes in optimal discontinuity group number identification for different rock models and orientation clustering algorithms.展开更多
In this work,low-softening-temperature and low-modulus SiO_(2) was introduced as an embedded interface between SiC nanowires(SiCnws)and a Ba_(x)Sr_(1−x)Al_(2)Si_(2)O_(8) ceramic matrix to enhance strength and toughnes...In this work,low-softening-temperature and low-modulus SiO_(2) was introduced as an embedded interface between SiC nanowires(SiCnws)and a Ba_(x)Sr_(1−x)Al_(2)Si_(2)O_(8) ceramic matrix to enhance strength and toughness of the ceramic.During the sintering process,molten SiO_(2) enhances the flowability of the ceramic powders and modifies the dispersion of SiCnws.The strengthening effect of SiCnws was fully realized,and the flexural strength of the optimized ceramics reached 193±16 MPa,which represents an increase of 52.6%.After the formation of the embedded SiO_(2) interface with a low modulus,cracks can deflect along the SiCnws surface,which is consistent with the criterion of He and Hutchinson.This can effectively extend the crack propagation path,and the fracture toughness(K_(IC))is thus improved by 94.0%,reaching 3.1±0.5 MPa·m^(1/2).展开更多
Rapid halide anion exchange easily occurring in metal-halide perovskite nanoparticles(NPs)makes it nearly impossible to create a single three-dimensional(3D)CsPbX_(3)(X=Cl,Br,I)NP that simultaneously comprises two sep...Rapid halide anion exchange easily occurring in metal-halide perovskite nanoparticles(NPs)makes it nearly impossible to create a single three-dimensional(3D)CsPbX_(3)(X=Cl,Br,I)NP that simultaneously comprises two separate perovskite components.To circumvent this problem,we first propose a Ni^(2+)-mediated halide anion-exchange strategy in zero-dimensional(0D)Ni^(2+)-doped Cs_(4)PbBr_(6)(Cs_(4)PbBr_(6):Ni)perovskites to achieve ultra-stable 3D CsPbX_(3)NPs with two coexisting different perovskite individuals of CsPbCl_(3)and/or CsPbBr_(3).By combining the experimental results with first-principles calculations,we confirm that the completely isolated[PbBr_(6)]4−octahedra in 0D Cs_(4)PbBr_(6):Ni NPs can restrict rapid halide anion exchange and the anion diffusion preferentially proceeds in the proximity of substitutional NiPb centers,namely[NiBr_(6)]4−octahedra in a meta-stable state,rather than in the 0D Cs_(4)PbBr_(6)and residual 3D CsPbBr_(3)regions,thereby delivering intrinsic dual-band excitonic luminescence from a single 3D CsPbX_(3)NP with a more stable and efficient CsPbCl_(3)component as compared to its counterparts synthesized using conventional methods.These new insights regarding the precise control of halide anion exchange enable the preparation of a new type of high-efficiency perovskite materials with suppressed anion interdiffusion for prospective optoelectronic devices.展开更多
The Permian basalts in the Central Asian Orogenic Belt(CAOB)are crucial for constraining the closure of the Paleo-Asian Ocean.However,the origin of these basalts is still under discussion.Here,we present comprehensive...The Permian basalts in the Central Asian Orogenic Belt(CAOB)are crucial for constraining the closure of the Paleo-Asian Ocean.However,the origin of these basalts is still under discussion.Here,we present comprehensive bulk-rock geochemical,Sr-Nd-Pb-Hf isotopic,and zircon U-Pb-Lu-Hf isotopic data of the Liuyuan basalts and coexisting gabbros,which are located in the Beishan Orogen in the southern CAOB,to constrain their emplacement setting and tectonic implications.Our new gabbro ages of ca.288–294 Ma are interpreted to represent the formation time of the Liuyuan basaltic belt.The Liuyuan basalts show MORB-like rare earth element(REE)patterns and bulk-rockε_(Hf)(t)andε_(Nd)(t)values of 11.0–15.4 and 4.6–9.2,respectively,suggesting an origination mainly from a depleted mantle source.However,positive Pb anomalies,Nb-Ta depletions,and high Th/Yb ratios as well as evolved Sr-Nd-Pb-Hf isotopic compositions of some samples indicate variable continental crustal contribution.According to the covariation of Pb anomalies(Pb^(*)=2×Pb_(N)/(Ce_(N)+Pr_(N)))with Sr-Nd-Pb-Hf isotopic compositions,we speculate that parent magma of the Liuyuan basalt was contaminated by continental crustal materials during the eruption rather than having been generated from an enriched mantle source.As revealed by mixing modelling,the Liuyuan basaltic magmas would require a minor(<10%)upper continental crustal assimilation to explain the enriched trace elemental and radiogenic Sr-Nd-Pb-Hf isotopic signatures.Consequently,the Liuyuan basaltic belt is believed to have been generated in a continental extensional environment instead of an oceanic setting and does not constitute a Permian ophiolitic suture zone as previously suggested,since the Paleo-Asian Ocean was already closed in the southern Beishan Orogen in the Early Permian.展开更多
Perovskite solar cells represent a promising third-generation photovoltaic technology with low fabrication cost and high power conversion efficiency.In light of the rapid development of perovskite materials and device...Perovskite solar cells represent a promising third-generation photovoltaic technology with low fabrication cost and high power conversion efficiency.In light of the rapid development of perovskite materials and devices,a systematic survey on the latest advancements covering a broad range of related work is urgently needed.This review summarizes the recent major advances in the research of perovskite solar cells from a material science perspective.The discussed topics include the devices based on different type of perovskites(organic-inorganic hybrid,all-inorganic,and lead-free perovskite and perovskite quantum dots),the properties of perovskite defects,different type of charge transport materials(organic,polymeric,and inorganic hole transport materials and inorganic and organic electron transport materials),counter electrodes,and interfacial materials used to improve the efficiency and stability of devices.Most discussions focus on the key progresses reported within the recent five years.Meanwhile,the major issues limiting the production of perovskite solar cells and the prospects for the future development of related materials are discussed.展开更多
The method of LA-MC-ICP-MS has become one choice for the analysis of many isotopic systems due to its relatively low cost,high analysis speed,high spatial resolution,and low matrix effect.However,there are still many ...The method of LA-MC-ICP-MS has become one choice for the analysis of many isotopic systems due to its relatively low cost,high analysis speed,high spatial resolution,and low matrix effect.However,there are still many challenges in the accuracy,precision,and spatial resolution of in situ isotopic composition determination by LA-MC-ICP-MS,which mainly include:(1)how to improve instrument sensitivity,further improve the spatial resolution,and achieve simultaneous determination of isotopes,multiple isotopes,or isotopes with trace elements in low-content samples?(2)how to deduct and correct interference to improve the accuracy of isotopic determination?(3)how to correct isotope fractionation?(4)how to reduce the matrix effect of isotopes?how to develop matrix-matched reference materials?and(5)how to achieve non-matrix-matched correction of isotopes?The high-sensitivity cone combinations,gas mixture,shield torch,and reasonable detector array can be applied to improve the elemental sensitivity.The interferences include the background interference and the interferences from the matrix elements(the isobaric interference,the polyatomic interference,and doubly charged ions interference).To reduce or even eliminate the interference,commonly used methods including interference elimination,background correction,and interference correction by evaluating with an interference-free isotope.Isotopic fractionation correction mainly involves external standard calibration and internal and pseudo-internal standard normalization.For non-matrix matched calibration,many methods can be applied,such as the femtosecond laser,line scan,low laser energy,wet plasma condition,optical setup below the sample surface,and matching the intensity of the sample and standard.In this review,we systematically summarized the above challenges and solutions to promote the study and application of LA-MC-ICP-MS in isotopic determination.展开更多
Perovskite solar cells (PSCs) have achieved significant progress in the past decade and a certified power conversion efficiency (PCE) of 26.0% has been achieved.The widely used organic hole transport materials (HTMs) ...Perovskite solar cells (PSCs) have achieved significant progress in the past decade and a certified power conversion efficiency (PCE) of 26.0% has been achieved.The widely used organic hole transport materials (HTMs) in PSCs are typically sensitive to the moisture environment and continuous light exposure.In contrast,the inorganic HTMs benefiting from their outstanding merits,such as excellent environmental stability,are considered as alternatives and have attracted much attention in PSCs.In this review,we provide a comprehensive summary of the fundamental properties and recent progress of inorganic HTMs in n-i-p and p-i-n structured PSCs.Additionally,we emphasize the importance of inorganic HTMs in the development of highly efficient and stable PSCs.展开更多
基金supported by the National Natural Science Foundation of China(U23A20204,31972474 and 31471157).
文摘Quality and yield are the primary concerns in kiwifruit breeding,but research on the genetic mechanisms of fruit size,shape,and ascorbic acid(ASA)content is currently very limited,which restricts the development of kiwifruit molecular breeding.In this study,we obtained a total of 8.88 million highly reliable single nucleotide polymorphism(SNP)markers from 140 individuals from the natural hybrid offspring of Actinidia eriantha cv.‘White’using whole genome resequencing technology.A genome-wide association study was conducted on eight key agronomic traits,including single fruit weight,fruit shape,ASA content,and the number of inflorescences per branch.A total of 59 genetic loci containing potential functional genes were located,and candidate genes related to single fruit weight,fruit length,ASA content,number of inflorescences per branch and other traits were identified within the candidate interval,such as AeWUSCHEL,AeCDK1(cell cycle dependent kinase),AeAO1(ascorbic oxidase)and AeCO1(CONSTANS-like 4).After constructing an RNAi vector for AeAO1 and injecting it into the fruit of cv.‘Midao 31’to interfere with the expression of the AeAO1 gene,the results showed that the activity of ascorbic oxidase in the fruit of‘Midao 31’significantly decreased,while the content of ASA significantly increased.This study provides valuable insights into the genetic basis of variation in A.eriantha fruit traits,which may benefit molecular marker-assisted breeding efforts.
基金supported by the National Key Research and Development Program of China under Grant2021YFB2500600the Youth Innovation Promotion Association CAS under Grant2022138+2 种基金the National Natural Science Foundation of China under Grant51901221the Institute of Electrical EngineeringCAS under GrantE155710201 and E155710301。
文摘High-performance Cu/Graphene composite wire synergistically strengthened by nano Cr_(3)C_(2) phase was directly synthesized via hot press sintering followed by severe cold plastic deformation, using liquid paraffin and CuCr alloy powder as the raw materials. Since graphene is in situ formed under the catalysis of copper powder during the sintering process, the problem that graphene is easy to agglomerate and difficult to disperse uniformly in the copper matrix has been solved. The nano Cr_(3)C_(2)-particles nailed at the interface favor to improve the interface bonding. The Cu/Graphene composite possesses high electrical conductivity, hardness, and plasticity. The composite wire exhibits high electrical conductivity of 96.93% IACS, great tensile strength of 488MPa, and excellent resistance to softening. Even after annealing at 400℃ for 1 h, the tensile strength can still reach 268 MPa with a conductivity of about 99.14% IACS.The wire's temperature coefficient of resistance(TCR) is largely reduced to 0.0035/℃ due to the complex structure,which leads the wire to present low resistivity at higher temperatures. Such Cu/Graphene composite wire with excellent comprehensive performance has a good application prospect in high-power density motors.
基金supported by funds from the National Natural Science Foundation of China(31972474,90717110)Hubei Natural Science Fund for Distinguished Young Scholars(2020CFA062).
文摘Kiwifruit is an economically and nutritionally important fruit crop with extremely high contents of vitamin C.However,the previously released versions of kiwifruit genomes all have a mass of unanchored or missing regions.Here,we report a highly continuous and completely gap-free reference genome of Actinidia chinensis cv.‘Hongyang’,named Hongyang v4.0,which is the first to achieve two de novo haploid-resolved haplotypes,HY4P and HY4A.HY4P and HY4A have a total length of 606.1 and 599.6 Mb,respectively,with almost the entire telomeres and centromeres assembled in each haplotype.In comparison with Hongyang v3.0,the integrity and contiguity of Hongyang v4.0 is markedly improved by filling all unclosed gaps and correcting some misoriented regions,resulting in∼38.6–39.5 Mb extra sequences,which might affect 4263 and 4244 protein-coding genes in HY4P and HY4A,respectively.Furthermore,our gap-free genome assembly provides the first clue for inspecting the structure and function of centromeres.Globally,centromeric regions are characterized by higher-order repeats that mainly consist of a 153-bp conserved centromere-specific monomer(Ach-CEN153)with different copy numbers among chromosomes.Functional enrichment analysis of the genes located within centromeric regions demonstrates that chromosome centromeres may not only play physical roles for linking a pair of sister chromatids,but also have genetic features for participation in the regulation of cell division.The availability of the telomere-to-telomere and gap-free Hongyang v4.0 reference genome lays a solid foundation not only for illustrating genome structure and functional genomics studies but also for facilitating kiwifruit breeding and improvement.
基金This work was supported by funds from the National Natural Science Foundation of China(31972474,31471157)the Open Fund of State Key Laboratory of Tea Plant Biology and Utilization(SKLTOF20150103).
文摘A high-quality genome is the basis for studies on functional,evolutionary,and comparative genomics.The majority of attention has been paid to the solution of complex chromosome structures and highly repetitive sequences,along with the emergence of a new‘telomere-to-telomere(T2T)assembly’era.However,the bioinformatic tools for the automatic construction and/or characterization of T2T genome are limited.Here,we developed a user-friendly web toolkit,quarTeT,which currently includes four modules:AssemblyMapper,GapFiller,TeloExplorer,and CentroMiner.First,AssemblyMapper is designed to assemble phased contigs into the chromosome-level genome by referring to a closely related genome.Then,GapFiller would endeavor to fill all unclosed gaps in a given genome with the aid of additional ultra-long sequences.Finally,TeloExplorer and CentroMiner are applied to identify candidate telomere and centromere as well as their localizations on each chromosome.These four modules can be used alone or in combination with each other for T2T genome assembly and characterization.As a case study,by adopting the entire modular functions of quarTeT,we have achieved the Actinidia chinensis genome assembly that is of a quality comparable to the reported genome Hongyang v4.0,which was assembled with the addition of manual handling.Further evaluation of CentroMiner by searching centromeres in Arabidopsis thaliana and Oryza sativa genomes showed that quarTeT is capable of identifying all the centromeric regions that have been previously detected by experimental methods.Collectively,quarTeT is an efficient toolkit for studies of large-scale T2T genomes and can be accessed at http://www.atcgn.com:8080/quarTeT/home.html without registration.
基金financially supported by National Natural Science Foundation of China (Grants Nos. 52273182, 21875122)。
文摘Layered two dimensional(2D) or quasi-2D perovskites are emerging photovoltaic materials due to their superior environment and structure stability in comparison with their 3D counterparts. The typical 2D perovskites can be obtained by cutting 3D perovskites along < 100 > orientation by incorporation of bulky organic spacers, which play a key role in the performance of 2D perovskite solar cells(PSCs). Compared with aliphatic spacers, aromatic spacers with high dielectric constant have the potential to decrease the dielectric and quantum confinement effect of 2D perovskites, promote efficient charge transport and reduce the exciton binding energy, all of which are beneficial for the photovoltaic performance of 2D PSCs. In this review, we aim to provide useful guidelines for the design of aromatic spacers for 2D perovskites. We systematically reviewed the recent progress of aromatic spacers used in 2D PSCs. Finally, we propose the possible design strategies for aromatic spacers that may lead to more efficient and stable 2D PSCs.
文摘Thoracic spinal stenosis (TSS) is a group of clinical syndromes caused by thoracic spinal cord compression, which always results in severe clinical complications. The incidence of TSS is relatively low compared with lumbar spinal stenosis, while the incidence of spinal cord injury during thoracic decompression is relatively high. The reported incidence of neurological deficits after thoracic decompression reached 13.9%.Intraoperative neurophysiological monitoring (IONM) can timely provide information regarding the function status of the spinal cord, and help surgeons with appropriate performance during operation. This article illustrates the theoretical basis of applying IONM in thoracic decompression surgery, and elaborates on the relationship between signal changes in IONM and postoperative neurological function recovery of the spinal cord. It also introduces updated information in multimodality IONM, the factors influencing evoked potentials,and remedial measures to improve the prognosis.
基金supported by grants from the National Natural Science Foundation of China(31972474,31671259,31471157,31900257,31400049,and 90717110)the Anhui Provincial Natural Science Foundation(1808085QC68)+5 种基金the National Foundation for the Germplasm Repository of Special Horticultural Crops in Central Mountain Areas of China(NJF2017-69)the National Science Fund for Distinguished Young Scholars(30825030)Key Project of the Government of Sichuan Province(2013NZ0014)Key Project of the Government of Anhui Province(2012AKKG07391808085MC57)the US National Science Foundation(IOS-1339287 and IOS-1855585).
文摘Kiwifruit(Actinidia spp.)plants produce economically important fruits containing abundant,balanced phytonutrients with extraordinarily high vitamin C contents.Since the release of the first kiwifruit reference genome sequence in 2013,large volumes of genome and transcriptome data have been rapidly accumulated for a handful of kiwifruit species.To efficiently store,analyze,integrate,and disseminate these large-scale datasets to the research community,we constructed the Kiwifruit Genome Database(KGD;http://kiwifruitgenome.org/).The database currently contains all publicly available genome and gene sequences,gene annotations,biochemical pathways,transcriptome profiles derived from public RNA-Seq datasets,and comparative genomic analysis results such as syntenic blocks and homologous gene pairs between different kiwifruit genome assemblies.A set of user-friendly query interfaces,analysis tools and visualization modules have been implemented in KGD to facilitate translational and applied research in kiwifruit,which include JBrowse,a popular genome browser,and the NCBI BLAST sequence search tool.Other notable tools developed within KGD include a genome synteny viewer and tools for differential gene expression analysis as well as gene ontology(GO)term and pathway enrichment analysis.
基金supported by Liaoning Provincial Hospital Reform Key Clinical Diagnosis and Treatment Capacity Building Project(Youth Project):Diabetic Foot Multidisciplinary Cooperative Comprehensive Treatment Model Construction Project.(201507-201707)
文摘Objective To evaluate the rates of wound healing and limb preservation following angiosome-targeted infrapopliteal endovascular revascularization in the treatment of diabetic limb ischemia. Methods We performed a retrospective analysis of data gathered from 102 infrapopliteal angioplasty cases(60 males and 42 females; mean age, 72 ± 11 years) with Fontaine IV ischemia(ankle-brachial index, ABI: 0.16 ± 0.06). Forty-seven angioplasties were performed based on the angiosome concept(direct revascularization, DR), while 55 did not incorporate the angiosome concept(indirect revascularization, IR). The curative effects of angioplasty were assessed by postoperative determinations of ABI performed every 3 months during clinical follow-up visits conducted to assess healing of the ischemic wound. Amputation and death events were recorded throughout the study. Results All 102 patients were successfully revascularized without complications, and during a mean follow-up period of 18 ± 11 months, the mean postoperative ABI improved to 0.84 ± 0.10. The postoperative 6 and 12 month healing rates in the DR group were 85.1% and 93.5%, respectively, while the limb-salvage rates were 100% and 93.5%, respectively. The postoperative 6 and 12 month healing rates in the IR group were 60% and 76.4%, respectively, while the limb-salvage rates were 90.1%, and 85.5%, respectively. Conclusion Angiosome-based Infrapopliteal angioplasty was associated with better wound healing and higher rates of limb salvage in cases of critical diabetic foot ischemia. Revascularization should be provided to patients who have undergone indirect perfusion of the ischemic angiosome, as acceptable rates of limb salvage are obtained.
基金supported by the National Science Fund of China for Distinguished Young Scholars(30825030)the National Natural Science Foundation of China(31671259).
文摘Fleshy fruit ripening is governed by multiple external and internal cues and accompanied by changes in color,texture,volatiles,and nutritional quality traits.While extended shelf-life and increased phytonutrients are desired,delaying ripening via genetic or postharvest means can be accompanied by reduced nutritional value.Here we report that the high pigment 1(hp1)mutation at the UV-DAMAGED DNA BINDING PROTEIN 1(DDB1)locus,previously shown to influence carotenoid and additional phytonutrient accumulation via altered light signal transduction,also results in delayed ripening and firmer texture,resulting at least in part from decreased ethylene evolution.Transcriptome analysis revealed multiple ethylene biosynthesis and signaling-associated genes downregulated in hp1.Furthermore,the hp1 mutation impedes softening of the pericarp,placenta,columella as well as the whole fruit,in addition to reduced expression of the FRUITFUL2(FUL2)MADS-box transcription factor and xyloglucan endotransglucosylase/hydrolase 5(XTH5).These results indicate that DDB1 influences a broader range of fruit development and ripening processes than previously thought and present an additional genetic target for increasing fruit quality and shelf-life.
文摘Objective:This study aimed to evaluate the clinical and angiographic outcomes of aneurysms that were completely or near-completely embolized and ascertain whether complete embolization is important in the stent-assisted coiling(SAC)of intracranial aneurysms.Methods:This retrospective study enrolled 390 patients(417 aneurysms).Among them,complete(100%)or nearcomplete(>90%)angiographic obliteration of the aneurysms on immediate angiography was accomplished.Baseline characteristics,complications,angiography follow-up results,and clinical outcomes were analyzed.Results:Cumulative adverse events occurred in 30 patients(7.7%),including thromboembolic complications in 17(4.4%),intraoperative rupture in 10(2.6%),and others in 3(0.8%).Statistical analyses revealed an increased intraprocedural rupture rate in the initial completely occluded aneurysms(5.6%compared with 1.0%).The incidence of cumulative adverse events was higher in patients with completely occluded aneurysms(11.1%)than in those with near-completely occluded aneurysms(5.5%).Angiography follow-up was available for 173 aneurysms.Aneurysm occlusion status at follow-up was correlated with stent placement(p?0.000,odds ratio?5.847),size(p?0.000,odds ratio?6.446 for tiny aneurysms;and p?0.001,odds ratio?5.616 for small aneurysms),and initial aneurysm occlusion status(p?0.001,odds ratio?3.436).Complete occlusion at followup was seen in 82.6%of the initial complete occlusion group versus 63.0%of the initial near-complete occlusion group.The incidence of complete occlusion at follow-up was higher in the initial completely occluded aneurysms with SAC(100%)than in the initial completely occluded aneurysms with non-SAC(65.2%).Conclusions:Initial complete treatment may lead to higher complication rates and good clinical outcomes at follow-up.Stent placement may enhance progressive aneurysm occlusion.Initial complete occlusion with SAC can provide durable closure at follow-up.
基金supported by National Science Foundation Plant Genome Program grant IOS-1855585 to JG and the US Department of Agriculture-Agricultural Research Service.
文摘Use of CRISPR-Cas9(Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)-CRISPR-associated 9)-mediated genome editing has proliferated for use in numerous plant species to modify gene function and expression,usually in the context of either transient or stably inherited genetic alternations.While extremely useful in many applications,modification of some loci yields outcomes detrimental to further experimental evaluation or viability of the target organism.Expression of Cas9 under a promoter conferring gene knockouts in a tissue-specific subset of genomes has been demonstrated in insect and animal models,and recently in Arabidopsis.We developed an in planta GFP(green fluorescent protein)assay system to demonstrate fruit-specific gene editing in tomato using a phosphoenolpyruvate carboxylase 2 gene promoter.We then targeted a SET-domain containing polycomb protein,SlEZ2,previously shown to yield pleiotropic phenotypes when targeted via ^(35)S-driven RNA interference and we were able to characterize fruit phenotypes absent additional developmental perturbations.Tissue-specific gene editing will have applications in assessing function of essential genes otherwise difficult to study via germline modifications and will provide routes to edited genomes in tissues that could not otherwise be recovered when their germline modification perturbs their normal development.
文摘A forest fire is a severe threat to forest resources and human life, In this paper, we propose a forest-fire detection system that has an artificial neural network algorithm implemented in a wireless sensor network (WSN). The proposed detection system mitigates the threat of forest fires by provide accurate fire alarm with low maintenance cost. The accuracy is increased by the novel multi- criteria detection, referred to as an alarm decision depends on multiple attributes of a forest fire. The multi-criteria detection is implemented by the artificial neural network algorithm. Meanwhile, we have developed a prototype of the proposed system consisting of the solar batter module, the fire detection module and the user interface module.
基金the National Natural Science Foundation of China(31900257,31972474).
文摘Flowers are an essential organ for sexual reproduction of higher plants.Severe lesions along with flower blight on tea(Camellia sinensis)plants were observed in the experimental tea plantation located in Hefei(China).The pathogens isolated from diseased flowers matched the morphological peculiarity of Alternaria alternata.The species characteristics of A.alternata were further confirmed by both pathogenicity tests and multi-gene phylogenetic analyses by using internal transcribed spacer(ITS),glyceraldehyde-3-phosphate dehydrogenase(GAPDH)and betatubulin(TUB).The combined phylogeny analysis using sequences derived from the ITS,GAPDH and TUB showed that the isolated pathogens belong to the genus Alternaria.Pathogenicity tests conducted on healthy tea flowers and leaves manifested typical symptoms of flower blight while weaker symptoms of leaf spot,demonstrating the A.alternata isolates were the causal agents of flower blight disease on tea plants.This fungus is first reported as a pathogen causing flower blight on C.sinensis in this study.
基金supported by the National Natural Science Foundation of China(Grant Nos.42272338,41827807 and 41902275)Shanghai Sailing Program(Grant No.18YF1424400)+7 种基金Joint Fund for Basic Research of High-speed Railway of National Natural Science Foundation of China,China Railway Corporation(U1934212)China State Railway Group Co.,Ltd.(P2019G038)Department of Transportation of Zhejiang Province(202213)China Railway First Survey and Design Institute Group Co.,Ltd.(19-21-1,2022KY53ZD(CYH)-10)China Railway Tunnel Group Co.,Ltd.(CZ02-02-08)PowChina Hebei Transportation Highway Investment Development Co.,Ltd.(TH-201908)Sichuan Railway Investment Group Co.,Ltd.(SRIG2019GG0004)The Science and Technology major program of Guizhou Province[2018]3011.
文摘Discontinuity is critical for strength,deformability,and permeability of rock mass.Set information is one of the essential discontinuity characteristics and is usually accessed by orientation grouping.Traditional methods of identifying optimal discontinuity set numbers are usually achieved by clustering validity indexes,which mainly relies on the aggregation and dispersion of clusters and leads to the inaccuracy and instability of evaluation.This paper proposes a new method of Fisher mixed evaluation(FME)to identify optimal group numbers of rock mass discontinuity orientation.In FME,orientation distribution is regarded as the superposition of Fisher mixed distributions.Optimal grouping results are identified by considering the fitting accuracy of Fisher mixed distributions,the probability monopoly and central location significance of independent Fisher centers.A Halley-Expectation-Maximization(EM)algorithm is derived to achieve an automatic fitting of Fisher mixed distribution.Three real rock discontinuity models combined with three orientation clustering algorithms are adopted for discontinuity grouping.Four clustering validity indexes are used to automatically identify optimal group numbers for comparison.The results show that FME is more accurate and robust than the other clustering validity indexes in optimal discontinuity group number identification for different rock models and orientation clustering algorithms.
基金supported by the National Key R&D Program of China(No.2022YFC2204500)the National Natural Science Foundation of China(No.52231007).
文摘In this work,low-softening-temperature and low-modulus SiO_(2) was introduced as an embedded interface between SiC nanowires(SiCnws)and a Ba_(x)Sr_(1−x)Al_(2)Si_(2)O_(8) ceramic matrix to enhance strength and toughness of the ceramic.During the sintering process,molten SiO_(2) enhances the flowability of the ceramic powders and modifies the dispersion of SiCnws.The strengthening effect of SiCnws was fully realized,and the flexural strength of the optimized ceramics reached 193±16 MPa,which represents an increase of 52.6%.After the formation of the embedded SiO_(2) interface with a low modulus,cracks can deflect along the SiCnws surface,which is consistent with the criterion of He and Hutchinson.This can effectively extend the crack propagation path,and the fracture toughness(K_(IC))is thus improved by 94.0%,reaching 3.1±0.5 MPa·m^(1/2).
基金supported by the Fund of Fujian Science&Technology Innovation Laboratory for Optoelectronic Information(grant nos.2020ZZ114 and 2022ZZ204)the Key Research Program of Frontier Science CAS(grant no.QYZDY-SSW-SLH025)+1 种基金the National Natural Science Foundation of China(grant nos.21731006 and 21871256)the Fund of Advanced Energy Science and Technology Guangdong Laboratory(grant no.DJLTN0200/DJLTN0240).
文摘Rapid halide anion exchange easily occurring in metal-halide perovskite nanoparticles(NPs)makes it nearly impossible to create a single three-dimensional(3D)CsPbX_(3)(X=Cl,Br,I)NP that simultaneously comprises two separate perovskite components.To circumvent this problem,we first propose a Ni^(2+)-mediated halide anion-exchange strategy in zero-dimensional(0D)Ni^(2+)-doped Cs_(4)PbBr_(6)(Cs_(4)PbBr_(6):Ni)perovskites to achieve ultra-stable 3D CsPbX_(3)NPs with two coexisting different perovskite individuals of CsPbCl_(3)and/or CsPbBr_(3).By combining the experimental results with first-principles calculations,we confirm that the completely isolated[PbBr_(6)]4−octahedra in 0D Cs_(4)PbBr_(6):Ni NPs can restrict rapid halide anion exchange and the anion diffusion preferentially proceeds in the proximity of substitutional NiPb centers,namely[NiBr_(6)]4−octahedra in a meta-stable state,rather than in the 0D Cs_(4)PbBr_(6)and residual 3D CsPbBr_(3)regions,thereby delivering intrinsic dual-band excitonic luminescence from a single 3D CsPbX_(3)NP with a more stable and efficient CsPbCl_(3)component as compared to its counterparts synthesized using conventional methods.These new insights regarding the precise control of halide anion exchange enable the preparation of a new type of high-efficiency perovskite materials with suppressed anion interdiffusion for prospective optoelectronic devices.
基金co-supported by the National Natural Science Foundation of China(No.41922021)the MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(No.MSFGPMR01-03)。
文摘The Permian basalts in the Central Asian Orogenic Belt(CAOB)are crucial for constraining the closure of the Paleo-Asian Ocean.However,the origin of these basalts is still under discussion.Here,we present comprehensive bulk-rock geochemical,Sr-Nd-Pb-Hf isotopic,and zircon U-Pb-Lu-Hf isotopic data of the Liuyuan basalts and coexisting gabbros,which are located in the Beishan Orogen in the southern CAOB,to constrain their emplacement setting and tectonic implications.Our new gabbro ages of ca.288–294 Ma are interpreted to represent the formation time of the Liuyuan basaltic belt.The Liuyuan basalts show MORB-like rare earth element(REE)patterns and bulk-rockε_(Hf)(t)andε_(Nd)(t)values of 11.0–15.4 and 4.6–9.2,respectively,suggesting an origination mainly from a depleted mantle source.However,positive Pb anomalies,Nb-Ta depletions,and high Th/Yb ratios as well as evolved Sr-Nd-Pb-Hf isotopic compositions of some samples indicate variable continental crustal contribution.According to the covariation of Pb anomalies(Pb^(*)=2×Pb_(N)/(Ce_(N)+Pr_(N)))with Sr-Nd-Pb-Hf isotopic compositions,we speculate that parent magma of the Liuyuan basalt was contaminated by continental crustal materials during the eruption rather than having been generated from an enriched mantle source.As revealed by mixing modelling,the Liuyuan basaltic magmas would require a minor(<10%)upper continental crustal assimilation to explain the enriched trace elemental and radiogenic Sr-Nd-Pb-Hf isotopic signatures.Consequently,the Liuyuan basaltic belt is believed to have been generated in a continental extensional environment instead of an oceanic setting and does not constitute a Permian ophiolitic suture zone as previously suggested,since the Paleo-Asian Ocean was already closed in the southern Beishan Orogen in the Early Permian.
基金supported by the National Natural Science Foundation of China(21975264,21925112,21875122,61935016,92056119,61935016,21771008)Beijing Natural Science Foundation(2191003)+1 种基金the Youth Innovation Promotion Association Chinese Academy of Sciences,the National Key Research and Development Project funding from the Ministry of Science and Technology of China(2021YFB3800100,2021YFB3800101,2020YFB1506400)the Basic and Applied Basic Research Foundation of Guangdong Province(2019B1515120083)。
文摘Perovskite solar cells represent a promising third-generation photovoltaic technology with low fabrication cost and high power conversion efficiency.In light of the rapid development of perovskite materials and devices,a systematic survey on the latest advancements covering a broad range of related work is urgently needed.This review summarizes the recent major advances in the research of perovskite solar cells from a material science perspective.The discussed topics include the devices based on different type of perovskites(organic-inorganic hybrid,all-inorganic,and lead-free perovskite and perovskite quantum dots),the properties of perovskite defects,different type of charge transport materials(organic,polymeric,and inorganic hole transport materials and inorganic and organic electron transport materials),counter electrodes,and interfacial materials used to improve the efficiency and stability of devices.Most discussions focus on the key progresses reported within the recent five years.Meanwhile,the major issues limiting the production of perovskite solar cells and the prospects for the future development of related materials are discussed.
基金funded by the National Key R&D Program of China (No. 2019YFA0708400)the National Natural Science Foundation of China (No. 41927803)+2 种基金the MOST (Ministry of Science and Technology) Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources (No. MSFGPMR01)the Natural Science Foundation of Hubei Province (No. 2020CFA045)the Fundamental Research Funds for the Central Universities,China University of Geosciences (Wuhan).
文摘The method of LA-MC-ICP-MS has become one choice for the analysis of many isotopic systems due to its relatively low cost,high analysis speed,high spatial resolution,and low matrix effect.However,there are still many challenges in the accuracy,precision,and spatial resolution of in situ isotopic composition determination by LA-MC-ICP-MS,which mainly include:(1)how to improve instrument sensitivity,further improve the spatial resolution,and achieve simultaneous determination of isotopes,multiple isotopes,or isotopes with trace elements in low-content samples?(2)how to deduct and correct interference to improve the accuracy of isotopic determination?(3)how to correct isotope fractionation?(4)how to reduce the matrix effect of isotopes?how to develop matrix-matched reference materials?and(5)how to achieve non-matrix-matched correction of isotopes?The high-sensitivity cone combinations,gas mixture,shield torch,and reasonable detector array can be applied to improve the elemental sensitivity.The interferences include the background interference and the interferences from the matrix elements(the isobaric interference,the polyatomic interference,and doubly charged ions interference).To reduce or even eliminate the interference,commonly used methods including interference elimination,background correction,and interference correction by evaluating with an interference-free isotope.Isotopic fractionation correction mainly involves external standard calibration and internal and pseudo-internal standard normalization.For non-matrix matched calibration,many methods can be applied,such as the femtosecond laser,line scan,low laser energy,wet plasma condition,optical setup below the sample surface,and matching the intensity of the sample and standard.In this review,we systematically summarized the above challenges and solutions to promote the study and application of LA-MC-ICP-MS in isotopic determination.
基金the financial support from the National Natural Science Foundation of China(Grants No.52273182)the National Key Research and Development Program of China(Grant No.2019YFA0705900).
文摘Perovskite solar cells (PSCs) have achieved significant progress in the past decade and a certified power conversion efficiency (PCE) of 26.0% has been achieved.The widely used organic hole transport materials (HTMs) in PSCs are typically sensitive to the moisture environment and continuous light exposure.In contrast,the inorganic HTMs benefiting from their outstanding merits,such as excellent environmental stability,are considered as alternatives and have attracted much attention in PSCs.In this review,we provide a comprehensive summary of the fundamental properties and recent progress of inorganic HTMs in n-i-p and p-i-n structured PSCs.Additionally,we emphasize the importance of inorganic HTMs in the development of highly efficient and stable PSCs.