综合创新实验:碳基钙钛矿太阳能电池的制备与性能表征

实验教学对于化学专业学生的创新能力培养至关重要。通过综合实验教学,培养化学专业学生发现问题和解决问题的能力,增强学生对太阳能光伏器件的研究兴趣,树立科研信心,培养学生的创新能力。采用表面工程提高可刮涂的碳基钙钛矿电池的性能,促进界面层间的空穴传输和钙钛矿/碳界面接触,提高电池器件的转换效率。该实验可操作性强,安全性高,可以直观感受光能与电能之间的转化,深入理解光伏器件的工作原理。

Draft genome sequence of cauliflower(Brassica oleracea L.var.botrytis)provides new insights into the C genome in Brassica species

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.

Haplotype-resolved genome of diploid ginger (Zingiber officinale) and its unique gingerol biosynthetic pathway

Ginger(Zingiber officinale),the type species of Zingiberaceae,is one of the most widespread medicinal plants and spices.Here,we report a high-quality,chromosome-scale reference genome of ginger‘Zhugen’,a traditionally cultivated ginger in Southwest China used as a fresh vegetable,assembled from PacBio long reads,Illumina short reads,and high-throughput chromosome conformation capture(Hi-C)reads.The ginger genome was phased into two haplotypes,haplotype 1(1.53 Gb with a contig N50 of 4.68 M)and haplotype 0(1.51 Gb with a contig N50 of 5.28 M).Homologous ginger chromosomes maintained excellent gene pair collinearity.In 17,226 pairs of allelic genes,11.9%exhibited differential expression between alleles.Based on the results of ginger genome sequencing,transcriptome analysis,and metabolomic analysis,we proposed a backbone biosynthetic pathway of gingerol analogs,which consists of 12 enzymatic gene families,PAL,C4H,4CL,CST,C3’H,C3OMT,CCOMT,CSE,PKS,AOR,DHN,and DHT.These analyses also identified the likely transcription factor networks that regulate the synthesis of gingerol analogs.Overall,this study serves as an excellent resource for further research on ginger biology and breeding,lays a foundation for a better understanding of ginger evolution,and presents an intact biosynthetic pathway for species-specific gingerol biosynthesis.

Correction:Haplotype-resolved genome of diploid ginger (Zingiber officinale)and its unique gingerol biosynthetic pathway

After online publication of the article 1,the authors noticed the affiliation“College of Landscape Architecture and Life Science/Institute of Special Plants,Chongqing University of Arts and Sciences,Yongchuan,Chongqing,China”for author Yiqing Liu was missing.

Pan-genome of Raphanus highlights genetic variation and introgression among domesticated,wild,and weedy radishes

Post-polyploid diploidization associated with descending dysploidy and interspecific introgression drives plant genome evolution by unclear mechanisms.Raphanus is an economically and ecologically important Brassiceae genus and model system for studying post-polyploidization genome evolution and introgres-sion.Here,we report the de novo sequence assemblies for 11 genomes covering most of the typical sub-species and varieties of domesticated,wild and weedy radishes from East Asia,South Asia,Europe,and America.Divergence among the species,sub-species,and South/East Asian types coincided with Quaternary glaciations.A genus-level pan-genome was constructed with family-based,locus-based,and graph-based methods,and whole-genome comparisons revealed genetic variations ranging from single-nucleotide polymorphisms(SNPs)to inversions and translocations of whole ancestral karyotype(AK)blocks.Extensive gene flow occurred between wild,weedy,and domesticated radishes.High fre-quencies of genome reshuffling,biased retention,and large-fragment translocation have shaped the genomic diversity.Most variety-specific gene-rich blocks showed large structural variations.Extensive translocation and tandem duplication of dispensable genes were revealed in two large rearrangement-rich islands.Disease resistance genes mostly resided on specific and dispensable loci.Variations causing the loss of function of enzymes modulating gibberellin deactivation were identified and could play an important role in phenotype divergence and adaptive evolution.This study provides new insights into the genomic evolution underlying post-polyploid diploidization and lays the foundation for genetic improve-ment of radish crops,biological control of weeds,and protection of wild species'germplasms.

Performance improvement approaches for optical fiber SPR sensors and their sensing applications

Optical fiber surface plasmon resonance(SPR) sensors point toward promising application potential in the fields of biomarker detection,food allergen screening,and environmental monitoring due to their unique advantages.This review outlines approaches in improving the fiber SPR sensing performance,e.g.,sensitivity,detection accuracy,reliability,cross-sensitivity,selectivity,convenience and efficiency,and corresponding sensing applications.The sensing principles of SPR sensors,especially the performance indicators and their influencing factors,have been introduced.Current technologies for improving the fiber SPR performance and their application scenarios are then reviewed from the aspects of fiber substrate,intrinsic layer(metal layer),and surface nanomaterial modification.Reasonable design of the substrate can strengthen the evanescent electromagnetic field and realize the multi-parameter sensing,and can introduce the in situ sensing self-compensation,which allows corrections for errors induced by temperature fluctuation,non-specific binding,and external disturbances.The change of the intrinsic layer can adjust the column number,the penetration depth,and the propagation distance of surface plasmon polaritons.This can thereby promote the capability of sensors to detect the large-size analytes and can reduce the full width at half-maximum of SPR curves.The modification of various-dimensionality nanomaterials on the sensor surfaces can heighten the overlap integral of the electromagnetic field intensity in the analyte region and can strengthen interactions between plasmons and excitons as well as interactions between analyte molecules and metal surfaces.Moreover,future directions of fiber SPR sensors are prospected based on the important and challenging problems in the development of fiber SPR sensors.

双叶型人工机械心脏瓣膜置换术后单瓣叶脱落2例

瓣叶脱落是人工心脏瓣膜置换术的罕见并发症。该文报道了2例双叶型人工机械心脏瓣膜置换术后单瓣叶脱落病例,并结合文献探讨了瓣叶脱落原因及处理策略。瓣叶脱落原因可能与瓣膜设计、瓣叶材质有关,需再次行瓣膜置换术。脱落瓣叶破损并严重影响远端血管者,应积极通过手术取出;未对远端血管损伤者,可暂不拆除,但需进行严密随访。

Small-signal Multi-frequency Model for Grid-connected Inverter System with PWM Effect

It is a well known fact that pulse width modulation(PWM)produces sideband effects.Taking this point into account,the accuracy of the grid-connected inverter model can be improved.In this paper,considering the aliasing effect of the PWM sideband components on the closed-loop control,a complete representation for the transfer function of the PWM is obtained.Furthermore,a multi-frequency model of grid-connected inverter system is derived.It is convenient for obtaining a PWM gain for grid-connected inverter system,which is PWM-controlled.In order to have an easy physical expression of the effects caused by the sideband components,an approximation is applied to simplify the PWM gain.The stability analysis is used to prove that PWM gain considering PWM effect is more precise than the conventional one.Experimental results verify the effectiveness of our proposal.

Pitch-derived 3D amorphous carbon encapsulated sulfur-rich cathode for aqueous Zn-S batteries

Rechargeable aqueous zinc batteries have attracted much attention due to their high security, plentiful zinc resources, and environmental friendliness. However, it can only offer limited specific capacity and energy density based on ion insertion chemistry cathode. Herein, we design a low-cost and high-energy density aqueous Zn-S battery where the conversion cathode was fabricated by pitch-derived three-dimensional(3D) amorphous carbon encapsulated industrial-grade sulfur powder. The cost of the chemical substances for this aqueous Zn-S battery might be reduced to $9.38 per kW h based on the affordable cost of the raw ingredients. It is found that the PAC/S-60.33% cathode reveals excellent electrochemical performance, including a high reversible capacity(633.5 mAh g^(-1)at 0.5 A g^(-1)), high energy density(297.5 Wh kg^(-1)), an excellent rate capability(204.5 mAh g^(-1) at 5.5 A g^(-1)), as well as good cycling stability(180 mAh g^(-1)after 400 cycles at 5.0 A g^(-1)). Besides, the reaction mechanism of the cathode was investigated using ex-situ X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), and transmission electron microscope(TEM). It was demonstrated that the cathode undergoes a conversion reaction between S and Zn S. Furthermore, the discoveries also offer prospective possibilities to fabricate more secure and inexpensive battery systems.

Dual modulation of homogeneous nanomaterialization and electrochemical activation enhancing zinc ion storage

Vanadium-based electrode materials are widely investigated,but the low specific capacity and slow electrochemical kinetics in aqueous zinc-ion batteries still limit their commercial development.Herein,the VS_(2)/Ca V_(4)O_(9)material with the morphology of nanoflower was synthesized by a one-step hydrothermal method.Compared to the blocky structure of pure VS_(2)material,the VS_(2)/Ca V_(4)O_(9)material is composed of thinner homogeneous nanosheets.The open structures could provide abundant electrochemical active sites and ion transport channels,and then promote the electrochemical reaction kinetics.In addition,they can also buffer the bulk strain during the reaction process.To improve the utilization of vanadium elements,an in-situ electrochemical activation strategy is used to explore the storage performance of the VS_(2)/Ca V_(4)O_(9)material,the different activation voltage range of 0.4–1.6 and 0.4–1.4 V are selected,respectively.Compared with the longer activation plateau of activated-VS_(2),the VS_(2)/Ca V_(4)O_(9)cathode could quickly reach the activation state in the range of 1.4–1.6 V and cause the release of additional Zn storage sites simultaneously.The VS_(2)/Ca V_(4)O_(9)cathode delivers a higher power density of 37,000 W kg^(-1)and a significant energy density of 423 Wh kg^(-1).At the high current density of 15 A g^(-1),the VS_(2)/Ca V_(4)O_(9)cathode still has a discharge capacity of 183.9m Ah g^(-1)after 5,000 cycles,and the capacity decay rate per cycle is only 0.0042%.Continuous cyclic voltammetry(CV)curves,electrochemical impedance spectroscopy(EIS)measurements,density functional theory(DFT)calculation and galvanostatic intermittent titration technique(GITT)measurements demonstrate that the VS_(2)/Ca V_(4)O_(9)cathode has a faster ion diffusion/charge transfer kinetics.Meanwhile,the assembled flexible device has an excellent mechanical stability.