Pressure-Induced Distinct Self-Trapped Exciton Emission in Sb^(3+)-Doped Cs_(2)NaInCl_(6)Double Perovskite

The Cs_(2)NaInCl_(6) double perovskite is one of the most promising lead-free perovskites due to its exceptional stability and straightforward synthesis.However,it faces challenges related to inefficient photoluminescence.Doping and high pressure are employed to tailor the optical properties of Cs_(2)NaInCl_(6).Herein,Sb^(3+)doped Cs_(2)NaInCl_(6)(Sb^(3+):Cs_(2)NaInCl_(6)) was synthesized and it exhibits blue emission with a photoluminescence quantum yield of up to 37.3%.Further,by employing pressure tuning,a blue stable emission under a very wide range from 2.7 GPa to 9.8 GPa is realized in Sb^(3+):Cs_(2)NaInCl_(6).Subsequently,the emission intensity of Sb^(3+):Cs_(2)NaInCl_(6) experiences a significant increase(3.3 times)at 19.0 GPa.It is revealed that the pressure-induced distinct emissions can be attributed to the carrier self-trapping and detrapping between Cs_(2)NaInCl_(6) and Sb^(3+).Notably,the lattice compression in the cubic phase inevitably modifies the band gap of Sb^(3+):Cs_(2)NaInCl_(6).Our findings provide valuable insights into effects of the high pressure in further boosting unique emission characteristics but also offer promising opportunities for development of doped double perovskites with enhanced optical functionalities.

基于工匠精神的中职青年教师培养载体的探索和实践

教师工匠精神的培养是促进教师专业发展及提高教学质量的关键,而国内中职青年教师工匠精神现状堪忧。在此背景下,从课堂和科研两个维度开展研究,给出了培养中职青年教师工匠精神的8个方面策略及实施过程,形成了较为成熟的青年教师工匠精神培养体系。

Performance comparison of heat exchangers using sextant/trisection helical baffles and segmental ones

The shell side flow fields of both sextant and trisection helical baffle heat exchangers are presented on meridian and multilayer hexagon slices.It verifies that the performance of sextant schemes is better than those of the other kinds of helical baffle heat exchangers.The main mechanisms are due to the restricted leakage flow in the minimized gaps with increased baffle number and by one row of tubes dampen the leakage flow in the circumferential overlapped area of the adjacent helical baffles.The performance features were simulated on two different angled sextant helical heat exchangers and each compared with two trisection ones of either identical helical pitch or identical incline angle.The results verified that the performances of helical heat exchangers are mainly determined by the helical pitch rather than the baffle incline angle.The average values of comprehensive index hoΔpo-1/3 of the trisection helical schemes T-24.1°and T-29.7°are correspondingly 3.47%and 3.34%lower than those of the sextant ones X-20°and X-25°with identical helical pitches.The comparison results show that the average values of shell side h.t.c.hoand comprehensive index hoΔpo-1/3 of the optimal dual helix sextant scheme DX30°are respectively 7.22%and 23.56%higher than those of the segment scheme S100.

Stability and band gap engineering of silica-confined lead halide perovskite nanocrystals under high pressure

SiO_(2)is the major mineral substance in the upper mantle of the earth.Therefore,studies of the silica-coated materials under high-pressure are essential to explore the physical and chemical properties of the upper mantle.The silica-confined CsPbBr_(3)nanocrystals(NCs)have recently attracted much attention because of the improved photoluminescence(PL)quantum yield,owing to the protection of silica shell.However,it remains considerable interest to further explore the relationship between optical properties and the structure of CsPbBr_(3)@SiO_(2)NCs.We systemically studied the structural and optical properties of the CsPbBr_(3)@SiO_(2)NCs under high pressure by using diamond anvil cell(DAC).The discontinuous changes of PL and absorption spectra occurred at~1.40 GPa.Synchrotron X-ray diffraction(XRD)studies of CsPbBr_(3)@SiO_(2)NCs under high pressure indicated an isostructural phase transformation at about 1.36 GPa,owing to the pressure-induced tilting of the Pb-Br octahedra.The isothermal bulk moduli for two phases are estimated about 60.0 GPa and 19.2 GPa by fitting the equation of state.Besides,the transition pressure point of CsPbBr_(3)@SiO_(2)NCs is slightly higher than that of pristine CsPbBr_(3)NCs,which attributed to the buffer effect of coating silica shell.The results indicate that silica shell is able to enhance the stabilization without changing the relationship between optical properties and structure of CsPbBr_(3)NCs.Our results were fascinated to model the rock metasomatism in the upper mantle and provided a new‘lithoprobe’for detecting the upper mantle.

Two new species of Xiphydriidae(Hymenoptera) from China

Two new Xiphydriidae species are described from Zhejiang,China:Hyperxiphia ruficephala Wei sp.nov.and Xiphydria tianmunica Wei sp.nov.Types examined in this study are deposited in the Asian Sawfly Museum,Nanchang(ASMN).

Two new species of Arge Schrank(Hymenoptera: Argidae) from China

The diagnostic characters of Arge nipponensis group and Arge mali group are briefly discussed. Two new species of Argidae are described from China: Arge wanziae Wei sp. nov. and Arge listoni Wei sp. nov. Arge wanziae is a member of the Arge nipponensis group and A. listoni is a member of Arge mali group.

Toward enhanced alkaline hydrogen electrocatalysis with transition metal‐functionalized nitrogen‐doped carbon supports

Superior catalyst supports are crucial to developing advanced electrocatalysts toward heterogeneous catalytic reactions.Herein,we systematically investigate the role of transition metal‐functionalized N‐doped carbon nanosheets(M‐N‐C,M=Mn,Fe,Co,Ni,Cu,Mo,and Ag)as the multifunctional electrocatalyst supports toward hydrogen evolution/oxidation reactions(HER/HOR)in alkaline media.The results demonstrate that all the M‐N‐C nanosheets,except Cu‐N‐C and Ag‐N‐C,can promote the alkaline HER/HOR electrocatalytic activity of Pt by accelerating the sluggish Volmer step,among which Mn plays a more significant role.Analyses reveal that the promotion effect of M‐N‐C support is closely associated with the electronegativity of the metal dopants and the relative filling degree of their d‐orbitals.For one,the metal dopant in M‐N‐C with smaller electronegativity would provide more electrons to oxygen and hence tune the electronic structure of Pt via the M‐O‐Pt bonds at the interface.For another,the transition metal in M‐N4 moieties with more empty d orbitals would hybridize with O 2p orbitals more strongly that promotes the adsorption of water/hydroxyl species.The results demonstrate the conceptual significance of multifunctional supports and would inspire the future development of advanced electrocatalysts.

Motivational Practices in Foreign Language Teaching:From the Perspective of Self-Determination Theory

This quantitative-oriented study investigates junior middle school EFL teachers’beliefs about motivational practices in the language teaching process.Grounded in self-determination theory,the study examined teachers’beliefs in three basic psychological needs(relatedness,competence and autonomy)and the effect of their teaching experience on these beliefs.Data were obtained from 84 Chinese junior middle school English teachers through a questionnaire.Results suggested that teachers recognized motivational practices for relatedness and competence satisfaction while showing relatively low recognition of a few motivating practices for autonomy satisfaction.Teaching experience was found to have no influence on teachers’conception of needs-related motivational practices.Findings reveal that traditional activities like collective lesson preparations may have a negative influence on teachers’beliefs about motivational practices.They also present the necessity for adjustments on educational regulations,and for modern professional training to help teachers understand students’basic psychological needs,and to encourage new ideas to bolster students’intrinsic motivation for language learning.

互花米草有利于我国海岸带蓝碳功能提升

Spartina alterniflora has rapidly and extensively encroached on China's coastline over the past decades.Among the coastal areas invaded by S.alterniflora,at most 93%are mudflats.However,the effect of S.alterniflora invasion on soil organic carbon(SOC)stocks of coastal mudflats has not been systematically studied on a national scale.Here,we quantified the nationwide changes in SOC stocks in coastal mudflats associated with S.alterniflora invasion between 1990 and 2020.We found that S.alterniflora invasion significantly enhanced SOC stocks in coastal China.Nonetheless,the benefit of S.alterniflora invasion of coastal SOC stock may be weakened by continuing human intervention.We found that S.alterniflora invading mudflats added 2.3 Tg SOC stocks to China's coastal blue carbon,while 1.78 Tg SOC stocks were lost mainly due to human activities,resulted in a net SOC stock gain of 0.52 Tg C.These findings overturned the traditionally thought that S.alterniflora invasion would reduce ecosystem services by highlighting that the historical invasion of S.alterniflora has broadly and consistently enhanced blue carbon stock in coastal China.

Metamorphism and zircon U–Pb dating of garnet amphibolite in the Baoyintu Group, Inner Mongolia

Garnet amphibolite in the Baoyintu Group, Inner Mongolia, is mainly composed of garnet, hornblende, plagioclase, quartz and minor rutile/ilmenite. Garnet occurs as porphyroblasts surrounded by plagioclase, forming typical ＂white-eye socket＂ texture. Garnet shows grossular content of 0.26-0.28 and pyrope of 0.11-0.13, without significant zoning. Plagioclase is generally zoned with anorthite （An） increasing from core to rim. The P-T pseu- dosection calculated using THERMOCALC in the system MnNCKFMASHTO shows that the garnet amphibolite experienced a clockwise P-T path with a peak at 1.3 GPa/725 ℃ defined from the minimum An content in plagioclase and maximum pyrope content in garnet, followed by an isothermal decompression. LA-ICP-MS zircon dating for the garnet amphibolite indicates metamorphic ages of 399 ± 6 Ma. The peak P-T condition corresponds to a thermal gradient of ～ 18 ℃/km, indi- cating typical medium-pressure type that commonly occurs in orogenic process with crustal thickening. We prefer to interpret this orogenic event to be a result of collision, following the closure of the Paleo-Asian Ocean before the early Devonian although there is a popular view that the Paleo-Asian Ocean may have lasted to the early Mesozoic.

Ribonuclease H-like gene SMALL GRAIN2 regulates grain size in rice through brassinosteroid signaling pathway

Grain size is a key agronomic trait that determines the yield in plants.Regulation of grain size by brassinosteroids(BRs)in rice has been widely reported.However,the relationship between the BR signaling pathway and grain size still requires further study.Here,we isolated a rice mutant,named small grain2(sg2),which displayed smaller grain and a semi-dwarf phenotype.The decreased grain size was caused by repressed cell expansion in spikelet hulls of the sg2 mutant.Using map-based cloning combined with a Mut Map approach,we cloned SG2,which encodes a plant-specific protein with a ribonuclease H-like domain.SG2 is a positive regulator downstream of GLYCOGEN SYNTHASE KINASE2(GSK2)in response to BR signaling,and its mutation causes insensitivity to exogenous BR treatment.Genetical and biochemical analysis showed that GSK2 interacts with and phosphorylates SG2.We further found that BRs enhance the accumulation of SG2 in the nucleus,and subcellular distribution of SG2 is regulated by GSK2 kinase activity.In addition,Oryza sativa OVATE family protein 19(OsOFP19),a negative regulator of grain shape,interacts with SG2 and plays an antagonistic role with SG2 in controlling gene expression and grain size.Our results indicated that SG2 is a new component of GSK2-related BR signaling response and regulates grain size by interacting with Os OFP19.

Young Leaf White Stripe encodes a P-type PPR protein required for chloroplast development

Pentatricopeptide repeat(PPR) proteins function in post-transcriptional regulation of organellar gene expression. Although several PPR proteins are known to function in chloroplast development in rice(Oryza sativa), the detailed molecular functions of many PPR proteins remain unclear.Here, we characterized a rice young leaf white stripe(ylws) mutant, which has defective chloroplast development during early seedling growth.Map-based cloning revealed that YLWS encodes a novel P-type chloroplast-targeted PPR protein with 11 PPR motifs. Further expression analyses showed that many nuclear-and plastid-encoded genes in the ylws mutant were significantly changed at the RNA and protein levels. The ylws mutant was impaired in chloroplast ribosome biogenesis and chloroplast development under low-temperature conditions. The ylws mutation causes defects in the splicing of atpF, ndhA, rpl2,and rps12, and editing of ndhA, ndhB, and rps14transcripts. YLWS directly binds to specific sites in the atpF, ndhA, and rpl2 pre-mRNAs. Our results suggest that YLWS participates in chloroplast RNA group II intron splicing and plays an important role in chloroplast development during early leaf development.

Epitaxial interface stabilizing iridium dioxide toward the oxygen evolution reaction under high working potentials

Proton exchange membrane water electrolyzer(PEMWE)driven by renewable electricity is a promising technique toward green hydrogen production,but the corrosive environment and high working potential pose severe challenges for developing advanced electrocatalysts for the oxygen evolution reaction(OER).Although Ir-based materials possess relatively balanced activity and stability for the OER,their dissolution behavior cannot be neglected,in particular under high working potentials.In this work,iridium dioxide(IrO_(2))nanoparticles(NPs)were anchored on the surface of exfoliated h-boron nitride(BN)nanosheets(NSs)toward the OER reaction in acid media.Highly active Ir(V)species were stabilized by the epitaxial interface between IrO_(2)and h-BN,and therefore the IrO_(2)/BN delivered stable performance at increased working potentials,while the activity of bare IrO_(2)NPs without h-BN support decreased rapidly.Also,the smaller lattice spacing of h-BN induced compressive strain for IrO_(2),resulting in improved activity.Our results demonstrate the feasibility of stabilizing highly active Ir(V)species for the OER in acid media by constructing robust interface and provide new possibilities toward designing advanced heterostructured electrocatalysts.

Genomic and transcriptomic analysis unveils population evolution and development of pesticide resistance in fall armyworm Spodoptera frugiperda

The fall armyworm(FAW),Spodoptera frugiperda,is a destructive pest native to America and has recently become an invasive insect pest in China.Because of its rapid spread and great risks in China,understanding of FAW genetic background and pesticide resistance is urgent and essential to develop effective management strategies.Here,we assembled a chromosome-level genome of a male FAW(SFynMstLFR)and compared re-sequencing results of the populations from America,Africa,and China.Strain identification of 163 individuals collected from America,Africa and China showed that both C and R strains were found in the American pop-ulations,while only C strain was found in the Chinese and African populations.Moreover,population geno-mics analysis showed that populations from Africa and China have close relationship with significantly genetic differentiation from American populations.Taken toge-ther,FAWs invaded into China were most likely origi-nated from Africa.Comparative genomics analysis displayed that the cytochrome p450 gene family is extremely expanded to 425 members in FAW,of which 283 genes are specific to FAW.Treatments of Chinese populations with twenty-three pesticides showed the variant patterns of transcriptome profiles,and several detoxification genes such as AOX,UGT and GST spe-cially responded to the pesticides.These findings will be useful in developing effective strategies for manage-ment of FAW in China and other invaded areas.

Developing Students’ Critical Thinking and Discourse Level Writing Skill Through Teachers’ Questions: A Sociocultural Approach

The present study adopts a quantitative design to explore the effects of pre-designed teachers' questions as the mediation tool to scaffold the development of students' critical thinking and their discourse level writing skills in English from a sociocultural perspective. The participants were 39 sophomores from two classes. The results showed that:(1) teachers' questions targeting specific critical thinking skill in the classroom and in after-class conferences, as well as in written homework feedback were effective;(2) students backslid a little while internalizing teachers' questions concerning critical thinking;(3) students improved reliably in terms of local and global coherence in their written production with the help of teachers' questions. The findings indicate that teachers' questions facilitate students' development of critical thinking and enhance their discourse level writing skill.

Knockdown of LjALD1, AGD2‐like defense response protein 1, influences plant growth and nodulation in Lotus japonicus

The discovery of the enzyme L,L‐diaminopimelate aminotransferase（LL‐DAP‐AT, EC 2.6.1.83） uncovered a unique step in the L‐lysine biosynthesis pathway in plants. In Arabidopsis thaliana, LL‐DAP‐AT has been shown to play a key role in plant‐pathogen interactions by regulation of the salicylic acid（SA） signaling pathway. Here, a full‐length cDNA of LL‐DAP‐AT named as LjALD1 from Lotus japonicus（Regel）Larsen was isolated. The deduced amino acid sequence shares 67% identity with the Arabidopsis aminotransferase AGD2‐LIKE DEFENSE RESPONSE PROTEIN1（AtALD1） and is predicted to contain the same key elements： a conserved aminotransferase domain and a pyridoxal‐5＇‐phosphate cofactor binding site.Quantitative real‐time PCR analysis showed that LjALD1 was expressed in all L. japonicus tissues tested, being strongest in nodules. Expression was induced in roots that had been infected with the symbiotic rhizobium Mesorhizobium loti or treated with SA agonist benzo‐（1, 2, 3）‐thiadiazole‐7‐carbothioic Researchacid. LjALD1 Knockdown exhibited a lower SA content, an increased number of infection threads and nodules, and a slight reduction in nodule size. In addition, compared with wild‐type,root growth was increased and shoot growth was suppressed in LjALD1 RNAi plant lines. These results indicate that LjALD1 may play important roles in plant development and nodulation via SA signaling in L. japonicus.

Effect of thickness on the photophysics and charge carrier kinetics of graphitic carbon nitride nanoflakes

We investigated the thickness effect on the photophysics and charge carrier kinetics of graphitic carbon nitride nanoflakes （g-CNN） by using ultraviolet visible diffuse reflectance spectroscopy, atomic force microscopy, femtosecond transient absorption spectroscopy, and picosecond time-correlated single photon counting measurement. For the first time, we found that g-CNN displays a layer-dependent indirect bandgap and layer-dependent charge carrier kinetics.