A comparison of decomposition dynamics among green tree leaves,partially decomposed tree leaf litter and their mixture in a warm temperate forest ecosystem

Decomposition dynamics were compared among green tree leaves, partially decomposed tree leaf litter （i.e., decayed tree leaf litter on forest floor） and a mixture of the two in a warm temperate forest ecosystem in central China to test the influence of litter chemical quality on the degree of decomposition. The study was conducted in situ at two contrasting forest sites, an oak forest dominated by Quercus aliena var. acuteserrata Maxim., and a mixed pine and oak forest dominated by Pinus armandii Franch. and Q. aliena var. acuteserrata. We found marked differences in the rate of decomposition among litter types at both forest sites; the litter decom- position constant, k, was about 39 % greater at the oak forest site and more than 70 % greater at the pine-oak forest site, for green leaves than for partially decomposed leaf litter. The decomposition dynamics and temporal changes in litter chemistry of the three litter types also greatly differed between the two forest sites. At both forest sites, the higher rate of decomposition for the green leaves was associated with a and lower carbon to N ratio higher nitrogen （N） content （C/N） and acid-unhydrolyz- able residue to N ratio （AUR/N）. We did not find any non- additive effects when mixing green leaves and partially decomposed leaf litter. Our findings support the con- tention that litter chemical quality is one of the most important determinants of litter decomposition in forest ecosystems at the local or regional scale, but the effect of litter chemical quality on decomposition differs between the contrasting forest types and may vary with the stage of decomposition.

Abrupt change of winter temperature over the Mongolian Plateau during 1961-2017

Studying the abrupt change of winter temperature(ACWT)over the Mongolian Plateau(MP,including Inner Mongolia Autonomous Region and State of Mongolia)is of great significance for understanding the spatiotemporal distribution of temperature and the mechanism of global climate change.Monthly temperature data during 1961–2017was collected,and the abrupt change point was determined by the Mann–Kendall test and sliding ttest,to analyze the characteristics and causes of ACWT.The results showed that(a)The winter temperature has rapidly increased with a trend of 0.41℃/10a,which was significantly higher than that of the rest area of Chinese mainland,indicating that climate change in the MP was more sensitive to global warming.(b)The abrupt change point occurred in 1988,with temperature of-15.5℃and-14.1℃before and after abrupt change,respectively.The ACWT in 50°N was 1–3 years later than that in 40°N,and the isotherms of different temperatures moved northward by 10–200 km,especially-16℃isotherms moved approximately 200 km northward after 1988.(c)The Arctic Oscillation(AO)and Mongolian High(MH)anomaly affects winter temperature over the MP.When the AO is unusually strong,the MH and East Asian winter monsoon are weak,and southerly winds prevail in most regions,which is not conducive to the cold air developing southward,leading to higher winter temperature in the MP.Overwise,abnormally northerly winds prevail and temperature is low.Meanwhile,the abrupt change time of AO occurred in 1987 before winter temperature.It shows that the AO indirectly causes winter temperatures to rise by influencing the MH and is also the main driving factor of ACWT.

Research on Optimizing the Distribution Path of Agricultural Cold Chain Logistics in Green Consumption Era

In recent years, with the rapid development of China's fresh market, cold chain logistics ushered in a new development opportunity. Because of the late start and slow development of cold chain logistics in China, it is difficult to achieve cross-regional and offseason sales activities, resulting in a situation of high output and small sales volume, which is also an important reason for the high price and poor quality of fresh agricultural products. With the passage of time, the characteristics of cold chain distribution of agricultural products have become an important direction for the future development of logistics industry. In this paper, aiming at the characteristics of agricultural cold chain distribution, the carbon emissions in the process of distribution were quantified as costs and added to the total cost, and an optimization model of agricultural cold chain logistics path with time window considering the minimum total cost as the objective function was constructed. The improved genetic algorithm was used to solve the problem. The simulation results show that the improved genetic algorithm is an effective method to solve the optimization problem of agricultural cold-chain logistics path considering carbon emissions, and has guiding significance for the selection of low-carbon and environmentally friendly distribution routes for agricultural cold-chain logistics distribution enterprises.

A Survey of English Majors'Chinese Culture Learning and Teaching Strategies in the Context of Culture Going Out

At present,there is a serious phenomenon of"Chinese cultural aphasia"in English teaching for English majors in Colleges and universities,and Chinese cultural knowledge has not received due attention in foreign language teaching.Therefore,in the context of culture going out,the author conducts a research on the current situation of Chinese culture learning and teaching strategies of English majors.Relevant research shows that solving these problems can be solved by rationally dealing with the relationship between Chinese culture and Western culture,enriching the cultural reserves of college English teachers,creating a Chinese cultural learning environment and improving students'intercultural communication skills.In addition,the Chinese cultural literacy of English teachers should be promoted to explore the teaching methods of diversified Chinese cultural resources.

Macroscopic,artificial active matter

Artificial active matters on a macroscopic scale,including vibrating particles,robots,and camphor boats,have attracted increasing attentions due to their uniform properties,rich and easily controllable parameters,convenient observation,and the independence of biochemical processes from physical processes,especially providing these unique advantages for researching the collective behaviors under strong confinement and crowded surroundings.In this review,we present an overview of motion models,mechanisms,and dynamic characteristics of various active particles,both in free and complex media.Additionally,we delve into the collective behaviors of“dry”active matter,covering structural and dynamic properties observed in experiments and theoretical models.We summarize the impact of hydrodynamic interactions on the dynamics and structures of these active particles within hydrodynamic environments.Lastly,we discuss emerging opportunities and challenges for future advancement of macroscopic artificial active matter.

Warming and increased precipitation alter soil carbon cycling in a temperate desert steppe of Inner Mongolia

Warming and precipitation are key global change factors driving soil carbon(C)dynamics in terrestrial ecosystems.However,the effects of warming and altered precipitation on soil microbial diversity and functional genes involved in soil C cycling remain largely unknown.We investigated the effects of warming and increased precipitation on soil C cycling in a temperate desert steppe of Inner Mongolia using metagenomic sequencing.We found that warming reduced plant richness,Shannon-Wiener and Simpson index.In contrast,increased precipitation signifcantly infuenced Shannon-Wiener and Simpson index.Warming reduced soil microbial species by 5.4%while increased precipitation and warming combined with increased precipitation led to increases in soil microbial species by 23.3%and 2.7%,respectively.The relative abundance of Proteobacteria,which involve C cycling genes,was signifcantly increased by warming and increased precipitation.Warming signifcantly reduced the abundance of GAPDH(Calvin cycle)and celF(cellulose degradation)while it enhanced the abundance of glxR(lignin degradation).Increased precipitation signifcantly enhanced the abundance of pgk(Calvin cycle),coxL(carbon monoxide oxidation),malZ(starch degradation),and mttB(methane production).Moreover,a wide range of correlations among soil properties and C cycling functional genes was detected,suggesting the synergistic and/or antagonistic relationships under scenario of global change.These results may suggest that warming is benefcial to soil C storage while increased precipitation negatively affects soil C sequestration.These fndings provide a new perspective for understanding the response of microbial communities to warming and increased precipitation in the temperate desert steppe.

Recent Advances of Cu-Based Materials for Electrochemical Nitrate Reduction to Ammonia

The pollution of nitrate in groundwater has become an environmental problem of general concern due to adverse human and ecological impacts. Treatment of nitrate-rich wastewater is of significance yet challenging for the conventional biological denitrification processes. Electrocatalytic nitrate-to-ammonia conversion emerges as one of the most promising avenues to remove environmentally harmful nitrate from various types of wastewaters while simultaneously producing value-added ammonia. Cu-based materials show great advantages in promoting selective electroreduction of nitrate to ammonia in terms of high nitrate conversion efficiency, ammonia selectivity and ammonia faradaic efficiency thanks to the 3d transition metal structure, low cost, high reserves, and excellent catalytic performance of Cu. In this review, we comprehensively overview the most recent advances in selective electrocatalytic nitrate-to-ammonia conversion using Cu-based materials. Various kinds of Cu-based materials including monometallic Cu catalysts, bimetallic Cu-based catalysts, Cu-based compounds, and Cu-based inorganicorganic hybrid materials and their derivatives are discussed in detail with emphasis on their structural and compositional features and functional mechanisms in promoting nitrate-to-ammonia conversion. Finally, a brief discussion on future directions, challenges and opportunities in this field is also provided.

Boosting electrochemical hydrogen evolution by coupling anodically oxidative dehydrogenation of benzylamine to benzonitrile

The electricity-driven water splitting acts as a promising pathway for renewable energy conversion and storage, yet anodic oxygen evolution reaction(OER) largely hinders its efficiency. Seeking the alternatives to OER exhibits the competitive advance to address this predicament. In this work, we show a more thermodynamically and kinetically favorable reaction, electrochemical oxidative dehydrogenation(EODH)of benzylamine to replace the conventional OER, catalyzed by a cobalt cyclotetraphosphate(Co_(2)P_(4)O_(12)) nanorods catalyst grown on nickel foam. This anodic reaction lowers the electricity input of 317 mV toward the desired current density of 100 mA/cm^(2), together with a highly selective benzonitrile product of more than 97%. More specifically, when coupling it with cathodic hydrogen evolution reaction(HER),the proposed HER||benzylamine-EODH configuration only requires a cell voltage of 1.47 V@100 mA/cm^(2),exhibiting an energy-saving up to 17% relative to conventional water splitting, as well as the near unit selectivity toward cathodic H_(2) and anodic benzonitrile products.

Synthesis,characterization and optical studies on Sm2+-doped CdSe nanocrystals:a blueshift and fixed emission with high quantum yields

CdSe:Sm nanocrystals(NCs) were synthesized by a water phase method,and their structures,shapes and optical properties were further characterized.X-ray diffraction(XRD) analysis suggested that both the CdSe and CdSe:Sm NCs contained(111),(220) and(311) lattice planes in the zinc blende structure overlapped with the(002),(110) and(112) lattice planes in the wurtzite structure,and the diameters were about 4.2,3.3 and 2.3 nm for CdSe,CdSe:Sm(8%) and CdSe:Sm(10%) NCs,respectively.All of the CdSe:Sm NCs were monodispersed and uniform spherical nanocrystals.The CdSe:Sm(10%) NCs prepared with different reaction times exhibited constant absorption spectra at 430 nm and a fixed emission peak at581 nm.Compared with those of pure CdSe NCs,the fluorescence emission of CdSe:Sm(10%) NCs blueshifted 20-36 nm,and the absorption peak initially redshifted and then blueshifted with the prolongation of reaction time.In addition,the Sm^2+ doping decreased the fluorescence lifetime and increased the quantum yields(QYs) of CdSe NCs.The QYs of CdSe:Sm NCs increased initially and then decreased with the increase in the amount of doped Sm2+.The initial pH and charge compensator concentration also exhibited significantly enhanced fluorescence emission of CdSe:Sm NCs.

Weighted Estimates for a Class of Global Maximal Operators Associated with Dispersive Equation

For a function Ф satisfying some suitable growth conditions,consider the following general dispersive equation defined by{i■tu+Ф(√-△)u=0,u(x,0)=f(x),(x,t)∈R^(n)× R,f∈S(R^(n) where Ф(√-△)is a pseudo-differential operator with symbol Ф(|ξ|).In the present paper,when the initial data f belongs to Sobolev space,we give the local and global weighted L^(q) estimate for the global maximal operator S^(**)Ф defined by S^(**)Фf(x)=sup_(t∈R)|S_(t,Ф)f(x)|,where S_(t,Ф)f(x)=(2π)^(-n)∫_(R^(n)e^(ix·ζ+itФ(|ζ+|)f(ζ)dζ is a formal solution of the equation(*).

Recycling rare earth from ultrafine NdFeB waste by capturing fluorine ions in wastewater and preparing them into nano-scale neodynium oxyfluoride

Ultrafine NdFeB waste is a relatively clean waste produced during NdFeB magnet processing.Fluorinecontaining wastewater is a common type of industrial wastewater,such as stainless steel pickling wastewater.In this work,rare earth element neodynium was recycled from ultrafine NdFeB waste by capturing fluorine ions in the fluorine-containing wastewater and prepared into neodynium oxyfluoride.The reaction process was investigated through UV-Vis-NIR,thermogravimetry/differential thermogravimetry(TG/DTG),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The neodymium hydroxide in the ultrafine NdFeB waste reacted with fluorine ions to form Nd(OH)_(2) F,and Nd(OH)_(2) F was then transformed into neodymium oxyfluoride after decomposition.The formed neodymium oxyfluoride is found to be particles with rhombohedral structure and a particle size of around 50 nm.The reaction kinetics of forming Nd(OH)_(2) F was investigated.The reaction kinetic equation was established and the reaction activation energy was calculated.The effect of fluorine ion concentration on the reaction rate and products was evaluated.The results show that the reaction rate increases with the increase of fluorine ion concentration in the range of 0.01-1.5 mol/L,but it has little effect.In addition,the fluorine ion concentration affects the crystallinity of formed neodymium oxyfluoride.The recycling process not only realizes the sustainable utilization of rare earths,but also reduces the concentration of fluorine ions in the fluorine-containing wastewater,achieving two goals with one stone.

Dimension of divergence sets for dispersive equation

Consider the generalized dispersive equation defined by{iδtu+Ф(√-△)u=0,(x,t)∈R^n×R,u(x,0)=f(x),F∈F(R^n),(*)whereФ(√-△)is a pseudo-differential operator with symbolФ(|ζ|).In the present paper,assuming thatФsatisfies suitable growth conditions and the initial data in H^s(R^n),we bound the Hausdorff dimension of the sets on which the pointwise convergence of solutions to the dispersive equations(*)fails.These upper bounds of Hausdorff dimension shall be obtained via the Kolmogorov-Seliverstov-Plessner method.

Fungal diversity notes 1277-1386:taxonomic and phylogenetic contributions to fungal taxa

This is the twelfth contribution to the Fungal Diversity Notes series on fungal taxonomy,based on materials collected from many countries which were examined and described using the methods of morphology,anatomy,and strain culture,combined with DNA sequence analyses.110 taxa are described and illustrated,including five new genera,92 new species,eight new combinations and other taxonomic contributions(one new sequenced species,one new host and three new records)which are accommodated in 40 families and 1 incertae sedis in Dothideomycetes.The new genera are Amyloceraceomyces,Catenuliconidia,Hansenopezia,Ionopezia and Magnopulchromyces.The new species are Amyloceraceomyces angustisporus,Amylocorticium ellipsosporum,Arthrinium sorghi,Catenuliconidia uniseptata,Clavulina sphaeropedunculata,Colletotrichum parthenocissicola,Coniothyrium triseptatum,Cortinarius indorusseus,C.paurigarhwalensis,C.sinensis,C.subsanguineus,C.xiaojinensis,Diaporthe pimpinel-lae,Dictyosporella guizhouensis,Diplodia torilicola,Fuscoporia marquesiana,F.semiarida,Hansenopezia decora,Helicoarcta-tus thailandicus,Hirsutella hongheensis,Humidicutis brunneovinacea,Lentaria gossypina,L.variabilis,Lycoperdon lahorense,L.pseudocurtisii,Magnopulchromyces scorpiophorus,Moelleriella gracilispora,Neodevriesia manglicola,Neodidymelliopsis salvia,N.urticae,Neoroussoella magnoliae,Neottiella gigaspora,Ophiosphaerella chiangraiensis,Phaeotremella yunnanensis,Podosphaera yulii,Rigidoporus juniperinus,Rhodofomitopsis pseudofeei,Russula benghalensis,Scleroramularia vermispora,Scytinopogon minisporus,Sporormurispora paulsenii,Thaxteriellopsis obliqus,Tomentella asiae-orientalis,T.atrobadia,T.atrocastanea,T.aureomarginata,T.brevis,T.brunneoflava,T.brunneogrisea,T.capitatocystidiata,T.changbaiensis,T.citri-nocystidiata,T.coffeae,T.conclusa,T.cystidiata,T.dimidiata,T.duplexa,T.efibulata,T.efibulis,T.farinosa,T.flavidobadia,T.fuscocrustosa,T.fuscofarinosa,T.fuscogranulosa,T.fuscopelliculosa,T.globospora,T.gloeocystidiata,T.griseocastanea,T.griseofusca,T.griseomarginata,T.inconspicua,T.incrustata,T.interrupta,T.liaoningensis,T.longiaculeifera,T.longiechinuli,T.megaspora,T.olivacea,T.olivaceobrunnea,T.pallidobrunnea,T.pallidomarginata,T.parvispora,T.pertenuis,T.qingyuanensis,T.segregata,T.separata,T.stipitata,T.storea,Trichoderma ceratophylletum,Tyromyces minutulus,Umbelopsis heterosporus and Xylolentia reniformis.The new combinations are Antrodiella descendena,Chloridium macrocladum,Hansenopezia retrocurvata,Rhodofomitopsis monomitica,Rh.oleracea,Fuscoporia licnoides,F.scruposa and Ionopezia gerardii.A new sequenced species(Graphis supracola),one new host(Aplosporella prunicola)and three new geographical records(Golovinomyces monardae,Paradictyoarthrinium diffractum and Prosthemium betulinum),are reported.