Linear magnetoresistance and structural distortion in layered SrCu_(4-x)P_(2) single crystals

We report a systematic study on layered metal SrCu_(4-x)P_(2) single crystals via transport, magnetization, thermodynamic measurements and structural characterization. We find that the crystals show large linear magnetoresistance without any sign of saturation with a magnetic field up to 30T. We also observe a phase transition with significant anomalies in resistivity and heat capacity at T_(p)~140 K. Thermal expansion measurement reveals a subtle lattice parameter variation near Tp, i.e.,?L_(c)/L_(c)~0.062%. The structural characterization confines that there is no structure transition below and above T_(p). All these results suggest that the nonmagnetic transition of SrCu_(4-x)P_(2) could be associated with structural distortion.

Magnetic and magnetotransport properties of layered TaCoTe_(2) single crystals

We present the synthesis of TaCoTe_(2) single crystals and a systematic investigation of the physical properties of bulk crystals and thin flakes.The crystal shows a semiconducting behavior with temperature decreasing from room temperature and turns to a metallic behavior below 38 K.When the magnetic field is applied,the temperature-dependent resistivity curves show an upturn below 10 K.Furthermore,we find that the TaCoTe_(2) single crystal can be easily exfoliated from the bulk crystal by the micromechanical exfoliation method.Our measurements suggest that the nanoflakes have properties similar to those of the bulk crystal when the thickness is lowered to 18 nm.

Subtle lattice distortion-driven phase transitions in layered ACu_(4)As_(2)(A=Eu,Sr)

The compounds composed of transition metal cations and pnictide anions provide a rich platform for studying novel physical phenomena.Here we report on the observation of a phase transition at~70 K and 145 K in layered compound EuCu_(4)As_(2)and SrCu_(4)As_(2),respectively.from both the transport and heat capacity.The thermal expansion measurements show that the variation of the lattice parameters(△L_(b)/L_(ab))around T_(P) is much less than that for a typical crystalline phase transition.Our experimental results reveal that the transition in EuCu_(4)As_(2)and SrCu_(4)As_(2)should be driven by subtle structural-distortion.

Predictive models for characterizing the atomization process in pyrolysis of methyl ricinoleate

Pyrolysis of methyl ricinoleate(MR)can produce undecylenic acid methyl ester and heptanal which are important chemicals.Atomization feeding favors the heat exchange in the pyrolysis process and hence increases the product yield.Herein,predictive models to characterize the atomization process were developed.The effect of spray distance on Sauter mean diameter(SMD)of atomized MR droplets was examined,with the optimal spray distance to be 40-50 mm.Temperature mainly affected the physical properties of feedstock,with smaller droplet size obtained at increasing temperature.In addition,pressure had significant influence on SMD and higher pressure resulted in smaller atomized droplets.Then,a model for SMD prediction,combining temperature,pressure,spray distance,and structural parameters of nozzle,was developed through dimensionless analysis.The results showed that SMD was a power function of Reynolds number(Re),Ohnesorge number(Oh),and the ratio of spray distance to diameter of swirl chamber in the nozzle(H/dsc),with the exponents of-1.6618,-1.3205 and 0.1038,respectively.The experimental measured SMD was in good agreement with the calculated values,with the error within±15%.Moreover,the droplet size distribution was studied by establishing the relationship between the standard deviation of droplet size and SMD.This study could provide reference to the regulation and optimization of the atomization process in MR pyrolysis.

Hydrodynamic cavitation as an efficient method for the formation of sub-100 nm O/W emulsions with high stability

Hydrodynamic cavitation,a newly developed process intensification technique,has demonstrated immense potential for intensifying diverse physical and chemical processes.In this study,hydrodynamic cavitation was explored as an efficient method for the formation of sub-100 nm oil-in-water(O/W) emulsions with high stability.O/W emulsion with an average droplet size of 27 nm was successfully prepared.The average droplet size of O/W emulsions decreased with the increase of the inlet pressure,number of cavitation passes and surfactant concentration.The formed emulsion exhibited admirable physical stability during 8 months.Moreover,the hydrodynamic cavitation method can be generalized to fabricate large varieties of O/W emulsions,which showed great potential for large-scale formation of O/W emulsions with lower energy consumption.

Insights into biobased epoxidized fatty acid isobutyl esters from biodiesel:Preparation and application as plasticizer

Biodiesel was used to prepare epoxidized fatty acid isobutyl esters(Ep-FABEs)as a biobased plasticizer in this work.Transesterification of biodiesel with isobutanol catalyzed by tetrabutyl titanate was carried out in a gas-liquid tower reactor.The conversion achieved nearly 100%within 5 h under the reaction temperature,the mass ratio of catalyst to fatty acid methyl esters(FAMEs),and isobutanol to FAMEs total molar ratio of 180℃,0.4%(mass),and 5.4:1,respectively.In addition,kinetic model of the transesterification reaction was developed at 150–190℃.The calculated activation energy was 48.93 kJ·mol^(-1).Then,the epoxidation of obtained fatty acid isobutyl esters(FABEs)was conducted in the presence of formic acid and hydrogen peroxide.The Ep-FABEs was further analyzed for its plasticizing effectiveness to replace dioctyl phthalate(DOP)and compared with conventional epoxy plasticizer epoxidized fatty acid methyl esters(Ep-FAMEs).The results indicated that the thermal stability and mechanical properties of PVC films with Ep-FABEs plasticizer were significantly improved compared with those plasticized with DOP.In addition,the extraction resistance and migration stability of Ep-FABEs were better than those of EpFAMEs.Overall,the prepared Ep-FABEs via structural modification of biodiesel proved to be a promising biobased plasticizer.

Species diversity, updated classification and divergence times of the phylum Mucoromycota

Zygomycetes are phylogenetically early diverging,ecologically diverse,industrially valuable,agriculturally beneficial,and clinically pathogenic fungi.Although new phyla and subphyla have been constantly established to accommodate spe-cific members and a subkingdom Mucoromyceta,comprising Calcarisporiellomycota,Glomeromycota,Mortierellomycota and Mucoromycota,was erected to unite core zygomycetous fungi,phylogenetic relationships within phyla have not been well resolved.Taking account of the information of monophyly and divergence time estimated from ITS and LSU rDNA sequences,the present study updates the classification framework of the phylum Mucoromycota from the class down to the generic rank:three classes,three orders,20 families(including five new families Circinellaceae,Protomycocladaceae,Rhizomucoraceae,Syzygitaceae and Thermomucoraceae)and 64 genera.The taxonomic hierarchy was calibrated with estimated divergence times:phylum earlier than 617 Mya,classes and orders earlier than 547 Mya,families earlier than 199 Mya,and genera earlier than 12 Mya.Along with this outline,all genera of Mucoromycota are annotated and 58 new species are described.In addition,three new combinations are proposed.In this study,we update the taxonomic backbone of the phylum Mucoromycota and reinforce its phylogeny.We also contribute numerous new taxa and enrich the diversity of Mucoromycota.

冰湖溃决洪水威胁高亚洲基础设施

青藏高原及其周边地区冰湖灾害频发,目前对其灾害特征及导致的破坏缺乏系统的分析.本研究旨在揭示冰湖灾害过去和未来的变化趋势及其对基础设施造成的影响,以指导区域及跨境流域冰湖灾害防控技术和策略的构建.研究梳理了1900-2022年间发生的298例冰湖灾害事件,发现其呈增长的趋势,尤其是1964年以来的部分冰湖灾害严重损坏了下游基础设施,不同类型冰湖灾害在空间分布、爆发和成灾特征等方面存在明显差异.例如,西斯帕冰川阻塞湖在2019-2022年连续爆发了5次溃决洪水,最近一次冲毁了下游中巴公路的桥梁和路基,影响中巴经贸.高山区冰川冰湖变化、交通和水电等基础设施及人口增长,致使冰湖灾害风险上升.为此,重大基础设施的规划应充分考虑相关风险,建立防控措施以保障人员和基础设施安全.

Guided by the principles of microbiome engineering:Accomplishments and perspectives for environmental use

Although the accomplishments of microbiome engineering highlight its significance for the targeted manipulation of microbial communities,knowledge and technical gaps still limit the applications of microbiome engineering in biotechnology,especially for environmental use.Addressing the environmental challenges of refractory pollutants and fluctuating environmental conditions requires an adequate understanding of the theoretical achievements and practical applications of microbiome engineering.Here,we review recent cutting-edge studies on microbiome engineering strategies and their classical applications in bioremediation.Moreover,a framework is summarized for combining both top-down and bottom-up approaches in microbiome engineering toward improved applications.A strategy to engineer microbiomes for environmental use,which avoids the build-up of toxic intermediates that pose a risk to human health,is suggested.We anticipate that the highlighted framework and strategy will be beneficial for engineering microbiomes to address difficult environmental challenges such as degrading multiple refractory pollutants and sustain the performance of engineered microbiomes in situ with indigenous microorganisms under fluctuating conditions.

氢氧化钠溶液吸收硫酰氟的传质反应动力学（英文）

研究目的:确定氢氧化钠溶液化学吸收硫酰氟的传质反应动力学区域,建立增强因子模型。研究方法:研究气液传质测定设备双搅拌釜中氢氧化钠溶液化学吸收硫酰氟的过程,并结合实验研究与理论分析建立了增强因子模型。重要结论:基于氢氧化钠溶液化学吸收硫酰氟过程的实验研究,确定了氢氧化钠溶液化学吸收硫酰氟的传质反应动力学区域为快速拟一级反应。得到了298 K下其二级反应速率常数为1.44 m3/(mol·s),并建立了增强因子模型E=68.08CBL1/2,为脱除熏蒸后残留硫酰氟的工业化应用提供了理论依据。

Rational design of bimetallic atoms supported on C3N monolayer to break the linear relations for efficient electrochemical nitrogen reduction

Linear relations between the adsorption free energies of nitrogen reduction reaction(NRR)intermediates limit the catalytic activity of single atom catalysts(SACs)to reach the optimal region.Significant improvements in NRR activity require the balance of binding strength of reaction intermediates.Herein,we have investigated the C_(3)N-supported monometallic(M/C_(3)N)and bimetallic(M_(1)M_(2)/C_(3)N)atoms for the electrochemical NRR by using density functional theory(DFT)calculations.The results show that this linear relation does exist for SACs because all the intermediates bind to the same site on M/C_(3)N.But the synergistic effect of the two atoms in M_(1)M_(2)/C_(3)N can create a more flexible adsorption site for intermediates,which results in the decoupling of adsorption free energies of key intermediates.Subsequently,the fundamental limitation of scaling relations on limiting potentials is broken through.Most notably,the optimal limiting potential is increased from−0.63 V for M/C_(3)N to−0.20 V for M_(1)M_(2)/C_(3)N.In addition,the presence of bimetallic atoms can also effectively inhibit the hydrogen evolution reaction(HER)as well as improve the stability of the catalysts.This study proposes that the introduction of bimetallic atoms into C_(3)N is beneficial to break the linear relations and develop efficient NRR electrocatalysts.

Eight-year trajectories of malalignment progression in symptomatic knee osteoarthritis

Background: Although various therapies have been developed to treat malalignment in osteoarthritic knees, the pattern of malalignment progression is still unclear. This study aimed to identify homogeneous subgroups with distinct trajectories of malalignment progression in subjects with symptomatic knee osteoarthritis (KOA) and to determine corresponding risk factors.Methods: Eight-year follow-up (from 2004 to 2012) data on 1252 participants with symptomatic KOA from the Osteoarthritis Initiative were included. Varus/valgus angle progression was characterized by group-based trajectory models. Time-varying covariates were introduced into the model to investigate how they affected trajectories. Multinomial logistic regression for trajectory group membership was applied to ascertain risk factors.Results: Five subgroups were identified. Participants in the varus worsening trajectory (n = 166) or valgus worsening trajectory (n = 118) proceeded to worsen malalignment over time. The neutral trajectory (n = 378), varus stable trajectory (n = 328), and valgus stable trajectory (n = 262) maintained close to the initial varus/valgus angle over 8 years. Higher baseline Kellgren and Lawrence grade (odds ratio [OR] = 4.35,P < 0.001 for varus;OR= 3.85,P < 0.001 for valgus) and "severe" baseline malalignment (OR = 13.57,P < 0.001 for varus;OR = 23.04,P < 0.001 for valgus) were risk factors for worsening trajectories. The cutoff point of the baseline varus/valgus angle to discriminate between stable or worsening trajectory was -4.5° for varus and 3.6° for valgus.Conclusions: This study identified the malalignment progression pattern - minor malalignment (-4.5° to +3.6°) tends to remain stable, while major baseline malalignment is likely to progress. This provides a reference for therapy to prevent malalignment from deteriorating and emphasizes the necessity of determining the trigger factors for malalignment onset.

Substrate availability and toxicity shape the structure of microbial communities engaged in metabolic division of labor

Metabolic division of labor(MDOL)represents a widespread natural phenomenon,whereby a complex metabolic pathway is shared between different strains within a community in a mutually beneficial manner.However,little is known about how the composition of such a microbial community is regulated.We hypothesized that when degradation of an organic compound is carried out via MDOL,the concentration and toxicity of the substrate modulate the benefit allocation between the two microbial populations,thus affecting the structure of this community.We tested this hypothesis by combining modeling with experiments using a synthetic consortium.Our modeling analysis suggests that the proportion of the population executing the first metabolic step can be simply estimated by Monod-like formulas governed by substrate concentration and toxicity.Our model and the proposed formula were able to quantitatively predict the structure of our synthetic consortium.Further analysis demonstrates that our rule is also applicable in estimating community structures in spatially structured environments.Together,our work clearly demonstrates that the structure of MDOL communities can be quantitatively predicted using available information on environmental factors,thus providing novel insights into how to manage artificial microbial systems for the wide application of the bioindustry.