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Managing above-ground plant carbon inputs can pave the way toward carbon neutrality and mitigating climate change. Chemical complexity of plant residues largely controls carbon sequestration. There exist conflicting opinions on whether residue chemistry diverges or converges after long-term decomposition. Moreover, whether and how microbial communities regulate residue chemistry remains unclear. This study investigated the decomposition processes and residue composition dynamics of maize straw and wheat straw and related microbiomes over a period of 9 years in three climate zones. Residue chemistry exhibited a divergent-convergent trajectory during decomposition, that is, the residue composition diverged during the 0.5–3 year period under the combined effect of straw type and climate and then converged to an array of common compounds during the 3–9 year period. Chemical divergence during the first 2–3 years was primarily driven by the changes in extracellular enzyme activity influenced by keystone taxa-guided bacterial networks, and the keystone taxa belonged to Alphaproteobacteria, particularly Rhizobiales. After 9 years, microbial assimilation became dominant, leading to chemical convergence, and fungi, particularly Chaetomium, were the main contributors to microbial assimilation. Overall, this study demonstrated that keystone taxa regulate the divergent-convergent trajectory in residue chemistry.

Managing above-ground plant carbon inputs can pave the way toward carbon neutrality and mitigating climate change. Chemical complexity of plant residues largely controls carbon sequestration. There exist conflicting opinions on whether residue chemistry diverges or converges after long-term decomposition. Moreover, whether and how microbial communities regulate residue chemistry remains unclear. This study investigated the decomposition processes and residue composition dynamics of maize straw and wheat straw and related microbiomes over a period of 9 years in three climate zones. Residue chemistry exhibited a divergent-convergent trajectory during decomposition, that is, the residue composition diverged during the 0.5–3 year period under the combined effect of straw type and climate and then converged to an array of common compounds during the 3–9 year period. Chemical divergence during the first 2–3 years was primarily driven by the changes in extracellular enzyme activity influenced by keystone taxa-guided bacterial networks, and the keystone taxa belonged to Alphaproteobacteria, particularly Rhizobiales. After 9 years, microbial assimilation became dominant, leading to chemical convergence, and fungi, particularly Chaetomium, were the main contributors to microbial assimilation. Overall, this study demonstrated that keystone taxa regulate the divergent-convergent trajectory in residue chemistry.

Winter jujube (Ziziphus jujuba‘Dongzao’) is an excellent late maturing variety of fresh-eating jujube in China. Fruit texture is an important indicator of sensory quality. To investigate the correlations among texture indices and establish an evaluation system for winter jujube texture, we used the TMS-Touch instrument to perform a texture profile analysis (TPA) on 1 150 winter jujubes from three major producing areas in China. Eight indices and their best-fit distribution were obtained, including fracture (Pearson), hardness (InvGauss), adhesive force (Weibull), adhesiveness (LogLogistic), cohesiveness (LogLogistic), springiness (BetaGeneral), gumminess (InvGauss), and chewiness (InvGauss). Based on the best-fit distribution curves, each index was divided into five grades (lower, low, medium, high and higher) by the 10th, 30th, 70th and 90th percentiles. Among the texture indices, 82% of the correlation coefficients were highly significant (P<0.01); meanwhile, chewiness was significantly (P<0.01) and positively correlated with springiness and gumminess, of which the correlation coefficients were up to 0.8692 and 0.8096, respectively. However, adhesiveness was significantly (P<0.01) and negatively related to adhesive force with a correlation coefficient of –0.7569. Among hardness, cohesiveness, springiness, gumminess, and chewiness, each index could be well fitted by a multiple linear regression with the remaining four indices, with the coefficients above 0.94 and the mean fitting error and mean prediction error lower than 10%. A comprehensive evaluation model was consequently established based on factor analysis to evaluate the texture quality of winter jujube. The results demonstrated that winter jujube with higher comprehensive scores generally exhibited higher springiness and chewiness, but had lower adhesive force and adhesiveness. We used factor analysis and clustering analysis to divide the eight studied texture into four groups (cohesive factor, adhesive-soft factor, tough-hard factor, and crispness factor), whose representative indices were springiness, adhesiveness, hardness, and fracture, respectively. Overall, this study investigated the variation in each index of winter jujube texture, explored the association among these indices, screened the representative indices, and established a texture evaluation system. The results provide a methodological basis and technical support for evaluating winter jujube texture.

The sluggish kinetics of the oxygen evolution reaction (OER) always results in a high overpotential at the anode of water electrolysis and an excessive electric energy consumption, which has been a major obstacle for hydrogen production through water electrolysis. In this study, we present a CoNi-LDH/Fe MOF/NF heterostructure catalyst with nanoneedle array morphology for the OER. In 1.0 M KOH solution, the heterostructure catalyst only required overpotentials of 275 and 305 mV to achieve high current densities of 500 and 1000 mA/cm2for OER, respectively. The catalytic activities are much higher than those of the reference single-component CoNi-LDH/NF and Fe MOF/NF catalysts. The improved catalytic performance of the heterostructure catalyst can be ascribed to the synergistic effect of CoNi-LDH and Fe MOF. In particular, when the anodic OER is replaced with the urea oxidation reaction (UOR), which has a relatively lower thermodynamic equilibrium potential and is expected to reduce the cell voltage, the overpotentials required to achieve the same current densities can be reduced by 80 and 40 mV, respectively. The cell voltage required to drive overall urea splitting (OUS) is only 1.55 V at 100 mA/cm2in the Pt/C/NF||CoNi-LDH/Fe MOF/NF two-electrode electrolytic cell. This value is 60 mV lower compared with that required for overall water splitting (OWS). Our results indicate that a reasonable construction of a heterostructure catalyst can significantly give rise to higher electrocatalytic performance, and using UOR to replace the anodic OER of the OWS can greatly reduce the electrolytic energy consumption.

The Bayin River, the largest river in the northeastern Qaidam basin, plays an important role in the source‐to‐sink system and landscape evolution at the basin‐mountain boundary between the Qilian Mountains and the Qaidam basin in the northern Tibetan Plateau. In this study, we conduct field observation, topographic analysis, zircon U–Pb dating, and apatite (U–Th)/He dating to constrain the landscape and tectonic evolution of the Bayin River watershed. Bedrock zircon U–Pb dating indicates the age group of 420–450 Ma for far‐source sediments and the age group of >1,700 Ma for near‐source sediments in the Bayin River watershed. Detrital zircon U–Pb dating results from the Mesozoic and Cenozoic strata in the Bayin River watershed reveal that the most important source transition occurred during the Cretaceous. The Zongwulong Mountains gradually uplifted throughout the Cenozoic, along with decreasing far source and increasing near source based on detrital zircon U–Pb dating. Rapid uplift occurred across the Qilian Mountains during the late Cenozoic, leading to high normalized steepness indices, young apatite (U–Th)/He ages, and deep incised valleys at the basin‐mountain transition zone. The knickpoints caused by the latest headward erosion just reach an elevation of ~3,800 m on the river longitudinal profiles, indicating that the latest uplift magnitude is ~300–400 m relative to the basin surface of the Qaidam basin. Elevation distribution and apatite (U–Th)/He ages reveal that river incision leads to high relief in the Zongwulong Mountains and influences its tectonic evolution. The tectonic setting of Bayin River watershed significantly changed from Jurassic to Cretaceous based on detrital zircon U‐Pb age spectrumSlight erosion in central Qilian Mountains and intense erosion at the basin‐mountain transition zone are revealed by apatite (U–Th)/HeRiver incision leads to high relief of the Zongwulong Mountains related to the central Qilian Mountains

Cell adhesion behaviors of stimuli-responsive surfaces have attracted significant attention for their potential biomedical applications. Distinct from temperature and pH stimuli, photoswitching avoids the extra input of thermal energy or chemicals. Herein, we designed a novel reusable cyclodextrin (CD)-modified surface to realize photoswitched specific cell release utilizing host–guest interactions between CD and azobenzene. The azobenzene-grafted specific cell capture agent was assembled onto the CD-modified surface to form a smart surface controlling cell adhesion by light radiation. After UV light irradiation, the azobenzene switched from trans- to cis-isomers, and the cis-azobenzene was not recognized by CD due to the unmatched host–guest pairs; thus, the captured MCF-7 cells could be released. Light-triggered specific cancer cell release with high efficiency may afford a smart surface with significant potential applications for the isolation and analysis of circulating tumor cells.

Organosilicon-modified epoxy esters resin was successfully prepared by solution polymerization and the effect of content of silica sol and silane coupling agent (KH560) on the resistance to water, acid, alkali and film dry, the polymerization mechanism, structure were studied, respectively. The results showed that: compared with the properties of resistance to water, acid, alkali and film dry of pure epoxy esters resin, to some extent, those of organosilicon-modified epoxy esters resin had been improved a lot. The properties of resistance to water, acid, alkali and aging increased at first and then changed little with the increase of the content of organosilicon. Especially, the comprehensive performance of composite resin was relatively excellent when the content of silica sol and KH560 was 10%, respectively. Keywords: Organosilicon; epoxy esters resin; silane coupling agent; solution polymerization

The contamination of copper to the environment is more and more serious.Nowadays,the sources of copper in the soil due to natural and human activity two kinds of sources, the former is derived from the rock and soil background value, while the latter is derived from the industrial “three wastes”. We can use soil washing for extracting contaminants from the contaminated soil and it is a possible remediation method. Natural organic acids seem to be hopeful environmentally friendly for removing toxic metals from soils. Batch soil-washing experiments were conducted to investigate the behavior of copper desorption from soils by dihydroxysuccinic acid.The experimental results show that the removal of copper with dihydroxysuccinic acid was highly dependented on the initial pH and the concentration of dihydroxysuccinic acid.When the pH was rapidly rising, the removal of copper declined sharply.On the contrary, copper desorption increased adding dihydroxysuccinic acid concentration. More than 80% copper was extracted from soil by 80 mmol L-1 dihydroxysuccinic acid.

Organosilicon-modified acrylate resin was successfully prepared by solution polymerization and the effect of content of silica sol and silane coupling agent (KH570) on the resistance to water, acid, alkali and aging, the polymerization mechanism, structure were studied,respectively. The results showed that: compared with the properties of resistance to water, acid, alkali and aging of pure acrylate resin, to some extent, those of organosilicon-modified acrylate resin had been improved a lot. The properties of resistance to water, acid, alkali and aging increased at first and then decreased with the increase of the content of organosilicon. Especially, the comprehensive performance of composite resin was relatively excellent when the content of silica sol and KH570 was 5% and 5.1%, respectively.

Solvent has a key role in the controllable synthesis of nanocrystals (NCs). Here, using X-ray absorption spectroscopy, we demonstrate that solvent can significantly influence the adsorption of thiols on Au NCs, and thereby affects their growth. It is shown that increasing the solvent polarities leads to the higher thiol coverage on the NC surface. The high coverage of thiols then retards the growth of particles, and as a result, the NCs’ sizes decrease with the increase in the solvents’ polarities. The underlying reason for the solvent dependence is proposed to be the synergistic effects of different hydrogen bond and hydrophobic interactions between the sulfhydryl and alkyl groups of thiols with the solvents molecules. This work addresses the important role of the solvent environments in the size-controlled synthesis of NCs.

The solubility of benzothiazolium methylsulfate ([HBt [CH3SO3]) in binary solvent mixtures of ethyl benzoate and alcohol was measured by equilibrium method. It was found that the solubility of [HBt [CH3SO3] in this mixture increased with alcohol in mixture scaling up at the same temperature. When the composition of mixture was the same, the increase rate of solubility of [HBt [CH3SO3] in binary solvents was very different at various temperature range. All the solubility data were correlated with three thermodynamics models, and the average relative deviation (ARD) of the calculated value of the three models and the measured values was all less than 2.94%. The thermodynamics models revealed that the degree of association of [HBt [CH3SO3] decreased with the alcohol ratio reducing in binary solvents, the fusion enthalpy of HBt [CH3SO3] remained the same at the range from 233.1K to 293.1K. At last, it was summarized that the change rule of content of related components of [HBt [CH3SO3] + ester + alcohol ternary system at different conditions, and some properties of the system were forecasted. The research in this text was hoped to provide meaningful reference for the use and recycling of ionic liquid.

Dieless drawing, as a flexible metal forming method, could form pipes with arbitrary variable section. In order to control the shape and dimensions accurately, based on the analysis of deformation mechanism of arbitrary variable section pipes via dieless drawing process, the calculation method of dieless drawing speed during pipe forming is proposed theoretically,Furthermore, mathematical model of dieless drawing speed control is established by using piecewise polynomial to approach continuous speed curve. The study provide the basis for the dieless drawing speed microcomputer control system. The results of experimental investigation showed that the mathematical model indicates variation of dieless drawing speed quite well, and it is available to schedule the speeds for arbitrary variable section pipes dieless drawing.

The effect of the quenched speed on the microstructure and electromagnetic properties of melt spun Nd3Fe68Co18B11 nanocomposites was investigated. XRD spectra showed that only α-Fe phase can be obtained for both quenched samples. The complex permeability () and permittivity () within 2-18GHz were measured by vector network analysis. By virtue of quenched speed increased, the flake-like Nd3Fe68Co18B11 decreased the value of permittivity while that of permeability slightly changed. According to transmission line theory, the reflection loss was calculated. With thin matching thickness of 1.5mm, The Nd3Fe68Co18B11 composites realized the optimum reflection loss RL=-5.3dB at 3.6GHz and RL=-3.5dB at 3.9GHz for quenched speed 30m/s and 20m/s, respectively. It showed that it is possible to obtain good microwave absorbing properties with appreciated quenched speed for as spun Nd-Fe-B nanocomposites.

A fine addition!A highly enantioselective and efficient procedure for the amino‐alcohol–zinc‐catalyzed addition of trimethylsilylacetylene to aromatic, α,β‐unsaturated, and aliphatic aldehydes has been developed (see scheme; R=aryl, alkynyl, or alkyl; TMS=trimethylsilyl; TBDMS=tert‐butyldimethylsilyl). The present protocol was successfully applied in the concise synthesis of the natural products marine alkynol and falcarindiol.

Three novel chiral selectors 4a–c were synthesized from (S)-amino acids and (R)-1-phenyl-2-(4-methylphenyl)ethylamine. 4a–c were connected to 3-aminopropylsilanized silica gel to be used as the chiral stationary phase for HPLC. Five amino acid derivatives and two pyrethroid insecticides were fairly resolved on these three new chiral stationary phases under normal phase condition.

Meeting the challenge: The zinc/amino alcohol catalyzed enantioselective addition of terminal alkynes to aldehydes is effective with both phenylacetylene and methyl propiolate, leading to chiral secondary propargyl alcohols with very high enantioselectivity (see scheme).

Mechanically alloyed FexNi77‐xCu1Nb2P14B6soft magnetic materials have been prepared with different atomic compositions. The alloy structures are investigated by X‐ray absorption fine structure (XAFS). The results show that mechanical alloying (MA) can drive the FexNi77‐xCu1Nb2P14B6powder mixture to produce amorphous alloy while the atomic concentration of Fe element is about and over 40%. On the contrary, the MA FexNi77‐xCu1Nb2P14B6is a solid solution with a fcc‐like structure in the region of lower Fe atomic concentration (<22%), preserving a medium‐range order around Ni and Fe atoms. Moreover, we have found that the local structure geometry of Fe atom is similar to that of Ni atom for all the MA FexNi77‐xCu1Nb2P14B6samples. It indicates that the local structures of Fe and Ni atoms in a FexNi77‐xCu1Nb2P14B6sample only depend on the x value of element Ni after ball milling.

The method can be applied to aromatic, aliphatic, and α,β‐unsaturated aldehydes to give the corresponding propargylic alcohols.

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