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The soil phosphorus (P) cycle and P transformation are largely driven by the soil bacterial microbial community. However, little is known about the effects of dazomet (DZ) soil fumigation on soil P and soil microbial communities associated with P transformation. This research investigated P released from three farm soils as a result of DZ fumigation and changes in enzyme activity, gene abundance, and the encoding alkaline phosphatase PhoDmicrobial community. After DZ fumigation, we observed a briefly significant increase in the available P and the active P fractionation. The soil ALP activity, 16s rRNAabundance, and the phoDgene decreased significantly after DZ fumigation. The abundance and diversity of phoD-harboring microbes also decreased shortly after fumigation, increased significantly 14–28 days later, and then decreased again toward the end of the experimental period of 86 days. The shared OTUs between treatments became fewer with increasing time after fumigation. The changes in available P and the active P fractionation after DZ fumigation were significantly correlated with the abundance of the dominant phoD-harboring microbes. DZ fumigation promoted P mineralization in these farm soils and changed the composition of phoD-harboring microbial communities, which will benefit crops able to absorb and use P.

As a substitute for methyl bromide, effects of allyl isothiocyanate (AITC) on nontarget microorganisms in soil are poorly understood. This study measured the half-life of AITC in the soil as well as its effects on the soil substrate-induced respiration (SIR) and on communities of soil bacteria and fungi. The results showed that AITC had a short half-life and a short-term inhibition of SIR; high-throughput sequencing analysis showed that AITC had less effect on bacterial than fungal communities. Fumigation reduced the diversity of soil bacteria temporarily, but stimulated the diversity of soil fungi in the long-term and significantly changed the structure of the fungal community. Following AITC fumigation there were significant increases in the relative abundance of probiotics such as Sphingomonas, Streptomyces, Hypocreales, Acremonium, Aspergillus, and Pseudallescheriathat help to control plant diseases. Our study provided useful information for assessing the ecological safety of AITC.

The mechanism of N2O production following chloropicrin (CP) fumigation was investigated in this study. Our results showed that CP fumigation increased N2O production from 23 to 25 times in comparison with the control and significantly decreased the abundance of 16S rRNA and N-cycling functional genes. CP also decreased the soil bacterial diversity and caused a shift in the community composition. The N2O emissions in fumigated soil were significantly correlated with soil environmental factors (NH4+, dissolved amino acid, microbial biomass nitrogen, and NO3–) but were not correlated with the abundance of functional genes. Metatranscriptomes and dual-label 15N–18O isotope analysis revealed that CP fumigation inhibited the expression of gene families involved in N2O production and sink processes and shifted the main pathway of N2O production from nitrification to denitrification. These results provided useful information for environmental safety assessments of CP in China, to improve our understanding of the N-cycling pathways in fumigated soils.

Crofton weed (Eupatorium adenophorumSpreng.) is an invasion in China and its spread speed rate has been faster than anticipated. Laboratory and greenhouse studies were employed to investigate the effect of heavy metal elements on several factors and the survivability mechanism of Crofton weed. Biochemical and ultrastructural methods revealed that this plant tolerated low concentrations of lead (Pb) or cadmium (Cd) individually or in combination as well, based on measurements of photosynthesis, the malondialdehyde and proline content, and the total electrolyte rate. After Pb, Cd or a mixture treatment, the total electrolyte rate, the malondialdehyde and proline content increased in Crofton weed, and leaves became darker than those of the control. Cellular ultrastructure observations showed that a cellular ultrastructure altered, including a thickened cell wall, chloroplast deformation, and damaged mitochondrial membrane. In addition, the activity of catalase, peroxidase and superoxide dismutase and the soluble protein content were affected after treatment with high concentrations of Pb, Cd or a combination. Taken together, these results suggest that Crofton weed has a high tolerance to Pb and Cd at low concentrations but becomes susceptible at high concentrations. These results may help control the environmental threat of Crofton weed or other invasive weed species.

Dazomet (3,5‐dimethyl‐1,3,5‐thiadiazinane‐2‐thione) is widely used as a soil fumigant for controlling soil‐borne diseases and pests in China and other agricultural countries. The active ingredient of dazomet is its degradation product, methyl isothiocyanate. Little is known about the environmental conditions that affect the degradation of dazomet in soil. In this study, we conducted laboratory incubation experiments to test the effects of several environmental factors, including soil texture, water content, temperature, pH, and soil amendments, such as chicken manure or urea fertilizer, on the decomposition of dazomet. Results showed that dazomet degradation in soil is an abiotic process strongly dependent on soil texture, water content, temperature, and pH. Decomposition rates differed greatly in various soils, depending mainly on soil physicochemical properties such as pH and organic matter content. The degradation rate increased by 15 to 24 times and by 16 to 37 times when soil temperature increased from 5 to 45°C, and water content increased from 10 to 30%, respectively. Dazomet degraded faster in alkaline versus acidic soil. Both chicken manure and urea fertilizer moderately slowed dazomet degradation. Dazomet was degraded in soil mainly by hydrolysis. The results of our study contribute to a better understanding of the environmental behavior of dazomet, potentially leading to its more efficient, safe, profitable, and effective use by farmers. Dazomet dissipation is highly dependent on soil type.Temperature and soil water content had a large impact on the degradation of dazometDazomet degraded faster in an alkaline soil than in acidic soil.Chicken manure and urea fertilizer moderately slowed dazomet degradation.Dazomet degradation is an abiotic process.

Developing non-expensive, highly active and highly stable electrocatalysts for hydrogen evolution has aroused extensive attention, owing to the necessity of novel clean and sustainable energy carriers. In this paper, we report a synthesis of free-standing three-dimensional hierarchical MoS2/CoS2heterostructure arrays through a convenient process. The investigation of electrocatalytic HER performance suggests that the MoS2/CoS2hybrid catalyst exhibits significant enhancement in HER (onsetpotential and potential at a current density of 100 mA cm−2are 20 mV and 125 mV, respectively) and superior durability (no shift of current density is observed after a continuous scanning of 3000 times) compared with individual CoS2and MoS2. The superior HER performance was attributed to the formation of the interface between CoS2and MoS2through the electrochemical characterization, Raman, XPS analysis, and the control experiment. The lower onsetpotential, higher current density, excellent durability, and the free-standing structure of the three-dimensional hierarchical MoS2/CoS2heterostructure array make it a promising cathode catalyst suitable for widespread application.

Main-chain nonlinear optical polymers based on novel chromophores with special structures presented good solubility in most of the organic solvents. Polymers PE-1 and PE-2 attained the thermal decomposition temperatures of 305 and 223 °C and glass transition temperatures of 113 and 108 °C, and exhibited only negligible decay in the SHG signal baked at 85 °C over hundreds of hours, respectively. The SHG coefficients of poled films from polymers PE-1 and PE-2 were 26.3 and 35.8 pm/V, respectively. These results indicated that this class of polymers can be used in the preparation of organic electro-optic devices.

9-Oxo-agerophorone is a cadinene sesquiterpene, isolated from the leaves of Eupatorium adenophorum. This study evaluated the antimicrobial activity of 9-oxo-agerophorone against three strains of Ralstonia solanacearumand four pathogenic fungi, with an emphasis on the growth and morphogenesis of fungi at scanning electron microscopy level. The determination of minimal inhibitory concentrations demonstrated that 9-oxo-agerophorone exhibited moderate bactericidal activity against R. solanacearumstrains. However, antifungal assays showed that 9-oxo-agerophorone has strong toxicity against Fusarium oxysporum, Bipolaris sorokiniana, Fusarium proliferatum, and Alternaria tenuissimawith median lethal concentrations ranging from 0.476 to 0.357 mg ml−1after 4 days incubation on potato dextrose agar medium. The main changes observed by scanning electron microscopy after 9-oxo-agerophorone treatment were fungal cell wall shrinkage, loss of conidia, formation of short branches in F. oxysporumand F. proliferatum, collapse, broken cell walls, and increased hyphae diameter in A. tenuissima. The tested treatments were also effective in inhibiting spore germination of Fusariumspecies. The results indicated that 9-oxo-agerophorone is a potential candidate as a phytotherapeutic agent for soil-borne fungal diseases.

9-Oxo-10,11-dehydroageraphorone (ODA) is a cadinene sesquiterpene isolated from Eupatorium adenophorum. The antimicrobial activity of ODA was tested in vitro against four fungal strains and four bacterial strains. The fungitoxicity of ODA was evaluated by percentage radial growth inhibition using the poisoned food technique. ODA inhibited Fusarium oxysporummore than the other tested strains, giving EC50values of 0.325 mg ml−1at 48 h and 0.365 mg ml−1at 96 h. Tests also revealed that ODA inhibits the germination of Fusarium oxysporumspores, reducing germination by 97 % at 0.5 mg ml−1concentration. The minimum inhibitory concentrations (MIC) of ODA against four tested strains of Ralstonia solanacearumranged from 0.25 to 1 mg ml−1using a micro-well dilution method. In addition, our scanning electron microscopy study revealed previously unreported, pronounced effects of ODA on Fusarium oxysporum, Bipolaris sorokiniana, Fusarium proliferatumand Alternaria tenuissima, including marked shrinkage in the mycelia of all tested strains, swelling at the ends of Bipolaris sorokinianamycelia and inhibition of spore production in the strains of Bipolaris sorokinianaand Fusarium proliferatum, providing firm evidence of the toxicity of ODA to these pathogenic fungi.

The paper presents a novel and universally applicable strategy to rapidly screen and identify non-target flavonoid components in invasive weeds by liquid chromatography hybrid ion trap time-of-flight mass spectrometry. This strategy consists of three steps of data processing including the diagnostic fragment ion (DFI) determination, the flavonoid component screening out based on the extracted ion chromatograms of DFIs and the final validation viamanual fragment comparison. The main advantages of this strategy are the complete non-target or semi-target identification and simplifying the complicated procedures of structural characterization by rapidly classifying the peaks into well-known chemical families. The flavonoid identification strategy was validated to be very useful and powerful for the identification of flavonoid components in three invasive weeds Flaveria bidentis(L.) Kuntze, Mikania micranthaKunth and Solanum rostratumDunal. Using this approach, a total of 17 flavonoid components have been detected rapidly and identified in Flaveria bidentis(L.) Kuntze, ten of which were in accordance with those in our previous publication using manual analysis; moreover, 7 new flavonoid components were also detected. This developed strategy is highly efficient and would be widely applicable to the component identification of other complex matrices like biological, alimental or environmental sources.

Bright funnels: A series of dendritic systems, which are capable of funneling energy from the periphery to the core, have been synthesized. The photophysical properties of dendrimers have been determined. Selective excitation of the donor leads to an efficient energy transfer (>90 %) to the acceptor. The approach provides a facile synthesis for the modification of near‐infrared BF2‐Azadipyrromethenes.

The organic charge-transfer (CT) complexes nanostructures of CuTCNQF4and AgTCNQF4(copper/silver tetrafluorotetracyanoquinodimethane) were successfully fabricated by organic solid-phase reaction. The morphologies of CuTCNQF4and AgTCNQF4nanostructures can be easily tuned by controlling the reaction temperature. The electron field-emission properties on these nanostructures were investigated. The current density and turn-on field are 4.25 mA/cm2and 5.48 V/μm for the nanowires of CuTCNQF4, and 1.82 mA/cm2and 5.21 V/μm for AgTCNQF4, respectively. The results demonstrated that the nanostructures of complexes CuTCNQF4and AgTCNQF4were potential candidates for the field-emission cathode.

A novel water‐soluble poly(para‐phenylene) derivative with pendant thymine and sulfonate units (PBTS) has been prepared and its metal ion sensing properties have been investigated. PBTS exhibited a reversible and selective fluorescence quenching behavior toward Hg2+ions as compared to Ag+, Ni2+, Mg2+, Ca2+, Hg2+, Co2+, Cd2+, Cu2+, Pb2+, Ba2+, Fe3+, and Zn2+ions in aqueous solution. The fluorescence quenching resulted from the interpolymeric π‐stacking aggregation which was induced by the specific thymine–Hg–thymine interaction.

We report a novel nanodevice using π-conjugated polymers and inorganic semiconductor dual composite P–N junctions single nanowire constructed by PEDOT–PbS–PPY (EPP) nanowire as a two-input OR gate. The nanodevices logic gate may show some key value in nanoelectronic components.