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The plant hormone ethylene is important for the ripening of climacteric fruit, such as pear (Pyrus ussuriensis), and the brassinosteroid (BR) class of phytohormones affects ethylene biosynthesis during ripening via an unknown molecular mechanism. Here, we observed that exogenous BR treatment suppressed ethylene production and delayed fruit ripening, whereas treatment with a BR biosynthesis inhibitor promoted ethylene production and accelerated fruit ripening in pear, suggesting BR is a ripening suppressor. The expression of the transcription factor BRASSINAZOLE-RESISTANT 1PuBZR1 was enhanced by BR treatment during pear fruit ripening. PuBZR1 interacted with PuACO1, which converts 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, and suppressed its activity. BR-activated PuBZR1 bound to the promoters of PuACO1 and of PuACS1a, which encodes ACC synthase, and directly suppressed their transcription. Moreover, PuBZR1 suppressed the expression of transcription factor PuERF2 by binding its promoter, and PuERF2 bound to the promoters of PuACO1 and PuACS1a. We concluded that PuBZR1 indirectly suppresses the transcription of PuACO1 and PuACS1a through its regulation of PuERF2. Ethylene production and expression profiles of corresponding apple (Malus domestica) homologs showed similar changes following epibrassinolide treatment. Together, these results suggest that BR-activated BZR1 suppresses ACO1 activity and the expression of ACO1 and ACS1, thereby reducing ethylene production and suppressing fruit ripening. This likely represents a conserved mechanism by which BR suppresses ethylene biosynthesis during climacteric fruit ripening.

A new method for preparing superhydrophobic nickel coating by magnetic field induced selective scanning electrodeposition based on additive manufacturing is proposed in this paper in which ferromagnetic nano-nickel particles (Nip) are added to the plating solution and the adsorption regulation of Nip achieve by changing the presence of the magnetic field. Adjusting the magnetic field strength can change the density of the coating micro-nano hierarchical structure, thereby affecting the hydrophobicity. The forming mechanism is mainly divided into four steps: pre-coating, loose adsorption, strong adsorption, and hierarchical structure formation. The surface roughness of the superhydrophobic coating reaches 17.584 μm. The pristine coating spontaneously changed from hydrophilic to superhydrophobic after being exposing to air for 5 days (CA = 155.4°). X-ray photoelectron spectroscopy analysis shows that this phenomenon is due to the oxidation of the coating to produce NiO and adsorbing a large amount of hydrocarbons. At the same time, the electrochemical test result shows that the superhydrophobic coating has great corrosion resistance.

A magnetic field-assisted scanning electrodeposition was used to prepare stable superhydrophilic Ni-SiC coating on copper sheets in this paper. The Ni-SiC mixed powder was added to a plating solution, and the magnetic field was parallel to the direction of the electric field. The freshly prepared coating exhibited strong hydrophilicity, completely wetting the coating within 2 s. After standing for 12 weeks in the air, the coating remained superhydrophilic. Scanning electron microscopy (SEM) images showed rough hierarchical structure and micro-gaps present on the surface. The formation of the hierarchical structure is the result of the coaction of a magnetic field and an electric field. Additionally, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) detected high surface energy SiC on the surface of the samples. X-ray photoelectron spectroscopy (XPS) results showed that the coating could maintain superhydrophilicity due to no excessive oxygen adsorption and SiC adsorption.

Ni-Co alloys and Ni-Co-SiC composite coatings were manufactured by magnetic field-induced jet electrodeposition. The microstructure and nanoparticles distribution of the coatings were characterized by field emission scanning electron microscopy, energy dispersive X-ray spectrometry, and X-ray diffraction. The surface roughness, adhesion and corrosion resistance of the coatings were measured using a three-dimensional profilometer, a scratch tester, and an electrochemical workstation. The cellular protrusions on the composite coatings decreased with the addition of nano-SiC particles. However, a large number of small spherical structures grew into large cellular protrusions with an extremely high SiC concentration under traditional jet electrodeposition. The composite coatings under magnetic field-induced jet electrodeposition showed a uniform growth and no protrusions, the nano-SiC particles were also uniformly distributed. The Ni-Co-SiC composite coating exhibited a single-phase solid solution structure, and its adhesion increased to 33.2 N, which was 2.65 times that of the Ni-Co alloy coating. The corrosion current density of the composite coating was 4.768 μAcm−2, which was sufficient to protect sintered NdFeB magnets.

In view of the corrosion failures of sintered NdFeB magnets in engineering, an Ni-Ni(S)-Ni(P) multilayer coating was prepared here via friction-assisted jet electroplating. As a comparison, Ni, Ni(S), Ni(P) single-layer, and Ni-Ni(S)-Ni(P) multilayer coatings were fabricated via jet electroplating without friction. The results revealed that the multilayer coating exhibited better physical and chemical properties compared to the single-layer coatings. After adding friction technology, the surface of the coating was smoother and the original cellular processes disappeared. In addition, the adhesion of the multilayer coating was up to 32.52 N, and the microhardness of the multilayer coatings increased from 557.43 HV to 626.5 HV, which was an increase of 12.39%. In terms of corrosion resistance, the self-corrosion potential of multilayers was up to −0.509 V, and the corrosion current density was as low as 3.564 × 10−6 A/cm2. Friction-assisted jet electroplating can effectively protect sintered NdFeB materials.

Widespread dam construction has reduced the hydrological connectivity of catchments of various sizes. Nutrients lost from upper catchments can be intercepted by dams and deposited in reservoir sediments, and this reduces downstream nutrient transportation. Few previous studies have assessed historical nutrient deposition rates (NDRs) in man-made reservoirs. Using 137Cs and 210Pbex deposition chronologies, this paper examines the total nitrogen (TN), total phosphate (TP), and organic matter (OM) concentrations in six sediment cores recovered from Xujiaya reservoir (catchment area 580 km2), provides estimates of historical NDRs by referencing the original capacity curve, and explores temporal changes to the NDR since dam construction. The results show that anthropogenic sources resulted in the increase in nutrient concentrations in the upper parts of the cores, whereas natural sources were the main contributors to nutrient deposition across the whole reservoir. In addition, sediment supply from the catchment was the main source of the nutrients deposited in the reservoir, and the changing patterns of NDRs were overall regulated by sediment yields. The TN, TP, and OM profiles in the six cores, together with the historical NDRs, reflect the pattern of nutrient deposition in the reservoir derived from this agricultural catchment over the past 60 years. The results provide new insight into the effect of dam construction on nutrient deposition at a medium-sized catchment scale against a background of recent environmental change influenced by human activity.

Colloidal surface engineering is of particular importance to impart modular functionalities to the colloidal systems. Here, a layer of Mn/Ni layered hydroxides (Mn/Ni(OH)x LDHs) can be successfully coated on various colloidal particles, such as silica spheres, silica rods, ferrite nanocrystal supraparticles, as well as FeOOH nanorods. Such layered hydroxides have intrinsic oxidase-mimetic activities, as demonstrated by catalytic oxidation of tetramethyl benzidine in the presence of oxygen. Furthermore, Mn/Ni(OH)x LDHs structure seems to capture bacteria (both Gram positive and Gram negative) and exhibit antibacterial properties in vitro. Moreover, local delivery of Mn/Ni-LDH structure fights against infection and reverses delayed wound healing procedures in mice models. Importantly, such hierarchical structures may have strong adhesive properties to the bacteria, which may maximize the contact between Mn/Ni(OH)x LDHs and the bacteria's surface. Overall, the present versatile colloidal surface engineering strategy will bring new insights in the field of antibiotics for its high efficiency toward antibacterial activity.

A simple and rapid electrochemical synthesis strategy for in-situ fabrication of toluidine blue (TB)-functionalized metal organic framework (TB@MOFs) thin films via one-step reduction approach was reported. The TB@MOFs thin layer has been synthesized on the working electrode surface in different times at room temperature, and its morphology and thickness was characterized by varied instruments, including scanning electron microscope, transmission electron microscope, and scanning ion conductance microscope. The prepared TB@MOFs shows exceptional electrochemical activity and stability under mild conditions, and its electrochemical response is dependent on the amount of TB molecules which are encapsulated in the MOFs. Based on the TB@MOFs sensing platform, a sensitive label-free electrochemical immunosensor for the detection of Indole-3-acetic acid (IAA, a plant hormone) was developed with a wide linear range (2.5 pg mL−1 - 5 ng mL−1) and a low detection limit (1.4 pg mL−1). Moreover, this immune sensor shows good sensitivity and selectivity in real samples for IAA detection.

The theories of impact dynamics and adiabatic temperature change were adopted to investigate the ionization degree of the plasma generated by the 2A12 aluminum target during 2A12 aluminum projectile hypervelocity impact, and the radiant temperature was also estimated during hypervelocity impact. A two-stage light gas gun combined with the plasma characteristic parameters measured by a triple Langmuir probe was applied, and then the fitting relationship between the plasma ionization degree and the theoretical impact temperature as well as the fitting relationship between the maximum electron density and impact velocity were obtained with the aid of the theoretical derivation of the plasma ionization degree and the electron temperature and electron density extracted from experiments.

To researching the damage characteristics of typical logical chip modules in spacecraft due to plasma generated by hypervelocity impacts, we have established a triple Langmuir probe diagnostic system and a logical chips measurement system, which were used to diagnose plasma characteristic parameters and the logical chip module's logical state changes due to the plasma created by a 7075 aluminum projectile hypervelocity impact on the 2A12 aluminum target. Three sets of experiments were performed with the collision speeds of 2.85 km/s, 3.1 km/s and 2.20 km/s, at the same incident angles of 30 degrees and logical chip module's positions by using a two-stage light gas gun loading system, a plasma characteristic parameters diagnostic system and a logical chip module's logical state measurement system, respectively. Electron temperature and density were measured at given position and azimuth, and damage estimation was performed for the logical chip module by using the data acquisition system. Experimental results showed that temporary damage could be induced on logical chip modules in spacecraft by plasma generated by hypervelocity impacts under the given experimental conditions and the sensors' position and azimuth.

Lactofen is a chiral herbicide and widely used against broadleaf weeds in agriculture. As a pesticide, it is directly released to the environment, and easily caused contamination in soil and aquatic ecosystem. The enantioselective degradation of lactofen in the environment has been reported, but the molecular biological mechanism of this phenomenon is still unclear. In this study, strain Edaphocola flava HME-24 could degrade 96.7% of 50 mg L−1 lactofen within 72 h. Lactofen was initially hydrolyzed to desethyl lactofen and subsequently acifluorfen by strain HME-24. A novel gene lanE, involved in lactofen transformation, was obtained from Edaphocola flava HME-24. Gene lanE encoded a protein of 471 amino acids that contained the conserved GXSXG esterase motif and clustered into esterase subfamily V. LanE shared the highest identity with esterase EstD (Q9WYH1) from Thermotoga maritima MSB8 (29.14%). This esterase was also able to transform p-nitrophenyl esters (C4–C8), and the activity decreased when the carbon chain length increased. LanE showed enantioselectivity during the degradation of lactofen, diclofop-methyl, and quizalofop-ethyl, with a higher degradation efficiency of (S)-enantiomers than (R)-enantiomers. The three-dimensional structure of LanE was simulated, and molecular docking revealed that when the (S)-enantiomers of lactofen occupied the active sites, the distance between the ligand molecule and the coordination atom was shorter than that when the (R)-enantiomers occupied the active sites, which facilitated the formation of the transition state complex. The results in this study enhanced our understanding of the preferential catabolism of the (S)-enantiomers of lactofen on the molecular level and could illustrate the reported enantioselective degradation of lactofen in the environment.

Assessment of long-term human impact on sediment yields from karst settings can improve our understanding of the pattern of soil erosion causing rocky desertification in the historical context of environmental change influenced by human activity. Few previous investigations have estimated this impact over time-scales longer than 50 years. This study used dated depression deposits to reconstruct human impact on sediment yields from a small karst catchment in the Three Gorges Reservoir Region, China, over the past 600 years. 137Cs, 210Pbex, and 14C techniques were used to determine short-term (~50 yr), medium-term (~100 yr), and long-term (~600 yr) sedimentation in the karst depression, respectively. Sedimentation rates and specific sediment yields in the catchment during six distinct stages (1351–1462, 1463–1701, 1702–1809, 1810–1916, 1917–1962, and 1963–2017) were determined from core samples. The results indicate that soil loss during the period 1351–1962 was more intensive than that since 1963, which reveals changing sediment yields impacted by human activity over the past 600 years. The high values during the three stages before 1810 can be attributed to the impacts of large-scale migration of people from Huguang to Sichuan during the Ming and Qing dynasties; the higher values during 1810–1916 might reflect increasing disturbance related to rapid population expansion; the highest values (1917–1962) were caused by large-scale deforestation in 1958 and a consistently increasing population; and low values since 1963 reflect constraints on the supply of sediment source materials. These results suggest that rocky desertification might be a long-term land-surface process induced by human activity over timescales of >100 years rather than a short-term modern process occurring over a number of decades. This is the first attempt to examine the long-term history of human impact on sediment yields from a karst catchment using depression deposits. This work improves our understanding of the influence of human activities on soil loss at a depression-catchment scale, and of the evolution and dynamics of rocky desertification in karst areas.

To improve the composite coating surface quality and performance, a magnetic-field-assisted method was used to manufacture Ni–SiC composite coating based on jet electrodeposition. The effect of different concentrations of SiC and the magnetic field on the surface morphology, microhardness, wear resistance, and corrosion resistance of the coating were investigated by (1) changing the content of nano-SiC particles in the bath, and (2) whether magnetic-field-assisted device was used. Results showed that adding nano-SiC can refine the coating grain size and reduce the surface roughness. The microhardness of the coating increased significantly from 442.65 HV to 514.03 HV for pure nickel coating, an increase of 16.12%; the microhardness increased to 542.76 HV with the introduction of a magnetic field. Magnetic field assistance can reduce cellular protrusions and improve flatness. The Ni–SiC coating wear resistance was strengthened with Magnetic-field-assisted, the wear mechanism changed from the fatigue wear to abrasive wear and adhesive wear. The corrosion resistance of Ni–SiC composite coating was also improved compared with pure Ni coating.