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A good soil environment helps to ensure the healthy growth of flue-cured tobacco plants, and the nutrients therein profoundly affect the sustainable development of planted tobacco resources. In exploring the spatial variability characteristics of soil nutrients, visualization methods and the construction of a comprehensive soil fertility evaluation system can provide a scientific reference for determining the nutrient content of tobacco planting soil. Using a bibliometric approach, we collected 90 published papers from 2008 to 2022 from the Web of Science and CNKI databases on the spatial variation in soil nutrient characteristics of flue-cured tobacco planting soil, with a focus on the conditions found in China. The current situation and potential issues were analyzed according to the indicator selection frequency, spatial variation visualization method, and influencing factors. There were 20 indicators reflecting the soil nutrients of flue-cured tobacco planting soil. The frequency of available zinc was the highest at 42.86%, followed by phosphorus, organic matter, pH, alkali-hydrolyzable nitrogen, and available potassium. Among the visualization methods, Kriging interpolation was the most widely used, with an application frequency of 68.80%. The influencing factors were divided into natural and human ones. Principal component analysis was commonly used to screen indicators and determine weights, and the soil fertility suitability index was used to evaluate the spatially integrated fertility of soil nutrients for flue-cured tobacco planting. Available zinc, available phosphorus, soil organic matter, soil pH, soil alkali-hydrolyzable nitrogen, and available potassium are important evaluation indices for determining the spatial variability of soil nutrients in flue-cured tobacco planting soil. The selection of indicators, the determination of their weights, and method selection all significantly affect the accuracy of soil nutrient evaluation; thus, future work should focus on the development of a comprehensive evaluation system for tobacco planting soil that also considers trends associated with natural and human factors and their effects on spatial variability. [ABSTRACT FROM AUTHOR]

Bilayers consisting of La0.67Ca0.33MnO3 (LCMO) and SrMnO3 (SMO) have been prepared by pulsed-laser deposition on SrTiO3 (001) substrates. Unconventional magnetic coupling was found after cooling in a small field. The LCMO/SMO bilayers exhibit an exchange bias field of 209 Oe, which vanishes as the temperature rises above 90 K. A small magnetization has been found above the Curie temperature of the pure LCMO thin films. Spin-cluster-like antiferromagnetic (AFM)/ferromagnetic (FM) clusters have been deduced to exist at the interface due to the competing types of magnetic order at the interface. The magnetic relaxation is found to follow a doubleexponential equation and a slow relaxation process is observed due to the strong exchange coupling between AFM/FM clusters and the LCMO layer. We speculate that the short-range high-temperature FM order of the Mn3+ and Mn4+ moments above the Curie temperature at the interface gives rise to the magnetic regions that pin the FM LCMO layer as the temperature decreases. [ABSTRACT FROM AUTHOR]

In-plane exchange bias (EB) in [Pt/Co]n/NiFe/NiO heterostructures with orthogonal easy axes is investigated. The reversible in-plane EB effect at the ferromagnetic (FM)/FM [Pt/Co]n/NiFe interface allows one to manipulate the value and direction of the EB of the heterostructures, which can be induced by applying a magnetic field larger than the perpendicular anisotropy field of the [Pt/Co]n multilayers. The difference between the EB of the heterostructures after field cooling and zero field cooling disappears at 120 K, which may originate from the exchange coupling at the FM/antiferromagnetic (AFM) NiFe/NiO interface. The NiFe thickness dependence of the bias field of the EB exhibits behavior similar to that in conventional FM/AFM bilayers. The EB can be maintained even at room temperature. [ABSTRACT FROM AUTHOR]

Mn60+xGa40-x (x=0, 5, 10, and 15) ribbons were prepared by the melt-spinning technique and subsequently by a heat treatment at 673K for 1 h. The magnetic phases Mn8Ga5, Mn1.86Ga, D019-Mn3Ga, and D022-Mn3Ga are found to appear in these annealed melt-spun ribbons. The Curie temperature TC of the ribbons varies from 125K to 185K as x changes from 0 to 5. For x=10, the hexagonal structure of the D019-Mn3Ga phase is distorted to an orthorhombic one below the phase transition temperature Td=185K. The optimized values for coercivity at room temperature are 0.13, 4.4, 8.1, and 7.7 kOe for the ribbons with x=0, 5, 10, and 15, respectively. The resistance measurements indicate that the ribbons show a typical metallic behavior for x=5-15. [ABSTRACT FROM AUTHOR]

Abstract: Numerous studies have reported that larval experience can affect subsequent host plants selection and future oviposition decisions of many different species, but the investigation of pre‐imaginal experiences on host preference of adults has rarely been tested for soil‐dwelling insects. In this study, we present evidence that larval feeding experience can affect adult host preference in the onion maggot, Delia antiqua. By rearing D. antiqua on different host plants, we were able to examine the role of the natal host of different generations and the effect of larval density on host‐choice behaviour. We also performed bioassays by means of switched host treatment to evaluate the host‐selection principle. Choice bioassays among the three host species demonstrated that D. antiqua females preferred to oviposit on their natal host in each generation and host‐switching treatments. Additionally, increasing larval density could intensify this ovipositional preference on the natal host. The overall results showed that host preference of female D. antiqua is determined by larval experience and density. These findings also add support for the controversial Hopkins’ host‐selection principle. [ABSTRACT FROM AUTHOR]

Two novel P450 cDNAs, CYP6A36 and CYP6A37, were isolated from house-flies. Putative protein sequences deduced from the cDNA sequences shared 58% identity. Predicted protein sequences of CYP6A36 and CYP6A37 from pyrethroid-resistant ALHF house-flies were identical to their corresponding orthologues in susceptible aabys flies. Expression of CYP6A36 was developmentally regulated with significant overexpression in ALHF compared with susceptible CS flies. Overexpression of CYP6A36 was detected in ALHF abdomen, where the primary detoxification organs of the midgut and fat body are located. CYP6A37, however, was expressed in all tested life stages, with no significant difference in expression between ALHF and CS. Genetic linkage analysis located CYP6A36 on autosome 5; overexpression of CYP6A36 was linked to the factors on autosomes 1 and 2, corresponding to the linkage of P450-mediated resistance in ALHF. This evidence suggests the importance of CYP6A36 in detoxification of insecticides and evolution of insecticide resistance in ALHF. [ABSTRACT FROM AUTHOR]

Strong effects of the magnetic anisotropy on the exchange coupling are observed in FM1/NiO(6 nm)/FM2 trilayers with ferromagnetic (FM) layers Co or Fe. Different magnetic properties are found for Co/NiO/Fe and Fe/NiO/Co trilayers with Ag sublayer and cover layer. The Ag sublayer strongly affects the magnetic anisotropy of FM/antiferromagnetic (FM/AF) bilayers and further influences the exchange coupling in FM1/NiO/FM2 trilayers. In particular, the sign of the magnetoresistance changes from negative after zero-field cooling to positive after field cooling, which is due to a reversal of the Co spin polarization. Furthermore, the interfacial coupling between FM and NiO enhances the blocking temperature of NiO. [ABSTRACT FROM AUTHOR]

A series of (100-x)NiO/(x)NiFe2O4 nanocomposites (x = 0, 2.5, 5, 8.3, 12.5, 25) synthesized by a chemical coprecipitation method have been investigated. The exchange bias field HE of the nanocomposites reaches a maximum at x = 2.5, and then decreases with increasing x. The decrease of HE is attributed to the formation of isolated ferrimagnetic NiFe2O4 clusters, which is confirmed by observation with the use of high resolution transmission electron microscopy. The temperature dependence of HE and the coercivity HC for pure NiO is different from those with other samples, which is due to the exchange coupling between the uncompensated antiferromagnetic core and disordered surface shell of NiO nanoparticles. [ABSTRACT FROM AUTHOR]

The exchange bias (EB) effect and its thermal stability in nanoscale Co/NiO antidot arrays and sheet films have been investigated. The EB field HE increases with increasing Co thickness (tCo) and reaches a maximum at tCo = 8 nm in the antidot arrays, whereas HE decreases with tCo in the sheet films. Compared with the sheet films, HE in the antidot arrays is either enhanced or decreased, depending on the thickness of the ferromagnetic Co layer, which is due to the three-dimensional effects in the antiferromagnetic NiO and ferromagnetic Co layers caused by the nanopores. A higher thermal stability is observed in the antidot arrays due to the out-of-plane anisotropy constant K1 of the misaligned antiferromagnetic magnetization component. [ABSTRACT FROM AUTHOR]