bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional carbon efficiency and corporate cash holdings: evidence from China
Authors: Chen Xiaohui , Chen Wen , Hu Tao , Yang Bo , Zeng Jianguang
Published: August 2023

Improving regional carbon efficiency is significant for achieving carbon emission peak and carbon neutrality. Local governments’ carbon reduction regulations to improve regional carbon efficiency greatly influence the macro environment of enterprise production and operation. However, only some studies have focused on the relationship between regional carbon efficiency and corporate production and operation. Based on the data of Chinese A-share listed companies from 2008 to 2019, this study aims to identify the impact and influencing mechanism of regional carbon efficiency on corporate cash holdings. The main results are as follows. (1) With the improvement of regional carbon efficiency, the cash holdings level of enterprises can be reduced. The reason is that facing the dual tasks of reducing carbon emissions and promoting economic growth, the uncertainty of China’s local government’s carbon reduction policy will be more obvious. This is bound to have uncertain impacts on enterprises in many aspects, resulting in local enterprises facing carbon risk. Regional carbon efficiency will reduce carbon risk and weaken the preventive motivation of enterprises holding cash under the condition of stabilizing enterprise cash flow, alleviating financing constraints and improving the availability of external funds. (2) Regional carbon efficiency reduces the cash holdings of enterprises by improving corporate debt financing capability and promoting long-term investment. That is because improvements in regional carbon efficiency can reduce the carbon risks faced by enterprises. In terms of cash source, it can alleviate the financing constraints of enterprises, while in terms of cash destination, it may promote enterprises to make long-term investments and reduce cash holdings. This study enriches the literature on the factors influencing corporate cash holdings, documents the initiative of Chinese enterprises to participate in peak carbon programs and carbon neutral actions, and may enhance support for carbon emissions reduction in developing countries.
Structural and optical characterization of thin AlInN films on c-plane GaN substrates
Authors: Xue Haotian , Palmese Elia , Song Renbo , Chowdhury Md Istiaque , Strandwitz Nicholas C. , Wierer Jonathan J.
Published: August 2023

The structure and optical characteristics of thin (∼30 nm) wurtzite AlInN films grown pseudomorphic on free-standing, c-plane GaN substrates are presented. The Al1−xInxN layers are grown by metalorganic chemical vapor deposition, resulting in films with varying In content from x = 0.142 to 0.225. They are measured using atomic force microscopy, x-ray diffraction, reciprocal space mapping, and spectroscopic ellipsometry (SE). The pseudomorphic AlInN layers provide a set where optical properties can be determined without additional variability caused by lattice relaxation, a crucial need for designing devices. They have smooth surfaces (rms < 0.29 nm) with minimum pit areas when the In content is near lattice-matched to GaN. As expected, SE shows that the refractive index increases and the bandgap energy decreases with increased In-content. Plots of bandgap energy vs In content are fitted with a single bowing parameter of 3.19 eV when using bandgap energies for AlN and InN pseudomorphic to GaN, which is lower than previous measurements and closer to theoretical predictions.
Computer-aided design of quadra-ridged waveguide transformers for full-band matching of half-height rectangular waveguides
Authors: Jiang Senjie , Wang Qingyuan , Su Rongrong
Published: August 2023

A quadra-ridged waveguide transformer (QRWT) is proposed for full-band matching between a standard waveguide and a half-height waveguide, which meets the need for compact waveguide components and the need for multiple sections of irregular transmission lines for better matching in wider operation bands. Unlike conventional matching circuits with monotonically changing impedances, QRWTs form abrupt cross-section changes between transmission line steps. The initial configuration of QRWT is built by CST MICROWAVE STUDIO, a system-level electromagnetic compatibility and general high frequency passive device simulation software, according to the basic electromagnetic (EM) concept and then is optimized by optimization functions from an advanced EM simulator, during the optimization, releasing restrictions as many as possible. To explain the concept, a sample QRWT is designed to match a standard rectangular waveguide WR34 to a half-height waveguide. The reflection coefficient is less than −24 dB in the full operation bandwidth, from 21.7 to 33 GHz. The optimized QRWT has a length of 3.088 mm, 0.218 times the waveguide wavelength at its center operation frequency of 27.35 GHz. For comparison, a two-stage quarter-wave transformer matching circuit is optimized. For similar reflection coefficients in the same bandwidth, the QRWT has a length 57% shorter than the conventional one, and it has an easier manufacturing method using wire-electrode cutting. To verify the design, a back-to-back matching circuit was fabricated using brass material without extra dielectric material. Its measured reflections are less than −16.6 dB, and the insertion loss is less than 0.2 dB.
Non-ideal explosive underwater explosion shockwave model
Authors: Kan Runzhe , Nie Jianxin , Liu Zheng , Jiao Qingjie , Sun Xiaole , Guo Xueyong , Yan Shi , Zhu Yanli
Published: August 2023

The non-ideal behavior of aluminized explosives significantly affects the characteristics of underwater explosion shockwaves, rendering the classical model for underwater explosion shockwaves difficult to apply. In this paper, we analyze the underwater explosion shockwave characteristics of a new generation of aluminized explosives and propose a non-ideal explosive underwater explosion shockwave model incorporating a non-ideal explosive shockwave parameter correction function controlled by the Al/O ratio. First, we conducted underwater explosion tank experiments to obtain four groups of Al/O ratios of shockwave parameters of underwater explosion with aluminized explosives and analyzed the effect of the Al/O ratio on them. Subsequently, we calculated the equation of state of aluminized explosives and established a one-dimensional simulation model of underwater explosion. We verified the reliability of the mesh quality and equation of state using the experimental data. Finally, we used the model to calculate the underwater explosion shockwave parameters of aluminized explosives with Al/O ratios of 0.1–1.3. Based on data analysis, we established a calculation model of the pressure peak and energy flow density of the underwater explosion shockwave of aluminized explosives containing non-ideality correction functions. Our results demonstrate that shockwave pressure peak and energy increase and then decrease with an increase in the Al/O ratio, and the non-ideal behavior of aluminized explosives makes the shockwave energy of underwater explosion more sensitive to the Al/O ratio. The proposed model can better predict the experimental results and can be of high practical value as a general structure for underwater explosion shockwave models of other aluminized or metalized explosives.
A temperature-dependent length-scale for transferable local density potentials
Authors: Szukalo Ryan J. , Noid W. G.
Published: August 2023

Recent coarse-grained (CG) models have often supplemented conventional pair potentials with potentials that depend upon the local density around each particle. In this work, we investigate the temperature-dependence of these local density (LD) potentials. Specifically, we employ the multiscale coarse-graining (MS-CG) force-matching variational principle to parameterize pair and LD potentials for one-site CG models of molecular liquids at ambient pressure. The accuracy of these MS-CG LD potentials quite sensitively depends upon the length-scale, rc, that is employed to define the local density. When the local density is defined by the optimal length-scale, rc*, the MS-CG potential often accurately describes the reference state point and can provide reasonable transferability across a rather wide range of temperatures. At ambient pressure, the optimal LD length-scale varies linearly with temperature over a very wide range of temperatures. Moreover, if one adopts this temperature-dependent LD length-scale, then the MS-CG LD potential appears independent of temperature, while the MS-CG pair potential varies linearly across this temperature range. This provides a simple means for predicting pair and LD potentials that accurately model new state points without performing additional atomistic simulations. Surprisingly, at certain state points, the predicted potentials provide greater accuracy than MS-CG potentials that were optimized for the state point.
Large recoverable energy storage density and efficiency in PbZrO3-xSrTiO3 thin films with polymorphic nanodomains
Authors: Shen Biwei , Huang Fengzhen , Lei Lin , Wu Zijing , Hu Xueli , Xu Zhaoqi , Liu Lin , Ye Yi , Lu Xiaomei
Published: August 2023

PbZrO3-xSrTiO3 solid solution thin films were designed and fabricated by a metal organic decomposition method, and their structural, ferroelectric, and energy storage characteristics were investigated systematically. It is found that the incorporation of SrTiO3 not only gradually transforms PbZrO3 from antiferroelectrics to relaxor ferroelectrics but also obviously increases its breakdown strength. Large ferroelectric polarization and electric-field-dependent effective permittivity are obtained in the PbZrO3-0.4SrTiO3 thin film due to the coexistence of rhombohedral (R), tetragonal (T), and orthorhombic (O) polymorphic nanodomains and polar clusters, which results in simultaneously improved recoverable energy storage density (Wrec ∼73.7 J/cm3) and efficiency (η ∼72%). Moreover, excellent temperature stability (the variations of Wrec and η are both less than 5% as temperature increases from 243 to 393 K) and distinguished fatigue endurance (the variations of Wrec and η are both less than 1% after 108 cycles) are realized in a PbZrO3-0.4SrTiO3 thin film. This study provides a feasible alternative method for designing energy storage materials based on antiferroelectrics.
Universal imprinting of chirality with chiral light by employing plasmonic metastructures
Authors: Ávalos-Ovando Oscar , Bahamondes Lorca Veronica A. , Besteiro Lucas V. , Movsesyan Artur , Wang Zhiming , Markovich Gil , Govorov Alexander O.
Published: August 2023

Chirality, either of light or matter, has proved to be very practical in biosensing and nanophotonics. However, the fundamental understanding of its temporal dynamics still needs to be discovered. A realistic setup for this are the so-called metastructures, since they are optically active and are built massively, hence rendering an immediate potential candidate. Here, we propose and study the electromagnetic-optical mechanism leading to chiral optical imprinting on metastructures. Induced photothermal responses create anisotropic permittivity modulations, different for left or right circularly polarized light, leading to temporal-dependent chiral imprinting of hot-spots, namely, “imprinting of chirality.” The above effect has not been observed yet, but it is within reach of modern experimental approaches. The proposed nonlinear chiroptical effect is general and should appear in any anisotropic material; however, we need to design a particular geometry for this effect to be strong. These new chiral time-dependent metastructures may lead to a plethora of applications.
Effects of wall wettability on vortex flows induced by collapses of cavitation bubbles: A numerical study
Authors: Huang Jianlin , Wang Jingzhu , Huang Jian , Lv Pengyu , Li Hongyuan , Wang Yiwei
Published: August 2023

The collapse of a cavitation bubble near a rigid wall induces a vortex flow that spreads along the wall with a high shear rate, and an important factor affecting the behavior of the bubble dictated by its contact lines is the wettability of the wall. However, the mechanism for the dynamics of the vortex flow and wall shear stress remains to be settled. A numerical study conducted using the multiphase compressible InterFoam solver in the OpenFOAM framework is reported here. The wall wettability is modeled by the contact angle β and slip velocity uslip, and the results show that compared with a neutral surface, superhydrophobic and hydrophilic surfaces broaden the wall-vortex regimes. The main area of shear stress is enlarged both spatially and temporally in the case of a superhydrophobic surface, while it is extended spatially and shortened temporally for a hydrophilic surface. The wall-vortex flow produces a long-term wall shear stress with high magnitude, the maximum value of which is 174.41 kPa for the superhydrophobic surface, 131.82 kPa for the hydrophilic surface, and 103.12 kPa for the neutral surface. Integrating the shear stress over time and space shows that the slip velocity uslip is mainly responsible for affecting the distribution of the shear stress in the vortex flow induced by the collapse of a cavitation bubble. The present findings provide a good guide for ultrasonic cleaning in engineering applications.
An energy tunable continuous 23S1 positronium beam
Authors: Newson D. M. , Babij T. J. , Cassidy D. B.
Published: August 2023

We describe the experimental production of a beam of 23S1 positronium (Ps) atoms obtained from charge-exchange collisions between a positron beam and Xe held in a gas cell. The angular divergence of the emitted Ps beam was recorded using two position sensitive detectors located at different distances from the gas cell. The fraction of the Ps beam produced in the 23S1 level was measured via the change in the Ps count rate after driving the 23S1 → 23P2 transition with microwave radiation; with optimal experimental parameters, we estimate that up to 10% of the Ps beam is formed in the 23S1 state. The measured properties of the beam were used to evaluate the feasibility of using the system for precision spectroscopy of the n = 2 Ps fine structure using Ramsey interferometry.
Environmental variation in an increasing incidence of dead trees in lowland to subalpine eucalypt forests and woodlands 2011–2021
Authors: Liu Zimeng , Kirkpatrick Jamie B.
Published: August 2023

Context There are not many analyses of variation in patterns and potential causes of tree death in eucalypt forests covering wide environmental gradients. Aims To determine the environmental patterns of standing and fallen dead trees in forests over 1200 m of elevation and whether tree death has increased as the climate has become warmer, drier and windier. Methods We measured tree death in 2011 and 2021 in the lowland to subalpine forests near Hobart, Tasmania, Australia and determined the best predictors of its incidence and change. High-resolution satellite images obtained from Nearmap were perused to count dead standing trees, fallen dead trees and live trees in a stratified random selection of 250, 4 ha sites, 10 of which were ground-truthed. Elevation, climatic variables, aspect, slope, fire history, soil type and vegetation type were used as potential predictors of tree death. General linear models were developed to explain response variables. Key results Standing dead trees increased 133% from 1.7 to 2.3 per ha between 2011 and 2021. Fallen dead trees increased 160%. Variables that were significant in at least one of the models for 2011 standing dead trees, 2011 fallen trees, change in standing dead trees 2011–2021 and changes in fallen dead trees 2011–2021 were elevation, fire history, aspect class, several vegetation types and several soil types. Conclusions Deficits in soil moisture as a major cause of death is consistent with several components of these models, with fire history possibly having a legacy effect and wind exposure possibly influencing the balance between standing and fallen dead trees. Implications Tree mortality is likely to move upslope with warming and drying. Managing the understorey of dry forests using fire might help in reducing competition for moisture, and, thus, reduce tree death in susceptible forest communities, but severe fires are likely to cause considerable mortality.
Utilisation FINN data version 2.5 for forecasting PM2.5 during forest fire 2019 in Sumatra by using WRF–Chem
Authors: Kombara Prawira Yudha , Pratama Alvin , Cahyono Waluyo Eko , Setyawati Wiwiek , Adetya Emmanuel , Fitriana Hana Listi
Published: August 2023

In 2019 there were forest fires in Sumatra, Indonesia, which co-occurred with a strong positive IOD. The forest fire disaster caused the thick smoke containing dusts such as particulate matter with a size of 2.5 μm (PM2.5). In this study, a model simulation was conducted to predict the distribution of PM2.5 using the WRF–Chem model when forest fires in 2019 occurred. The prediction was produced by adding the latest version of fire inventory from NCAR (FINN) input data, version 2.5. The prediction result was verified and compared with ground station data from the Ministry of Environment and Forestry (KLHK) station and NASA’s EOSDIS satellite imagery. There are three ground stations that were used for verification: the Jambi, Palembang and Pekanbaru stations. Of the three stations, the prediction results at the Palembang station are the best in correlation and RMSE value. Spatially, the distribution of PM2.5 from the model result is similar and can follow the pattern of smoke distribution from satellite imagery observations. Even though, generally the WRF–Chem model equipped with the latest FINN data still cannot produce an accurate prediction for the 2019 forest fires event yet in Sumatra region.
Synaptic and cellular endocannabinoid signaling mechanisms regulate stress-induced plasticity of nucleus accumbens somatostatin neurons
Authors: Kondev Veronika , Najeed Mustafa , Loomba Niharika , Brown Jordan , Winder Danny G. , Grueter Brad A. , Patel Sachin
Published: August 2023

Interneuron populations within the nucleus accumbens (NAc) orchestrate excitatory-inhibitory balance, undergo experience-dependent plasticity, and gate-motivated behavior, all biobehavioral processes heavily modulated by endogenous cannabinoid (eCB) signaling. While eCBs are well known to regulate synaptic plasticity onto NAc medium spiny neurons and modulate NAc function at the behavioral level, how eCBs regulate NAc interneuron function is less well understood. Here, we show that eCB signaling differentially regulates glutamatergic and feedforward GABAergic transmission onto NAc somatostatin–expressing interneurons (NAc
SOM+
) in an input-specific manner, while simultaneously increasing postsynaptic excitability of NAc
SOM+
neurons, ultimately biasing toward vHPC (ventral hippocampal), and away from BLA (basolateral amygdalalar), activation of NAc
SOM+
neurons. We further demonstrate that NAc
SOM+
are activated by stress in vivo and undergo stress-dependent plasticity, evident as a global increase in intrinsic excitability and an increase in excitation–inhibition balance specifically at vHPC, but not BLA, inputs onto NAc
SOM+
neurons. Importantly, both forms of stress-induced plasticity are dependent on eCB signaling at cannabinoid type 1 receptors. These findings reveal eCB-dependent mechanisms that sculpt afferent input and excitability of NAc
SOM+
neurons and demonstrate a key role for eCB signaling in stress-induced plasticity of NAc
SOM+
-associated circuits.
CD44 acts as a coreceptor for cell-specific enhancement of signaling and regulatory T cell induction by TGM1, a parasite TGF-β mimic
Authors: van Dinther Maarten , Cunningham Kyle T. , Singh Shashi Prakash , White Madeleine P. J. , Campion Tiffany , Ciancia Claire , van Veelen Peter A. , de Ru Arnoud H. , González-Prieto Román , Mukundan Ananya , Byeon Chang-Hyeock , Staggers Sophia R. , Hinck Cynthia S. , Hinck Andrew P. , Dijke Peter ten , Maizels Rick M.
Published: August 2023

Long-lived parasites evade host immunity through highly evolved molecular strategies. The murine intestinal helminth,
Heligmosomoides polygyrus
, down-modulates the host immune system through release of an immunosuppressive TGF-β mimic, TGM1, which is a divergent member of the CCP (Sushi) protein family. TGM1 comprises 5 domains, of which domains 1-3 (D1/2/3) bind mammalian TGF-β receptors, acting on T cells to induce Foxp3
+
regulatory T cells; however, the roles of domains 4 and 5 (D4/5) remain unknown. We noted that truncated TGM1, lacking D4/5, showed reduced potency. Combination of D1/2/3 and D4/5 as separate proteins did not alter potency, suggesting that a physical linkage is required and that these domains do not deliver an independent signal. Coprecipitation from cells treated with biotinylated D4/5, followed by mass spectrometry, identified the cell surface protein CD44 as a coreceptor for TGM1. Both full-length and D4/5 bound strongly to a range of primary cells and cell lines, to a greater degree than D1/2/3 alone, although some cell lines did not respond to TGM1. Ectopic expression of CD44 in nonresponding cells conferred responsiveness, while genetic depletion of CD44 abolished enhancement by D4/5 and ablated the ability of full-length TGM1 to bind to cell surfaces. Moreover, CD44-deficient T cells showed attenuated induction of Foxp3 by full-length TGM1, to levels similar to those induced by D1/2/3. Hence, a parasite protein known to bind two host cytokine receptor subunits has evolved a third receptor specificity, which serves to raise the avidity and cell type–specific potency of TGF-β signaling in mammalian cells.
Aerial treatment of the Australian plague locust, Chortoicetes terminifera (Orthoptera: Acrididae) with Metarhizium anisopliae (Deuteromycotina: Hyphomycetes)
Authors: Hunter D.M. , Milner R.J. , Spurgin P.A.
Published: August 2023

Between October 1999 and April 2000, nearly 4000 ha of nymphal bands and adult swarms of Chortoicetes terminifera (Walker) were aerially treated using a ULV oil formulation of strain FI-985 of Metarhizium anisopliae var. acridum. During the mild weather (maxima 22–30°C) of spring (October), there was little change in nymphal bands during the first week but at all doses between 25–100 g (1–4 × 1012 conidia) ha−1, the bands rapidly declined 9–12 days after treatment reaching > 90%mortality by 14 days. Metarhizium persisted for some time as there was 50% mortality of locusts fed vegetation collected from the treated blocks seven days after treatment. Persistence was confirmed by the high mortality of bands that invaded from untreated areas and of nymphs that hatched on the plot five to seven days after treatment, though mortality was then delayed until early in the third week. During summer (January), temperatures were high (maxima 36–42°C), and at all doses between 25 and 125 g (1–5 × 1012 conidia) ha−1, there was a rapid decline seven to ten days after treatment. By 12–14 days, there was a > 90% decline in numbers in most blocks which was confirmed by helicopter surveys two weeks after treatment that found very few adults within or near treated areas. Mortality was delayed in the high dose where there were blockages of spray equipment during treatment. The clear demonstration that Metarhiziumcan suppress small local populations of C. terminifera led to the limited operational use of Metarhizium on an organic farm and in a National Park where nearly 2500 ha of bands and swarms were treated. Continued research is needed to develop a commercially viable product so that Metarhizium can form a significant part of a programme of integrated pest management of locusts in Australia.
Modelling population dynamics of Orius laevigatus and O. albidipennis (Hemiptera: Anthocoridae) to optimize their use as biological control agents of Frankliniella occidentalis (Thysanoptera: Thripidae)
Authors: Sanchez J.A. , Lacasa A.
Published: August 2023

Orius laevigatus (Fieber) and O. albidipennis (Reuter) play an important role in the control of Frankliniella occidentalis (Pergande) in crops and natural vegetation in the Mediterranean area. The biological parameters of the two anthocorids were studied and modelled in relation to temperature to optimize their use in thrips control programmes. Development times and reproductive parameters of O. laevigatus and O. albidipennis were determined at 20, 25, 30 and 35°C. Pre-imaginal development times ranged from 34.6 and 37.2 days at 20°C to 12.3 and 10.2 days at 35°C in O. laevigatus and O. albidipennis, respectively. The lower thermal development threshold was significantly higher for O. albidipennis (14.2 ± 0.9°C) than for O. laevigatus(11.3 ± 0.7°C). No significant differences in fecundities between the two anthocorids were observed at 20, 25 and 30°C. At 35°C, O. albidipennishad a significantly higher fecundity than O. laevigatus. Non-linear models were used to explain reproduction and female survivorship in relation to temperature. The upper reproductive thresholds were estimated at 40.9 ± 0.3 and 35.5 ± 0.1°C for O. albidipennis and O. laevigatus, respectively. The different optimum temperatures may explain, at least in part, the different distributions of the two species in the Palaeartic region and their population dynamics in greenhouses and natural vegetation in the south of Spain. The estimation of rmas a function of temperature showed high variability between years. Three release rates of 0.75–0.25 Orius per plant are recommended from early March to mid May to deal with thrips outbreaks in pepper crops.
Mitochondrial DNA sequence divergence among Schizaphis graminum (Hemiptera: Aphididae) clones from cultivated and non-cultivated hosts: haplotype and host associations
Authors: Anstead J.A. , Burd J.D. , Shufran K.A.
Published: August 2023

A 1.0 kb region of the mitochondrial cytochrome oxidase subunit I gene from the greenbug aphid, Schizaphis graminum (Rondani), was sequenced for 24 field collected clones from non-cultivated and cultivated hosts. Maximum likelihood, maximum parsimony and neighbour-joining phylogenies were estimated for these clones, plus 12 previously sequenced clones. All three tests produced trees with identical topologies and confirmed the presence of three clades within S. graminum. Clones showed no relationship between biotype and mtDNA haplotype. At least one biotype was found in all three clades, suggesting exchange among clades of genetic material conditioning for crop virulence, or the sharing of a common ancestor. However, there was a relationship between host and haplotype. Clade 1 was the most homogenous and contained 12 of 16 clones collected from cultivated hosts and five of the six collected from johnsongrass, Sorghum halepense, a congener of cultivated sorghum, S. bicolor. Four of the six clones collected from Agropyron spp. were found in clade 2. Clade 3 contained two clones from wheat, Triticum aestivum, and four from non-cultivated hosts other than Agropyron spp. A partitioning of populations by mtDNA haplotype and host suggests the occurrence of host adapted races in Schizaphis graminum.
A density-dependent model with reinvasion for estimating tsetse fly populations (Diptera: Glossinidae) through trapping
Authors: Gouteux J.-P. , Artzrouni M. , Jarry M.
Published: August 2023

A simple density-dependent reinvasion model is described and used to estimate tsetse fly populations on the basis of removal trapping experiments. The model was tested on Glossina fuscipes fuscipes Newstead in the Central African Republic and G. palpalis palpalis (Robineau-Desvoidy) in the Republic of Congo (Brazzaville). The density-dependence is modelled by postulating that the inflow of flies each day is proportional to the deficit relative to the equilibrium population. Non-linear least square techniques were used to estimate the following parameters: the daily capture rate, the strength of the density-dependence, and the equilibrium fly population, at the beginning and at the end of the trapping experiment. The model ignores birth and death rates of flies and is applicable only when a rapid decrease in population occurs over a short period (between 10 and 20 days). Over longer periods one could not ignore the natural growth of the populations as well as other more complex density-dependent mechanisms.
Behaviour of the adult seven spot ladybird, Coccinella septempunctata (Coleoptera: Coccinellidae), in response to dimethoate residue on bean plants in the laboratory
Authors: Singh S.R. , Walters K.F.A. , Port G.R.
Published: August 2023

The sub-lethal effects of dimethoate residue on the distribution and locomotor activity of adults of Coccinella septempunctata Linnaeus on Vicia faba plants were investigated in the laboratory. The presence of dimethoate residues on the upper half of the plant caused C. septempunctata to spend significantly less time on the plants overall. When given a choice of treated and untreated surfaces, C. septempunctata spent proportionately more time on the untreated areas of the plant. The locomotor activity of C. septempunctata was also altered following encounter with dimethoate residues resulting in a significant increase in the proportion of time spent walking and a reduction in the proportion of time spent resting. The proportion of time spent on plant parts was also affected, with a reduction in the time spent on the apex and an increase in the proportion of time spent on the stem, indicating a possible avoidance response. The proportion of time spent on the adaxial leaf surface was significantly increased following dimethoate treatment. The implications for integrated pest management are considered.
Effectiveness of introduced biocontrol insects on the weed Parthenium hysterophorus (Asteraceae) in Australia
Authors: Dhileepan K.
Published: August 2023

Six species of insects and a rust fungus have been successfully established for biocontrol of the weed Parthenium hysterophorus L. in Queensland, Australia. Effectiveness of biocontrol insects was evaluated at two properties in Queensland during 1996–97 based on an exclusion experiment using insecticides. Parthenium-infested plots with and without biocontrol insects were sampled at monthly intervals and the impact of biocontrol insects on parthenium at individual plant and whole population levels monitored. Biocontrol insects were more effective at Mt Panorama (central Queensland) than at Plain Creek (north Queensland). At Mt Panorama, the leaf-feeding beetle Zygogramma bicolorata Pallister caused 96% defoliation and the stem-galling moth Epiblema strenuana Walker affected 100% of the plants, resulting in reductions of 90% in weed density, 40% in plant height, and 82% in flower production. Exclusion of biocontrol insects resulted in a 52% increase in seedling emergence and a seven-fold increase in the soil seed bank in the following season. At Plain Creek, E. strenuana was the only prominent agent. It affected 92% of the plants and prevented 32% of plants from producing any flowers, reduced plant height by 40% and flower production by 49%, but did not reduce the plant biomass, weed density or soil seed bank. However, exclusion of biocontrol insects resulted in an eight-fold increase in the soil seed bank in the following season.
Importance of nutrition and host availability on oogenesis and oviposition of Cephalonomia stephanoderis (Hymenoptera: Bethylidae)
Authors: Lauzière I. , Pérez-Lachaud G. , Brodeur J.
Published: August 2023

A variety of host and non-host meals were tested for their potential in triggering oogenesis and oviposition in females of Cephalonomia stephanoderis Betrem, a synovigenic parasitoid of the coffee berry borer, Hypothenemus hampei (Ferrari). The consumption of non-host meals or meals composed of honey and crushed host eggs or pupae was insufficient to initiate oogenesis. The presence of suitable hosts for oviposition appeared essential for inducing oogenesis and oviposition in this parasitoid. Whereas females may host-feed on all developmental stages of H. hampei, these were not equally suitable in stimulating oogenesis and oviposition. In no-choice tests, oogenesis and oviposition were observed only in females supplied with fully-developed larvae, prepupae and pupae. Direct contact with hosts apparently stimulated egg maturation and egg-laying. Delaying the allocation of energy to egg production until suitable hosts are available for oviposition may be an adaptive attribute of a parasitoid of a concealed and patchily distributed host such as H. hampei.
Radar studies of the vertical distribution of insects migrating over southern Britain: the influence of temperature inversions on nocturnal layer concentrations
Authors: Reynolds D.R. , Chapman J.W. , Edwards A.S. , Smith A.D. , Wood C.R. , Barlow J.F. , Woiwod I.P.
Published: August 2023

Insects migrating over two sites in southern UK (Malvern in Worcestershire, and Harpenden in Hertfordshire) have been monitored continuously with nutating vertical-looking radars (VLRs) equipped with powerful control and analysis software. These observations make possible, for the first time, a systematic investigation of the vertical distribution of insect aerial density in the atmosphere, over temporal scales ranging from the short (instantaneous vertical profiles updated every 15 min) to the very long (profiles aggregated over whole seasons or even years). In the present paper, an outline is given of some general features of insect stratification as revealed by the radars, followed by a description of occasions during warm nights in the summer months when intense insect layers developed. Some of these nocturnal layers were due to the insects flying preferentially at the top of strong surface temperature inversions, and in other cases, layering was associated with higher-altitude temperature maxima, such as those due to subsidence inversions. The layers were formed from insects of a great variety of sizes, but peaks in the mass distributions pointed to a preponderance of medium-sized noctuid moths on certain occasions.
Histological studies of damage by pod-sucking bugs (Heteroptera: Coreoidea) associated with cowpea Vigna unguiculata ssp. unguiculata in Nigeria
Authors: Soyelu O.L. , Akingbohungbe A.E.
Published: August 2023

Histological studies were conducted on cowpea pods fed upon by the coreoid pod-sucking bugs, Anoplocnemis curvipes (Fabricius), Clavigralla tomentosicollis Stå;l, C. shadabi Dolling, Riptortus dentipes (Fabricius) and Mirperus jaculus (Thunberg). Various degrees of tissue and cellular disruption were apparent, especially in the brachysclereids. They were manifested in terms of plasmolysis, cell enlargement and cell wall disintegration depending on the coreoid species involved. The feeding site and its periphery had all the cells of the brachysclereids plasmolysed, with the parenchyma having broken cell walls in the case of A. curvipes. Riptortus dentipes and M. jaculus showed similar patterns of feeding activity but less extensive levels of damage. The Clavigralla spp., however, caused cell enlargement in the brachysclereids, and broken cell walls in both the brachysclereids and the parenchyma. Damage symptoms were observed in cells far away from the feeding sites of the bugs, suggesting the possibility of sucrase activity which has been reported to cause osmotic pump feeding in the Coreidae.
Selecting the right statistical model for analysis of insect count data by using information theoretic measures
Authors: Sileshi G.
Published: August 2023

Researchers and regulatory agencies often make statistical inferences from insect count data using modelling approaches that assume homogeneous variance. Such models do not allow for formal appraisal of variability which in its different forms is the subject of interest in ecology. Therefore, the objectives of this paper were to (i) compare models suitable for handling variance heterogeneity and (ii) select optimal models to ensure valid statistical inferences from insect count data. The log-normal, standard Poisson, Poisson corrected for overdispersion, zero-inflated Poisson, the negative binomial distribution and zero-inflated negative binomial models were compared using six count datasets on foliage-dwelling insects and five families of soil-dwelling insects. Akaike's and Schwarz Bayesian information criteria were used for comparing the various models. Over 50% of the counts were zeros even in locally abundant species such as Ootheca bennigseni Weise, Mesoplatys ochroptera Stål and Diaecoderus spp. The Poisson model after correction for overdispersion and the standard negative binomial distribution model provided better description of the probability distribution of seven out of the 11 insects than the log-normal, standard Poisson, zero-inflated Poisson or zero-inflated negative binomial models. It is concluded that excess zeros and variance heterogeneity are common data phenomena in insect counts. If not properly modelled, these properties can invalidate the normal distribution assumptions resulting in biased estimation of ecological effects and jeopardizing the integrity of the scientific inferences. Therefore, it is recommended that statistical models appropriate for handling these data properties be selected using objective criteria to ensure efficient statistical inference.
Longevity and pheromone output in stored-product Bostrichidae
Authors: Edde P.A. , Phillips T.W.
Published: August 2023

Information on longevity and on the effect of ageing on pheromone signalling in Bostrichidae infesting stored products is important because pheromones play a crucial role in mediating aggregation by the species in storages. The longevity of starved and unstarvedProstephanus truncatus(Horn) andRhyzopertha dominica(Fabricius) were determined at 28±1°C, 65±2% RH and L12:D12 cycle. Additionally, the effects of ageing on rate of pheromone emission were investigated inR. dominicaby comparing emission rates of the aggregation pheromones Dominicalure-1 (DL1) and Dominicalure-2 (DL2) released by adult males ranging from 4, 8, 12, 24 and 48 weeks of age. Mean survival time of starved male and femaleP. truncatuswas 8.6±0.6 and 9.1±0.4 days, respectively. StarvedR. dominicamales lived for 5.7±0.2 days, and females for 4.7±0.1 days. However, mean survival times were not significantly different for starved males vs. females of either species. Mean survival time of unstarved male and femaleP. truncatuswas 27.5±2.0 and 18.0±3.3 weeks, respectively, and for unstarved male and femaleR. dominicawas 26.1±2.8 and 16.7±2.9 weeks, respectively. Difference in mean survival times of unstarved males vs. females in bothP. truncatusandR.dominicawere significant. Between species, no significant difference was observed in mean survival time between unstarved males ofP. truncatusorR. dominica, nor between females of both species. Rate of pheromone emission inR. dominicawas higher when the insects were relatively young (4, 8 and 12 weeks old), but declined by almost 55% in treatments where the insect were at about 24 or 48 weeks old, suggesting that recruitment potential ofR. dominicamight reduce substantially as the insects age.
Biodiversity vs. biocontrol: positive and negative effects of alternative prey on control of slugs by carabid beetles
Authors: Symondson W.O.C. , Cesarini S. , Dodd P.W. , Harper G.L. , Bruford M.W. , Glen D.M. , Wiltshire C.W. , Harwood J.D.
Published: August 2023

Environment-friendly farming techniques seek to increase invertebrate biodiversity in part with the intention of encouraging greater numbers of predators that will help to control crop pests. However, in theory, this effect may be negated if the availability of a greater abundance and diversity of alternative prey diverts predators away from feeding on pests. The hypothesis that access to alternative prey can lead to reduced pest suppression under semi-field conditions was tested. Alternative prey type and diversity were manipulated in 70 mesocosms over 7+ weeks in the presence of the carabidPterostichus melanarius(Illiger), a known predator of slugs, and reproducing populations of the slugDeroceras reticulatum(Müller). Significantly fewer slugs survived where no alternative prey were provided. Maximum slug numbers and biomass were found in treatments containing either carabids plus a high diversity of alternative prey (many species of earthworm and three of Diptera larvae) or a single additional prey (blowfly larvae,Calliphora vomitoriaLinnaeus). In these treatments slug numbers and biomass were as high as in plots lacking predators. The effects of alternative prey were taxon-specific. Alternative prey strongly affected carabid fitness in terms of biomass and egg load. The fittest predators (those with access to high alternative prey diversity orC. vomitorialarvae) reduced slug numbers the least. The mean individual slug weights were greater in treatments with alternative prey than where no alternative prey were provided to the carabids. These results suggest that pests may survive and reproduce more rapidly in patches where predators have access to alternative prey.
Corrosion resistance of structural metals depending on the sample orientation and initial exposure conditions in coastal and rural atmospheres. Part 1. Corrosivity toward structural metals at coastal and rural test sites under various exposure conditions
Authors: Panchenko Yulia , Marshakov Andrey , Nikolaeva Ludmila , Igonin Timofey
Published: August 2023

Four 1-year tests of metal samples (carbon steel, zinc, copper, aluminum, and D16 alloy) were carried out at locations with coastal and rural atmospheres to determine corrosion losses and the rate of chloride deposition ([Cl-]) on the upper and lower sample sides. [Cl-] were determined for different orientations relative to the sea winds on coastal sites. A methodology for testing metal samples is presented and the values of the first-year corrosion losses of metals (C1) are reported. It is shown that the corrosion of metals is significantly affected by the season of when the samples are installed. The atmosphere corrosivity under each conditions of sample exposure is estimated by the C1 values calculated using the developed dose-response functions (DRFs). It has been shown that the DRFs can be used to predict C1 and estimate the atmosphere corrosivity categories at locations with various types of atmosphere and under various exposure conditions.
Surface defect identification based on broadband laser-generated Rayleigh wave with wavenumber filtering
Authors: Liu Xuekun , He Jun , Cheng Qichao , Yang Shixi , Li Miaoshuo
Published: August 2023

As a non-contact, couplant-free and nondestructive technique, the laser ultrasonic technology has great potential for detecting surface defects. In this paper, we propose a surface defect identification method based on broadband laser-generated Rayleigh wave with wavenumber filtering in an area scanning mode. Firstly, a particular lowpass filter is constructed in frequency-wavenumber domain to extract the scattered wave generated by the defects, and then a surface defect image can be reconstructed based on the broadband scattered wave wavenumbers. Secondly, a threshold denoising method is employed to enhance the signal-to-noise ratio and improve the image sharpness. Thirdly, the experimental validation is carried out, in which a laser ultrasonic detection system is used to detect the surface defects of aluminum alloy specimens and identify their different parameters. The experimental results verify that the proposed method can identify the location, size and orientation of surface defects effectively, meanwhile, its imaging effect shows significantly superior to that of the conventional reflected wave energy and standing wave energy methods. Furthermore, the correlation between maximum local scattered wave energy and the depth of defects is found, which can characterize the severity of the surface defects.
An effective method to calculate the electron impact excitation cross sections of helium from ground state to a final channel in the whole energy region
Authors: Sun 孙 Rui 瑞 , Zeng 曾 De-Ling 德灵 , Jin 金 Rui 锐 , Han 韩 Xiao-Ying 小英 , Gao 高 Xiang 翔 , Li 李 Jia-Ming 家明
Published: August 2023

The electron impact excitation (EIE) cross sections of an atom/ion in the whole energy region are needed in many research fields, such as astrophysics studies, inertial confinement fusion researches and so on. In the present work, an effective method to calculate the EIE cross sections of an atom/ion in the whole energy region is presented. We use the EIE cross sections of helium as an illustration example. The optical forbidden 1 1S–n
1S (n = 2–4) and optical allowed 1 1S–n
1P (n = 2–4) excitation cross sections are calculated in the whole energy region using the scheme that combines the partial wave R-matrix method and the first Born approximation. The calculated cross sections are in good agreement with the available experimental measurements. Based on these accurate cross sections of our calculation, we find that the ratios between the accurate cross sections and Born cross sections are nearly the same for different excitation final states in the same channel. According to this interesting property, a universal correction function is proposed and given to calculate the accurate EIE cross sections with the same computational efforts of the widely used Born cross sections, which should be very useful in the related application fields. The datasets presented in this paper are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00142.
Cement-based composites modified by graphene oxide nano-materials: porosity and thermal conductivity
Authors: Tian Weixin , Chai Junrui , Cao Jing
Published: August 2023

This study looked into the way graphene oxide (GO) affects the porosity and thermal conductivity of composite materials fabricated from cement. Different concentrations ascribed to GO at 0.02%, 0.05, 0.07, and 0.1% were added to the cement samples (as per cement mass). The porosity showed a trend of first decreasing and then increasing, with the decrease in macroporosity being particularly pronounced. The porosity and thermal conductivity of GO-cement composites were measured. The findings demonstrated by incorporating GO, the thermal conductivity of GO-cement composites was firstly boosted, which later decreased with the largest enhancement at 0.02%. This study holds the promise of providing a basis for GO’s multi-field coupling of cement under multiple enhancements of mechanics, heat conduction, and hydration and contributing significantly to the application of GO.
The method of growing InGaAs nanowires in a dual-temperature zone tube furnace
Authors: Miao Teng , Liu LinSheng
Published: August 2023

In this paper, InAs, GaAs, and InGaAs nanowires are grown by CVD using a dual-temperature zone tube furnace. The grown nanowires are characterized and analyzed. Based on the traditional chemical vapor deposition method, a small quartz tube is innovatively used to first deliver group III materials to fuse with gold particles, thus forming a higher quality eutectic alloy. It then pushes in InAs and GaAs source materials for normal growth. With growing InGaAs nanowires, the source temperature of InGaAs nanowire growth is controlled by using a dual-temperature zone to achieve the control of InGaAs nanowire components.
One-dimensional rheological consolidation study on two-sided semi permeable boundary and fractional viscoelastic saturated soil under cyclic loading
Authors: Lu Yimiao , He Bo , Sun Yufei , Wang Jinbao
Published: August 2023

Considering the viscoelastic of soft clay, the fractional kelvin model is used to describe the constitutive relationship of soft clay. At the same time, considering that both sides of the soft clay layer have certain permeability, the two-sided semi-permeable boundary is used as its boundary condition. Combined with the cyclic load of different waveforms, the one-dimensional consolidation settlement of saturated soft clay is analyzed. Firstly, the consolidation equation is obtained through Laplace transformation, and the semi-analytic result is obtained by Laplace inverse transformation. The accuracy of the solve method and the model’s applicability are checked by the degradation of boundary conditions and the model. Finally, one-dimensional consolidation settlement under cyclic load with different waveforms is compared.