bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequential sampling protocols for Spodoptera frugiperda (Lepidoptera: Noctuidae), on Zea mays fields: influence of sampling unit size
Authors: Serra G.V. , Trumper E.V.
Published: August 2023

Spodoptera frugiperda (J.E. Smith) is a major pest in maize fields in Argentina. However, a sampling method that accounts for spatial pattern and allows reliable pest density estimations is still lacking. This paper addresses the issue of how sampling unit size can influence the characterization of S. frugiperda spatial pattern and the performance of sampling plans. An intensive sampling programme for S. frugiperda larvae was carried out in maize fields from October until March in four growing seasons. On each sampling date, 12 to 20 sampling units were taken at random. Each unit consisted of 1, 2, 4, 6, 8, 10 or 12 consecutive plants along a row. The linearized version of the Taylor's power law (TPL) was fitted to mean and variance estimated for each sampling date and data set through least squares regression. In general, b values from TPL were significantly >1 (P<0.05), indicating an aggregated sampling distribution. Regression slopes (b) ranged from 1.28 to 1.48 in small larvae and from 1.06 to 1.24 in large larvae, indicating stronger clumping in the former. TPL parameters were used to develop constant precision sampling plans. The efficiency of these plans in terms of expected total cost (searching and handling sampling units) was very sensitive to the size of the sampling units with small larvae but not with large larvae. The influence of sampling unit size and spatial pattern on TPL parameters and sampling costs is discussed.
Potential for classical biological control of the potato bug Closterotomus norwegicus (Hemiptera: Miridae): description, parasitism and host specificity of Peristenus closterotomae sp. n. (Hymenoptera: Braconidae)
Authors: Haye T. , van Achterberg C. , Goulet H. , Barratt B.I.P. , Kuhlmann U.
Published: August 2023

The potato bug, Closterotomus norwegicus (Gmelin) (Hemiptera: Miridae) is an introduced pest of lucerne, white clover and lotus seed crops in New Zealand and a key pest of pistachios in California, USA. Efforts were made to identify potential biological control agents of C. norwegicus in Europe. A total of eight parasitoids, including six primary parasitoids from the genus Peristenus (Hymenoptera: Braconidae) and two hyperparasitoids from the genus Mesochorus (Hymenoptera: Ichneumonidae), were reared from C. norwegicus nymphs collected in various habitats in northern Germany. With a proportion of more than 85% of all C. norwegicus parasitoids, Peristenus closterotomae (Hymenoptera: Braconidae), a new species, was the most dominant parasitoid, whereas other parasitoid species only occurred sporadically. Peristenus closterotomae did not fit in the keys to any described species and is described as new to science. Parasitism caused by P. closterotomae was on average 24% (maximum 77%). To assess the host specificity of parasitoids associated with C. norwegicus, the parasitoid complexes of various Miridae occurring simultaneously with C. norwegicus were studied. Peristenus closterotomae was frequently reared from Calocoris affinis (Herrich-Schaeffer), and a few specimens were reared from Calocoris roseomaculatus (De Geer) and the meadow plant bug, Leptopterna dolobrata (Linnaeus) (all Hemiptera: Miridae). The remaining primary parasitoids associated with C. norwegicus were found to be dominant in hosts other than C. norwegicus. Whether nymphal parasitoids may potentially be used in a classical biological control initiative against the potato bug in countries where it is introduced and considered to be a pest is discussed.
Effects of temperature on predation by the stinkbugsPicromerus bidensandPodisus maculiventris(Heteroptera: Pentatomidae) on noctuid caterpillars
Authors: Mahdian K. , Vantornhout I. , Tirry L. , De Clercq P.
Published: August 2023

Environmental risks associated with the use of non-indigenous organisms for augmentative biological control have received growing attention. In Europe, the native pentatomid predatorPicromerus bidens(Linnaeus) has been considered a potential alternative to the North American pentatomidPodisus maculiventris(Say) for the control of lepidopteran, coleopteran and hymenopteran defoliator pests. In the current study, prey consumption and developmental duration of the predatory stages ofP. bidensandP. maculiventriswere investigated at three temperatures (18, 23 and 27°C) in the laboratory using caterpillars ofSpodoptera littoralisas prey. Development time from second to fifth instar was longer forP. bidensthan forP. maculiventris, taking on average 17–44 and 14–32 days, respectively, at the different temperatures. Total nymphal consumption of fourth instarS. littoraliscaterpillars indicated a greater voracity ofP. bidensas compared withP. maculiventrisat both the low and high temperatures tested (18 and 27°C). At 23°C, however, the predation rate ofP. maculiventrisnymphs exceeded that ofP. bidensnymphs. Effect of temperature on the functional response ofP. bidensto densities of fourth instarSpodoptera exiguawas assessed on potted green bean plants. Female adults ofP. bidensexhibited a type II functional response at 18 and 23°C but a type III response at 27°C. Searching efficiency was not affected by temperature but handling time decreased from 4.2 to 1.4 h as temperature increased from 18 to 23°C. However, the predator spent twice as much time handling prey at 27°C (2.9 h) than at 23°C. This study indicates high predation rates ofP. bidensat a wide range of temperatures and suggests that the species may be a valuable asset for the biological control of defoliating caterpillars, provided that obstacles to its mass production can be overcome.
Susceptibility of Plodia interpunctella (Lepidoptera: Pyralidae) developmental stages to high temperatures used during structural heat treatments
Authors: Mahroof R. , Subramanyam B.
Published: August 2023

Heating the ambient air of a whole, or a portion of a food-processing facility to 50 to 60°C and maintaining these elevated temperatures for 24 to 36 h, is an old technology, referred to as heat treatment. There is renewed interest in adopting heat treatments around the world as a viable insect control alternative to fumigation with methyl bromide. There is limited published information on responses of the Indian meal moth, Plodia interpunctella (Hübner), exposed to elevated temperatures typically used during heat treatments. Time-mortality relationships were determined for eggs, fifth-instars (wandering-phase larvae), pupae, and adults of P. interpunctella exposed to five constant temperatures between 44 and 52°C. Mortality of each stage increased with increasing temperature and exposure time. In general, fifth-instars were the most heat-tolerant stage at all temperatures tested. Exposure for a minimum of 34 min at 50°C was required to kill 99% of the fifth-instars. It is proposed that heat treatments aimed at controlling fifth-instars should be able to control all other stages of P. interpunctella.
The ecology of Helicoverpa spp. (Lepidoptera: Noctuidae) in the Riverina region of south-eastern Australia and the implications for tactical and strategic management
Authors: Duffield S.J. , Steer A.P.
Published: August 2023

Decisions on the choice of appropriate tactical and strategic control techniques require an understanding of the seasonal distribution and ecology of the target species. To address this need, data were collected from 1997 to 2000 using crop surveys, field sampling and pheromone trapping to monitor the population trends of Helicoverpa armigera (Hübner) and H. punctigera (Wallengren) in the Riverina region of south-eastern Australia. The data gathered are compared to predictions from the HElicoverpa Armigera and Punctigera Simulation (HEAPS) model, that simulates Helicoverpa population dynamics to assist in identifying the drivers of regional populations and provide a framework to make informed decisions. The results highlight the contrasting seasonal dynamics of H. punctigera and H. armigera within the region. Helicoverpa punctigera populations peak in the spring, driven by large scale spring migration into the region and subsequently decline. Helicoverpa armigera populations, conversely, are characterized by a period of spring recruitment of adults from overwintering pupae within the region, followed by a within-season population increase leading to severe late season pressure. The within-season increase of H. armigera is a result of the succession of crop and non-crop hosts with the main driver being sequentially sown, unsprayed maize. Tactical and strategic management options are discussed in light of these findings.
Effects of cattle treatment with a cypermethrin/cymiazol spray on survival and reproduction of the dung beetle species Euoniticellus intermedius (Coleoptera: Scarabaeidae)
Authors: Kryger U. , Deschodt C. , Davis A.L. , Scholtz C.H.
Published: August 2023

In a bioassay to determine non-target ecotoxicological effects of a pyrethroid spray (Ektoban®) on dung beetles, dung from both cypermethrin/cymiazol-treated and control cattle was collected one, two, three, five, seven, 14, 21 and 28 days after treatment and fed to a treatment and control group (respectively) of beetles of the species Euoniticellus intermedius (Reiche). This was done to assess whether a spray formulation of cypermethrin may affect dung beetles differently than previously tested pour-on formulations. Following three beetle generations for two weeks each, the experiment retrieved no significant differences in adult or larval survival, egg production, fecundity and fertility between the control and treatment group. These results demonstrated that the used spray formulation of cypermethrin is likely to be far less detrimental to dung beetles than previously tested pour-ons.
Residual symmetry, CRE integrability and interaction solutions of two higher-dimensional shallow water wave equations
Authors: Liu 刘 Xi-Zhong 希忠 , Li 李 Jie-Tong 界通 , Yu 俞 Jun 军
Published: August 2023

Two (3+1)-dimensional shallow water wave equations are studied by using residual symmetry and the consistent Riccati expansion (CRE) method. Through localization of residual symmetries, symmetry reduction solutions of the two equations are obtained. The CRE method is applied to the two equations to obtain new Bäcklund transformations from which a type of interesting interaction solution between solitons and periodic waves is generated.
Rheological Properties of Warm Mixed Asphalt
Authors: Chang Rong , Qin Yongchun , Wang Peng
Published: August 2023

Adding a warm mixing agent to asphalt can lower the working temperature of asphalt construction by 20–40 °C. It is difficult to evaluate the impact of the existing warm mixed agent on the quality and effect of asphalt due to its wide variety. In this study, 70 # asphalt and 3 kinds of surfactants were selected to prepare warm mix asphalt. The result of different warm mix agents on the rheological properties of asphalt was evaluated through a rheological experiment. The results explained that the warm mixing agent could lower the Brookfield viscosity of asphalt. With the increase in asphalt temperature, the viscosity difference of different types of asphalt binder becomes smaller and smaller. A warm mixing agent will also reduce the creep stiffness of asphalt. In the multiple stress creep recovery test, the average recovery rate of asphalt and the average value of irrecoverable creep compliance have obvious stress dependence.
The effect of calcium carbonate whiskers on the thermal stability of environmentally friendly and energy-saving building composites
Authors: Tang Haoling , Hu Xiaojun
Published: August 2023

This paper studied the effects of different whiskers on the thermal stability of environmentally friendly and energy-saving building composites by exploring the strengthening mechanism of calcium carbonate whiskers on the thermal stability and mechanical properties of the composites. The results show calcium carbonate whiskers can significantly improve composites’ mechanical properties by reducing the matrix’s micro cracks. When the content of calcium carbonate whisker is 6%, the composite’s tensile strength and water absorption are increased by 43.7% and 25.1%, respectively. In addition, calcium carbonate whiskers have high thermal stability when the content is lower than 65 °C. Therefore, it can be proven that adding calcium carbonate whiskers within this temperature range can significantly enhance the thermal stability of environmentally friendly and energy-saving building composites.
Effects of plasma treatment on surface insulation properties of epoxy composites
Authors: He Guangyuan , An Yongke
Published: August 2023

The surface of epoxy composite material working in DC electric field for a long time is easy to accumulate charge and cause flashover, which seriously reduces its insulation level and poses a threat to the safe operation of electrical equipment. In this study, SiO
x
films were deposited on the surface of nano-SiO2/ER nanoparticles by atmospheric pressure dielectric barrier discharge plasma vapor deposition technology using ethyl nor-silicate as a precursor. The effects of different deposition time on the deposition effect and the pressure level of the film surface were studied. Scanning electron microscope and atomic force microscope were used to characterize the surface morphology of the material, and the flashover voltage before and after deposition was measured. The results show that SiO
x
films of different thicknesses can be formed on the surface of the material at different times of plasma deposition. After extending the deposition time of the film, the film becomes more uniform and dense, the surface roughness of the material decreases continuously, and the electrical conductivity and flashover voltage along the surface increases continuously. After 10 min plasma treatment, the conductivity increased from 1.78×10−16 S to 2.3×10−13 S, while the flashover voltage along the surface increased from 19.29 kV to 22.66 kV, an increase of about 17.5%.
A Novel Geometric Nonlinear Analysis Method for Planar Beam Structures Based on Co- Rotation and Substructure Method
Authors: Liang Luyi , Deng Jihua
Published: August 2023

Nonlinear behavior analysis of structures using finite element methods requires multiple iterative solutions. Therefore, improving computational efficiency while ensuring the accuracy of nonlinear calculations is crucial. In this paper, a new geometric nonlinear analysis method for planar beam structures is proposed, based on the co-spinning method and the substructure method, using a substructure containing two planar beam elements as an example. The co-spinning method accurately calculates small deformations by subtracting rigid body displacement from the large displacement of the structure. The substructure method condenses the degrees of freedom of internal nodes into boundary nodes, greatly reducing the order of the nonlinear equilibrium equation group of the structure. The two methods are combined, and a calculation program is developed using the arc length method, which has good performance in solving nonlinear equation groups. Two classic examples are used to verify the correctness of the proposed method by comparing the results with existing literature.
The effect of wetness at the bonding interface on the bond strength of epoxy mortars for repairing hydraulic concrete
Authors: Xu Zengguang , Sun Tong
Published: August 2023

An experimental study was carried out concerning the effect of the degree of wetness of the concrete interface on the bond strength. Different interface agents were first selected after cutting and treating the precast concrete, and new epoxy mortar was added to form concrete repair specimens after 24 hours. Different matrix moisture contents were set, and the bond strength under bending was evaluated by bending resistance test under different curing ages. The analysis of the results showed that the substrate moisture content affected the bond strength of the interface, and the bond strength was higher at 0% to 50% moisture content. The epoxy interface agent was selected to improve the durability of the concrete effectively.
First principles study of hydrogen induced the grain boundaries decohesion in fcc Ag
Authors: Hu Shiwei , Yin Yihui , Liang Hao
Published: August 2023

Hydrogen embrittlement (HE) is a pervasive but harmful physical (chemical) phenomenon, and it has a profound effect on the mechanical properties of metals. Although the study of HE began as early as the near century and a half ago, the essential mechanism of HE still cannot be completely figured out yet. The metallic-H atoms interaction at the atomistic scale is considered the essence of the HE. Especially the interaction of interstitial H and host atoms at grain boundaries is crucial for revealing the HE mechanism. Here, the first principles simulation is applied to study the effect of the trapped H atoms on the grain boundaries (GBs) cleavage behavior. We construct the GBs with different orientations of the face-cantered cubic (fcc) Argentum (Ag) and conduct the ab initio tensile test for all the GBs. The strength of GBs during cleavage, the distortion of GBs structure, and the electronic structure variation induced by trapped H atoms are analyzed. We find the GBs cleavage strength is generally decreased by trapping H atoms at GBs. The decohesion mechanism is the GBs distortion induced by the local electron density variation of the GBs trapping H atoms.
Design of a strength model for foamed lightweight soil
Authors: Li Zhili , Chen Qi , Zhang Xuqun , Tai Pei , Wang Hao , Chen Rui
Published: August 2023

Foamed lightweight soil has been widely used in civil engineering, and the model for foam concrete has been employed to predict its strength. However, various previous strength models of foam concrete are generally based on the assumption of complete hydration, which is not the case for foamed lightweight soil. For example, Nambiar’s model (reference), a simple and widely used model, sets the ratio of hydrated water to cement by weight as an empirical constant, which is actually related to the water-cement ratio before the completion of hydration for foamed lightweight soil. To address this issue, an improved strength model tailor-made for foamed lightweight soil was proposed to establish a relationship between the ratio of hydrated water to cement and the water-cement ratio. The improved model and the original Nambiar’s model were compared with actual strength data, which shows that this improved model is more effective for foamed lightweight soil.
Topology Optimization of Minimum Compliance for Continuous Fiber-Reinforced Polymer
Authors: Yang Jiaxi , Ye Hongling , Dong Yongjia
Published: August 2023

Continuous fiber-reinforced polymer (CFRP) has been paid more attention to due to its advantages of high strength, high stiffness, and lightweight. However, it is challenging for topology optimization to achieve CRRP structure design. A topology optimization (TO) model with minimizing structural compliance under volume fraction constraint is established based on the independent continuous mapping (ICM) method. The continuous fiber angle optimization (CFAO) method solves the fiber orientation. Meanwhile, the local optimal solution problem caused by the CFAO method is greatly avoided by the direction of principal stress. The effectiveness of the method is verified by classic numerical examples. This paper has a significant reference for the TO design of CFRP structure.
Effects of irregular pores on the shear properties of the plane
Authors: Wang Xiaoyu , Liu Liu
Published: August 2023

Through section analysis and optical microscope observation of thick-section composite materials, it is found that there are significant differences in pore micro-characteristics of samples with different thicknesses. It is pointed out that the difference in pore micro-characteristics in the composite matrix is one of the reasons for the change in the interlaminar shear strength of composite materials. In this paper, irregular pore profiles are obtained through image processing, and the parameters to quantitatively characterize the microscopic characteristics are proposed. A randomly generated three-dimensional representative volume element (RVE) model including fiber, matrix, fiber/matrix interface, and pores. The effect of irregular pores with different sizes and distributions on the interlaminar shear strength of composite materials is given. The RVE numerical analysis results show that the interface failure between the fiber and the matrix near the pore causes damage. At the same porosity, the shear strength decreases with the increase of the maximum pore size. At the same time, the porosity concentration also has a significant effect on the interlaminar shear strength of thick section composite. The numerical results verify that the influence of pores on the interlaminar shear properties of thick-section composites is related to the microscopic characteristic parameters of pores.
Flexible PLA/MWCNTs-PDMS Based Hybrid Nanogenerator for Biomechanical Energy Harvesting
Authors: Liu Yi , Lv Ruyue
Published: August 2023

With the development of technology, self-powering devices by harvesting bioenergy is an efficient way to achieve sustainable system operation. In this paper, we fabricated a flexible hybrid nanogenerator (HNG) based on multilayer nanocomposites, innovatively using biocompatible Polylactic acid (PLA) as piezoelectric material and multi-walled carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS) as triboelectric material. A simple method was used to prepare the MWCNTs/PDMS films with surface microstructure. By coupling the triboelectric effect and the piezoelectric effect, a 3 cm × 3 cm HNG can generate an output of 80 V and 125 nA under a pressure stimulation of 20 N. Furthermore, due to the good flexibility and biocompatibility of our device, we can use it to harvest human energy.
Research on the Hydraulics of Microfluidics Bifurcation
Authors: Lin Yao , Cheng Xiaofang , He liqun
Published: August 2023

Microfluidics is a fluid-based manipulating technology for particle assembling or/and chemical reaction on microscope scales, where the viscous stress of fluid is more significant than its inertia. In microfluidics chips, the viscous stress can be determined by the layout of channels, and at design, one can lay out the viscous stress in terms of the hydraulic resistance of straight channels. Here, we carry out a numerical study on the hydraulic resistances of junctions of straight channels, and we manage to understand the bifurcations in particular in views of straight and side branching.
Experimental study on cleaning efficiency of independent traveling solar panel cleaning machine
Authors: Zhu Yongchao , Chen Yanwei , Li Qi , Ma Weifeng
Published: August 2023

As a kind of clean energy, solar energy plays a great role in helping China achieve the “double carbon” goal. However, dust cover will greatly affect the power generation efficiency of solar panels. In order to solve this problem, based on the self-designed independent traveling solar panel cleaning machine, orthogonal experiments were carried out, to study the influence of factors such as the no-load rotating speed of the roller brush, the flow rate of the front water spray component, the flow rate of the rear water spray component and the nozzle type on the improved value of the cleanliness after cleaning. The experimental verification of the optimal parameters of the power generation was also conducted. The results show that the nozzle type has the greatest impact on the cleaning effect, followed by the spray flow of the spray components on both sides of the roller brush. Taking the cleaning effect as the optimization index, the water mist nozzle should adopt the wide-angle small-aperture fan-shaped nozzle (11004 type), the cleaning water flow on both sides of the roller brush should be controlled at 500 L/h, and the rotational speed of the roller brush off the plate should be controlled at 200 rpm. If it is necessary to pay attention to water conservation, the water spray flow of the two ways can be moderately reduced. The optimized cleaning efficiency parameter configuration scheme has an obvious cleaning effect on the photovoltaic array, which can greatly improve the power generation of the array.
Study on the Coordination Effect of Different Flexible Polybenzimidazoles with Copper Ions
Authors: Liu Tianmeng , Wang Yan , Hu Zuming
Published: August 2023

High-performance polymers such as polybenzimidazole (PBI) can have their thermomechanical properties greatly enhanced by the coordination of their rich imidazole groups with metal ions. The molecular chain’s flexibility influents on metal ion coordination greatly. In this paper, PBI with different chain flexibility was synthesized by varying the number of ether bond-containing monomers during the polymerization process. Rheological characterization of supramolecular networks obtained by coordination of different flexible PBI with copper ions was performed to explain in depth the effect of molecular chain flexibility on the reaction between copper ions and imidazole groups. The enhanced mechanical properties of the copper ion coordination polymer networks were compared to provide insight into the enhanced toughening mechanism of PBI with metal ion coordination.
Interfacial Structural and Dynamical Properties of [BMI+] [PF6
-] Ionic Liquids on the MXene Electrode: A Molecular Dynamics Simulation Study
Authors: Xu Chenxuan , Zheng Wenjin , Wen Binbin , Chen Xiaolin , Hua Jing , Wang Xinhao , Qian Xu , Si Linjun , Chen Gang , Yang Huachao
Published: August 2023

Two-dimensional MXene nanomaterials are attracting more and more research interests as electrodes in energy storage applications. In this work, the interfacial structural and dynamical properties of solvent-free ionic liquids ([BMI+] [PF6
-]) on the MXene electrode are investigated using molecular dynamics simulation. Multiple alternating structures of [BMI+] cation and [PF6
-] anions on the MXene surface are observed. Interestingly, the ion diffusion coefficients are remarkably reduced (by 30~40%) in the interfacial Helmholtz layer. Importantly, an asymmetric bell-shaped differential capacitance profile with a maximum capacitance of ~7.04 μF/cm2 is observed. This is chiefly correlated with the structural properties of counterions rather than coins in the interfacial areas.
Modulation Technique Design of An Improved Zero Common Mode Voltage (CMV)
Authors: Guo Yujing , Zhang Junhuai
Published: August 2023

Voltage imbalance of neutral-point and CMV are hot issues in the research of three-level inverters. This paper first introduces the three-level topology of the neutral-point clamped (NPC) inverter. Aiming to eliminate CMV of three-level NPC and balance the voltage of the neutral point simultaneously, a virtual space vector pulse modulation (VSVPWM) strategy is proposed. Virtual voltage vectors of this strategy are composed of 3 medium vectors. The voltage of the neutral point is balanced since the average current of the neutral point is 0. Therefore, the balance index is introduced to redefine virtual voltage vectors, so the voltage of the neutral point can recover quickly when the capacitors’ voltage of the dc-link is imbalanced.
A carbonized coconut husk for supercapacitor electrode
Authors: Chu Ruixia , Tan Shiwei , Qiao Yi , Fu Wenjun , Zhang Kesong , Zhu Peidong , Liu Dongying , Huang Wanyou
Published: August 2023

As a new environment-friendly green device for energy storage, supercapacitor has been favored for its advantages of long service life and huge power density. As the material produced electrode of double-layer supercapacitors, much attention are given arise to carbon materials owning to their wide source, low price, environmental protection and other characteristics, especially biomass-based carbon materials. In this paper, coconut husk was used as raw material, which was carbonized by common hydrothermal pre-treatment and high-temperature pyrolysis carbonization. The materials obtained under different reaction conditions were tested in three-electrode system. The electrochemical tests implied that the carbonized coconut husk has the best energy storage characteristics when the pre-treatment time was 24 h and the activator was KOH. This study explored a carbon electrode derived by a new raw biomass material for energy storage in supercapacitors.
Photoelectric properties and persistent photoconductivity of GaN-based ultraviolet photodetectors
Authors: Yue Zhongyu
Published: August 2023

Persistent photoconductivity deeply affects the performance of the photodetector, and has been studied in a variety of semiconductor optoelectronic devices. In this work, AlGaN/GaN metal-heterojunction-metal (MHM) ultraviolet (UV) detectors and GaN metal-semiconductor-metal (MSM) ultraviolet detectors were prepared using transverse Schottky contacts, and characterized at different temperatures, light intensity and bias voltage. The two-dimensional electron gas (2-DEG) at the Schottky heterojunction of AlGaN and GaN is used to generate high-speed electron mobility, which significantly improves the response speed and responsivity of photogenerated carriers. Under the illumination of 365 nm center ultraviolet light with an intensity of 4.4 mW/cm2, the photocurrent can reach 434 μA-MHM and 38 μA-MSM (25 °C), and the attenuation rate increase by 2.8 times, 5 times and 3.7 times with temperature (25 °C-250 °C), bias voltage (5/10/15 V), and light intensity (0.33/1.1/4.4 mW/cm2), respectively, and the attenuation rate reaches 50∼80 times.
Scaling Mechanism and Permeability Evolution of Sandstone Reservoir
Authors: Lv Fei , Chen Hongnian , Tan Xianfeng , Liu Xiao , Zhang Fan
Published: August 2023

Knowledge of scaling mechanisms and the permeable behavior of rocks is highly important for geothermal energy development. In this study, the sandstone was soaked in a solution with the same chemical composition as geothermal water in Linyi City, Shandong Province. Permeability tests, scanning electron microscope tests, and nuclear magnetic resonance tests were performed on sandstone samples after different soak times (0, 30, 60, and 90 days) and temperatures (25 and 85 °C) to characterize the changes in microstructure and permeability properties. In addition, the changes in ion concentration in chemical solutions were compared. The results show that the wet mass and porosity of sandstone increase with the increase of soak time (0-70 d), and then entered the stable periods (70-90 d). As the soaking time, the medium and large pores inside the sandstone are transformed into small pores. The permeability of sandstone shows an overall decreasing trend, with the maximum decline when the soaking time is 30 d. At 25 °C, the scaling behavior is mainly involved by Ca2+, but at 85 °C Mg2+ is also involved in the scaling behavior. The scaling mechanism becomes the joint participation of Ca2+ and Mg2+. The results of the PHREEQC simulations are almost the same as the laboratory test results, indicating that sodium feldspar, potassium feldspar, and chlorite are generated slowly during the fouling process.
Preferred Selection of Fractured Sweet Spot Section for Horizontal Shale Oil Well in West 233 Area
Authors: Liu Zhidi , Xie Zhenglong , Wang CiXun , Zhang Leizhao
Published: August 2023

Six parameters, which can effectively reflect the reservoir quality and the completion quality, have been selected, including the sand structure index, the physical parameters, the oil content index, the brittleness index reflecting, the stress difference coefficient and the fracture pressure. The evaluation index of fracturing sweet spots in shale oil horizontal wells was constructed, and the fracturing sweet spot selection criteria for shale oil horizontal wells in the study area were established. Combined with dynamic production data, the fracturing sweet spots were classified into Class I (high quality reservoir), Class II (secondary reservoir) and Class II (non-fracturing sweet spot), which provided technical support for the preferential selection of fracturing formations in shale oil horizontal well.
Geopolymers for 3D print
Authors: Hájková P , Soukup A , Kohout J , Kohoutová E , Koutník P
Published: August 2023

3D print of building materials has increasing popularity in the construction industry all around the world. However, geopolymer material, which stands out for its high temperature resistance and low CO2 emissions compared to concrete, is very rarely used for 3D printing. This work is focused on a composite material based on a geopolymer binder, which is suitable for 3D printing of building elements. The properties of the developed geopolymer composite and the parameters that influence them are described in detail. One of the most important properties of the geopolymer composite for 3D print is setting time and its influence possibilities. The optimal setting time of the developed geopolymer material was 50 minutes. This composite reached up to 70 MPa at room temperature and 35 MPa after exposure to temperature of 800°C.
The influence of lithium silicate impregnation on the properties of surface layer of cementitious composites
Authors: Jansová K , Fládr J , Bílý P , Kalina L
Published: August 2023

The degradation processes in surface layers of cementitious composites can be mitigated either by optimizing of the material or by applying surface protection. In this paper, the effect of lithium silicate (LS) sealer is investigated. Water absorbance is studied on standard cement mortar; frost resistance and porosity are examined on two types of concrete (C30/37 and C50/60). The results indicate that LS impregnation improves the water absorbance only slightly and only in the case of short exposure to water; water absorbance was reduced by 15–25% immediately after applying the LS sealer, but the effect was negligible (2–8%) after 24 hours of immersion in water. Frost resistance was not affected by LS impregnation, but a significant improvement of mechanical parameters (flexural tensile strength and weight loss after 50 freeze-thaw cycles) was observed. The resistivity of the concrete surface was increased by LS impregnation by 36–40%, indicating the improvement of quality of the surface layer, while the porosity was practically unaffected.
Low-temperature synthesis of binder with belite content
Authors: Staněk T , Rybová A , Khongová I , Zezulová A
Published: August 2023

Sol-gel methods or hydrothermal treatment in combination with low-temperature burning are used for low-temperature syntheses of hydraulically active dicalcium silicate. The paper describes a two-stage preparation process without the use of an autoclave. In the first phase, the precursors of hydraulically active phases are prepared. In the second phase, burning up to 1000 °C takes place to form a C2S-based binder. Unlike commonly used procedures of the sol-gel method, solid raw materials and water are used. The main raw materials are quicklime and a source of SiO2 and then various activators. X-ray diffraction analysis and electron microscopy methods were used for the research. The resulting binders are similar to hydraulic lime, they achieve low initial strengths, the long-term strengths are satisfactory. It is suitable for the preparation of mortars and plaster mixtures.
The effect of the bent of FRP rebar on its short-term mechanical properties
Authors: Lagiň J , Prokeš J , Girgle F , Kostiha V , Vašátko D , Bezděk O , Sedláček O , Štěpánek P
Published: August 2023

In the construction industry, FRP (fibre-reinfoced-polymer) reinforcement is used mainly because of its high resistance to aggressive environments. The production and design of straight FRP rebars are now very well understood and described. However, when designing concrete elements, it is usually necessary to adapt the reinforcement to the structure shape and to use bent rebars. However, during the production process, unfavourable changes in the fibre distribution across the cross-section may occur at the bent section. It has a significant effect on the short and long-term properties of the rebar. The paper addresses the highly topical issue of the composition, manufacturing and testing of shaped composite rebar. Consequently, the article presents experimentally determined values of mechanical characteristics obtained from the performed tests.
Study of the possibility of using vacuum insulation panels in building construction in comparison with conventional insulators
Authors: Zach J , Peterková J , Novák V , Bubeník J , Košir M. , Božiček D.
Published: August 2023

The use of super insulating materials in the construction industry, including vacuum insulation, closely corresponds to the ever-increasing requirements for the construction of low-energy and passive buildings. Their indisputable advantage is their excellent thermal insulation properties at low thickness compared to conventional thermal insulation materials. However, there are also many risks associated with the experience and practice of the personnel involved in the application of these materials to structures. The paper focuses on the overall comparison of the possible use of vacuum insulation panels in modern building structures in terms of possible design solutions and achieved properties. The paper presents the results of selected case studies of the optimal use of vacuum insulation panels (VIP) in the construction industry, which are focused on different areas of building structures, specifically on the detail of the transition of the terrace and the adjacent floor, as well as on the solution of the filling of openings - doors. Based on the results of the studies carried out, it can be concluded that, provided that all procedures for maintaining the VIP properties are followed in the implementation of these materials in structures, vacuum insulations represent a more suitable solution for structural details in selected details (less thickness and comparable thermal insulation properties compared to conventional insulations).
Improvement of quantum walks search algorithm in single-marked vertex graph
Authors: Li Xinying , Shang Yun
Published: August 2023

Quantum walks are powerful tools for building quantum search algorithms. However, these success probabilities are far below 1. Amplitude amplification is usually used to amplify success probability, but the soufflé problem follows. Only stop at the right step can we achieve a maximum success probability. Otherwise, as the number of steps increases, the success probability may decrease, which will cause troubles in the practical application of the algorithm when the optimal number of steps is unknown. In this work, we define generalized interpolated quantum walks instead of amplitude amplification, which can not only improve the success probability but also avoid the soufflé problem. We choose a special case of generalized interpolated quantum walks and construct a series of new search algorithms based on phase estimation and quantum fast-forwarding, respectively. Especially, by combining our interpolated quantum walks with quantum fast-forwarding, we both reduce the time complexity of the search algorithm from

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and reduce the number of ancilla qubits required from

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, where ɛ denotes the precision and

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denotes the classical hitting time. In addition, we show that our generalized interpolated quantum walks can improve the construction of quantum stationary states corresponding to reversible Markov chains. Finally, we give an application to construct a slowly evolving Markov chain sequence by applying generalized interpolated quantum walks, which is the necessary premise in adiabatic stationary state preparation.
Dimensional measures of generalized entropy
Authors: Zhdankin Vladimir
Published: August 2023

Entropy is useful in statistical problems as a measure of irreversibility, randomness, mixing, dispersion, and number of microstates. However, there remains ambiguity over the precise mathematical formulation of entropy, generalized beyond the additive definition pioneered by Boltzmann, Gibbs, and Shannon (applicable to thermodynamic equilibria). For generalized entropies to be applied rigorously to nonequilibrium statistical mechanics, we suggest that there is a need for a physically interpretable (dimensional) framework that can be connected to dynamical processes operating in phase space. In this work, we introduce dimensional measures of entropy that admit arbitrary invertible weight functions (subject to curvature and convergence requirements). These ‘dimensional entropies’ have physical dimensions of phase-space volume and represent the extent of level sets of the distribution function. Dimensional entropies with power-law weight functions (related to Rényi and Tsallis entropies) are particularly robust, as they do not require any internal dimensional parameters due to their scale invariance. We also point out the existence of composite entropy measures that can be constructed from functionals of dimensional entropies. We calculate the response of the dimensional entropies to perturbations, showing that for a structured distribution, perturbations have the largest impact on entropies weighted at a similar phase-space scale. This elucidates the link between dynamics (perturbations) and statistics (entropies). Finally, we derive corresponding generalized maximum-entropy distributions. Dimensional entropies may be useful as a diagnostic (for irreversibility) and for theoretical modeling (if the underlying irreversible processes in phase space are understood) in chaotic and complex systems, such as collisionless systems of particles with long-range interactions.
Discrete Wigner–Weyl calculus for the finite lattice
Authors: Zubkov M A
Published: August 2023

We develop the approach of Felix Buot to construction of Wigner–Weyl calculus for the lattice models. We apply this approach to the tight-binding models with finite number of lattice cells. For simplicity we restrict ourselves to the case of rectangular lattice. We start from the original Buot definition of the symbol of operator. This definition is corrected in order to maintain self-consistency of the algebraic constructions. It appears, however, that the Buot symbol for simple operators does not have a regular limit when the lattice size tends to infinity. Therefore, using a more dense auxiliary lattice we modify the Buot symbol of operator in order to build our new discrete Weyl symbol. The latter obeys several useful identities inherited from the continuum theory. Besides, the limit of infinitely large lattice becomes regular. We formulate Keldysh technique for the lattice models using the proposed Weyl symbols of operators. Within this technique the simple expression for the electric conductivity of a two dimensional non-equilibrium and non-homogeneous system is derived. This expression smoothly approaches the topological one in the limit of thermal equilibrium at small temperature and large system area.
Health literacy, numeracy, graph literacy, and digital literacy: an overview of definitions, evaluation methods, and best practices
Authors: Reading Turchioe Meghan , Mangal Sabrina
Published: August 2023

Health literacy is an important skill for people receiving care. Those with limited literacy face disparities in their care and health outcomes when strategies for addressing literacy are not used when delivering health information. In this article, we introduce the importance of considering health literacy, defining it and related concepts including numeracy, graph literacy, and digital literacy, and discuss open questions about measuring health literacy in clinical care. Finally, we present best practices, including assuming ‘universal precautions’, carefully considering wording, leveraging visualizations, recognizing cultural differences in interpretation, providing guidance on pilot testing, and considering digital literacy when developing electronic materials.
The Relative Importance of Crown Position and Vigor in Determining the Growth and Mortality of Sugar Maple Trees
Authors: Cecil-Cockwell Malcolm J L , Caspersen John P
Published: August 2023

In northern hardwood forests, selection silviculture aims to remove low-vigor trees that are likely to die or grow slowly to increase the growth of the remaining high-vigor trees, particularly those afforded more exposure to direct light. However, few studies have quantified the relative importance of crown position and vigor in determining growth and mortality. In this article, we did so for the most common species, sugar maple (Acer saccharum Marsh.), and we quantified the difference in growth and mortality between each of four crown classes to determine whether fewer classes can be used to describe competition-related variation in growth. Our results show that mortality is primarily determined by vigor, competition reduces growth more than the defects used to assess vigor, and there is only a modest difference in growth between dominant and co-dominant trees, indicating that these two classes can be merged because they are effectively released, unlike trees that are surrounded by competitors. Based on these results, we conclude that stand improvement should not be prioritized over crown spacing, and that tree markers should release surrounded trees to whatever extent possible, including as many trees as possible and low-vigor trees where necessary.

Study Implications: We identified three ways to balance stand improvement and crown spacing in selection-managed northern hardwood forests. First, tree markers should not only release high-vigor trees, but also low-vigor trees that will be retained. Second, tree markers should focus on releasing trees surrounded by competitors rather than dominant and co-dominant trees. Third, rather than maximizing lateral light exposure for a few select trees, tree markers should release trees to whatever extent possible, including as many trees as possible and low-vigor trees where necessary. Finally, we provide a heuristic method for classifying crown position and implementing our spacing recommendations.