Ordinary Temperatures Research Articles

Optimized emamectin benzoate trunk injection: addressing temperature limitations for pine wilt disease control.

Pine wilt disease (PWD), caused by the pinewood nematode Bursaphelenchus xylophilus, poses a significant threat to global forestry, resulting in extensive economic and ecological damage. Traditional trunk injection agents (TIAs) are limited by environmental factors, such as high winter temperatures and vigorous resin flow, particularly in southern China. This study aimed to develop an ordinary temperature trunk injection agent (OTTIA) for year-round application and to evaluate its performance under high-temperature conditions in comparison to commercial TIAs. Extensive laboratory and field tests identified N,N-Dimethylformamide (DMF) and benzyl acetate as optimal solvents and Tween-40 as an effective emulsifier for the OTTIA formulation. The new agent was fully absorbed by Pinus massoniana within 3 h at temperatures exceeding 30 °C, outperforming existing commercial agents. Treated trees maintained comparable emamectin benzoate (EB) levels but achieved lower LC90 lethal concentration values (27.65 mg L-1), indicating greater efficacy. The OTTIA provided protection against PWD for ≤360 days postinjection. The development of OTTIA marks a significant advancement in PWD management, offering an effective solution for high-temperature regions and potentially transforming year-round treatment strategies. The results highlight the critical role of optimizing solvent and emulsifier combinations to enhance the efficacy and application of trunk injection agents, contributing to sustainable forest management and improved protection against PWD. © 2024 Society of Chemical Industry.

The relationship of δD and δ18O in soil water and its implications for soil evaporation across distinct rainfall years in winter wheat field in the North China Plain

Soil evaporation plays a key role in regulating local climate and water loss. Stable isotope ratios of water (²H/¹H and ¹⁸O/¹⁶O) are effective tracers for studying water flux. This study examines three isotope-based indicators deuterium excess (d-excess), the slope of the soil water evaporation line (SEL), and line-conditioned excess (lc-excess) across three wheat growing seasons: wet, ordinary, and dry years. The influencing factors of d-excess, SEL, and lc-excess, respectively, soil, vegetation, and meteorology, were analyzed using various methods. Wheat yields varied significantly, reaching 6.69 t ha⁻¹ in wet years, 8.66 t ha⁻¹ in dry years, and 9.28 t ha⁻¹ in ordinary years. The lc-excess was highest in ordinary years, and d-excess peaked during dry years. A negative correlation between d-excess and SEL slope, and between lc-excess and SEL slope, was observed in dry and ordinary years (P<0.05), but not in wet years (P>0.05). Multivariate regression showed that net radiation (Rn) was the primary factor influencing SEL, contributing 54.19 %, 11.58 %, and 29.27 % in wet, dry, and ordinary years, respectively. Leaf area index (LAI) was the most significant factor affecting lc-excess (37.91 % in wet years, 32.22 % in dry, and 30.92 % in ordinary years). Vapor pressure deficit (VPD) affected d-excess in wet and ordinary years, while air (Ta) and soil temperature (Ts) were key in dry years. Variation partitioning revealed meteorological factors primarily influenced SEL, lc-excess, and d-excess in wet years, while soil, vegetation, and climate interactions had greater effects in dry and ordinary years. The lc-excess, integrating multiple factors, is a better indicator of soil evaporation than SEL.

Copper-Nickel/SiC composites for applications on contact electrodes

Novel copper-nickel matrix composites reinforced with silicon carbide (SiC) micro particles for metal contact applications were manufactured by powder metallurgy technology and were experimentally characterized. Cu and Cu alloys are commonly used as metal contact for either vacuum, oil, or SF6 in low-voltage circuit breaker devices, but their application in environments with the presence of oxygen is limited due to their tendency to form high-resistance copper oxides. Thus, the addition of Ni as an alloying element provides resistance to both humidity and several corrosive environments and increases the composites' hardness, mechanical strength, and wear resistance. Moreover, SiC was chosen due to its contribution to mechanical strength, mouldability, low production cost, and non-reactive nature at ordinary temperatures. Here, three SiC particle size distributions were considered, and it was found that the composites' physical properties are also dependent on the ceramic loading. After evaluating these properties, two specific SiC concentrations were potentially considered for electrode applications: 10 wt% and 20 wt%. The obtained hardness values are in the range of 55 – 65 HR30T which guarantees the necessary strength without detriment of the contact area whereas the welding is minimized. In addition to a homogeneous particle distribution in the solid material, specific wear resistance of ∼10-5 mm3N-1m-1 and electrical conductivities of ∼20 %IACS were obtained. Considering these parameters, Cu-Ni/SiC composites' performance is not compromised compared to commercial Ag/WC materials commonly used in metal contact applications.

Analysis of viscoelastic rheological properties and storage stability of solvent cold patching asphalt

Solvent cold patching asphalt (CPA) is commonly mixed with aggregate for rapid pavement pothole repairing in cold and wet seasons, as its ordinary temperature fluidity and gradually increased viscosity. Currently, the evaluation criteria and expectations for the CPA are often related to the modified asphalt without considering the metastable viscoelastic properties of CPA required to ensure the preparation and storage effectiveness. This paper selects diesel oil, kerosene, aromatics solvent oil and isomeric hexadecane four solvents to prepare CPAs, and investigates the viscoelastic properties and storage stability of CPAs with considering the storage time, temperature and solvents incorporation proportion based on penetration test, viscosity test and dynamic shear rheological test. The experimental results show that the optimal dosage of the four diluents is 20%, among which IH-CPA has better storage stability at 30℃, and its 30d viscosity change is the smallest, which is 19.2%. Moreover, the interaction mechanism between solvent and asphalt is explored through molecular simulation model. The research outcome shows that findings from this research can contribute to a better understanding of the metastable structure of CPA, and furnish the high-performance CPA production and storage strategies.

Synergistic adsorption of ethyl xanthate and butyl xanthate on pyrite surfaces: A DFT study

AbstractPyrite is the most widely distributed sulfide mineral with a wide range of uses, and pyrite is mainly recovered by means of flotation in practical production, and the commonly used flotation collectors are mainly xanthates with good flotation performance. The adsorption behavior of commonly used collectors ethyl xanthate and butyl xanthate on the surface of pyrite is investigated by using the density functional tight bounding theory (DFTB). The results show that when a single reagent acts on the pyrite surface, butyl xanthate has a stronger effect than ethyl xanthate, and the adsorbed mineral surface shows obvious hydrophobicity. The interaction between ethyl xanthate and butyl xanthate had a stronger effect than that of a single reagent, and the simulation of the flotation environment at ordinary temperature using molecular dynamics revealed that the synergistic adsorption of the two different reagents on the surface of pyrite was more hydrophobic, that is, the synergistic adsorption of the combined collector of ethyl xanthate and butyl xanthate on the surface of pyrite was stronger. The results of the study are of great significance for the synergistic effect between the combined collector and the mineral.

Evaluated the effects of nature α-olefins (limonene, β-caryophyllene and camphene) as additives on the cold flow properties of diesel fuel

Pour Point Depressants (PPDs) are currently deemed the most efficacious methodology to enhance the low-temperature fluidity of diesel fuel. However, the majority of these PPDs present complications such as high costs, intricate synthesis procedures, and exhibit potential biotoxicity. To address these challenges, natural α-olefins (β-caryophyllene, limonene and camphene) with 1-hexadecene in varying ratios (5, 10, 15, 20, 25:1) were successfully polymerized at ordinary temperature as poly-α-olefine pour point depressant (PAO PPD), and designated as 1-hexadecane-β-caryophyllene (C16-SZX), 1-hexadecane-limonene (C16-NMX), 1-hexadecane-camphene (C16-KX). An in-depth examination was conducted on the cold filter plugging point (CFPP) and solid point (SP) of both untreated and PPD-added diesel. Subsequently, the finding clearly demonstrates that the CFPP and SP were separately reduced 10 and 32 °C in diesel treated with a molar ratio of 10:1 of C16-KX at the dosage of 2000 ppm. Meanwhile, a comprehensive study was undertaken to investigate the influence of natural α-olefins on the reduction of low-temperature fluidity in diesel fuel. The inhibitory impacts of natural molecular formations on wax crystals were meticulously scrutinized, particularly their roles in modifying the growth patterns of these crystals. Eventually, a novel mechanism by which poly-α-olefine alters the crystalline behavior of wax crystals is proposed.

Multiple factors influenced the aggregation behavior of adult Eucryptorrhynchus scrobicuatus (Coleoptera: Curculionidae).

Eucryptorrhynchus scrobiculatus (Motschulsky) (Coleoptera: Curculionidae) is a notorious pest of Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae). E. scrobiculatus adults typically aggregate under leaves and in soil crevices at the base of A. altissima in the field. We hypothesize that the environmental factors and conspecific signals determine their aggregation behavior. To test this, we investigated adult numbers in light-exposed and shaded areas of the sample trees and conducted experiments in both field and lab settings. Results revealed that (i) greater adult distribution in shaded areas; (ii) significant influence of temperature and illumination on aggregation tendency in the field; (iii) no gender-based difference in aggregation degree and maximum aggregation between light and dark; (iv) the host plant triggering the aggregation tendency, negatively affected in the absence; (v) the aggregation tendency of E. scrobiculatus weakened with the temperature gradually changing to ordinary temperature; and (vi) mutual attraction and chemical attraction between males and females. Thus, the aggregation behavior was influenced by factors including temperature, light intensity, host plant, and conspecific signals, but light's role was not obvious in the lab.

Influence of Few-Layer Graphene on Frictional Properties of Lithium Compound Grease

The frictional properties of lithium compound grease (LCG) with different percentage compositions of few-layer graphene (FLG) were investigated, and the mechanisms of temperature and loading effects on LCG containing FLG are also considered. The concluding effect shows that 1 wt% FLG is more appropriate for friction and wear modifiers for lithium compound grease at elevated temperatures and less suitable at ordinary temperatures. Thickener chemisorption film, FLG layering film, and tribo-reaction film consisting of FeO(OH), Fe2O3, Fe3O4, Li2O, and other oxides assist in the establishment of a lubricating boundary film on the friction interfaces lubricated with LCG containing FLG. The poor fluidity of lithium compound grease at low temperatures leads to poor dispersion of FLG, decreasing friction reduction capability. Under elevated temperature and low load condition, adding 1wt% FLG to LCG can only improve its wear-resistant property, the abrasion volume of steel plate reduced by 24.49%. Under elevated temperature and high load condition, adding 1wt% FLG to LCG can only enhance its anti-friction characteristics.. Conversely, FLG is unsuitable as an anti-friction and wear-resistant additive for LCG at low-temperature conditions.

Mechanical properties and impact behavior of frozen clay: Insights from static mechanical tests, fly-plate tests, and split-Hopkinson pressure bar analysis

The presence of frozen clay as a natural protective material makes it a crucial layer of defense against potential impacts in various engineering projects. Studying the strength and deformation characteristics of frozen clay is, therefore, particularly important. In this study, static mechanical tests, the Hopkinson impact test, and fly-plate tests were conducted on frozen clay to identify its mechanical properties under an impact load. The uniaxial compression strength, flexural strength, and elastic modulus displayed a linear increase with the change in temperature. The fractal dimension was used to describe the failure characteristics of frozen clay, yielding values ranging from 1.5691 to 1.8785. At the same temperature, the fractal dimension exhibited a strain rate effect as the strain rate increased. A light gas gun system was then used to conduct fly-plate tests on frozen clay at varying temperatures (−3, −20 °C, and ordinary temperature). The impact process was meticulously analyzed, considering factors such as shock wave velocity, particle velocity behind the shock wave, impact pressure, and volume strain. Moreover, our investigation plotted the D–u (volume strain–particle velocity) and P–μ shock (impact pressure–shock wave velocity) adiabatic curves. Notably, we observed that samples with a higher initial strength exhibited an increased resistance to compression under an identical initial density and moisture content, resulting in a discernible leftward shift of the P–μ curve. The results provide a theoretical basis and technical support for similar projects in the future.

The variable water temperature control strategy of the air-source heat pump compatible with floor heating system for an apartment

The adjustment of operating parameters and control strategies of an air-source heat pump (ASHP) heating system is of great significance for achieving system energy-saving. Ordinary constant supply water temperature setting could lead to higher energy consumption without concerning the changing of outdoor ambient temperature. In order to save the operational cost, we proposed a variable water temperature control strategy based on the hourly outdoor temperatures. In combination of TRNSYS simulation and experimental study, the system performance under variable supply water temperature control strategy were investigated and compared with four-period-adjusted supply water strategy and constant supply water strategy. The results showed that compared to operating at a constant supply water temperature of 35 °C, the daily power consumption of the system decreased by 56.7 % and 29.5 %, respectively under the typical high and low ambient temperature circumstances. Relative to operation with four-period-adjusted supply water temperature, the power consumption of the system decreased by 53.6 % and 24.6 %, respectively. Moreover, the variable water temperature control strategy could improve the coefficient of performance (COP) of the heating system. The control method proposed in this study would provide design reference for equipment manufacturers and help users to efficiently operate the ASHP unit.

Study on the Performance Degradation of LRB Under the Combination of Low Temperature Cycles and Superstructure Weight

ABSTRACT Lead rubber bearing (LRB) may be subjected to low temperature effect and superstructure weight when it was used in the cold regions, which will affect the durability of the bearing. To investigate the performance degradation of the LRB under combination of low temperature cycles and superstructure weight, five specimens were designed to conduct 0, 20, 40, 60, 80, and 100 low temperature cycles while maintaining super load of 0, 4, 7, 10, and 12 MPa. The use of ultra low temperature and ordinary temperature room to simulate the environment of low temperature effect and the specimen was kept under compression to simulate superstructure weight. The degradation of the mechanical properties of LRB was analyzed by conducting vertical compression tests and horizontal shear tests on the specimens. The results show that the vertical compression stiffness, equivalent horizontal stiffness, post-yield stiffness, yield force, and equivalent damping ratio of LRB show a decreasing trend under the low temperature cycles and superstructure weight. With the increase of superstructure weight, the degradation of equivalent horizontal stiffness is aggravated, the equivalent damping ratio does not degenerate, and the degradation of post-yield stiffness and yield force is weakened. Finally, the least squares method is used to analyze the change of its horizontal shear performance and give the degeneration curve and degeneration function for 50 years. The degradation curve of the horizontal shear performance of LRB is basically in the form of an exponential function.

Mechanism of Potassium Release from Feldspar by Mechanical Activation in Presence of Additives at Ordinary Temperatures.

To improve the potassium availability of feldspar at ordinary temperatures, the mechanical grinding and addition of sodium hydroxide/salts were employed to study the effects of mechanical activation and strong alkali addition on particle characteristics, water-soluble potassium, and the available potassium of feldspar. A laser particle size analyzer was utilized for the direct determination of particle size distribution (PSD) using ground samples. The Brunauer-Emmett-Teller (BET) method was employed for specific surface areas. X-ray diffraction (XRD) was employed for structural characterization, scanning electron microscopy (SEM) for morphology exploration, and energy dispersive spectroscopy (EDS) to determine the chemical composition of potassium feldspar powder. The results revealed that the mechanical activation of potassium feldspar could reduce the particle size and produce agglomerated nanoparticles in the later period. The addition of NaOH and sodium salt did not cause agglomeration, and NaOH dissolved the nanoparticles. The water-soluble potassium content of feldspar in each treatment increased during mechanical grinding, from 21.64 mg kg-1 to 1495.81 mg·kg-1, by adding NaOH 5% weight of potassium feldspar powder and to 3044.08 mg·kg-1 by adding NaOH 10% weight with effects different from those of mechanical shaking. By comparison, only 162.93 mg·kg-1 water-soluble potassium was obtained by adding NaOH 5% weight. The dissolved potassium in the former case was significantly higher than in the latter, and the addition of NaOH and sodium salts significantly enhanced the water-soluble potassium contents due to ion exchange. Furthermore, the addition of sodium hydroxide improved the water-soluble potassium due to its mechanochemical action on potassium feldspar. The mechanical energy changed the crystal structure of potassium feldspar, explaining the increase in available potassium. The addition of sodium salts did not promote change in the feldspar's structure, thereby did not raise the available potassium content. The reason for this was related to the mechanochemical action on sodium hydroxide and feldspar, which could promote the dissolution of fine particles, thereby incrementing the available potassium.

Effects of exogenous trehalose on filling characteristics and sugar component content of wheat under high temperature stress during the filling period.

Taking the heat-sensitive wheat variety 'Fanmai 5' (FM5) and the heat-tolerant variety 'Huaimai 33' (HM33), which were screened out in the previous experiments, as experimental materials, we conducted a field experiment with passive heat-enhancing shelters to simulate post-flowering high-temperature environment (average temperature increase of 5.13 ℃) during 2021-2022. During the filling period, we analyzed the effects of exogenous trehalose (10, 15 and 20 mmol·L-1) on the filling characteristics and sugar fraction under high temperature, with no spraying at ordinary temperature as control (CK). The results showed that treating without spraying exogenous trehalose at high temperature (H) significantly reduced wheat grain yield and grain weight during the filling period, and spraying exogenous trehalose alleviated the reduction of grain yield and grain weight at the filling stage under high temperature stress. Compared with the H treatment, grain yield and grain weight of HM33 and FM5 wheat varie-ties increased by 3.5%, 6.7% and 4.2%, 5.4%, respectively. High temperature stress significantly increased the trehalose content and trehalase (THL) activity in flag leaves of both wheat varieties, and decreased the fructose and glucose contents. Spraying exogenous trehalose increased the contents of trehalose, fructose, and glucose in flag leaves, and decreased the trehalase activity in flag leaves compared with H treatment, which could improve the glucose metabolism capacity of wheat at filling stage. The increasing effect of FM5 was higher than that of HM33. High temperature stress significantly reduced starch content of flag leaves and grains, while spraying exogenous trehalose alleviated the decrease of starch content of flag leaves and grains under high temperature stress, which was profit able for the substance accumulation of wheat grains under high temperature stress. Under the conditions of this experiment, spraying 15 mmol·L-1 trehalose at flowering stage was the best treatment for the two wheat varieties.

Grain refinement and mechanical property of Al-Cu-Mg-Si-Ti-Sc alloy in the state of deformation treatment condition

Al-Cu-Mg-Si-Ti-Sc compound metal with distinct content of Sc increment was prepared by using metallurgical engineering processing. The formation of Sc in Al-4.5%Cu-1.3%Mg-0.6%Si-0.2%Ti-xSc compound metal and its microstructural observation was studied with SEM. The mechanical performances of the compound metal were measured by tensile and fatigue tests in the state of machining distortion conditions. The result reveals that the increment of 0.2% rare earth Sc can fine Al-Cu-Mg-Si-Ti-Sc compound metal grain crystals, which enhances ordinary temperature tensile strength, yield strength, and elongation. The low cycle fatigue of Al-5.2Mg-0.8Si-0.25Cr-0.1Zr-0.2Sc compound metal reveals a cyclic steady state, which mainly relies on the amplitude of the density of movable dislocations and gross applied strain during cyclic distortion. Meanwhile, under external action, the dislocation slip is more in-homogeneous, and materials are more prone to trans-granular crack in which grain crystals can coordinate distortion.

Experimental Investigation on a Novel Temperature-Controlled Phase Change Aggregate Concrete: Thermo-Mechanical Properties and Hydration Heat Control.

To reduce the structural deterioration of mass concrete structures from temperature cracks, and lower energy consumption caused by the traditional mass concrete hydration heat cooling process, this paper reports the preparation of concrete temperature-controlled phase change aggregate (PCA) by a vacuum compaction method using light and high-strength black ceramite and No. 58 fully refined paraffin wax as phase change material (PCM), and the encapsulation technology of the aggregate by using superfine cement and epoxy resin. Further, through laboratory tests, the cylinder compressive strength, thermal stability and mixing breakage rate of the encapsulated PCA were tested, and the differences in mechanical properties such as compressive strength, flexural strength and splitting tensile strength between phase change aggregate concrete (PCAC) and ordinary concrete were studied. A test method was designed to test the heat storage effect of PCA, and the temperature control effect of PCAC was analyzed based on the law of conservation of energy. The research conclusions are as follows: (1) Both superfine cement and epoxy resin shells increase the strength of the aggregate, with the epoxy resin increasing it more than the superfine cement. The thermal stabilization of the PCA is good after encapsulation of superfine cement and epoxy resin. However, PCA encapsulated in superfine cement is more easily crushed than that encapsulated in epoxy resin. (2) Under the condition of water bath heating and semi-insulation, when the water bath temperature reaches 85 °C, the temperature difference between the PCA and the common stone aggregate can be up to 6 °C. Based on the law of energy conservation, the test results will be converted to mass concrete with the same volume of aggregate mixture;, the difference of PCAC and ordinary concrete temperature can be up to 10 °C, so the temperature control effect is significant. (3) The mechanical properties of PCAC with 100% aggregate replacement rate compared to ordinary concrete are reduced to varying degrees, and the performance decline of the epoxy-encapsulated PCA is smaller than that encapsulated with superfine cement; in an actual project, it is possible to improve the concrete grade to make up for this defect.

An unexpected high-pressure stability domain for a lower density polymorph of benzophenone

For over a century, it was thought that the crystalline polymorph II of benzophenone does not possess a stable domain in the pressure–temperature phase diagram. With a combination of new experimental results and literature data, this case of crystalline dimorphism has finally been solved and it is shown that form II possesses a stable domain at high pressure and high temperature, even though its density is lower than that of form I, the stable form under ordinary pressure and temperature conditions. The phase diagram of benzophenone is a clear demonstration of the fact that to understand the phase behaviour of a chemical substance both the exchange of heat (due to the change in intermolecular interactions) and work (due to the change of volume at a given pressure) need to be taken into account.

On Redox Processes of Gold(III) Complexes with Biologically Important Thiols: Cysteine, Glutathione, Thiomalate

AbstractThe interaction of a number of gold(III) complexes: Au(phen)X2+, Au(bipy)X2+ (X=Cl, OH, phen=1,10‐phenanthroline, bipy=2,2’‐bipyridile), Au(en)23+ and Au(dien)Cl2+ with anions of thiol‐containing acids (thiomalate, cysteine and glutathione) in an aqueous solution at pH 2.0 and 7.4, CNaCl=0.2 M was studied. In all cases, the products of gold(III) reduction were highly stable gold(I) thiolate complexes: polymeric Aum(RS)n or monomeric Au(RS)2, depending on the conditions. For bipy and phen complexes, the processes were fast and usually completed in less than 1 minute. For the complex with dien, the stage of inner‐sphere reduction was the slowest among the complexes under consideration. For this complex, at pH 7.4 and with a large excess of glutathione, the formation of a relatively long‐lived gold(III) complex was observed, which, according to MS data, has the composition Au(GSH)45–. At ordinary temperature, it decomposes by about 90 % in 20 hours. For other thiols, similar complexes are also formed, but the rate of their decomposition is about 10 times higher.

Fracture Characteristics of Super Duplex Stainless Steel after Hot Tensile Testing

This study’s temperature range of hot tensile testing is 1000–1200 °C, which is consistent with ordinary industrial hot working temperatures. The fractography of super duplex stainless steel S32750 after hot tensile testing is investigated with Optical Microscopy and Scanning Electron Microscopy, and Electron Back-scatter Diffraction and Transmission Electron Microscopy study hot deformation behaviors of the necking area. The results reveal that ~1050–1150 °C is the optimal hot working temperature range regarding hot ductility and cracking sensitivity. The micro-voids nucleate at the ferrite-austenite interphase boundaries following the Kurdjumov-Sachs (K-S) or Nishiyama-Wasserman (N-W) orientation relationship at 1000 °C. Therefore, a quasi-cleavage fracture forms along the interphase boundaries. At the temperature range 1050–1150 °C, a uniform distribution of fracture surface is formed, and the highest Reduction in Area appears at 1150 °C. Dynamic phase transformation occurs with the formation of secondary austenite at ferrite grain boundaries at 1200 °C, which results in an intergranular fracture surface morphology.

Novel application of Zn‐containing Zeolitic Imidazolate Frameworks in promoting the vulcanization and mechanical properties of natural rubber composites

AbstractThree kinds of Zn‐containing Zeolitic Imidazolate Frameworks (Zn‐ZIFs, including ZIF‐8, ZIF‐11 and ZIF‐14) based on the zinc ions coordinating with different imidazolate ligands were added into the natural rubber (NR) using the DM and TMTD binary accelerators system, respectively. The influences of Zn‐ZIFs on the sulfur vulcanization behaviors and mechanical properties of NR matrix were evaluated. The results indicated that the addition of ZIF‐8 or ZIF‐14 could realize the fast vulcanization of NR at 130°C (the ordinary vulcanization temperature of NR is above 150°C), while ZIF‐11 did not show the obvious accelerating performance. Amongst the three Zn‐ZIFs, ZIF‐8 benefited NR matrix for the acquirement of the highest tensile strength and the largest crosslinking density. As an optimal additive, ZIF‐8 with 0.6 phr distinctly improved the physical‐mechanical, thermo‐oxidative aging resistance and dynamic mechanical properties of NR composites. It proved that Zn atom and its coordination porous network in Zn‐ZIFs played synergistic effects in accelerating vulcanization and enhancing mechanical properties of NR matrix besides its role of reinforcement filler. Then the above ZIF‐8/DM/TMTD vulcanization system was used to prepare the UHMWPE fibers/NR composites. The mechanical properties of the UHMWPE/NR composites were significantly improved in contrast to the pure NR matrix.

No Surviving SN Ia Companion in SNR 0509-67.5: Stellar Population Characterization and Comparison to Models

The community agrees that Type Ia supernovae arise from carbon/oxygen white dwarfs undergoing thermonuclear runaway. However, the full progenitor system and the process that prompts the white dwarf to explode remain unknown. Most current models suggest that the white dwarf explodes because of interaction with a binary companion that may survive the process and remain within the resulting remnant of the exploded star. Furthermore, both the pre-supernova interaction process and the explosion of the primary are expected to imprint a significant departure from ordinary stellar radii and temperatures onto the secondary, making the star identifiable against the unrelated stellar population. Identification of a surviving companion inside an SN Ia remnant might confirm a specific corresponding SN Ia progenitor channel based on the identity of the companion. We conducted a surviving companion search of the Type Ia remnant SNR 0509−67.5 based in the Large Magellanic Cloud. The well-constrained distance to and foreground extinction of the Large Magellanic Cloud allow for Bayesian inference of stellar parameters with low correlation and uncertainties. We present a deep catalog of fully characterized stars interior to SNR 0509−67.5 with radii, effective temperatures, and metallicities inferred using combined Hubble Space Telescope photometric observations across multiple visits. We then compile a list of surviving companion models appropriate for the age of the remnant (roughly 400 yr after the explosion). We compare these predictions with the inferred stellar parameters and conclude that none of the stars are consistent with the predicted signatures of a surviving companion.