Normal Temperature Environment Research Articles

Alleviation of heat stress by ACC Deaminase and Exopolysaccharide Producing Plant-Growth-Promoting Rhizobacteria in Solanum melongena L.

Background: The current study was carried out to assess the alternative role of high temperature tolerant plant growth promoting rhizobacteria (PGPR) in alleviation of heat stress adverse effect in eggplant.Methods: PGPR was assessed for PGP potentialities and investigated for1‐aminocyclopropane‐1‐carboxylate (ACC deaminase), and exopolysaccharide under normal and high temperature environment. The impact of PGPR application on plant physiology and biochemistry was investigated under normal and high temperature environments and plant growth regulators were evaluated using High Performance Liquid Chromatography (HPLC).Results: A significant impediment for morphological and physiological parameters of eggplant cultivars was observed during heat stress in absence of PGPR inoculation. The results showed that ACC‐deaminase produced by PGPR boosted up significantly the extracellular polymeric substances (EPS) accumulation, conversion of ACC into α‐ketobutyrate and ammonia, and reduce consequently the impact of high temperature on eggplant development.Conclusion: PGPR inoculation showed an alternative strategy to improve eggplant growth and development under high temperature condition in order to preserve agriculture sustainability and healthy crops.Keywords: ACC‐deaminase; Extracellular polymeric substances; Heat stress; PGPR; Solanum melongena

Differential impact of heat and hypoxia on dynamic oxygen uptake and deoxyhemoglobin parameters during incremental exhaustive exercise.

Purpose: This study aims to explore the relationship between the dynamic changes in oxygen uptake () and deoxyhemoglobin (HHb) and peripheral fatigue in athletes during incremental exhaustive exercise under different environmental conditions, including high temperature and humidity environment, hypoxic environment, and normal conditions. Methods: 12 male modern pentathlon athletes were recruited and performed incremental exhaustive exercise in three different environments: normal condition (23°C, 45%RH, FiO2 = 21.0%, CON), high temperature and humidity environment (35°C, 70%RH, FiO2 = 21.0%, HOT), and hypoxic environment (23°C, 45%RH, FiO2 = 15.6%, HYP). Gas metabolism data of the athletes were collected, and muscle oxygen saturation (SmO2) and total hemoglobin content in the vastus lateralis muscles (VL) were measured to calculate the deoxyhemoglobin content. Linear and nonlinear function models were used to fit the characteristic parameters of and HHb changes. Results: The results showed that compared to the CON, , , and exercise time were decreased in the HOT and HYP (p < 0.05). and OUES were reduced in the HOT and HYP compared to the CON (p < 0.05). The Gas exchange threshold in the CON corresponded to higher than in the HYP and HOT (p < 0.05). was reduced in the HOT compared to the HYP (p < 0.05). ΔEHHb was higher in the HOT compared to the CON (p < 0.05). ΔEHHb-1 was increased in the HYP compared to the CON (p < 0.05). There was a negative correlation between ΔEHHb and corresponding in the HOT (r = -0.655, p < 0.05), and a negative correlation between ΔEHHb-1 and corresponding in the HYP (r = -0.606, p < 0.05). Conclusion: Incremental exhaustive exercise in hypoxic environment and high temperature and humidity environments inhibits gas exchange and oxygen supply to skeletal muscle tissue in athletes. For athletes, the accelerated deoxygenation response of skeletal muscles during incremental exhaustive exercise in high temperature and humidity environments, as well as the excessive deoxygenation response before BP of deoxyhemoglobin in hypoxic environment, may be contributing factors to peripheral fatigue under different environmental conditions.

The Polarization and Heat Generation Characteristics of Lithium-Ion Battery with Electric–Thermal Coupled Modeling

This paper investigates the polarization and heat generation characteristics of batteries under different ambient temperatures and discharge rates by means of using a coupled electric–thermal model. This study found that the largest percentage of polarization is ohmic polarization, followed by concentration polarization and electrochemical polarization. The values of the three types of polarization are generally small and stable under normal-temperature environments and low discharge rates. However, they increase significantly in low-temperature environments and at high discharge rates and continue to rise during the discharge process. Additionally, ohmic heat generation and polarization generation also increase significantly under these conditions. Reversible entropy heat is less sensitive to ambient temperature but increases significantly with the increase in the discharge rate. Ohmic heat generation and polarization heat generation contribute to the total heat generation of the battery at any ambient temperature, while reversible entropy heat only contributes to the total heat generation of the battery at the end of discharge.

Transcriptome Analysis Revealed Potential Genes of Skeletal Muscle Thermogenesis in Mashen Pigs and Large White Pigs under Cold Stress.

Pigs are susceptible to cold stress due to the absence of brown fat caused by the partial deletion of uncoupling protein 1 during their evolution. Some local pig breeds in China exhibit potential cold adaptability, but research has primarily focused on fat and intestinal tissues. Skeletal muscle plays a key role in adaptive thermogenesis in mammals, yet the molecular mechanism of cold adaptation in porcine skeletal muscle remains poorly understood. This study investigated the cold adaptability of two pig breeds, Mashen pigs (MS) and Large White pigs (LW), in a four-day cold (4 °C) or normal temperature (25 °C) environment. We recorded phenotypic changes and collected blood and longissimus dorsi muscle for transcriptome sequencing. Finally, the PRSS8 gene was randomly selected for functional exploration in porcine skeletal muscle satellite cells. A decrease in body temperature and body weight in both LW and MS pigs under cold stress, accompanied by increased shivering frequency and respiratory frequency, were observed. However, the MS pigs demonstrated stable physiological homeostasis, indicating a certain level of cold adaptability. The LW pigs primarily responded to cold stress by regulating their heat production and glycolipid energy metabolism. The MS pigs exhibited a distinct response to cold stress, involving the regulation of heat production, energy metabolism pathways, and robust mitochondrial activity, as well as a stronger immune response. Furthermore, the functional exploration of PRSS8 in porcine skeletal muscle satellite cells revealed that it affected cellular energy metabolism and thermogenesis by regulating ERK phosphorylation. These findings shed light on the diverse transcriptional responses of skeletal muscle in LW and MS pigs under cold stress, offering valuable insights into the molecular mechanisms underlying cold adaptation in pigs.

Thermal-hydraulic performance of microchamber heat sinks with run-through metal pillar arrays and hot-spot oriented manifold inlets

Microchannel heat sinks have great potential in cooling miniaturized electronics with high heat flux. However, manufacturing difficulties and pressure drop penalty are concerns need to be considered. In this work, pizza-box shaped microchambers were embedded in LTCC substrates to cool high power SiP modules. Each microchamber heat sink has a manifold inlet located just below the hot spot to generate vertical impingement jet for direct cooling of the hot spot. By adopting the form of microchamber instead of microchannels, the pressure drop was reduced. A flow rate of 10ml/min driven by a pressure below 1 kPa was sufficient to reduce the maximum temperature from 180 °C to 50°C. Run-through Ag pillar arrays were also used to enhance both conductive and convective heat transfer. The substrate thermal resistance was decreased by two orders of magnitude to about 0.2 K/W. The Nusselt number was increased by 60% ∼ 110%. An index with obvious physical significance, ease measurement, and small uncertainty has been defined to evaluate the cooling efficiency. The cooling efficiency of the microchamber heat sinks could reach 95% under normal temperature environment. Fast and effective cooling has been achieved and high system reliability was also guaranteed.

Hydrophobic aerogel-modified hemostatic gauze with thermal management performance.

Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients, water evaporation and ice crystal growth. To address these challenges, we engineered a biocompatible hemostatic system with thermoregulatory properties for harsh conditions by combining the asymmetric wetting nano-silica aerogel coated-gauze (AWNSA@G) with a layer-by-layer (LBL) structure. Our AWNSA@G was a dressing with a tunable wettability prepared by spraying the hydrophobic nano-silica aerogel onto the gauze from different distances. The hemostatic time and blood loss of the AWNSA@G were 5.1 and 6.9 times lower than normal gauze in rat's injured femoral artery model. Moreover, the modified gauze was torn off after hemostasis without rebleeding, approximately 23.8 times of peak peeling force lower than normal gauze. For the LBL structure, consisting of the nano-silica aerogel layer and a n-octadecane phase change material layer, in both hot (70°C) and cold (-27°C) environments, exhibited dual-functional thermal management and maintained a stable internal temperature. We further verified our composite presented superior blood coagulation effect in extreme environments due to the LBL structure, the pro-coagulant properties of nano-silica aerogel and unidirectional fluid pumping of AWNSA@G. Our work, therefore, shows great hemostasis potential under normal and extreme temperature environments.

Research on Structural Design and Optimization of Battery Thermal Management System

The quality of the thermal management control strategy of the power battery is directly related to the energy consumption and the use state of the battery. The lithium battery will generate heat in the process of charging and discharging, which will lead to its own temperature rise, and the temperature rise will affect the performance of the lithium battery. In this paper, the simulation analysis from the cell to the battery pack is carried out, and the thermal simulation analysis of the air-cooled and liquid-cooled battery pack is carried out by using different control strategies. This paper mainly analyzes the thermal simulation of three discharge rates of single lithium battery under normal temperature environment, and designs the type I liquid cooled battery pack and type S liquid cooled battery pack. By setting the same liquid cooling control strategy, the inlet temperature is 20℃, the flow rate is 1m/s, the initial temperature of the battery in normal temperature environment is 25℃, and the cooling medium is ethylene glycol (50% water and ethylene glycol mixture). Through simulation analysis and comparison of the heat dissipation effect under the three discharge ratios, the research results show that the maximum temperature of the type I liquid cooled battery pack is lower than that of the type S liquid cooled battery pack, and the effect is more significant.

Ultimate pressure-bearing capacity of Type III onboard high-pressure hydrogen storage tanks under typical accident scenarios

Sufficient pressure-bearing performance was the basis for ensuring the safety of hydrogen storage tanks in service for the entire life cycle. The aim of this study was to analyze the ultimate pressure-bearing capacity of tanks under possible working conditions, such as room temperature, fire, and after flame exposure. The results show that the actual burst pressure of a Type III tank of 48 L and 70 MPa at room temperature was 209.80 MPa, which had sufficient explosion-proof behavior. Compared with the room temperature, the critical failure pressure of the tank under fire conditions dropped sharply by ca. 63.1 %, which readily induced pressure-bearing failure. However, after cooling to room temperature, the residual burst pressure of the tank thermally damaged by fire was only roughly 14.5 % lower than the ultimate pressure-bearing pressure at room temperature, and still maintained a certain strength. The grey correlation analysis model of influencing factors on the ultimate pressure-bearing performance of tanks in normal temperature and fire environments was established for the first time. This paper reports quantitatively that, in addition to the nominal working pressure, the design wall thickness of the tank at room temperature has the most prominent effect on the pressure-bearing performance. While the initial filling pressure and flame exposure time in fire environments were considered to be the key factors affecting the pressure bearing performance.

Effects of heat exposure and vitamin C intervention on oxidative stress and blood pressure changes in treadmill rats

Objective: To investigate the effect of oxidative stress caused by heat exposure on the blood pressure increase of treadmill rats and the intervention of antioxidants. Methods: In June 2021, Twenty-four healthy SD male rats were randomly divided into four groups: normal temperature feeding, normal temperature treadmill, high temperature treadmill and high temperature treadmill supplementation with vitamin C groups, 6 rats in each group. The rats run on the platform in normal temperature or heat exposure environment for 30 min in the morning and in the afternoon daily, 6 days per week. The daily vitamin C supplement dose of high temperature treadmill supplementation with vitamin C group was 10 mg/kg. BP recordings were done at the end of the week. The rat vascular lipofuscin (LF) was detected by ELISA, the rat serum nitric oxide (NO) was detected by nitrate reductase method, the serum malondialdehyde (MDA) was detected by thibabituric acid method, the serum glutathione peroxidase (GPx) and superoxide dismutase (SOD) were detected by chemiluminescence method, and the serum catalase (CAT) was detected by ammonium molybdate method. The total antioxidant capacity (T-AOC) of serum was measured by iron reduction/antioxidant capacity method, and the content of nuclear erythroid 2-related factor 2 (Nrf2) in vascular tissue was measured by Western blot. The intra-group mean was compared by repeated measurement analysis of variance, and the inter-group mean was compared by single-factor analysis of variance and post-event LSD-t test. Results: Compared with the previous time point, the systolic BP and diastolic BP of the high temperature treadmill group were significantly increased at 7, 14 and 21 d, and decreased at 28 d which were higher than the initial level (P<0.05), and the systolic BP and diastolic BP values at each experimental time point were significantly higher than those of normal temperature treadmill group (P<0.001). The changes of thickening of the artery wall, no smoothing of the endodermis and irregular arrangement of muscle cells in high temperature treadmill group were observed. Compared with the normal temperature treadmill group, the content of MDA in serum, and LF in vascular tissue were significantly increased, the activities of SOD, CAT, T-AOC, the content of NO in serum, and the expression of Nrf2 in vascular tissue were significantly decreased in high temperature treadmill group (P<0.05). Compared with the high temperature treadmill group, the systolic BP and diastolic BP values at 7, 14, 21 and 28 d, the content of serum MDA and LF in vascular tissue were significantly decreased, the activities of CAT and T-AOC, and the expression of Nrf2 in vascular tissue significantly increased (P<0.05), the histopathological changes of the artery wall improved in high temperature treadmill supplementation with vitamin C group. Conclusion: Heat exposure has effect on oxidative stress, which may be related to the increase of BP. Vitamin C as an anti-oxidative enhancer can prevent those negative effects, which could alleviate the pathological changes of vessel intima in heat-exposed rats. And the Nrf2 may be a regulated factor to vascular protection.

Research on Energy Management Strategy of Range Extender Electric Vehicle considering Temperature Effect under Different Heat Demands

In order to further improve the energy utilization of the range extender electric vehicle (REEV), the energy management strategy of the REEV under different heat demands and operating temperatures is studied. Firstly, for reducing the extra fuel consumption caused by engine operating temperature, the influence of engine lubricating oil temperature on the equivalence factor is analyzed, and a novel method is proposed, which can determine the equivalence factor by three parameters, including engine temperature, operating condition type, and battery state of charge (SOC). Secondly, to reduce the influence of frequent engine start/stop on fuel consumption, a method to establish the penalty factor based on battery SOC is proposed. Finally, the engine temperature rise law under low-temperature environment and the compressor drive mode determination method under high-temperature environment are studied according to the heat demand under different ambient temperatures. An adaptive equivalent consumption minimization strategy (ECMS) considering the effect of temperature under different heat demands is proposed on the basis of the above research. The simulation under the worldwide harmonized light vehicle test cycle (WLTC) drive cycle reveals that by using the adaptive ECMS, the vehicle operating cost is reduced by 5.69% in normal temperature environment, 0.53%-2.39% in a low-temperature environment, and 0.2%-2.01% in a high-temperature environment.

Identification and validation of coding and non-coding RNAs involved in high-temperature-mediated seed dormancy in common wheat.

Seed dormancy (SD) significantly decreases under high temperature (HT) environment during seed maturation, resulting in pre-harvest sprouting (PHS) damage under prolonged rainfall and wet weather during wheat harvest. However, the molecular mechanism underlying HT-mediated SD remains elusiveSeed dormancy (SD) significantly decreases under high temperature (HT) environment during seed maturation, resulting in pre-harvest sprouting (PHS) damage under prolonged rainfall and wet weather during wheat harvest. However, the molecular mechanism underlying HT-mediated SD remains elusive. Here, the wheat landrace 'Waitoubai' with strong SD and PHS resistance was treated with HT from 21 to 35 days post anthesis (DPA). Then, the seeds under HT and normal temperature (NT) environments were collected at 21 DPA, 28 DPA, and 35 DPA and subjected to whole-transcriptome sequencing. The phenotypic data showed that the seed germination percentage significantly increased, whereas SD decreased after HT treatment compared with NT, consistent with the results of previous studies. In total, 5128 mRNAs, 136 microRNAs (miRNAs), 273 long non-coding RNAs (lncRNAs), and 21 circularRNAs were found to be responsive to HT, and some of them were further verified through qRT-PCR. In particular, the known gibberellin (GA) biosynthesis gene TaGA20ox1 (TraesCS3D02G393900) was proved to be involved in HT-mediated dormancy by using the EMS-mutagenized wheat cultivar Jimai 22. Similarly, a novel gene TaCDPK21 (TraesCS7A02G267000) involved in the calcium signaling pathway was validated to be associated with HT-mediated dormancy by using the EMS mutant. Moreover, TaCDPK21 overexpression in Arabidopsis and functional complementarity tests supported the negative role of TaCDPK21 in SD. We also constructed a co-expression regulatory network based on differentially expressed mRNAs, miRNAs, and lncRNAs and found that a novel miR27319 was located at a key node of this regulatory network. Subsequently, using Arabidopsis and rice lines overexpressing miR27319 precursor or lacking miR27319 expression, we validated the positive role of miR27319 in SD and further preliminarily dissected the molecular mechanism of miR27319 underlying SD regulation through phytohormone abscisic acid and GA biosynthesis, catabolism, and signaling pathways. These findings not only broaden our understanding of the complex regulatory network of HT-mediated dormancy but also provide new gene resources for improving wheat PHS resistance to minimize PHS damage by using the molecular pyramiding approach.

Research on the influence factors of brake regenerative energy of pure electric vehicles based on the CLTC

The braking energy recovery system (BERS) is an important support for the improvement of the mileage of pure electric vehicles. However, the actual feedback effect of the BERS is seriously affected by factors such as ambient temperature and road conditions. To explore the influence factors of the BERS of pure electric vehicles, a widely popular pure electric vehicle is selected as the research object. Based on the CLTC, the 11 segments can be obtained through segment division firstly. Then, the research on the variation law of the brake regenerative energy of pure electric vehicles affected by the normal and low temperature environment and the different segment characteristics can be carried out in this paper. The research shows that the segment characteristics are strongly correlated with the vehicle brake regenerative energy. And the strong braking deceleration and large deceleration means more brake regenerative energy. The ambient temperature indirectly affects the process of the BERS feedbacking energy by causing changes in the total braking energy, the battery charging power and loss and the braking energy distribution ratio. And the low temperature environment means less brake regenerative energy. The research results provide guiding significance for the formulation of the braking energy recovery control strategies of pure electric vehicles.

Research of Property and Calibrate Method for Pressure Release Device of Power Transformer in the Grid

This paper introduces the types, internal structures and working principles of common non-electricity protection devices, and theoretically analyzes the cooperation between non-electricity protection devices. For pressure relief devices, the requirements of relevant standards for pressure relief valves are introduced, matters needing attention in field use of pressure relief valves are summarized, and factors affecting the performance of pressure relief valves are analyzed. Finally, using the calibration platform, through a large number of experiments, the influence of external environment temperature, caliber and pressure release times on pressure release performance parameters was studied. The results show that the average opening pressure at high temperature (95°C) is significantly lower than the average opening pressure of 10 times at normal temperature. At the same time, with the increase of ambient temperature, the aging opening pressure and the average opening pressure will obviously decrease, while the average closing pressure will increase. In addition, under normal temperature environment, the test values of aging opening pressure, average opening pressure and average closing pressure have little change. For pressure relief valves with different calibers, under the same rated opening pressure, the calibers of the pressure relief valves are different, which has little influence on the actual opening pressure. Through the research on the operation reliability of qualified pressure relief valves, it is found that the opening pressure after 50 operations and the first measured opening pressure and closing pressure data after 500 operations are relatively stable.

Study on direct refrigerant cooling for lithium-ion batteries of electric vehicles

For the purpose of improving the working efficiency of lithium-ion batteries for electric vehicles (EVs), prevent battery catching fire and improve the economy of battery thermal management systems (BTMS), in this study a BTMS simulation model with direct cooling struct is built. The evaporator in the cooling circuit of the battery cells directly exchanges heat with the batteries. The performance of models using conventional R134a and environmentally friendly R1234yf was investigated without changing the model structure. The results show that: in normal temperature environment, the BTMS can effectively restrain the battery temperature from rising, the battery temperature would be suppressed under 305 K, the minimum difference of battery pack maximum temperature (T max ) and energy consumption of the BTMS using two refrigerants is 2 K and 2.3% respectively; when the working temperature is high, the BTMS can quickly drop the cells temperature below 313 K, and the shortest time difference that falling to 313K, is only 66s, and the minimum power consumption difference is 3.2%.

The Effect of Temperature on Intestinal Flora Imbalance Based on Time Series Prediction Model

A series of effects caused by temperature change are the biggest problems faced by biological systems. These irregular environmental characteristics have brought new challenges to people and even animal groups. The immune function of human intestinal flora has a great protective effect on other organs and the body environment. It can help the human body carry out intestinal digestion, food absorption, nutritional metabolism, and so on. Based on the above situation, this paper uses the time series prediction model to study the factors affecting the imbalance of intestinal flora in the process of temperature change. Firstly, biological experiments are carried out with animals to simulate the human environment. Based on the sequence information of historical temperature change parameters, a temperature prediction device based on time series model is proposed. The effects of air factors and carbon dioxide content on the prediction results are evaluated by statistical analysis. Secondly, in order to ensure the accuracy of the experimental data, the neural network algorithm is used to optimize the model, and the white blood cell count is used to analyze the influence of temperature change on the intestinal flora structure of the two organisms. Finally, the experimental results are applied to the human environment to analyze the research results. The results showed that with the irregular change of temperature, the number of intestinal flora and internal colony structure also changed. The richness index in the normal temperature environment is relatively large, which can effectively explain the high richness of intestinal microflora in the experimental population. Further analyze the subjects and distinguish the animals according to sex. The number of Bacteroides in the intestinal flora of male animals was higher than that of female animals, but this phenomenon disappeared immediately after physical ligation. In addition, the intestinal flora abundance of female animals is higher than that of male animals, and the metabolic level is faster.

Thermal stability measurement of terminal face relative pose for complex structure based on coordinate measuring machine

Abstract The coordinate measuring machine has high measurement accuracy, but it is only suitable for the precise measurement of the geometric size of the component in the normal temperature environment, and some complex structures need to assess the stability of the terminal face relative pose in the high and low temperature environment. In order to apply the high-precision measurement of the coordinate measuring machine to the thermal stability evaluation of the relative pose of the terminal face of complex structures, an extended temperature control method based on the coordinate measuring machine is proposed. The method realizes the loading control of the temperature environment of the specimen by the mobile temperature control module and the temperature control medium circulation module. The flexible connection mode is used between the temperature control module and the temperature control medium circulation module to reduce the influence of mechanical vibration on the measurement accuracy. The mixing fan and the temperature control medium dryer are installed in the pipeline to avoid frosting and dewing in the temperature control box and ensure the uniform distribution of the temperature field, so as to realize the accurate measurement of the relative pose of the terminal face of the complex structure under the high and low temperature environment by the coordinate measuring machine. The method is applied to the thermal stability test of the relative pose of the end face of a joint component, and the test results are good, which provides a new idea for the extended application of coordinate measuring machines.

Wear Resistance of FeCrAlNbNi Alloyed Zone via Laser Surface Alloying on 304 Stainless Steel

In order to enhance the wear resistance of 304 stainless steel, a FeCrAlNbNi alloyed zone (AZ) was deposited on its surface using laser surface alloying technology, and the wear resistance of the AZ was investigated. The results found that the AZ had a dense and fine structure and no obvious defects, and the microstructure was mainly composed of equiaxed dendrites. A large amount of iron compounds and iron-based solid solutions in the AZ made the average microhardness of the AZ about 2.6 times higher than of the substrate. The friction and wear performance of the AZ at 25 °C, 200 °C, 400 °C and 600 °C better than that of the substrate. As far as the AZ was concerned, the abrasion resistance was the best under normal temperature environment. At 200 °C and 400 °C, due to the repeated extrusion and grinding of the friction pair, the oxide layer formed on the AZ surface was prone to microcracks and peeling off, which reduces the wear resistance. Especially at 400 °C, the formation and peeling speed of the oxide layer is accelerated, and the wear resistance is the lowest. However, when the temperature reached 600 °C, an Al2O3 layer was formed. And the Al2O3 has greater wear resistance to protect the AZ. At this time, the wear resistance was greatly improved compared to 200 °C and 400 °C. Therefore, as the temperature increased, the wear resistance of the AZ first decreased and then increased.

Study of a nondestructive inspection system by guide wave traveling to axis direction of a hot pipe using a long ultrasonic waveguide

Corrosion inspection of high temperature pipes for heat exchange installed in gas turbine buildings is important for safe operation management. Ultrasonic inspection is one of the promising inspection methods, but ultrasonic sensor systems are vulnerable to high temperatures. In this research, we aim to use an ultrasonic sensor system in a normal temperature environment by using a long waveguide to overcome this problem. For that purpose, we report the results of the ultrasonic sensor ability installed in the long waveguide, the propagation characteristics of the waveguide, and the ultrasonic wave characteristics from the waveguide to the pipe.

One-step calcination synthesis of accordion-like MXene-derived TiO2@C coupled with g-C3N4: Z-scheme heterojunction for enhanced photocatalytic NO removal

This work explored an effective treatment method for removing NO from simulated flue gas at normal temperature. We synthesized accordion-like MXene-derived TiO2@C coupled with g-C3N4 (TiO2@C/g-C3N4) via one-step calcination utilizing Ti3AlC2, fluoride salts and melamine as raw materials in CO2 atmosphere. One-step calcination process simultaneously achieved the etch of Al layers of Ti3AlC2 by molten fluoride salts, the generation of g-C3N4 with melamine as precursor and the oxidation of Ti3C2 by CO2. TiO2@C/g-C3N4 for photocatalytic activation of hydrogen peroxide (H2O2) had as high as 94.0% removal rate of NO at parts per million level in a normal temperature environment. This efficiency was 5.3 times and 8.0 times that of TiO2@C/g-C3N4 and H2O2 individually, due to the synergy between photocatalysis and H2O2 oxidation. Meantime, TiO2@C/g-C3N4 exhibited an enhanced performance compared with g-C3N4 (40.3%) and TiO2@C (64.1%) for Z-type heterojunction accelerating the separation of electron-hole pairs. The mechanism was proposed that Z-type TiO2@C/g-C3N4 heterojunction activated H2O2 under visible light to generate hydroxyl radical and superoxide radical for oxidation of NO.

Effect of Temperature on the Microwave-Absorbing Properties of an Al2O3–MoSi2 Coating Mixed with Copper

To obtain a high temperature-resistant microwave absorbing coating, an Al2O3–MoSi2/Cu composite coating was prepared by atmospheric plasma spraying. Compared with a normal temperature environment, there are a few reports on Cu as an absorbent for high temperature microwave absorbing coatings. Therefore, in this regard, wave absorbing property can be improved by using a Cu absorbent. The microstructure of a Al2O3–MoSi2/Cu coating was observed, and the dielectric properties of the composite coating in the high-temperature environment of the X-band were tested. The experimental results show that with the increase in temperature, Cu transforms Cu2O in the high-temperature environment and improves the coating’s wave absorption performance with MoSi2. In addition, a 1.4 mm-thick coating showed best microwave absorbing performance at 700 °C. The reflection loss was −19.09 dB, and the effective microwave absorbing bandwidth was 2.83 GHz (Reflection Loss &lt; −10 dB). It was found that the Al2O3–MoSi2/Cu composite coating has good wave-absorbing performance in a 700 °C high-temperature environment.