Temperature Coefficient Research Articles

Structure and tunable temperature coefficient of magnetization of Mn4-xGaxC alloys prepared by induction melting method

Abstract The magnetization of most magnetic materials decreases monotonically with increasing temperature. In this work, we found that the temperature coefficient of magnetization of Mn4-xGaxC alloys can be tuned from negative values to positive values by controlling the composition x. The antiperovskite-type Mn4-xGaxC (0.05≤x≤0.75) alloys were prepared by using induction melting method, which is more efficient in large-scale production and obtaining full-density alloys in comparison with the traditional solid-state-reaction method. The values of the temperature coefficient of magnetization of Mn4-xGaxC change continuously from negative to positive with decreasing x. The Mn4-xGaxC alloys with highly thermal-stable magnetization is expected to present in the composition range of 0.15<x<0.25. The saturation magnetization of Mn4-xGaxC increases with increasing x, owing to the reduced number of antiferromagnetically coupled Mn atoms at the cubic corner with the face-centered Mn atoms. Most Mn4-xGaxC alloys with varying x display near-zero remanent magnetization and coercivity at room temperature. The Currie temperature of Mn4-xGaxC decreases with increasing x. The X-ray photoelectron spectra of Mn 2p, Ga 2p, and C 1s reveal distinct splitting due to the diverse chemical states of these atoms at different lattice positions and/or phases. Our work has developed a class of alloys capable of offering a desired temperature coefficient of magnetization across a broad temperature range, thereby offering a method to manipulate the thermodynamics of magnetization.

Numerical investigation of the geometric parameters effect of helical blades installed on horizontal geo heat exchanger

In this study, we investigate the enhancement of horizontal geothermal heat exchangers equipped with helical fins on the pipe's exterior and internally ribbed turbulators. Our approach focuses on the interplay between geometry and thermal efficiency through innovative design modifications. Utilizing the finite element method, three-dimensional numerical simulations assessed the effects of varying geometric parameters such as the diameter and thickness of the fins. Our findings indicate significant increases in heat transfer efficiency with the addition of helical fins; specifically, increasing the fin diameter from 5 mm to 10 mm results in a 15 % increase in the heat transfer rate, while doubling the fin thickness from 2 mm to 4 mm enhances the rate by 10 %. These improvements are due to the expanded surface area facilitating greater heat exchange. Optimization using the desirability function approach yielded models with high performance, achieving desirability scores of 0.9879 for outlet temperature and 0.9534 for the heat transfer coefficient. This reflects the effective tuning of geometric parameters to maximize thermal performance. The study also introduces two predictive mathematical models for the outlet temperature and convective heat transfer coefficient of the U-shaped pipe equipped with these enhancements. These models, derived from extensive numerical data, provide practical tools for future design and operational applications of geothermal heat exchangers. This research advances the design and operational efficiency of geothermal heat exchange systems, establishing new benchmarks for thermal efficiency in the field with actionable insights and robust mathematical tools.

A flexible resistive strain gauge with reduced temperature effect via thermal expansion anisotropic composite substrate

Strain gauge plays vital roles in various fields as structural health monitoring, aerospace engineering, and civil infrastructure. However, traditional flexible strain gauge inevitably brings the pseudo-signal caused by the substrate temperature effect and determines its accuracy. Here, we present an anisotropic composite substrate designed to modify the thermal expansion performance via Micro-electro-mechanical System (MEMS) technology, which facilitates the development of strain gauges that are minimally affected by substrate temperature-induced effect. Compared to the isotropic flexible substrate, the simulated expansion displacement in the thermal insensitive direction is reduced by 53.6% via introducing an anisotropic thermal expansion structure. The developed strain gauge exhibits significantly reduced sensitivity to temperature-induced effect, with a temperature coefficient of resistance decreasing from 87.3% to 10%, along with a notable 47.1% improvement in TCR stability. In addition, the strain gauge displays a sensitivity of 1.99 and boasts a wide strain operational range of 0–6000 µε, while maintaining excellent linearity. Furthermore, stress response conducted on a model of an aircraft wing illustrates the rapid monitoring of the strain gauge, which can detect strain as low as 100 µε. This study strongly highlights the potential applicability of the developed strain gauge in the aircraft, ships, and bridges for monitoring stress.

Laminar burning velocity of NH3 at elevated preheating temperatures and with N2 dilution: Measurements and evaluation of kinetic models

Ammonia is a promising hydrogen carrier and carbon-free fuel. In this work, new laminar burning velocity data of ammonia under intensified preheating (773K–848K) and N2 diluted condition is provided. Temperature coefficient that reflects the exponentially positive effect of preheating is reevaluated and compared with literature data at lower preheating temperatures, which is in the range of 2.08–2.30 with an improved accuracy. In contrast, dilution is of a linearly negative effect. The laminar burning velocity decreases by more than 20% as the O2 content drops from 21% to 19%. Besides, 11 recently published kinetic models are evaluated based on the experimental data. The Otomo18 model makes the best prediction with a small relative difference (≤±5%). Accordingly, the effects of radiation heat loss and dilution are analyzed in detail. The former is found insignificant, and the latter is mainly attributed to the adiabatic flame temperature drop.

Liquid state property and rapid peritectic solidification of refractory Mo-33.3 at.% Zr alloy under electrostatic levitation condition

The thermophysical properties and rapid solidification mechanism of liquid Mo-33.3 at.% Zr peritectic alloy were investigated by electrostatic levitation technique, which attained a maximum undercooling of 387 K (0.16 TL). At its liquidus temperature, the density, surface tension, viscosity and solute diffusion coefficient of this refractory alloy were determined as 8.14 g/cm3, 1.60 N/m, 11.32 mPa·s and 1.41 × 10−9 m2/s, respectively. The primary (Mo) dendrite growth started from multi-point nucleation, while its growth velocity agreed well with the prediction of LKT/BCT dendrite growth theory and reached an upper value of 43 mm/s. The subsequent peritectic transition was characterized by a power-law kinetics relation between the nominal growth velocity of peritectic Mo2Zr phase and peritectic undercooling, displaying a maximum velocity of 46 mm/s. The increase of liquid undercooling facilitated the completion of peritectic transition and refined the microstructure of residual primary (Mo) phase, thus enhancing the Vickers hardness of this alloy gradually up to 1190.9 HV at the maximum undercooling.

Memristive behaviour of Al/rGO-CdS/FTO device at different temperatures: A MATLAB-integrated study

In the present work, a comprehensive study is carried out to investigate the memristive behaviour of reduced graphene oxide (rGO) conjugated cadmium sulphide quantum dot (CdS QD) nanocomposites (rGO-CdS), offering insights into their dynamic response under varying thermal conditions. The study integrates experimental analysis with MATLAB simulation to provide a detailed understanding of the complex interplay between different operating temperature (300K, 350K, 400K, and 450K) and memristive behavior in rGO-CdS nanocomposites. Different structural and chemical characterizations were carried out which confirms the formation of rGO-CdS nanocomposites. A sandwich structured device was fabricated with the synthesized rGO-CdS nanocomposites using Aluminum (Al) as top and Fluorine doped tin oxide (FTO) as bottom electrode. The influence of operating temperature on hysteresis behaviour of the fabricated Al/rGO-CdS/FTO device was investigated using Keithley 2450 source meter by sweeping a direct current (dc) voltage (−5 V → 5 V → −5 V). Notably, we observe a positive temperature coefficient in the device current, with maximum and minimum recorded current of |1.29mA| and |0.66mA| at 450K and 300K respectively. The current-voltage (I-V) behavior observed in the device reveals that in the low resistance state (LRS), conduction is dominated by bulk-limited mechanisms. However, in the high resistance state (HRS), conduction involves contributions from both Schottky barriers and the Pool-Frenkel effect. A MATLAB based linear drift model was used to simulate the device responses at different temperatures using the experimental data. The study provides first comprehensive analysis of temperature dependent hysteresis behaviour of Al/rGO-CdS/FTO device, integrating MATLAB simulation to glean valuable insights into its operation and possible applications as memristive material across different temperature regimes.

High thermal stability of the microwave dielectric properties of ZnNb2O6 with CaTiO3 addition

This paper presents a study of the dielectric properties of ZnNb2O6 (ZNO) with added CaTiO3 (CTO) in the microwave (MW) region. An X-ray diffraction analysis is performed, and a reaction between ZNO and CTO is demonstrated that results in the formation of other crystalline phases. The dielectric properties in the MW region show no significant change in permittivity (ε'r), whereas the addition of CTO results in an increase in the dielectric loss (tan δ). The thermal stability is also measured, and the temperature coefficient of resonant frequency (τf) is varied from −88.95 to −8.16 ppm °C−1. Numerical simulations are carried out to evaluate these materials for use as a dielectric resonator antenna, and the results show a reflection coefficient (|S11|) of below −10 dB, a radiation efficiency above 96 %, a bandwidth ranging from 100 to 170 MHz, and a gain of above 4.50 dBi. The values obtained here show that these materials could be employed in electronic devices acting in the C- and S-bands.

Effect of insulator matrix on electrical transport properties of iron-insulator discontinuous multilayers

This work presents the results of the study of structural and electrical transport properties of the iron-insulator discontinuous multilayers (DMIMs). SiO2, HfO2, and MgO were chosen as the materials for the insulating layers. The discontinuous multilayers were prepared by the sequential magnetron sputtering on ceramic substrates. Obtained systems were annealed at different temperatures in an Ar + N2(2 %) environment using an annealing furnace with a continuous gas flow. Crystal structure analysis showed that the effect of annealing on the crystal structure of the samples varies and depends on the annealing temperature and the type of insulator. It has been demonstrated that the formation of iron oxide during annealing can be reduced by using HfO2 as the insulating layer material. The resistivity and temperature coefficient of resistance variation with temperature and the effective thicknesses of the ferromagnetic layers were analyzed.

Unveiling the potential of a novel inorganic perovskite for NTC thermistor and energy-storage applications

Inorganic perovskite-oriented materials are renowned for their multifunctional characteristics, making them candidates for various advanced applications. This study focuses on the synthesis and characterization of a novel inorganic perovskite material, (Ni0.5Sm0.5FeO3)0.5(BaTiO3)0.5, prepared via the cost-effective solid-state reaction method. Detailed structural and microstructural analyses were conducted to determine phase formation and grain size effects. Rietveld analysis was employed to identify the crystallographic phases, while field emission scanning electron microscopy (FE-SEM) provided insights into the sample’s morphology. FTIR and RAMAN spectroscopy were used to investigate the vibrational modes of the material. The dielectric properties and electrical characteristics were measured across a range of frequencies and temperatures using an impedance analyzer. The material’s potential for energy storage and NTC-type thermistor applications was evaluated through its temperature coefficient of resistance (TCR) and thermistor constant (β) analysis. Additionally, the ferromagnetic property was assessed through M−H hysteresis loop analysis, highlighting the material’s multifunctional capabilities.

AgNPs with CNTs to construct multifunctional flexible sensor with dual conductive network structure

Flexible sensors play an important role in the field of smart devices. However, most flexible sensors suffer from poor sensing signal stability and monofunction. In this study, a multifunctional film (named PM) with dual conductive network structure was fabricated by nanocellulose crystal dispersed with silver nanoparticles and carbon nanotube. The PM film exhibited excellent conductivity (24.6 S/m) along with antimicrobial effects against Staphylococcus aureus and Escherichia coli. Furthermore, the PM sensor showed excellent electrothermal performance, reaching 133.1 °C within 50 s at 12 V, and an excellent temperature coefficient of resistance (TCR = −0.65 % °C−1) over a temperature range of 36–124 °C. More importantly, the PM sensor demonstrated a high strain sensitivity (GF = 1.66) and durability (320 cycles), capable of detecting minute human body movements at a strain as low as 1 %. Additionally, the PM sensor maintained a stable sensing performance even after 30 d of exposure to air. Therefore, the multifunctional integration of the PM sensor shows great potential for application in the field of flexible electronics.

Determination of acoustic properties of paraffin oil mixed with activated coal nanoparticles or SPAN80 using only BAW time delay measurement

An important aspect of controlling the properties of liquids relates to their use in modern engines powered by composite materials. In this context, controlling the properties of industrial fluids containing micro- and nanoscale particles is essential. Understanding the temperature-dependent behavior of fluid density and elasticity is crucial for proper engine operation. Seven physical parameters of pure paraffin oil, paraffin oil with varying concentrations of activated coal nanoparticles or sorbitane monooleate (SPAN 80) were simultaneously determined using only BAW time delay measurement in the single experimental run. This technique relies on propagating LBAW through the test fluid and measuring the time delay and amplitude of these waves at different temperatures. By calculating temperature coefficients for velocity, density, time delay, and expansion using well-established formulas the physical properties of fluids under study were determined. The frequency of the LBAW used in the experiment was 13 MHz. The length of the liquid sample in the propagation direction of LBAW was ∼ 5 mm. The experiments were carried out within a temperature range of −20 °C to +90 °C. The volume of the test sample was around 1 milliliter. The comparison of the physical properties of different suspensions under these conditions allows us to demonstrate the dependence of the measured properties on the type and composition of the medium tested.

Improved microwave dielectric properties of LaZn1/2Ti1/2O3 through Y3+ substitution

LaZn1/2Ti1/2O3 is a double perovskite with promising microwave dielectric properties for applications towards dielectric resonators and antennas. Its dielectric properties can be enhanced through the substitution of suitable ions in either A- or B-sites. In this paper, we report a significant improvement in the quality factor (Q) by substituting Y3+ in the La site with a marginal reduction in dielectric constant (εr). A single phase is confirmed in XRD indicating the formation of La1-xYxZn1/2Ti1/2O3 (0 ≤ x ≤ 0.25) solid solutions. The substitution results in an expansion of lattice along the b direction while there is a contraction in both a and c directions, leading to a reduction in unit cell volume. The dielectric constant, εr, is observed to reduce from 33.4 to 29.6 due to the polarizability of A-site atoms. The temperature coefficient of resonant frequency (τf) increases with an increase in x which does not appear to correlate with reducing tolerance factor (t). This non-conventional behaviour of τf in this perovskite based solid solutions brings bond valence of O site (VO) into picture. VO appears to show competing effect on τf. The non-monotonic behaviour is observed in Q×f with a maximum value of 41,400 GHz at x = 0.15 and a sharp decline for x > 0.15. This observation is correlated with variations in the A-site bond valence (VA) and a long-range ordering (LRO) of B-site ions. LRO is associated with Ag mode at 710 cm−1 in the Raman spectra. The low frequency (< 250 cm−1) Raman modes shift to a higher frequency with the increase in Y3+. Y3+ substitution also induces lattice distortion which is discussed in terms of variations in FWHM and relative intensity of the Raman modes.

A Novel Battery Temperature-Locking Method Based on Self-Heating Implemented with an Original Driving Circuit While Electric Vehicle Driving: A Numerical Investigation

In extremely cold environments, when battery electric vehicles (BEVs) are navigating urban roads at low speeds, the limited heating capacity of the on-board heat pump system and positive temperature coefficient (PTC) device can lead to an inevitable decline in battery temperature, potentially falling below its permissible operating range. This situation can subsequently result in vehicle malfunctions and, in severe cases, traffic accidents. Henceforth, a novel battery self-heating method during driving is proposed to maintain battery temperature. This approach is ingeniously embedded within the heating mechanism within the motor driving system without any necessity to alter or modify the existing driving circuitry. In the meantime, the battery voltage can be regulated to prevent it from surpassing the limit, thereby ensuring the battery’s safety. This method introduces the dead zone into the space vector pulse width modulation (SVPWM) algorithm to form the newly proposed dSVPWM algorithm, which successfully changes the direction of the bus current in a PWM period and forms AC, and the amplitude of the battery alternating current (AC) can also be controlled by adjusting the heating intensity defined by the ratio of the dead zone and the compensation vector to the original zero vector. Through the Simulink model of the motor driving system, the temperature hysteresis locking strategy, grounded in the field-oriented control (FOC) method and employing the dSVPWM algorithm, has been confirmed to provide controllable and sufficiently stable motor speed regulation. During the low-speed phase of the China Light Vehicle Test Cycle (CLTC), the battery temperature fluctuation is meticulously maintained within a range of ±0.2 °C. The battery’s minimum temperature has been successfully locked at around −10 °C. In contrast, the battery temperature would decrease by a significant 1.44 °C per minute without the implementation of the temperature-locking strategy. The voltage of the battery pack is always regulated within the range of 255~378 V. It remains within the specified upper and lower thresholds. The battery voltage overrun can be effectively avoided.

Preparation, structural, electrical, and ferroelectric properties of solid and lead zirconium titanate ink

The novelty of the work lies in the design and development of a significantly low-cost lead zirconate titanate (PZT) ink similar in its electrical properties to its original solid materials, which can be used for 3-D printing to print electronic circuits, shape memory, and devices quickly. The Zr/Ti=52/48 ratio was achieved during the solid-state reaction to create the PZT powder. XRD, FT-IR, and SEM characterized the synthesized material. The PZT powder was found to form in a tetragonal phase. The PZT powder was used to prepare PZT ink with a 13 % Wt/Wt solid content composition. The ink's rheological characteristics and physical properties, such as particle size distribution, surface tension, viscosity, and electrical properties, were studied. Dielectric properties like dielectric constant (ε/) and dielectric loss (ε") indicate the poly-dispersive nature of the material. The temperature-dependent dielectric constant (ε/) curve indicates relaxor behavior with a maximum at high temperatures. The poly-dispersive nature of the material was analyzed using Cole-Cole plots. The frequency dependence of AC conductivity follows the universal power law. The temperature dependence of dc-conductivity follows the Arrhenius law, with an activation energy of 0.14 eV at lower temperatures and 0.85 eV at higher temperatures. The electrical conductance study showed that PZT ceramic can be used in electronic circuits because of its high resistivity value and small temperature coefficient of resistance. The piezoelectric measurement displays d33 as 129 pC/N at room temperature.

Probing the Temperature-Dependent Thermal Conductivity of Violet Phosphorus via Optothermal Raman Spectroscopy.

The temperature-dependent thermal conductivity of violet phosphorus on a perforated SiO2/Si substrate has been investigated via optothermal Raman spectroscopy. The obtained temperature coefficients of the Tg mode and Ptub mode of the violet phosphorus sample are -0.01268 and -0.01789 cm-1 K-1, respectively. On the basis of the temperature coefficients and power coefficients, the thermal conductivity of the violet phosphorus has been calculated to be 44.642 ± 4.995 W/mK at room temperature, which is higher than that of other two-dimensional materials such as black phosphorus and MoS2 due to the effect of boundary scattering and the phonon mean free path. Additionally, the thermal conductivity of violet phosphorus decreases as a power exponential function of the temperature, which is primarily associated with the phonon mean free path and phonon group velocity. This work provides a scientific foundation for thermal management and heat dissipation in designing micro-nano devices with violet phosphorus.

Kinetic insights into double-branched acyclic ether: Methyl tert-butyl ether and 2,2-dimethoxypropane

This study presents the first kinetic mechanism for methyl tert-butyl ether (MTBE) containing low-temperature chemistry, as well as the first mechanism for 2,2-dimethoxypropane (DMP). The mechanisms have been validated against ignition delay time experiments conducted in a high-pressure shock tube and rapid compression machine. The rapid compression machine conditions were set to 20 and 40 bar for MTBE, and 10 and 20 bar for DMP in a temperature range of 584 to 946 K. Shock tube experiments have been performed for DMP at 20 and 40 bar for stoichiometric and fuel-lean conditions in air at temperatures ranging from 913 to 1173 K. A pronounced negative temperature coefficient regime with two-stage ignition has been observed for both fuels. The developed mechanism consists of reaction rate constants that were primarily modeled in analogy to iso-octane and dimethoxymethane, and calculated thermodata on the G4//B3LYP-D3BJ/def2-TZVP level of theory. Simulations have been performed to analyze the fuel oxidation at different temperatures. Over the full temperature range, H-atom abstraction occurs mainly on the α-side for DMP and on the β-side for MTBE. At low temperatures, both fuels isomerize to the peroxy radical. The dominant MTBE radicals then tend to produce cyclic ether, while the DMP radicals react with O2, enabling significant chain branching and explaining the higher reactivity of DMP. With rising temperature, β-scission of the fuel radicals and unimolecular elimination reactions start to dominate the oxidation process.Novelty and Significance StatementThe novelty of this research is the first observation of a two-stage ignition of methyl-tert butyl ether (MTBE) in an RCM and a discussion of its fundamental ignition chemistry, which is based on a developed detailed kinetic mechanism. In addition, 2,2-dimethoxypropane (DMP) has been investigated experimentally and theoretically to explain the difference in reactivity to MTBE despite their strong molecular similarity. The experiments include RCM and shock tube experiments. The kinetic model is based on rate constant analogies and newly calculated thermo data on the G4//B3LYP-D3BJ/def2-TZVP level of theory. This work is significant, as MTBE is still a widely used octane booster and the developed model could help to improve engine simulations. Furthermore, the findings of DMP provide insights into future fuel design.

Influence of variable valence metal oxides on physico-chemical and antibacterial properties of semi-coated glazes

The paper presents the results of studies on the production of semi-coated glazes with antibacterial activity by introducing variable valence oxides CeO2, WO3, Bi2O3, Fe2O3, MnO2 and MoO3 into their composition. The raw polycomponent compositions were comprised of aluminosilicate multi-calcium glass frit, dolomite powder, feldspar, alumina, quartz sand, wet-enriched kaolin and refractory clay. The coatings were obtained by single firing on a ceramic-based porcelain stoneware at a temperature of 1 200 ± 5 °C in a high-speed mode for 60 ± 2 minutes. The study focused on the processes of glaze formation of coatings and the influence of the components of glaze charges on decorative and aesthetic characteristics of coatings (color, texture, gloss and whiteness). Parameters of physical and chemical properties were determined in accordance with the existing specification for the products, i. e. temperature coefficient of linear expansion, heat resistance, chemical resistance, microhardness, frost resistance, wear resistance, etc. Antibacterial activity of the coatings towards Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538 test strains was studied.

Mussel-inspired adhesion for layer-by-layer assembly towards multi-functional electrically conductive cotton fabric

Layer-by-layer (LBL) assembly has been widely utilized for constructing functional coatings to fabricate versatile materials. However, challenges arise when the assembly building blocks are electrically neutral. To address this issue, we report the use of mussel-inspired adhesion as a unique driving force for LBL assembly to fabricate electrically conductive cotton fabric (ECCF) with carbon nanotubes & graphene as conductive materials and poly(vinyl alcohol-graft-3,4-dihydroxybenzyl acetal) (PVD) as a mussel-inspired adhesive. The robust adhesion provided by PVD endowed the ECCF with excellent stability against sandpaper friction, tape peeling, and water washing. The use of the ECCF in some advanced application such as strain sensing, temperature sensing, and electric heating was studied in detail. The ECCF exhibited fast response and remarkable sensitivity in strain sensing, enabling real-time detection of various human motions such as bending, twisting, and swallowing. In temperature sensing, the ECCF exhibited a negative temperature coefficient effect and offered a linear response within the temperature range of 30–100 °C. In addition, the ECCF demonstrated exceptional electric heating performance, leading to potential use in outdoor insulation and thermal rehabilitation therapy. This innovative application of mussel-inspired adhesion in LBL assembly not only paves the way for advanced smart fabrics but also enhances functionality.

Bio-inspired spreadable multi-signal self-sensing covering composite material for intelligent devices

The spreadable materials with multi-sensing capabilities offer a wide range of application possibilities. They can be applied directly to the surface of intelligent devices, facilitating the creation of self-sensing shells. Despite significant progress in the development of such materials, expanding their diverse sensing capabilities remains a critical focus in this field. Here, we present a spreadable material endowed with multiple signal self-sensing capabilities. The material, which can be easily applied to the surface of devices, offers real-time monitoring of temperature, humidity, and device damage. This material comprised carbon black nanoparticles, carbon nanotubes, and sodium carboxymethyl cellulose, exhibiting excellent electrical conductivity. It exhibited a temperature coefficient of resistivity (TCR) of approximately 0.35%per°C, a humidity sensing sensitivity ranging from 3.57 to 4.31 Ω/RH%, and a strain sensing sensitivity gauge factor value of approximately 2.3. We anticipate that the proposed strategy utilizing spreadable multi-signal sensing materials will be extensively applied to the surfaces of various intelligent equipment, thereby furnishing a diverse range of signal data crucial for both safeguarding intelligent systems and enhancing environmental monitoring capabilities.

Application of deep learning in summer climate prediction over northwestern China based on CWRF model

This study analyzes the performance of the Climate–Weather Research and Forecasting (CWRF) model in predicting the summer temperature and precipitation in northwestern China (NWC) for the 1991–2021 period. It also examines the improvements in prediction resulting from the implementation of convolutional neural network (CNN) and long short-term memory (LSTM) downscaling methods. The results indicate that the CWRF model demonstrates reasonable ability in capturing the characteristics of climatological temperature and precipitation in NWC. Both the climatological temperature and precipitation predictions consistently demonstrate a systematic underestimation, revealing evident biases in regions characterized by complex terrain. In terms of interannual variation, the temperature prediction outperforms the precipitation prediction, whereas there is no significant difference in the temperature predictions for lead Months 1–3. However, uncertainties increase as the lead time is extended in precipitation prediction. Therefore, the combination of dynamical and statistical downscaling is employed to the summer temperature and precipitation prediction over NWC. It is shown both the CNN and LSTM downscaling methods can improve the prediction ability of the CWRF model for summer climatological temperature and precipitation. The LSTM method significantly reduces the root mean square error (RMSE) of precipitation and temperature predictions, indicating an improvement in predicting the spatial structure. At the interannual scale, the CNN method is less dependent on the lead time of prediction than the LSTM method is, and the interannual correlation coefficient of precipitation and temperature is greater than 0.1 compared with that of the raw CWRF model. These results provide valuable insights into understanding the prediction capabilities of the CWRF model in NWC and highlight the necessity of applying downscaling methods to the CWRF model to increase its prediction ability.