Er Values Research Articles

Numerical investigation of spindle position effects on steam ejector performance with a nonequilibrium condensation model

AbstractThis research studied the performance of a spindle‐controlled steam ejector using models such as ideal gas and wet steam under various operating conditions based on computational fluid dynamics (CFD). A wet steam model incorporating nonequilibrium condensation was employed to simulate the complex flow phenomena within the ejector. The structure of the flow, entrainment ratio (Er), and shock wave characteristics of the steam ejector were examined in two different models. Results indicate that the spindle position has a substantial impact on steam ejector performance. For the ideal gas and wet steam models, the optimal spindle position (SP‐5) at a .1 MPa motive pressure achieves the highest entrainment ratios (Er) of 1.01 and 1.042, respectively. However, an ejector with a fixed geometry achieves Er values of only .517 and .549 for the ideal gas and wet steam models, under identical working conditions. This represents a substantial improvement of 89.8% over the fixed‐geometry ejector. The wet steam model consistently predicts 2%–4% higher Er values compared with the ideal gas model across all spindle positions. The study also reveals that increasing the motive pressure from .1 to .3 MPa reduces Er by up to 45.8% at the optimal spindle position, with the shock train length extending to 35% of the mixing chamber at .3 MPa. These findings offer insights for improving the design and optimization of variable‐geometry steam ejectors, potentially increasing efficiency in industrial applications.

Ta doping effect on microstructure and microwave dielectric properties of CoNb2O6‐based ceramics and mechanism study

AbstractAs communication technology continues to evolve, 5G technology is becoming more mature, and 6G technology is steadily advancing. Microwave equipment is moving toward high frequency, miniaturization, low loss and high temperature stability, and microwave dielectric ceramics have been deeply applied in this field. To elevate the Q × f value of CoNb2O6 system, Ta5+ was introduced into CoNb2O6, and CoNb2‐xTaxO6 (0.0 ≤ x ≤ 0.8) ceramics were prepared by the traditional solid‐phase method. By X‐ray diffraction, it was observed that at x = 0.8, in addition to a single niobium ferrite phase, information of tantalate phase also appeared. Raman spectral detection and group theory analysis indicate that Ag(2) and Ag(3) modes are the dominant Raman vibrations at ≈873 cm−1. Furthermore, the polarization rate affects the εr value, and the bond energy of Nb/Ta‐O and the recovery force characterized by the average deformation of the [Nb/TaO6] octahedron are the key elements influencing the temperature coefficient of the resonance frequency (τf). The internal strain, ordered induced size, and chemical bonding valence of ionic valence states are the key factors that can increase the Q × f value. Moreover, the introduction of ions with lower electronegativity leads to an enhanced electronic compensation of oxygen vacancies, which also reduces the dielectric loss. This paper enriches the theory related to low dielectric loss and shows that CoNb1.8Ta0.2O6 (εr = 21.4832, Q × f = 100723 GHz, τf = ‐61.38 ppm/°C) ceramics with superior microwave dielectric properties are expected to be used in wireless communication devices.

Enhanced Energy Storage Properties of Four-Layer Composite Films via Strategic Macrointerface Modulation.

Dielectric capacitors play a crucial role in the field of energy storage; however, the low discharged energy density (Ue) of existing commercial dielectrics limits their future applications. Currently, further improvement in the Ue of dielectrics is constrained by the challenge of simultaneously achieving high permittivity (εr) and high breakdown electric field strength (Eb). To address this issue, we designed a series of four-layer poly(vinylidene fluoride) (PVDF)-based composite films comprising three functional layers: a sodium bismuth titanate (NBT) plus PVDF composite (NBT&PVDF) layer to achieve high εr values and a pure PVDF layer and a boron nitride (BN) plus PVDF composite (BN&PVDF) layer to achieve high Eb values. This design synergistically enhanced the εr and Eb values of the composite films by exploiting low-loss macrointerface polarization via adjustment of the functional layer stacking order, as supported by simulation analyses. Ultimately, the composite film with a topmost layer of pure PVDF, followed by an NBT&PVDF layer, another pure PVDF layer, and a BN&PVDF layer achieved an enhanced Ue value of 26.42 J·cm-3 and excellent efficiency of 80.03% at an ultrahigh Eb value of 770 MV·m-1. This approach offers an innovative pathway for developing advanced energy storage composite dielectrics via macrointerface manipulation.

Design and Fabrication of a C-Band Patch Antenna with Low Loss BaM4Si5O17 Microwave Dielectric Ceramics.

Single-phase BaM4Si5O17 (M = Yb, Er, Y, Ho) ceramics have been investigated for their crystal structures, microwave dielectric properties, flexural strength, and potential applications in dielectric antennas. Rietveld refinement and TEM analysis revealed that the BaM4Si5O17 ceramics exhibit a monoclinic structure (space groups: P21/m). The εr of the BaM4Si5O17 ceramics was dominated by ionic polarizability and ρrel. The Q × f values were considerably larger at BaM4Si5O17 (M = Yb and Y) ceramics with the high Utotal and low intrinsic dielectric loss. The τf values were controlled by the MO6 octahedron distortion and -VBa. The flexural strength was mainly dominated by pores and average grain size and reached the maximum value (156 MPa) at BaY4Si5O17 ceramic with small average gain sizes and high relative density. Additionally, a patch antenna was fabricated using high-performance BaY4Si5O17 ceramic characterized by a εr value of 9.02, a Q × f value of 60620 at 12.30 GHz, and a τf value of -37.65 ppm/°C. This design achieved a high simulated radiation efficiency of 82.70% and a gain of 5.60 dBi at 6.97 GHz. indicating potential applications of BaY4Si5O17 ceramic because of its low dielectric loss and high flexural strength.

Microwave dielectric properties of LiM(PO3)3 (M = Mg2+, Zn2+) ceramics

Microwave dielectric ceramics with low dielectric permittivity εr combined with low ceramic sintering temperatures have raised considerable research interest recently due to their potential application in LTCC technology for 5G wireless communications. Here in this study, ceramic processing, crystal structure, and microwave dielectric properties of LiM(PO3)3 (M = Mg2+, Zn2+) ceramics were comprehensively investigated. Optimized LTCC compatible ceramic sintering processes were developed at 725 °C and 625 °C for 10 hours, respectively, leading to high relative densities of 96.27% and 94.09%. Low microwave εr values of 5.74 and 6.30 and Q×f values of 16,660 GHz and 9,629 GHz (at 14 GHz) were obtained, where such values were found to be affected by the grain microstructure. LiMg(PO3)3 exhibited a small τf of -11 ppm/°C, while LiZn(PO3)3 showed -58 ppm/°C. Complementary impedance spectroscopy measurements indicated modest Li+-ion conductivity with a higher value of 2.92·10-7 (Ωcm)-1 at 560 K (287 °C) in LiZn(PO3)3. Both ceramics were found to be dielectrically homogeneous without any perceptible contributions from the grain boundaries.

Characteristics and risk assessments of mercury pollution in a county region undergoing industrialization in northeastern China: a case study in Gongzhuling

Mercury pollution in emerging industrial zones and surrounding areas, especially in industrial concentration areas, has attracted much attention. So as to clarify the characteristics of Hg in the environment in China’s small and medium-sized industrial emerging and surrounding areas, central urban area of Gongzhuling, a traditional agricultural town with a high degree of industrialization in northeast Changchun industrial base, is taken as the scope. Geological accumulation trin (Igeo) was used to study the degree of soil mercury contamination in Gongzhuling area, latent Er (ecological risk) trin was used to appraise the Er of soil Hg in the study area, and non-carcinogenic risk assessment of mercury in soil using human exposure risk assessment model. The results showed that 34% of soil samples had higher Hg content than the background value of the province’s soil (0.04 mg kg−1). The Igeo results showed that Hg pollution rate of soil in study area was 9% (index >0). In conclusion, the level of soil Hg pollution in Gongzhuling area was low, and the pollution area is mainly concentrated in the northwestern part of the study range. The highest and lowest Er values of soil Hg from the study sample were 2.23 and 214.83, and 24% of the samples had Er > 40, that means they pose a moderate or higher potential ecological risk, and most of these points are located in the northeast of the study range. The main route of human exposure to Hg is oral ingestion. The HQ (non-carcinogenic risk index) and HI (total non-carcinogenic risk value) of soil mercury were both much less than 1, it indicates that the present level of soil Hg in the study range does not pose a threat to local adult health for the time being. This study provides reference for other urban pollution risk assessment, and further defines the direction of future work.

Novel single-phase Li2SiO3 microwave dielectric ceramic with low permittivity

Novel low-permittivity lithium metasilicate (Li2SiO3) ceramics were synthesized to explore the relationships between crystal structure parameters and dielectric properties. X-ray diffraction and Rietveld refinement indicated that the Li2SiO3 ceramics formed a single orthorhombic structure with a Cmc21 space group. Optimal microwave dielectric properties of εr = 6.20 ± 0.02, Q×f = 30,550 ± 250 GHz (f0 = 15.5 GHz), and τf = −40.95 ± 0.56 ppm/℃ were achieved through sintering at 1025 ℃. Raman spectroscopy analysis showed that the values of εr and Q×f were negatively correlated with the Raman shift and full width at half maximum of the strongest peak at 982 cm−1, respectively. Meanwhile, the Phillips–Vechten–Levine theory revealed that the εr values and the Q×f values were closely related to the average bond ionicity and the lattice energy of the Si-O bonds, respectively. Moreover, the increase in τf values depended on the increase in oxygen bond valence and the distortion of the [LiO4] tetrahedron. These results on the Li2SiO3 ceramics could provide some theoretical information for developing high-performance microwave dielectric ceramics.

Process Modeling and Simulation of Sugarcane Bagasse Gasification using different Oxidizing Medium: A Universal Gasification Model

Biomass gasification is gaining significant interests among the researchers as the syngas/producer gas obtained from gasification of biomass can be versatile in usage. However, the outcome of gasification (gas composition/LHV/CGE) varies with the gasification medium employed. This article presents the process modeling of sugarcane bagasse gasification for three different gasifying media, namely air, steam and air-steam, using cycle tempo software to identify the best among different gasification processes for the considered response variables. A process model has been developed, and the gas composition predicted by the proposed model is validated with published experimental results for different biomass feeds. The influence of important operational parameters such as SBR, ER and gasification temperature on gas composition, LHV, and CGE were analyzed and compared for all three gasifying media. SBR, ER and gasification temperature have a very strong impact on the gas composition, LHV, and CGE. With the increase in SBR value, H2 concentration increases, whereas the concentration of CO decreases. The maximum concentration of H2 was observed to be 57.81 % at an SBR of 2 and at a gasification temperature of 750ºC for steam gasification. For air-steam gasification, optimum values of SBR and ER are observed to be 0.5 and 0.2, respectively, at a gasification temperature of 750ºC, where LHV (9.91 MJ/kg) and CGE (84.14%) were found to be maximum.

Effect of Mn2+ substitution on the dielectric properties of NaMg(PO3)3 ceramics at microwave and terahertz frequencies

In this study, NaMg1-xMnx(PO3)3 (0.00 ≤ x ≤ 0.0625) ceramics with low dielectric constant were prepared via the solid-state reaction method. The effects of Mn2+ substitution on the microstructure and dielectric properties (at microwave and terahertz frequencies) of the NaMg(PO3)3 ceramics were studied by means of the Rietveld refinement, morphology, and ionic polarizability analysis. It is obtained that the NaMg0.0975Mn0.025(PO3)3 ceramic sintered at 880 °C for 4 h exhibited optimal dielectric properties at microwave frequencies, where εr = 4.585, Q × f = 48,313 GHz (@17.228 GHz), and τf = −40.83 ppm/°C. The Q × f and τf values were changed by 74.2 % and 27.8 %, as compared to the values of 27,728 GHz and −56.52 ppm/°C for the pure NaMg(PO3)3 ceramic, respectively. For terahertz frequencies (0.2–1.0 THz), the εr values were decreased to 3.79–3.98, and the tanδ values were between 0.0203 and 0.1152. All the experimental results indicate that this system exhibits great potentials both at microwave and terahertz frequencies.

Effect of Ge4+-substituted on the structure characteristics and microwave/terahertz dielectric properties of ultra-low εr, high Q·f cordierite ceramics

In this study, Ge4+-substituted cordierite, Mg2Al4(Si1–xGex)5O18 ceramics, were successfully prepared by the traditional solid-state method to broaden its application potential. Notably, the excellent dielectric properties with εr = 4.90, Q·f = 128,200 GHz, and τf = −21.01 ppm °C–1 were achieved. The increase in εr value is mainly due to the heightened content of Ge4+ with high polarizability. The Q·f value improved by 2.21 times compared to the cordierite matrix, which can be primarily attributed to enhanced lattice energy, bond covalency, and hexagonal ring symmetry. The alteration in τf value arises from the variation of bond energy, bond strength, and distortion in the [MgO6] octahedra. These conclusions provide valuable insights for the design of silicate ceramics with higher Q·f values. In addition, the dielectric properties in the microwave and terahertz bands were compared. The higher Q·f and lower εr values in the terahertz band mainly result from the withdrawal of partial polarization mechanisms and differences in measurement methods. Mg2Al4(Si0.92Ge0.08)5O18 ceramics, demonstrating an ultra-low εr value of 4.54 and an ultra-high Q·f value of 286,533 GHz in the terahertz band, emerge as formidable contenders for future terahertz communications materials. Finally, a microstrip patch antenna was fabricated, achieving a bandwidth of 150 MHz at 4.78 GHz, which confirms the application in the n79 band for wireless communication.

Microwave dielectric properties of novel Mg3Ga2TiO8 ceramic

Mg3Ga2TiO8 ceramics were prepared using a solid-phase method. The ceramics sintered at 1440 °C exhibited excellent microwave dielectric properties (εr = 12.07, Q × f = 89,270 GHz, and τf = −40.7 ppm/°C). The typical spinel structure of the Mg3Ga2TiO8 ceramic was confirmed through Rietveld refinement and Raman spectroscopy. High-resolution transmission electron microscopy indicated local lattice distortion in the Mg3Ga2TiO8 ceramics, with a Vickers hardness of 12.53 GPa. The values of εr and Q × f for the Mg3Ga2TiO8 ceramics were affected by the relative density. The theoretical εr obtained from the C-M equation was lower than the measured εr, plausibly due to underestimation of the polarizability of the Ti ions. According to the P-V-L theory, Ti2-O1 has the highest fi value, contributing 29.92 % to εr. The contribution rate of the Ga2-O1 bond to U was 35.76 %, with the greatest impact on Q × f.

Low-loss and low-temperature sintering of SrNb2V2O11 with a large positive τf value as an effective temperature compensator

Novel SrNb2V2O11 microwave dielectric was synthesized and proposed as a temperature compensator for Low-temperature cofired ceramics (LTCC)/Ultra-low-temperature cofired ceramics (ULTCC) applications. The X-ray diffractometer (XRD) patterns matched well with the SrNb2V2O11 phase, exhibiting a monoclinic structure and Cc space group over the entire experiment. The presence of the Nb-rich second phase at 850 °C was attributed to the melting of the samples. The microwave dielectric properties were highly correlated with the chemical bond parameters, which were intensively investigated using the P-V-L theory. The specimen sintered at 820 °C reveals dielectric properties, combining an εr of 74.5, Q × f of 13,000 GHz, and τf of 517 ppm/°C. The large positive τf can make the ceramic an effective temperature compensator for LTCC applications. Moreover, the medium-high εr value can also act as a practical material for dielectric resonators used in the base stations, where a stable environment and limited temperature changes are crucial.

La3+ doped CaCu3Ti4O12 ceramics: Investigation of its microstructural and dielectric properties against varying sintering durations

This article reports the relationship between microstructure and dielectric properties of the title material were prepared through combination of solid-state and sol–gel methods and then sintered by varying durations. XRD indicates Im-3 space group with a body centred cubic structure, and Rietveld refinement analysis showed good fits for all samples, with R-factors below 10 % and GoF less than 2. The XPS analysis revealed the existence of Ca 2p, La 3d, Cu 2p, Ti 2p, O 1s, and C 1s retained their correct oxidation states. SEM results show grain sizes of 1.10 (±0.25) μm, 1.24 (±0.10) μm, and 1.75 (±0.31) μm for 8, 12, and 16 h of sintering, respectively. EDS analysis confirms the presence of Ca, Cu, Ti, La, and O, indicating the purity of the ceramics. As the sintering duration increases, grain enlargement consistently leads to higher εr values with very low tanδ. At a low frequency of 50 Hz, εr increases with sintering duration, reaching values of 5.65 × 103, 5.90 × 103 and 9.94 × 103. Meanwhile, tanδ remains significantly low (<0.1) at 1 kHz. The Nyquist plots demonstrate deviation from Debye type relaxation with NTCR behaviour. The frequency-dependent AC conductivity follows Jonscher’s power law, with activation energy values of 0.44 eV, 0.46 eV, and 0.49 eV for ceramics sintered for 8, 12, and 16 h, respectively.

Effect of modified Ca-Al adsorbents on heavy metal fixation during co-combustion of coal and coconut shells: Experiments and simulations

As an alternative fuel, bio-waste coconut shells have shown promise in reducing pollution during the co-combustion process. In this study, a novel metal-mineral adsorbent, Ca-Al (Ca5Al6O14), was prepared and physically (ultrasonic) and chemically (ethylene glycol) modified to enhance its adsorption properties. Thermal adsorption experiments investigated the effect of the adsorbents on the fixation of six heavy metals (HMs): Cr, Cu, Mn, Ni, Pb, and Zn. XRD, SEM, BET, and XPS were used to analyze the adsorbents and the adsorption mechanism was investigated by combining lattice oxygen concentration and Factsage simulation calculations. The ecological risk assessment of heavy metals was used to comprehensively evaluate the fixation effects of the three Ca-Al adsorbents at different additive levels. The results showed that the modification significantly changed the morphological characteristics and oxygen activity of the Ca-Al adsorbents, increased the lattice oxygen and chemisorbed oxygen concentration, and laid the foundation for promoting the chemisorption process in the fixation of heavy metals. In combination with the Er (environmental risk factors), adding all three adsorbents reduced Ri (Risk index). Among them, Ca-Al (EG) at 3% had the best effect on Ri. 3% Ca–Al (EG) reduced the Er value of Ni by 49.02%. 5% Ca–Al (EG) reduced the Er value of Cr by 86.01%. 5% Ca–Al (UM) had the best effect on Mn, with a reduction of 46.13%. The addition of 10% Ca–Al (UM) reduced Er of Ni by 50.43%. Considering the practical application in coal-fired power plants, Ca-Al(EG), which exhibits a higher fixation rate at small additions, is more suitable.

One Turán Type Problem on Uniform Hypergraphs

Let n,m,p,r∈N with p≥n≥r. For a hypergraph, if each edge has r vertices, then the hypergraph is called an r-graph. Define er(n,m;p) to be the maximum number of edges of an r-graph with p vertices in which every subgraph of n vertices has at most m edges. Researching this function constitutes a Turán type problem. In this paper, on the one hand, for fixed p, we present some results about the exact values of er(n,m;p) for small m compared to n; on the other hand, for sufficient large p, we use the combinatorial technique of double counting to give an upper bound of e(n,m;p) and obtain a lower bound of er(n,m;p) by applying the lower bound of the independent set of a hypergraph.

Soil quality and heavy metal contamination in an open dumpsite in Navrongo, Ghana.

The increasing proximity of the Dudumbia dumpsite, an open dumpsite in Navrongo, Ghana, to human settlements necessitates an investigation of the soil quality to safeguard the environment from heavy metal toxicity. This study examined the impact of waste dumping activities on the physicochemical properties of the soil, as well as the level of heavy metal (Pb, Cd, Ni, Cr, As, Hg, Cu, Mn, and Zn) contamination and associated risks. Various contamination and risk assessment tools were used, including the geoaccumulation index (Igeo), pollution load index (PLI), potential ecological risk (Er), and potential ecological risk index (PERI). The study found significant improvements in notable soil attributes such as phosphorus (P), organic carbon (C), total nitrogen (N), calcium (Ca), magnesium (Mg), potassium (K), sodium (Na), and effective cation exchange capacity, with percentage increases ranging from 50.8 to 2078.3%. Igeo values ranged from 2.07 to 6.20, indicating contamination levels from moderate to extreme. The PLI and PERI values were 16.241 and 1810, respectively. The Er values for the heavy metals ranged from 36 to 607, indicating ecological risk levels from low to very high, with Cd and Hg posing very high risks. These results suggest that while the dumpsite soil shows improvements in some characteristics favourable for plant cultivation, waste dumping significantly contributes to heavy metal contamination. The soil at the dumpsite is deteriorated and poses significant health risks, particularly due to Cd and Hg. Therefore, remediation efforts should prioritise mitigating the risks posed by Cd and Hg.

Enhancing the thermal stability of the dielectric property by tilting the NbO6 octahedra in (Na1-zKz)NbO3-SrTiO3 ceramics

(1-x) (Na0.2K0.8)NbO3-xSrTiO3 [(1-x) (N0.2K0.8)N-xST] ceramics with a homogeneous perovskite structure were well-sintered in the range of 1080–1160 °C. The 0.9(N0.2K0.8)N-0.1ST ceramic was found to have a temperature-stable dielectric constant (εr) that complies with the X9R multilayer ceramic capacitor (MLCC) requirement. The temperature stability of the εr value was also investigated for the 0.9(N1-zKz)N-0.1ST ceramics (0.0 ≤ z ≤ 1.0). The results indicated that as z (or K+ ions) increased, the Curie temperature (TC) decreased, and its peak broadened. The broadening of the TC peak was attributed to the development of the relaxor property owing to the tilting of the NbO6 octahedra. The 0.9(N1-zKz)N-0.1ST ceramics (0.7 ≤ z ≤ 1.0) exhibited a temperature-independent εr value, thus fulfilling the X9R MLCC requirement because of the broad TC peak. The MLCC fabricated from 0.9(N0.2K0.8)N-0.1ST thick films complied with the X9R MLCC requirement with excellent capacitance stability under the supplied electric field. Hence, 0.9(N1-zKz)N-0.1ST ceramics (0.7 ≤ z ≤ 1.0) are good candidates for X9R MLCCs.

Distributions of Some Heavy Metals in Agricultural Soil and Their Environmental Impacts in Chamchamal District, Sulaymaniya Governorate, Northeastern Iraq

Soil samples were collected from Sangaw, Qadir Karam, and Takiat Gabbary sites of Chamchamal agricultural soil Sulaymaniya Governorate, Northeastern Iraq. The heavy metals Co, Cr, Cu, Ni, Cd, Zn, Pb, As, and Mn. in Eighteen soil samples were studied and used as an indicator for pollution by using many indices such as the contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), pollution load index (PLI), pollution ecological risk (Er), and risk index (RI). The results showed that the heavy metal concentration values were as follows: Mn&gt; Ni&gt; Zn&gt; Cr&gt; Cu&gt; Pb&gt; Co&gt; As&gt; Cd. The CF data showed that the soil in the study area has low contamination with Co, Cr, Cu, and Mn and moderate contamination with Ni, Pb, Zn, and As. Also, the soil samples are considerably contaminated by Cd and As in the Qadir Karam site. According to the results of Igeo, the soil was unpolluted for Co, Cr, Ni, Cu, Pb, Zn, and Mn, while being unpolluted to moderately polluted for Cd and As. The EF calculation results indicated that Co, Cr, Cu, and Mn have deficient to minimal enrichment, and have moderate enrichment for Ni, Pb, and Zn, while, for Cd and As is significant enrichment. According to the Er values, all the heavy metals in the studied sites reflect a low potential ecological risk. The risk index (RI) value is classified as moderate ecological risk for heavy metals in all sampling sites.

The entropy effect on the structure and microwave dielectric properties of high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics

In present study, high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics (x = 0.00–0.45) were synthesized using solid-state reaction route, which formed a single-phase spinel structure with a Fd-3m space group. The reduction in unit cell volume and lattice parameters were attributed to the compression of polyhedral structures. A moderate content of Li+ ions promoted the grain growth and improved the densification of ceramics. The internal connection among the conformational entropy (ΔSconfig), structure, and microwave dielectric properties in high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics was systematically studied. The dielectric constant (εr) was largely affected by the polarizability, and relatively high conformational entropy helped to increase the phonon vibrational energy and enhance the bond strength, resulting in low εr values. Additionally, the high concentration of oxygen vacancies, high packing fraction, low internal strain/fluctuation and suppressed damping behavior were closely related to relatively low conformational entropy. Notably, the introduction of oxygen vacancy leaded to the Al3+ ions preferentially occupy tetrahedral sites enhancing the covalency. These factors collectively reduced the intrinsic losses and improved the quality factor (Q×f). Moreover, relatively high conformational entropy conduced to the structural stability by improving the M-O (M = Li, Mg, Zn, Co, and Ni) bond strength and valence, which contributes to achieve near-zero temperature coefficient of resonant frequency (τf). As ΔSconfig changes, high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics presented great microwave dielectric properties: εr values of 5.46 ∼ 8.49, Q×f values of 3,540 GHz (f = 14.84 GHz) ∼ 56,950 GHz (f = 12.99 GHz), and τf values of −58 ppm/°C∼ −14 ppm/°C. Our study demonstrates that the high-entropy strategy effectively enhances microwave dielectric properties. This approach has potential applications across a broad spectrum of microwave dielectrics ceramics.

A Single-Arm Phase II Clinical Trial of Fulvestrant Combined with Neoadjuvant Chemotherapy of ER+/HER2- Locally Advanced Breast Cancer: Integrated Analysis of 18F-FES PET-CT and Metabolites with Treatment Response.

This Phase II trial was objected to evaluate the efficacy and safety of adding fulvestrant to NCT in patients with ER+/HER2- locally advanced breast cancer (LABC). Additionally, the study aimed to investigate the association of 18F-FES PET-CT and metabolites with efficacy. Fulvestrant and EC-T regimen were given to ER+/HER2- LABC patients before surgery. At baseline, patients received 18F-FES PET-CT scan, and plasma samples were taken for LC-MS analysis. The primary endpoint was ORR. Secondary endpoints included tpCR and safety. Among the 36 patients enrolled, the ORR was 86.1%, the tpCR rate was 8.3%. The incidence of grade ≥3 TEAEs was 22%. The decrease in ER value in sensitive patients was larger than that in non-sensitive patients, as was Ki-67 (p<0.05). The SUVmax, SUVmean, TL-ER of 18F-FES PET-CT in sensitive patients were significantly higher than those in non-sensitive patients (p<0.05). Moreover, these parameters were significantly correlated with MP grade and the change in ER expression before and after treatment (p<0.05). Thirteen differential expressed metabolites were identified, which were markedly enriched in 19 metabolic pathways. This regimen demonstrated acceptable toxicity and encouraging antitumor efficacy. 18F-FES PET-CT might serve as a tool to predict the effectiveness of this therapy. Altered metabolites or metabolic pathways might be associated with treatment response.