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• The inorganic-organic hybrid insulating layer was successfully prepared. • The μ e of the AMPCs maintained excellent frequency stability up to 10 MHz. • Performance of Fe-based AMPCs declines after the crystallization appears. • The AMPCs annealed at 480 °C exhibited lower core loss and superior permeability. In order to improve the magnetic properties of soft magnetic composites (SMCs), the Fe-based amorphous powder cores (AMPCs) based on spherical FeSiBCCr amorphous magnetic powders coated with inorganic-organic (TiO 2 -epoxy resin) hybrid insulating layer were prepared. The influence of annealing temperature on the soft magnetic properties of the AMPCs has been systematically researched in this work. It was found that the reasonable annealing temperature could increase the permeability and decrease the core loss of the AMPCs. The AMPCs annealed at 480 °C showed a constant permeability of 81.5 up to 10 MHz, and low total core loss of 275 mW/cm3. This study demonstrated that the present Fe-based AMPCs with inorganic-organic hybrid insulating layer have a great promising future in the field of medium and high frequency for the various electronic components. [ABSTRACT FROM AUTHOR]

The welding joints of Zircaloy-4 plates obtained by diffusion welding at 800X under pressure in vacuum were cracked during autoclave tests at 400X superheated steam after exposure longer than 150 days. The section of specimens was examined by optical microscopy and the composition at the tips of cracking was analyzed by electron microprobe. The result shows that the combination of oxidation and hydriding induced cracking is responsible for this failure of the welding joints. [ABSTRACT FROM AUTHOR]

Hydrogen–disproportionation–desorption–recombination (HDDR) Nd–Fe–B magnetic powders are promising to prepare bulk anisotropic magnets, but high magnetic performance has not been achieved due to the absence of an Nd-rich phase in the powder and the low degree of orientation of the bulk magnets. In this study, an alternative process of pre-orientation sintering via magnetic alignment followed by spark plasma sintering was proposed to prepare the precursor of hot-deformation (HD) magnets, and a high maximum energy product of 294 kJ m−3 was achieved in the HD magnet with a relatively low height reduction of 35%, then an improved coercivity of 1107 kA m−1 could be obtained followed by a grain boundary diffusion of Pr40Tb30Al20Cu10. Microstructure analysis indicates that pre-orientation of HDDR powders facilitates grain rotation and alignment during the HD process, thereby reducing the minimum deformation ratio. It helps to obtain the deformed grains with lower shape anisotropy and smaller grain size, enabling a good compatibility of magnetic and mechanical behaviors. In-situ Lorentzian transmission electron microscopy results show that the magnetic domains have been strongly fixed by the thick intergranular RE-rich phase and the fully Tb-diffused grains, which contributes to the improved coercivity after grain boundary diffusion. This study provides a guiding significance for the preparation of the anisotropic Nd–Fe–B HDDR magnets with optimized performance. [ABSTRACT FROM AUTHOR]

Back extrusion is an important process to prepare radially oriented NdFeB ring magnets. In this work, we fabricate the ring magnets using amorphous magnetic powders as the raw material. The microstructure, magnetic properties, corrosion resistance, and mechanical properties of the backward extruded magnet at different positions along the axial direction have been investigated, and the inhomogeneity of the magnet is clarified. The results showed that the grains in the middle region of the ring magnet exhibit a strong c-axis orientation, whereas the grains at the bottom and top regions are disordered with random orientation. The microstructure variation is related to the distribution of the grain boundary phase and the degree of grain deformation. Due to the microstructure difference, the magnetic properties, temperature stability, corrosion resistance, and mechanical properties in the middle region of the magnet are higher than those in the top and bottom regions. The exchange coupling between grains also varies in different regions, which is related to the grain size and grain boundary thickness. In addition, different Co element segregations were observed in different regions, which has a crucial effect on the Curie temperature and thermal stability of the magnet. The microstructure difference also leads to the variation of corrosion resistance and mechanical properties for the samples from different regions of the magnet. This work suggests that the amorphous powder can be used to directly prepare radially oriented ring magnets, and the inhomogeneity of the magnet should be fully understood. [ABSTRACT FROM AUTHOR]

Grain boundary diffusion (GBD) is an effective process to enhance coercivity for Nd–Fe–B magnets with relatively low consumption of expensive heavy rare earths (HREs). For conventional GBD, the surface of the magnet is evenly covered by diffusion source, followed by diffusion heat treatment. In this work, a macroscopically heterogeneous GBD (MHGBD) process is proposed in order to further reduce the use of HRE resource. Based on the micromagnetic simulations, magnetically strengthening the edge area of the magnet is more effective than strengthening the center area in terms of coercivity enhancement for whole magnet. Hence, the HRE-based diffusion source was used for enhancing the edge area and the light rare-earth-based source was used for the center area. In details, Tb70Al20Cu10 and Pr70Al20Cu10 diffusion sources were covered at the edge and center areas of the two c-planes of a sintered Nd–Fe–B magnet, respectively. After the MHGBD by using Tb70Al20Cu10/Pr70Al20Cu10 (1:1, at.%), the magnet exhibits the increased coercivity from 1182 to 1911 kA/m. For comparison, the homogeneous diffusion of HRE-based Tb70Al20Cu10 source only enhances the coercivity to 1798 kA/m. The microstructure characterizations indicated that diffusion source of Tb70Al20Cu10 can form Tb-rich shells with high anisotropy field on the surface of Nd2Fe14B grains, and Pr70Al20Cu10 can provide more liquid grain boundary phase for GBD. The synergistic effect between these two sources improves the infiltration of Tb at the edge area of the magnet. Compared with the homogeneous Tb70Al20Cu10 diffusion, MHGBD process can not only exhibit higher diffusion efficiency, but also enhance the performance/cost ratio of the diffused magnets, evident by the increased coercivity enhancement per unit source from 0.23 to 0.51 kA m−1/($/kg). [ABSTRACT FROM AUTHOR]

BACKGROUND: Two-dimensional (2D) - shear wave elastography (SWE) has made promising advances in the diagnostic of breast lesions. However, few studies have assessed whether the diagnostic effectiveness of different platforms employing 2D-SWE is equal or different. OBJECTIVE: To compare the diagnostic effectiveness of 2D-SWE techniques from two different systems in differentiating malignant breast lesions from benign ones. METHODS: A total of 84 breast lesions were retrospectively analyzed by experienced radiologists using 2D-SWE on two ultrasound systems, i.e. system-1 (LOGIQ E9 system, GE Healthcare, Wauwatosa, WI, USA), and system-2 (Aixplorer US system, SuperSonic Imagine, Aix-en-Provence, France). Qualitative and quantitative parameters including color sign, the maximum elasticity modulus values (E-max), the mean elasticity modulus values (E-mean) and standard deviation (E-sd) of elasticity modulus values in two 2D-SWE systems were analyzed. The diagnostic performance between system-1 and system-2 were evaluated in terms of the areas under the receiver operating characteristic curves (AUROCs). RESULTS: Among the 84 lesions in this study, 66 (78.6%) were benign and 18 (21.4%) were malignant. E-max in system-1 showed the best diagnostic performance with a cut-off value of 174.5 kPa with the associated sensitivity and specificity of 100.0% and 80.3% respectively. Meanwhile, E-sd in system-2 displayed the best diagnostic performance with a cut-off value of 12.7 kPa, with the associated sensitivity and specificity of 94.4% and 80.3% respectively. The diagnostic performance of the two 2D-SWE systems was not statistically different according to receiver operating characteristic curve (ROC) analysis of E-max, E-mean, and E-sd. CONCLUSION: For identifying breast lesions, system-1 and system-2 appear to be similar in diagnostic performance. However, different cut-off values for different parameters might be selected to obtain the best diagnostic performance for the two 2D-SWE systems. [ABSTRACT FROM AUTHOR]

Unique among the known plant and animal viral suppressors of RNA silencing, the 2b protein interacts directly with both small interfering RNA (siRNA) and ARGONAUTE1 (AGO1) and AGO4 proteins and is targeted to the nucleolus. However, it is largely unknown which regions of the 111-residue 2b protein determine these biochemical properties and how they contribute to its diverse silencing suppressor activities. Here, we identified a functional nucleolar localization signal encoded within the 61–amino acid N-terminal double-stranded RNA (dsRNA) binding domain (dsRBD) that exhibited high affinity for short and long dsRNA. However, physical interaction of 2b with AGOs required an essential 33-residue region C-terminal to the dsRBD and was sufficient to inhibit the in vitro AGO1 Slicer activity independently of its dsRNA binding activities. Furthermore, the direct 2b–AGO interaction was not essential for the 2b suppression of posttranscriptional gene silencing (PTGS) and RNA-directed DNA methylation (RdDM) in vivo. Lastly, we found that the 2b–AGO interactions in vivo also required the nucleolar targeting of 2b and had the potential to redistribute both the 2b and AGO proteins in nucleus. These findings together suggest that 2b may suppress PTGS and RdDM in vivo by binding and sequestering siRNA and the long dsRNA precursor in a process that is facilitated by its interactions with AGOs in the nucleolus. [ABSTRACT FROM AUTHOR]

The mining of coal resources in eastern China has entered the stage of deep mining, and many mines have reached the depth of 1000 meters. Different from shallow and moderate depth mining, the temporal and spatial evolution regulation of surface movement and deformation under deep mining has its particularity. Combining with the geological and mining conditions of Fengfeng mining area, this paper systematically studies the characteristics of surface movement under the condition of shallow, moderate, and near kilometer mining depth. By means of field measurement, InSAR monitoring, we get the subsidence data under different mining depth and get the relevant subsidence parameters by inversion. Through comparative analysis, the special law of subsidence under the mining depth of 1000 meters is obtained. The results show that under the condition of nearly 1000 meters mining depth, the surface movement and deformation have the characteristics of large displacement angle, small displacement deformation value, and large main influence radius. The regulation of small proportion of active period of maximum subsidence point, gentle shape of surface movement basin, and low mining adequacy are obtained. The research results provide technical references for deep mining under buildings, railways, and water bodies and provide basis and reference for scientific mining and safe recovery of coal pillars in kilometer deep mine. [ABSTRACT FROM AUTHOR]

Axially chiral biaryl scaffolds are prevalent in natural products, chiral ligands, and organocatalysts. However, N‐heterocyclic carbene (NHC) catalyzed de novo construction of an aromatic ring with concomitant axial chirality induction for the synthesis of biaryl atropisomers is far less developed, and the efficient synthesis of axially chiral tetra‐ortho‐substituted biaryls remains an unsolved problem under NHC catalysis. Reported here is an NHC‐catalyzed de novo synthesis of axially chiral benzothiophene/benzofuran‐fused biaryls from enals and 2‐benzyl‐benzothiophene/benzofuran‐3‐carbaldehydes through a [2+4] annulation, decarboxylation, and oxidative aromatization cascade with central‐to‐axial chirality conversion. The developed method provides efficient and general access to novel axially chiral benzothiophene/benzofuran‐fused biaryls in high enantioselectivities and works well for the synthesis of tetra‐ortho‐substituted biaryls. [ABSTRACT FROM AUTHOR]

[Display omitted] • The FeSiBPC/Fe 3 O 4 @EP double-layer core-shell structure was successfully prepared. • The FeSiBPC AMPCs exhibited excellent magnetic performance with superior Q of 160. • The FeSiBPC AMPCs exhibited low P cv of 187 mW/cm3 at 100 kHz @0.05 T. • The thickness of the insulation coating is controlled by hydrothermal oxidation time. Fe-based amorphous magnetic powder cores (AMPCs) with excellent comprehensive properties were successfully fabricated via using the uniform double insulating layer core-shell structured FeSiBPC/Fe 3 O 4 @Epoxy resin (EP). The effects of the in-situ hydrothermal oxidized time on the magnetic properties of the AMPCs have been systematically investigated on the basis of the growth mechanism of the insulating layer of spherical amorphous powder in alkaline environment. The hydrothermal oxidation process could well ensure the uniformity of the oxide layer composed of Fe 3 O 4 nanoparticle. The evolution of the insulating layer is a process of homogeneous nucleation and growth at different hydrothermal oxidation time. After 10 h of hydrothermal oxidation, a thin and dense layer composed of Fe 3 O 4 nanoparticle was formed on the surface of the amorphous powder. As a consequent, the FeSiBPC AMPCs exhibit excellent performance such as stable effective permeability of 49.5 at 2 MHz, a very low core loss of 187 mW/cm3 at 100 kHz@0.05 T and high-quality factor of 160 at 600 kHz. The results indicate that the thickness of the Fe 3 O 4 insulating layer can be completely controlled via the reaction parameters, and can effectively suppress the eddy current loss, which is promising for high-frequency electromagnetic systems. [ABSTRACT FROM AUTHOR]

Semiactive hydraulic engine mounts (HEMs) offer better noise, vibration and harshness (NVH) performance in a wider frequency band than passive HEMs and provide acoustic and vibrational comfort for passenger cars that rivals that of active engine mounts (AEMs); these advantages lead to the wider use of HEMs than AEMs. In limited control modes, broadening the vibration isolation band as much as possible is the fundamental purpose of semiactive HEMs. This paper focuses on an analytical and experimental study of a unique semiactive HEM with four-chamber and three-fluid-channel whose lengths shorten successively while the cross-sectional areas increase successively. The semiactive HEM presents dynamic characteristics in a two-step style and thus can offer good NVH performance in a relatively wider band. The first step is induced by the resonance of the longest fluid channel, and the second step is induced by the resonance of the shortest fluid channel corresponding to a separate decoupling membrane (DM) fluid chamber. The relationship of bulk stiffness between the DM and the main rubber spring is switched from an in-series connection for the first step to an in-parallel connection for the second step, which is an intrinsic reason for effectively widening the vibration isolation band. To better clarify the two-step dynamics, the influence of the DM is further investigated by introducing frequency-dependent bulk stiffness in-series and in-parallel. Moreover, two additional HEMs and their experimental two-step dynamics are illustrated to validate the frequency-dependent bulk stiffness. The ideal control strategies for semiactive HEMs with four-chamber and three-fluid-channel are developed and numerically verified by minimizing the force transmissibility in a wider frequency band. The findings of this paper can facilitate the design of dynamics for HEMs with a DM. Proper matching and relationship switching of the bulk stiffness between the DM and the main rubber spring can effectively improve NVH performance for passenger cars. [ABSTRACT FROM AUTHOR]

In this work, dense and pinhole-free poly-para-xylylene (PPX) with high thermal stability, high insulating property and high lubricity has been designed as coating layer for Fe-based amorphous powder. Three ultra-thin PPX layers have been successfully deposited on the surface of FeSiBPNbCr amorphous powder via chemical vapor deposition (CVD) polymerization. The micromorphology and chemical structure of the PPX layer on the powder surface, as well as the conversion mechanisms, has been investigated systematically. Several methods have been used to estimate the amount and thickness of PPX layers. The corresponding amorphous powder cores (AMPCs) were also prepared. With the increasing thickness of the PPX layer, the saturation magnetization (M s) of the powder decreased slightly but the magnetic flux density (B s) of the AMPCs kept at a similar level thanked to the enhanced green density. In addition, the DC bias performance was improved and core loss (P cv) was reduced. Compare with other coating materials like epoxy and silicon resin, the PPX layer provided better insulation and higher lubricity for the AMPCs, thus reduced the P cv and improved the DC bias performance. The AMPCs coated by PPX-3 exhibited excellent comprehensive soft magnetic properties, which were promising for high-power and high-frequency applications. Unlabelled Image • Poly-para-xylylene has first designed as coating layer for amorphous powder cores. • Three layer thickness has been designed and estimated by several methods. • APTES can enhance binding force between coating layer and powder. • The powder cores show high DC bias performance (54.3%) and low P cv (770 mW/cm3). [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) depletion and low ROS production that result from the intratumoral redox metabolism equilibrium and low energy conversion efficiency from ultrasound mechanical energy to ROS‐represented chemical energy, respectively, are two vital inhibitory factors of sonodynamic therapy (SDT). To address the two concerns, a tumor metabolism‐engineered composite nanoplatform capable of intervening intratumoral ROS metabolism, breaking the redox equilibrium, and reshaping the tumor microenvironment is constructed to reinforce SDT against tumors. In this metabolism‐engineered nanoplatform, Nb2C nanosheets serve as the scaffold to accommodate TiO2 sonosensitizers and l‐buthionine‐sulfoximine. Systematic experiments show that such nanoplatforms can reduce ROS depletion via suppressing glutathione synthesis and simultaneously improving ROS production via the Nb2C‐enhanced production and separation of electron–hole pairs. Contributed by the combined effect, net ROS content can be significantly elevated, which results in the highly efficient anti‐tumor outcomes in vivo and in vitro. Moreover, the combined design principles, that is, tumor metabolism modulation for reducing ROS depletion and electron–hole pair separation for facilitating ROS production, can be extended to other ROS‐dependent therapeutic systems. [ABSTRACT FROM AUTHOR]

The grain boundary diffusion using mixed rare earths (REs) as the diffusion source is very effective in enhancing the coercivity of Nd-Fe-B magnets. Here, we firstly investigated the Gd added Tb-Cu diffusion alloys and found that the coercivity of Nd-Fe-B magnets can be improved from 1094 kA/m to 1704, 1677 and 1593 kA/m by Tb 70 Cu 30 , Tb 60 Gd 10 Cu 30 and Tb 50 Gd 20 Cu 30 diffusion, respectively. The material cost of diffusion source in grain boundary diffusion process can be reduced from 1091 $/kg of Tb 70 Cu 30 to 788 $/kg of Tb 50 Gd 20 Cu 30. Binary Gd-Cu alloy source has no positive effect on the coercivity enhancement. The enhanced thermal stability with increased temperature coefficient of coercivity from −0.62 %/°C for the initial magnet to −0.55 %/°C and −0.56 %/°C is also obtained by Tb 70 Cu 30 and Tb 50 Gd 20 Cu 30 diffusion, respectively. Tb exhibits a higher diffusion coefficient than Gd, but the introduction of Gd decreases the melting point of Tb-Cu alloy and promotes the infiltration of Tb. The typically core-shell structure with Tb-rich shell is observed after diffusion, which enhances the coercivity. The effects of RE elements in the Tb-RE-Cu diffusion source on the diffusion behavior of Tb has also been discussed. Y and Gd elements tend to enter into RE 2 Fe 14 B grain, resulting in the reduction of thickness for the Tb-rich shell, but Pr, La and Ce elements prefer to stay in the grain boundaries, which provides the diffusion channel for Tb, leading to the increased diffusion depth. This work provides a design idea for the RE-based diffusion sources of Nd-Fe-B magnets. [Display omitted] • Magnetic properties of Nd-Fe-B magnets after Tb-Gd-Cu diffusion were investigated. • The thermal stability of Nd-Fe-B magnets can be enhanced by Tb-Gd-Cu diffusion. • The formation of typically Tb-rich shell leads to the enhancement of coercivity. • Effects of various RE elements on the diffusion behavior of Tb-RE-Cu are discussed. [ABSTRACT FROM AUTHOR]

Frequency-Domain Blind Source Separation (FD-BSS) is an efficient way to analyze convolutive mixed speech. To improve the quality of the separated speech, a permutation algorithm based on Dynamic Time Warping (DTW) is proposed in this paper. Because signals in adjacent frequency bins have high similarity, DTW technology is used to compare them and generate adjustment matrices to solve the permutation ambiguity. Our approach is evaluated through simulated and practical experiments. Using Signal to Distortion Ratio (SDR), Signal to Interference Ratio (SIR), Signal to Artifacts Ratio (SAR), and Perceptual Estimation of the Speech Quality (PESQ) for measurements. To examine the quality of the separated speech in a practical acoustic environment, we adopt the accuracy ratio of Automatic Speech Recognition (ASR). In the experiments, we compare our approach with other classical permutation criteria such as K-L divergence distance, envelope correlation and higher-order statistics. The experimental results show that the proposed algorithm performs permutation alignment more accurately and improves the acoustic quality of separation. [ABSTRACT FROM AUTHOR]

As one of the important structural materials in nuclear industry, the corrosion resistance of zirconium alloy limits their in-pile application. Therefore, it is necessary to investigate the corrosion mechanism of zirconium alloys. The zirconium-oxygen reaction at the O/M interface is one of the factors that affect the oxidation process. There are few reports in this regard. Ideally, the reaction process at the O/M interface has certain relevance with the initiation oxidation of zirconium, which provided a new way to investigate the reaction process by observing the initiation oxidation behaviours. To investigate the oxidation behaviours of zirconium alloy at the initial stage, in this paper, zircaloy-4 TEM thin foil specimens in 3 mm diameter were studied by TEM observation after heating in air condition with a vacuum of 3 Pa at 280 °C, 290 °C and 300 °C for 30 min exposures. The results show that, ZrO 2 begin to nucleate at a size of 3–5 nm at a high Zr/O ratio of 10.4 and oxide layer formed while Zr/O was 4.6. As a result of stress caused by the P.B ratio of Zr, slip bands formed and a bcc structure sub-oxide b-ZrOx (a = 0.51 nm) grew up along with the slip bands was observed. At both sides of b-ZrOx, two hcp structure sub-oxides having the same a -axis lattice parameter and different c -axis lattice parameter were detected. [ABSTRACT FROM AUTHOR]

Hot pressed and hot deformed nanocrystalline Nd-Ce-Fe-B magnets were prepared by dual-alloy method using melt-spun Nd-Fe-B and Ce-Fe-B powders with various weight ratios. For both hot pressed and hot deformed magnets, increasing Ce-Fe-B addition reduces the magnetic properties, but 10 wt. % Ce-Fe-B leads to an abnormal increase of coercivity. As a result, the remanence J r = 1.21 T, intrinsic coercivity H cj = 1215 kA/m, and maximum energy product (BH) max = 266 kJ/m3 are obtained for the magnets with 10 wt. % Ce-Fe-B. To modify their properties, the dual-main phase magnets are treated by grain boundary diffusion of Nd 50 Tb 20 Cu 30 alloy. The coercivity of the deformed magnet with 10 wt. % Ce-Fe-B addition increased from 1215 kA/m to 1402 kA/m after diffusion, which is comparable to that of the as-diffused Nd-Fe-B magnets (1495 kA/m). For the magnet with 30 wt. % Ce-Fe-B addition, a 50% increase of coercivity, about 376 kA/m, was obtained by diffusion. The microstructure characterizations demonstrated that the modification of grain boundary phase by the elimination of RE 5 Fe 17 phase and the formation more significant core-shell structure of the Nd-rich hard magnetic 2:14:1 phase by Tb diffusion are responsible for the improved coercivity. • Coercivity abnormal increased by adding 10 wt% Ce-Fe-B in Nd-Ce-Fe-B magnet. • For diffusion, the Nd-Ce core-shell structure of Nd-rich main phase was found. • Tb tends to form (Nd,Ce)-Tb core-shell structure, further enhancing the coercivity. [ABSTRACT FROM AUTHOR]

Grain boundary diffusion of heavy rare earth-based alloys can effectively enhance the coercivity of Nd-Fe-B magnets. Although the light rare earth elements can further improve the diffusion efficiency of Dy and Tb, they generally lead to reduced anti-corrosion properties of the magnets. Here, we successfully enhanced the coercivity and corrosion resistance of Nd-Fe-B magnets by GBD of Ni alloyed Pr-Tb-Cu diffusion source. The ternary Pr 35 Tb 35 Cu 30 alloy diffusion increased the coercivity of Nd-Fe-B magnet from 1330 to 1923 kA/m, but the coercivity was enhanced to 1990 kA/m by Pr 35 Tb 35 Ni 15 Cu 15 alloy diffusion. The formation of high-anisotropy (Nd,Tb) 2 Fe 14 B phase is the main reason for the coercivity improvement. Partially substitution of Cu by Ni can reduce the melting point of Pr 35 Tb 35 Cu 30 alloy, which is effective in promoting the infiltration of Tb. Cu is also a necessary element for improving the diffusion process, and the diffusion of Pr 35 Tb 35 Ni 30 alloy only increased the coercivity to 1747 kA/m. More interestingly, the diffusion of Pr 35 Tb 35 Ni 15 Cu 15 also enhanced the chemical stability of the magnet in NaCl solution. Scanning Kelvin probe force microscopy characterized that the modified GB phase in Pr 35 Tb 35 Ni 15 Cu 15 treated magnet exhibits a higher Volta potential than the 2:14:1 main phase, which is the main reason for the improved corrosion resistance. The present results suggest that the non-rare earth elements in the alloy diffusion sources play important roles in enhancing both coercivity and corrosion resistance of Nd-Fe-B magnets. • Both coercivity and corrosion resistance of Nd-Fe-B magnet are distinctly enhanced. • Ni alloying lowers melting point of Pr-Tb-Cu and deepens the infiltration of Tb. • Ni alloying results in higher potential of grain boundary than that of 2:14:1 phase. • Scanning Kelvin probe force microscopy was used to measure local potential. [ABSTRACT FROM AUTHOR]

Abstract: The feasibility of applying the grain boundary engineering (GBE) processing to Alloy 690 tube manufacturing for improving the intergranular corrosion resistance was studied. Through small amount of deformation by cold drawing using a draw-bench on a production line and subsequent short time annealing at high temperature, the proportion of low Σ coincidence site lattice (CSL) grain boundaries of the Alloy 690 tube can be enhanced to about 75% which mainly were of Σ3 n (n =1, 2, 3, …) type. In this case, the grain boundary network (GBN) was featured by the formation of highly twinned large size grain-clusters produced by multiple twinning during recrystallization. All of the grains inside this kind of cluster had Σ3 n mutual misorientations, and hence all the boundaries inside the cluster were of Σ3 n type and formed many interconnected Σ3 n type triple junctions. The weight losses due to grain dropping during intergranular corrosion for the samples with the modified GBN were much less than that with conventional microstructure. Based on the characterization by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) technique, it was shown that the highly twinned large size grain-cluster microstructure played a key role in enhancing the intergranular corrosion resistance: (1) the large grain-cluster can arrest the penetration of intergranular corrosion; (2) the large grain-cluster can protect the underlying microstructure. [Copyright &y& Elsevier]

As nuclear fuel cladding, Zr alloys have need for a good corrosion resistance. For decades, several generations of Zr alloys with excellent corrosion resistance have been developed through adjusting content of Sn and Nb. However, the mechanism of Sn and Nb influencing the corrosion resistance is still not clear. Here, our computational simulations indicate, Sn or Nb can segregate at grain boundary (GB) of surface oxide film which results in variation of GB cohesion and influences the corrosion resistance. Using the first-principles method, we find that Sn segregation reduce GB cohesion and decrease oxide film protectiveness; In contrast, Nb segregation enhance GB cohesion and improve oxide film protectiveness. The results are well consistent with the previous experiments that reducing Sn or adding Nb can promote corrosion resistance of Zr alloys. These findings provide a basis for understanding the roles of alloying elements in the corrosion resistance of Zr alloys, which is useful to future design of new Zr alloys. [Display omitted] [ABSTRACT FROM AUTHOR]

Axially chiral diaryl ethers are present in numerous natural products and bioactive molecules. However, only few catalytic enantioselective approaches have been established to access diaryl ether atropisomers. Herein, we report the N-heterocyclic carbene-catalyzed enantioselective synthesis of axially chiral diaryl ethers via desymmetrization of prochiral 2-aryloxyisophthalaldehydes with aliphatic alcohols, phenol derivatives, and heteroaromatic amines. This reaction features mild reaction conditions, good functional group tolerance, broad substrate scope and excellent enantioselectivity. The utility of this methodology is illustrated by late-stage functionalization, gram-scale synthesis, and diverse enantioretentive transformations. Control experiments and DFT calculations support the association of NHC-catalyzed desymmetrization with following kinetic resolution to enhance the enantioselectivity., (© 2023 Wiley-VCH GmbH.)

The magnetic properties of magnetic nanocomposites consisting of hard and soft magnetic phases are dependent not only on the intrinsic properties but also on the grain structure and volume ratio of the two phases. In this study, we performed a systematic micromagnetic simulation on the magnetic properties of Ce 2 Fe 14 B/α-Fe and Nd 2 Fe 14 B/α-Fe nanocomposites. The volume fractions of the hard magnetic Nd 2 Fe 14 B or Ce 2 Fe 14 B phase were varied from 80% to 40%, and the grain sizes of the hard magnetic phase and the soft magnetic α-Fe phase were changed independently from 10 nm to 40 nm. The results show that when the grain size of both hard and soft phases is 10 nm and the volume fraction of the hard phase is 70%, the highest maximum magnetic energy product can be obtained in both Ce 2 Fe 14 B/α-Fe and Nd 2 Fe 14 B/α-Fe nanocomposites. The hard magnetic properties of Ce 2 Fe 14 B/α-Fe nanocomposite decrease significantly when the volume fraction of the α-Fe phase exceeds 30%. However, for the Nd 2 Fe 14 B/α-Fe system, this situation only occurs when the α-Fe volume fraction exceeds 40%. The reason for this is not only because of the low anisotropic field and the smaller exchange coupling length between the soft and hard magnetic phases, but also because of the lower saturation magnetization of the hard phase. The grain size has greater effects on the magnetic properties compared to the volume fraction of the hard magnetic phase. The main reason is that as the grain size increases, the remanence of the nanocomposite decreases sharply, which also leads to a rapid decrease in the maximum magnetic energy product. The simulation results on the effects of phase ratio and grain size have been verified by experiments on melt-spun Ce 2 Fe 14 B/α-Fe alloys with various compositions prepared by melt-spinning followed by annealing for various lengths of time. Due to the influence of demagnetization energy, the hard magnetic phase with high saturation magnetization is preferred for the preparation of high-performance nanocomposite magnets.

Direct synthesis of ketones from aldehydes features high atom- and step-economy. Yet, the coupling of aldehydes with unactivated alkyl C(sp 3 )-H remains challenging. Herein, we develop the synthesis of ketones from aldehydes via alkyl C(sp 3 )-H functionalization under photoredox cooperative NHC/Pd catalysis. The two-component reaction of iodomethylsilyl alkyl ether with aldehydes gave a variety of β-, γ- and δ-silyloxylketones via 1,n-HAT (n = 5, 6, 7) of silylmethyl radicals to generate secondary or tertiary alkyl radicals and following coupling with ketyl radicals from aldehydes under photoredox NHC catalysis. The three-component reaction with the addition of styrenes gave the corresponding ε-hydroxylketones via the generation of benzylic radicals by the addition of alkyl radicals to styrenes and following coupling with ketyl radicals. This work demonstrates the generation of ketyl radical and alkyl radical under the photoredox cooperative NHC/Pd catalysis, and provides two and three component reactions for the synthesis of ketones from aldehydes with alkyl C(sp 3 )-H functionalization. The synthetic potential of this protocol was also further illustrated by the late-stage functionalization of natural products., (© 2023. The Author(s).)

To inhibit the magnetic dilution effect of Ce in Nd-Ce-Fe-B magnets, a dual-alloy method is employed to prepare hot-deformed dual-main-phase (DMP) magnets using mixed nanocrystalline Nd-Fe-B and Ce-Fe-B powders. A REFe 2 (1 : 2, where RE is a rare earth element) phase can only be detected when the Ce-Fe-B content exceeds 30 wt%. The lattice parameters of the RE 2 Fe 14 B (2 : 14 : 1) phase exhibit non-linear variation with the increasing Ce-Fe-B content due to the mixed valence states of Ce ions. Owning to inferior intrinsic properties of Ce 2 Fe 14 B compared to Nd 2 Fe 14 B, the magnetic properties of DMP Nd-Ce-Fe-B magnets almost decrease with the increase of Ce-Fe-B addition, but interestingly, the magnet with 10 wt% Ce-Fe-B addition exhibits an abnormally increased intrinsic coercivity H cj of 1215 kA m -1 , together with the higher temperature coefficients of remanence ( α = -0.110%/K) and coercivity ( β = -0.544%/K) in the temperature range of 300-400 K than the single-main-phase (SMP) Nd-Fe-B magnet with H cj = 1158 kA m -1 , α = -0.117%/K and β = -0.570%/K. The reason may be partly attributed to the increase of Ce 3+ ions. Different from the Nd-Fe-B powders, the Ce-Fe-B powders in the magnet are difficult to deform into a platelet-like shape because of the lack of low melting point RE-rich phase due to the precipitation of the 1 : 2 phase. The inter-diffusion behavior between the Nd-rich region and Ce-rich region in the DMP magnets has been investigated by microstructure analysis. The significant diffusion of Nd and Ce into Ce-rich and Nd-rich grain boundary phases, respectively, was demonstrated. At the same time, Ce prefers to stay in the surface layer of Nd-based 2 : 14 : 1 grains, but less Nd diffuses into Ce-based 2 : 14 : 1 grains due to the 1 : 2 phase presented in the Ce-rich region. The modification of the Ce-rich grain boundary phase by Nd diffusion and the distribution of Nd in the Ce-rich 2 : 14 : 1 phase are beneficial for magnetic properties., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Viscosity and sulfur dioxide levels are important factors to evaluate the changes of cell micro-environment because a series of diseases usually occur when they are abnormal. At present, dual-response probes that can detect both viscosity and sulfur dioxide are rare. Therefore, we developed a novel fluorescent probe CBN for simultaneous detection of sulfur dioxide and viscosity. Besides, probe CBN could target lysosome of which normal function will be disrupted by the abnormality of viscosity. Therefore, probe CBN has the potential to be served as an effective biological tool to monitor the intracellular micro-environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Anaerobic ammonium oxidation (ANAMMOX) is widely used for treatment of ammonium-rich wastewater because of its economic and environmental benefits. However, ANAMMOX bacteria are sensitive to environmental conditions, especially to heavy metals. The short-term and long-term effects of Ni(Ⅱ) on ANAMMOX were studied by batch and continuous flow experiments, respectively. Results showed that low concentrations of Ni(Ⅱ) had promoted nitrogen removal by ANAMMOX and high concentrations inhibited ANAMMOX performance during a short-term period. Compared with the specific anaerobic ammonium oxidation activity (SAA) without Ni(Ⅱ) addition, SAA with 1 mg·L -1 Ni(Ⅱ) addition increased by 11.14% and the SAA with 100 mg·L -1 Ni(Ⅱ) addition reduced by 49.55%. The IC 50 of Ni(Ⅱ) for ANAMMOX was determined to be 83.86 mg·L -1 . In contrast, long-term Ni(Ⅱ) addition significantly suppressed nitrogen removal of ANAMMOX, and the suppression threshold of Ni(Ⅱ) on ANAMMOX was 15 mg·L -1 . The Monod model was applied to simulate the kinetics of ANAMMOX without Ni(Ⅱ) addition. The q max0 (TN/VSS) and K S0 values were 12.25 mg·(g·h) -1 and 405.36 mg·L -1 , respectively. The modified Haldane model was suitable to describe the kinetics of ANAMMOX with 50 mg·L -1 Ni(Ⅱ) addition. The q max (TN/VSS), K S , and K i values were 6.78 mg·(g·h) -1 , 313.2 mg·L -1 , and 1.32, respectively. The inhibition of ANAMMOX by Ni(Ⅱ) is anticompetitive inhibition. In addition, the inhibition of Ni(Ⅱ) on ANAMMOX was mainly related to the content of intracellular Ni(Ⅱ). The IC 50intracellular Ni(Ⅱ) (VSS) of intracellular Ni(Ⅱ) was 0.072 mg·g -1 .

In order to evaluate the sIgA-ELISA method reported previously for differentiating Mycoplasma hyopneumoniae (M. hyopneumoniae) infected from vaccinated pigs, dynamics of anti-M. hyopneumoniae secretory IgA (sIgA) antibody secretion in nasal mucus and IgG antibodies in serum from 10 pigs experimentally infected with M. hyopneumoniae or vaccinated with an inactivated vaccine were examined using sIgA-ELISA and a commercial M. hyopneumoniae antibody detection kit (IgG-ELISA), respectively. In addition, nasal swabs and serum samples from 2368 pigs of different ages originating from 10 pig farms with different M. hyopneumoniae infection and vaccination status were examined using the two ELISA. In the experimental model, anti-M. hyopneumoniae IgG antibodies were detected in both, the challenge group and the vaccine group. Anti-M. hyopneumoniae sIgA antibodies were detected in the challenge group from 7 days post challenge onwards, but not in the vaccine group. According to the data obtained from pig farms maintaining administration of inactivated vaccine, the prevalence of anti-M. hyopneumoniae sIgA antibody positive pigs was significantly lower than that of IgG antibody positive pigs. In non-vaccinating herds, the prevalence of sIgA antibodies was correlated with the severity of clinical symptoms typical for porcine enzootic pneumonia. In all suckling pigs, no matter vaccinated or not, the prevalence of anti-M. hyopneumoniae sIgA antibody positives was significantly lower than that of IgG antibody positives. These results prove that the sIgA-ELISA is a valuable method enabling the surveillance of M. hyopneumoniae infections in pig herds without interference due to maternally derived antibodies or antibodies induced by administration of inactivated vaccines., (Copyright © 2018 Elsevier B.V. All rights reserved.)

To establish a method for determining the contents of six alkaloids (jatrorrhizine hydrochloride, columbamine hydrochloride, epiberberine hydrochloride, coptisine hydrochloride, palmatine hydrochloride, berberine hydrochloride) in six types of Coptidis Rhizoma pieces (crude pieces, ginger juice stir-fried pieces, vinegar stir-fried pieces, wine steamed pieces, wine stir-fried pieces, evodiae juice stir-fried pieces) by RP-HPLC, and explore the relationship with the curative effect of traditional Chinese medicine (TCM) and pharmacodynamics results. The chromatographic column was Welch XtimateTM C₁₈ (4.6 mm×250 mm, 5 μm), with 0.1% triethylamine solution (adjust pH at 10 with ammonium bicarbonate and ammonia) as mobile phase A and acetonitrile as mobile phase B for gradient elution (0-15 min, 10%-25%B; 15-25 min, 25%-30%B; 25-40 min, 30%-45%B) at a rate of 1.0 mL•min⁻¹. The column temperature was set at 30 ℃, and the wavelength was set at 270 nm. The six alkaloids showed a good linear relationship within the range of 0.85-16.96 mg•L⁻¹ (r=0.999 7), 1.25-24.96 mg•L⁻¹ (r=0.999 9), 2.05-40.96 mg•L⁻¹ (r=0.999 9), 3.65-72.96 mg•L⁻¹ (r=0.999 9), 2.88-57.60 mg•L⁻¹ (r=0.999 8), and 13.25-264.96 mg•L⁻¹ (r=0.999 6) respectively. The average recoveries (n=9) of the six alkaloids were 102.4% (RSD 1.2%), 101.8% (RSD 1.3%), 100.3% (RSD 1.8%), 100.7%(RSD 1.8%), 101.2% (RSD 1.5%) and 97.90% (RSD 2.0%) respectively, and their average contents were 3.55, 4.49, 9.12, 19.17, 15.69, 62.56 mg•g⁻¹, respectively. This determination method was accurate and repeatable, which could be used for the content determination in six types of Coptidis Rhizoma pieces. Data analysis on contents determination and preliminary pharmacodynamics results was conducted by using principal component analysis (PCA) and hierarchical clustering analysis (HCA). The analysis results showed that three types of Coptidis Rhizoma pieces (wine steamed pieces, wine stir-fried pieces, and evodiae juice stir-fried pieces) had significant differences with crude pieces, and the wine steamed Coptidis Rhizoma pieces showed most difference with crude pieces especially, mainly related to triglyceride (TG) and fasting blood glucose levels (FBG) in serum. In addition, columbamine hydrochloride was most affected among the six alkaloids. Those three types of Coptidis Rhizoma pieces (wine steamed pieces, wine stir-fried pieces, and evodiae juice stir-fried pieces), had more advantages for "anti-diabetes" in TCM clinical application, especially in the treatment of diabetic hyperlipidemia., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Background: It is controversial whether chromophobe renal cell carcinoma (chRCC) or clear cell renal cell carcinoma (ccRCC) is associated with better survival. We conducted a clinical-based cohort study and meta-analysis to evaluate the prognostic role of histology between chRCC and ccRCC., Methods: A cohort of 1540 patients (166 with chRCC and 1374 with ccRCC) were selected from Sun Yat-sen University and The Cancer Genome Atlas databases. The clinicopathological parameters and overall survival (OS) were compared between patients with chRCC and those with ccRCC. For the meta-analysis, we searched the PubMed, Cochrane Library, and Ovid databases for studies comparing OS or cancer-specific survival (CSS) between chRCC and ccRCC., Results: The cohort study revealed that patients with chRCC were younger (median 52 vs. 55 years, P < 0.001), were more commonly female (47.0 vs. 33.0%, P < 0.001), and had a larger tumor size (mean 7.1 vs. 5.9 cm, P < 0.001), and they had a lower stage compared with those with ccRCC. Five-year OS rates for chRCC and ccRCC were 90.3 and 75.3%, respectively (P < 0.001). We found significantly better survival for chRCC in stratification analysis by age, sex, tumor size, and stage. Similar results were observed on both univariate [hazard ratio (HR), 0.30; 95% confidence interval (CI) 0.16-0.55, P < 0.001] and multivariate analyses (HR 0.42; 95% CI 0.23-0.79, P = 0.006). Ten studies were included in our meta-analysis. Eight of them provided data on univariate analysis. The pooled HR was statistically significant for OS (pooled HR 0.49; 95% CI 0.30-0.79, P = 0.004) and CSS (pooled HR 0.49; 95% CI 0.37-0.64, P < 0.001). Seven studies reported the HR on multivariate analysis. The pooled HR was also statistically significant for OS (pooled HR 0.63; 95% CI 0.51-0.77, P < 0.001) and CSS (pooled HR 0.72; 95 % CI 0.57-0.90, P = 0.003). These data indicate that patients with chRCC had better outcomes than those with ccRCC., Conclusions: Our large cohort study and meta-analysis confirmed that chRCC had better survival than ccRCC.

Objective: To explore natural herbs to maintain the bactericidal activity of hydrogen peroxide (H)., Methods: Eighteen extracts of Chinese herbs were prepared complying with the standard protocol. Each of the solutions was then mixed with 1% H2O2. The mixtures were handled with two approaches: autoclaved daily for one, two or three times; stored at room temperature from one through five years. Then the bactericidal activity were evaluated by assaying the minimal bactericidal concentration (MBC) and minimal inhibitory concentration (MIC) against Gram positive (Staphylococcus aureus, ATCC25923) and Gram negative (Escherichia coli, ATCC12421) bacteria., Results: While mixed with 1% H2O2, 10 out of 18 kinds of assessed Chinese herbs displayed MBC values at 1:12800 or higher after three times of autoclaving, and 8 of them preserved such level of MBC value after stored at room temperature for three years. Some Chinese herbs, i.e. R. Scutellariae, R. Coptidis, R. Bupleuri, H. Epimedii, C. Phelledendri and F. Chrysanthemi, can significantly maintain the bactericidal activity of diluted H2O2., Conclusions: Certain Chinese herbs can effectively stabilize the bactericidal activity of H2O2 undergoing autoclave or long-term storage. This paper reported a brandnew pharmaceutical function of Chinese herbs and provided experimental data for the potential enhancement of H2O2 usage while its stability level is promoted.