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This study used high-temperature melting experiments, optical microscopy, and scanning electron microscopy to investigate the effects of various Ce contents (0 wt.%~0.0165 wt.%) on the microstructure and TiN precipitation behavior in high-titanium steel during slow cooling solidification. The findings show that the microstructure of the solidified steel in each experiment are equiaxed grains at a cooling rate of 0.17 ℃/s. TiN mainly precipitates in the Liquid + δ two-phase region in this experimental steel. CeAlO3 and Ce2O2S precipitate before TiN, and their small lattice misfit with TiN (7.55% and 7.90%, respectively) are the primary cause of their propensity to act as the cores of TiN heterogeneous nucleation. The TiN area density in each experimental steel increases from 38.6 no./mm2 → 61.4 no./mm2 → 89.3 no./mm2 → 105.8 no./mm2 when the Ce content in the steel rises from 0 wt.% → 0.0015 wt.% → 0.0058 wt.% → 0.0165 wt.%. [ABSTRACT FROM AUTHOR]

The corrosion resistance and pitting corrosion behavior of free-cutting austenitic stainless steels with different contents of sulfur were systematically studied by electrochemical workstation and scanning electron microscope. As the content of sulfur in the steel decreased from 0.270 to 0.089%, the corrosion rate decreased from 10.55 to 2.83 μm/a. The morphologies of manganese sulfide inclusions in the 0.089% S-containing steel were short rod-shaped and globular. The morphologies of manganese sulfide inclusions in the 0.270% S-containing steel were cluster-shaped, long strip-shaped and globular. Various-morphology manganese sulfide inclusions could lead to different degrees of damage to the metal matrix during the process of the pitting corrosion. The order of damage degree from the most to the less was cluster-shaped > long strip-shaped > short rod-shaped. [ABSTRACT FROM AUTHOR]

Objective To observe the clinical effect of Sancai combined acupuncture on discogenic sciatica. Methods 162 patients with discogenic sciatica admitted to the Department of Rehabilitation Medicine of our hospital from February 2021 to December 2022 were randomly divided into control group, conventional acupuncture group and Sancai acupuncture group. The control group was treated with non-steroidal anti-inflammatory drugs for oral analgesia, the conventional acupuncture group was treated with conventional acupuncture, and the Sancai acupuncture group was treated with combined acupuncture based on Sancai theory, that is, the traditional scalp acupuncture combined with Shanyuan's new scalp acupuncture was used in the sky, the fire needle was used in the ground to rob the root point, and the human body was treated with the movement acupuncture after the press needle was buried. All three groups were intervened for 4 weeks. The pain visual analogue score (VAS) and Oswestry dysfunction index (ODI) were evaluated before, 4 weeks after and 2 and 4 weeks after the intervention in the three groups, and the levels of serum substance P (SP), chemokine ligand 10 (CXCL10), calcitonin related gene peptide (CGRP) were collected before and after the intervention, and the motor conduction velocity (MCV) and sensory conduction velocity (SCV) of the sural nerve were measured. Results There was an interaction between treatment method and time on VAS and ODI (P < 0.05), and the main effect of treatment method and time on VAS and ODI was significant (P < 0.05 ). The VAS and ODI results of the three groups at 4 weeks, - weeks and 4 weeks after treatment were better than those before treatment, and the difference was statistically significant (P < 0.05). The VAS score and ODI score of Sancai acupuncture group at the end of - and 4 weeks of treatment were lower than those of the other two groups, with significant difference (P < 0.05) ; However, after 4 weeks of treatment, the levels of SP, CXCL10 and CGRP in the three groups were lower than those before treatment, and the levels of MCV and SCV were higher than those before treatment, except for CXCL10, MCV and SCV in the control group (P < 0.05). In comparison between groups, the levels of CXCL10 and CGRP in Sancai acupuncture group were lower than those in the other two groups (P < 0.05 ), lower in SP Sancai acupuncture group than those in the control group (P < 0.05), and there was no difference between the two groups (P > 0.05). In MCV and SCV, Sancai acupuncture group was higher than those in the other two groups (P < 0.05 ). Conclusion Sancai combined acupuncture can effectively intervene the pain and dysfunction of patients, improve many laboratory indicators, and increase nerve conduction velocity, which is worthy of further study. [ABSTRACT FROM AUTHOR]

In order to prevent premature failure of high nickel ductile iron used for engine exhaust manifold due to thermal fatigue, the precipitation morphology, nucleation and growth mechanism of graphite particles in high-nickel ductile iron were systematically studied by optical and SEM microscopy and the growth kinetic equation of graphite particles was derived. The results show that the precipitation density and average size of graphite particles within the austenite grain of high-nickel ductile iron are 44.1 particles/mm2 and 2.2 µm, respectively, and the precipitation density and average size of graphite particles on the austenite grain boundaries are increased to 76.6 particles/mm2 and 17 µm, respectively. The main nucleation mechanism of graphite particles in high nickel austenitic ductile iron is grain boundary nucleation. The maximum nucleation rate temperature of graphite particles nucleated on grain boundary is 650–850 °C, the fastest precipitation temperature is close to 680 °C, and the time from the beginning to the end of the growth of graphite particles nucleated by grain boundary is about 3400 s. The average size of graphite particles precipitated by grain boundary nucleation can grow to grade 7 (15–30 µm) under the high temperature of 715–805 °C for a long time (over 3400 s), which is beneficial to the thermal fatigue property of high nickel ductile iron. The local temperature at manifold should not be higher than 800 °C under long times. [ABSTRACT FROM AUTHOR]

The dynamic recrystallization behavior and texture evolution of surface, quarter and center layers of as-cast Fe-4.53%Si non-oriented electrical steel during hot compression were studied by optical microscope and electron backscatter diffraction. The surface layer of cast ingot exhibited elongated columnar grains with pronounced {001}<130> and {001}<120> textures, while the quarter and center layers of ingot were mainly large equiaxed grains corresponding to strong {100}<0vw> texture. During hot compression, the shear bands were easy to form in the deformed grains with higher stored energy such as {110}<001>, {014}<114> and {312}<332> grains which is conducive to promoting recrystallization. Due to that the shear band was not easy to form in the {100}<0vw> grain with lower stored energy, the large grains corresponding to strong {100}<0vw> texture in the quarter and center layers of ingot undergone obvious deformation and slight orientation transformation during hot compression process which proved the good heritability of as-cast {100} texture. [ABSTRACT FROM AUTHOR]

The electric field distribution of Ag nanoparticles under femtosecond laser is simulated by solving Maxwell equations in this article. The results show that with the same laser energy, the coupling electric field between adjacent nanoparticles becomes stronger and stronger as the spacing between nanoparticles decreases, while the enhancement factor decreases rapidly when the spacing between nanoparticles is less than 1 nm, because under this condition, its mechanism includes not only the coupling of two dipoles, but also the electron tunneling between two surfaces. Besides laser energy, the electric field of Ag nanoparticles is greatly affected by the nanoparticles size and their spatial distribution. With the same laser energy and spacing, the smaller the particle size, the higher the peak value of electric field intensity, but the faster the attenuation with distance. In the polarization direction of the laser, the enhancement factor of the electric field is more obvious. When the laser acts on several Ag nanoparticles, the electric field of nanoparticles in the range of spot size is quite different from that of the nanoparticles outside the spot. [ABSTRACT FROM AUTHOR]

The thermal field distribution of Ag nanoparticles induced by femtosecond laser is calculated by using two-temperature equation in this paper, and its characteristics of Ag nanoparticles with single layered and multi-layered were compared and analyzed. It is found that there will be a local "hot spot" in the electromagnetic coupling region of adjacent particles, because of the electron tunneling effect and the plasma model for electron transfer, the temperature gradient in this region shows a trend of increasing at the beginning and then decreasing. The influence of the thermal field mainly comes from two aspects, one is the electromagnetic coupling of the plasmon mode, the other is the "cumulative effect" of temperature, and with the increase of irradiation time, the influence of the laser energy accumulation becomes more and more obvious on the thermal field distribution. At the same time, the results show that the smaller Ag nanoparticles will have higher temperature and temperature gradient with the same laser energy. It is also found that the electron and lattice temperature of Ag nanoparticles will reach the thermodynamic equilibrium distribution in 20 to 30 picoseconds. [ABSTRACT FROM AUTHOR]

The effects of Si content (0.73%, 2.23%, 4.57%) and solidification rate (10 µm/s, 35 µm/s, 80 µm/s) on the as-cast microstructure and crystal orientation of 0.27% Al non-oriented electrical steel have been studied by directional solidification technology. Si atoms were inclined to segregate on the trunks and stems of cells and dendrites, and precipitate in the form of quadrilateral Fe-Si particles with size less than 4 μm. Increasing Si content would lead to a decrease in thermal conductivity of steel and directly cause an increase in temperature gradient of liquid steel, and as a result, make solid–liquid interface more stable and easier to grow as cell crystal. Moreover, decreasing solidification rate could further aggravate Si segregation at solid–liquid interface. Higher Si content (4.57%) together with lower solidification rate (10 µm/s) was more beneficial to the grain nucleation with {100} <001> orientation, whereas higher solidification rate (80 µm/s) played a major role in the grain nucleation with {110} <001> orientation. [ABSTRACT FROM AUTHOR]

Multifunctional molecules are capable of assembling via different supramolecular synthons, or hydrogen bond motifs, between the same or different functional groups, leading to the possibility of cocrystal. Utilization of the interplay of dimensionality (1-D, 2-D and 3-D), orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. N-unsubstituted 1H-benzotriazole and carboxylic acid, being self-complementary molecules, offer a broad scope of study of binary compounds based on the complementary combination of H-bonding/donating sites. We report here the construction of three extended molecular networks in cocrystals of the carboxylic acid group of the acid and the 1H-benzotriazole triazole moiety. We have been able to identify four major supramolecualr synthons that would be helpful in the prediction of structural motifs for these kinds of studies. Interestingly, these heterosynthons are strikingly similar, to those of the homosynthons of the individual functional groups. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus leading to the formation of various supramolecular assemblies. Thermal stability of these compounds has been investigated by thermogravimetric analysis (TGA) of mass loss. [ABSTRACT FROM AUTHOR]

Solid complexes of lanthanide picrates with 1,1′-(3,6,9-trioxaundecanedionyl)diphenothiazine (L), [Ln(pic) 3 L] (Ln = La, Nd, Eu, Gd, Er, Y), have been prepared and characterized by elemental analysis, IR and 1 H NMR spectra. The molecular structure of [Er(pic) 3 L]·1/2C 2 H 5 OH shows that five oxygens of L form a ring-like coordination structure. Er(III) is 9-coordinated by L together with the other two unidentate and one bidentate picrate anions, revealing a tri-capped distorted trigonal prism geometry. Solvent extraction of Ln(III) with L has been carried out in a water-nitrobenzene system by use of the multitracer method. The relationship between the complex structure and extractabilities of the ligand is discussed. [ABSTRACT FROM AUTHOR]

Four solid complexes of alkaline earth picrates with N,N,N′,N′-tetraphenyl-3,6,9-trioxaundecanediamide (TTD), M (Pic)2TTD ( 1, M = Mg; 2, M = Ca; 3, M = Sr; 4, M = Ba), have been prepared and characterized by elemental analysis, conductivity measurement, IR spectra, 1H NMR spectra and TG-DTA techniques. Crystal structure of complex 3 shows that the Sr(II) ion is 9-coordinated by five oxygen atoms from TTD and four oxygen atoms from two bidentate picrates, and the coordination polyhedron is distorted tricapped trigonal prism. TTD as a pentadentate ligand forms a right-handed helical coordination structure. The chelating helical chain has a relative fixed radius and then shows a high coordination selectivity to metal ion. The high selectivity of TTD to alkaline earth ions is explained elementarily from the special coordination structures. [ABSTRACT FROM AUTHOR]

The extraction of Am3+ and Eu3+ from aqueous picric acid solution by N, N′-dinaphthyl-N, N′-diphenyl-3,6-dioxaoctanediamide (LI) and 1, 1′-(3, 6, 9-trioxaundecanedionyl)diphenothiazine (LII) was investigated by a radioactive tracer technique. Extraction distribution ratios of Am3+ and Eu3+ have been measured as a function of pH, picric acid concentration, extractant concentration, diluent and temperature. The extraction of Am3+ is preferred to that of Eu3+ for both LI and LII, and the latter gives larger separation factor than the former. The equilibrium constants and thermodynamic parameters of extraction reactions were also calculated. [ABSTRACT FROM AUTHOR]