Full waveform inversion based on hybrid gradient

The low-wavenumber components in the gradient of full waveform inversion(FWI)play a vital role in the stability of the inversion.However,when FWI is implemented in some high frequencies and current models are not far away from the real velocity model,an excessive number of low-wavenumber components in the gradient will also reduce the convergence rate and inversion accuracy.To solve this problem,this paper firstly derives a formula of scattering angle weighted gradient in FWI,then proposes a hybrid gradient.The hybrid gradient combines the conventional gradient of FWI with the scattering angle weighted gradient in each inversion frequency band based on an empirical formula derived herein.Using weighted hybrid mode,we can retain some low-wavenumber components in the initial lowfrequency inversion to ensure the stability of the inversion,and use more high-wavenumber components in the high-frequency inversion to improve the convergence rate.The results of synthetic data experiment demonstrate that compared to the conventional FWI,the FWI based on the proposed hybrid gradient can effectively reduce the low-wavenumber components in the gradient under the premise of ensuring inversion stability.It also greatly enhances the convergence rate and inversion accuracy,especially in the deep part of the model.And the field marine seismic data experiment also illustrates that the FWI based on hybrid gradient(HGFWI)has good stability and adaptability.

Traditional medicine in cancer:what is new in 2022

Cancer is one of the leading causes of death in most countries and regions,accounting for about ten million deaths each year worldwide.Despite the endeavors and achievements made in treating cancer during the past decades,rapid resistance to the current clinically used targeted drugs or targeted chemotherapeutic agents continues to be a major problem in cancer therapies.Moreover,many cancer patients are suffering from tumor complications or cancer-related symptoms.Traditional medicine has been practiced for thousands of years and is also currently diffusely used worldwide as an alternative therapy for cancer.Areas of investigation of traditional medicine in cancer treatment,such as traditional formulas,chemical components derived from herbal medicines,and acupuncture,have received increasing attention,especially in recent years.Here,we included selected studies reported last year regarding traditional medicine for cancer treatment in an attempt to summarize the most relevant findings,providing a valuable reference for the future investigation of traditional medicine in the cancer field.

Gelation Mechanism of Erythromycin Ethylsuccinate During Crystallization

In this paper, the gelation mechanism of erythromycin ethylsuccinate(EES) during crystallization is investigated for the first time. The generated semisolid gel-like phase exhibited a 3D fibrillar network morphology and the typical rheological properties of gels. The fibers inside the gel-like phase were confirmed to be new types of EES solvates using powder X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, and gas chromatography. The gelation and crystallization regions in EES-1-propanol solid–liquid phase diagram were determined. Analyses of solvent parameters showed that moderate solvent polarity may promote EES gelation. Fourier transform infrared spectra, nuclear magnetic resonance spectra, and scanning electron microscopy analyses indicated that through intermolecular hydrogen bonds, EES and solvent molecules assembled into fibers via crystallographic mismatch branching growth. The fibers intertwined into a 3D network microstructure and formed a gel-like phase, completely immobilizing the solution.

Synthesis, Growth, and Characterization of a New Thiourea and Bismuth Chloride Complex with Excellent Nonlinear Optical Properties

Crystals of a new organometallic nonlinear optical （NLO） compound, di-ta-chloro-bis[chlorotri（thiourea）bismuth（Ⅲ）]- pentachloro（thiourea）bismuth-ate（Ⅲ） （DCBPB）, have been successfully grown from formic acid aqueous solutions of thio-urea and bismuth chloride by a slow evaporation technique. The crystal structure and atomic composition of DCBPB have been confirmed by single crystal X-ray diffraction （SCXRD）, Fourier transform infrared spectra, and elemental analysis. The SCXRD results proved that DCBPB crystallizes in triclinic space group P1 with unit cell dimensions of a = 7.0606（2） A, b = 8.8106（4） A, c = 16.3247（8） A, a = 99.242（4）°, fl = 95.309（3）°, ）/= 105.856（3）°, and Z= 2. DCBPB crystal exhibits excel-lent transmittance from 500 to 2500 nm and green fluorescence with maximum emission at 508 nm. The thermogravimetric-differential scanning calorimetry （TG-DSC） analysis indicates that a solid-phase reaction took place at 170.1 ℃, whereas the decomposition temperature of the crystal material was 189℃. The NLO property obtained by the Kurtz powder test showed that the second harmonic generation efficiency of DCBPB crystal is two-seventh of KDP crystal.

Ternary phase diagrams and solvate transformation thermodynamics of omeprazole sodium in different solvent mixtures

Omeprazole sodium(OMS), a typical non-hydrogen bond donors API, is only available in solvates so far, including monohydrate, ethanol solvate and methanol solvate. The methanol solvate was found for the first time. Solvate transformation thermodynamics of OMS was studied in this paper. First, the ternary phase diagrams forming two solvates for OMS in binary solvent mixtures including methanol + water, ethanol + water, and methanol+ ethanol were measured at temperature ranging of T =(278.15 to 313.15) K under atmospheric pressure. Further, the standard equilibrium constants of the solvate transformation reactions were evaluated according to the chemical reaction isothermal equation. The standard molar Gibbs free energy, the standard molar enthalpy, and the standard molar entropy of solvate transformation reactions were then calculated based on van't Hoff equation. Moreover, the thermodynamic stability of the OMS solvate was analyzed based on phase diagram. The results are of great importance to develop a crystallization process for manufacturing OMS solvate, and could be helpful to other solvate transformation research.

The Role of Solvent in Tautomer Solvate Crystallization: A Case of 6-Amino-1,3-Dimethyl-5-Nitrosouracil

Tautomers are structural isomers that readily interconvert and may exhibit diff erent properties.The eff ect of solvent on tautomeric equilibria in solution has been a subject of some research.Tautomer solvate is less common,and the role of solvent in the crystallization of tautomer solvate remains an interesting topic.In this work,we used 6-amino-1,3-dimethyl-5-nitrosouracil(NAU)as the tautomeric model material,which can present in nitrone–enamine form(Tautomer A)or oxime–imine form(Tautomer B).A solvate with NAU/DMSO ratio of 1:1 was discovered and characterized using single/powder X-ray diff raction and thermogravimetry.The crystal structure of NAU·DMSO was determined for the fi rst time,where only Tautomer A was formed in the tautomeric crystal.Quantum chemical calculation and molecular dynamics simulation were conducted to determine the tautomeric form in DMSO solution.Electrostatic potential analysis,radial distribution function analysis,and binding energy suggested possible DMSO–NAU interaction modes and stable tautomer complexes in solution.Tautomer A-containing complexes were found to dominate in solution,as verifi ed by comparing predicted and experimental 1 H NMR spectra.Findings reveal that the hydrogen bonding between DMSO and NAU is similar in solution and in NAU–DMSO solvate crystal,which helps preserve the form of Tautomer A during solvate crystallization.

Concurrent Structural and Electronic Phase Transitions in V_(2)O_(3)Thin Films with Sharp Resistivity Change

The relationship between structural and electronic phase transitions in V_(2)O_(3)thin films is of critical importance for understanding of the mechanism behind metal–insulator transition(MIT)and related technological applications.Despite being extensively studied,there are currently no clear consensus and picture of the relation between structural and electronic phase transitions so far.Using V_(2)O_(3)thin films grown on r-plane Al2O3 substrates,which exhibit abrupt MIT and structural phase transition,we show that the electronic phase transition occurs concurrently with the structural phase transition as revealed by the electrical transport and Raman spectra measurements.Our result provides experimental evidence for clarifying this issue,which could form the basis of theoretical studies as well as technological applications in V_(2)O_(3).

Compounds from the flowers and fruits of Abelmoschus esculentus (L.) Moench

The Abelmoschus esculentus(L.)Moench was previously reported to have various phytochemicals.Chemical fractionation yielded from the ethanolic extract of the A.esculentus ten compounds,including four alkaloids(4-6,8)and six phenolic acids(1-3,7,9-10).The structures of the compounds were elucidated through extensive spectra analyses and comparison of the experimental data with reported data.It is worth mentioning that compounds 1,2 and 5-10 were isolated from Abelmoschus esculentus(L.)for the first time.

Measurement and correlation of the solid-liquid equilibrium of 2-（tert-butyl）-5-methylphenol and 2-（tert-butyl）-4- methylphenol binary system

In this work, the enthalpy of fusion and melting points of 2-（tert-butyl）-5-methylphenol （2B5MP） and 2-（tert-butyl）-4-methylphenol （2B4MP） were measured by differential scanning calorimetry （DSC）. The binary solid-liquid equilibrium （SLE） of both compounds were predicted by integrated computer aided system （ICAS） and measured by DSC. The corresponding eutectic molar composition is 0.6998 and the eutectic temperature is 281.96 K. The quasi-static heat capacities of 2B5MP and 2B4MP were evaluated by stochastic temperature modulation DSC technique （TOPEM）. The SLE experimental data were correlated using the Margules, Wilson, and non-random two liquid （NRTL） equations and a good agreement between measurement and calculation could be obtained.

Control of the agglomeration of crystals in the reactive crystallization of 5-（difluoromethoxy）-2-mercapto-lH- benzimidazole

5-（Difluoromethoxy）-2-mercapto- 1H-benzimi- dazole （DMB） was precipitated by adding acetic acid to the DMB sodium salt solution. The spherical agglomeration of DMB during the reactive crystallization in a batch crystallizer was monitored by real-time Particle Video Microscope （PVM）. We found that the low feeding rate of acetic acid, high crystallization temperature, low agitation rate or adding seed crystal can facilitate the formation of spherical agglomerates. By using a simple model, the mean crystal agglomerate size of DMB thus predicted is generally in agreement with the experimental data. In addition, the crystallization process of DMB was optimized by a new control strategy of supersaturation to avoid disadvantages brought by agglomeration.