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In the paper, in view of two monotonicity rules for the ratios of two functions and of two Maclaurin power series expansions, the authors establish several sharp inequalities involving (hyperbolic) tangent, tanc, cosine, and their reciprocals. [ABSTRACT FROM AUTHOR]

A method of high performance liquid chromatography tandem high resolution mass spectrometry (HPLC-HRMS) was developed for the separation and identification of chemical components in Rheum lhasaense A. J. Li et P. K. Hsiao extract. The separation of compounds was carried out on an Agilent Zorbax SBC18 column (150 mm×4.6 mm×5 μm). The mobile phase was composed with acetonitrile and water with the flow rate of 0.5 mL/min. Electrospray ionisation source (ESI) was used, and Rheum lhasaense A. J. Li et P. K. Hsiao extract was analyzed by MS and MSn full scan at positive and negative ion modes. Through comprehensive analysis of the mass spectra and chromatographic behaviors of the compounds, and comparing with the related data from standard substrates, literatures and database, the main chemical components of Rheum lhasaense A. J. Li et P. K. Hsiao extract were deduced and identified. A total of 63 compounds are identified from Rheum lhasaense A. J. Li et P. K. Hsiao extract at negative ion mode, and 54 compounds are identified at positive ionization mode. These compounds contain 22 tannins, 28 stilbenes, 6 flavonoids, 3 phenylpropanoids, 2 butyrophenones and 2 organic acids, which of 53 compounds are firstly discovered in Rheum lhasaense A. J. Li et P. K. Hsiao. And as reported in the literature, enquinones are not found. This method is fast and sensitive, which not only improves the identification efficiency of trace compounds in Rheum lhasaense A. J. Li et P. K. Hsiao complex matrix, but also achieves the analysis and identification of different types of compounds. It is helpful to provide scientific basis for further clarifying the material basisand quality control standards of Rheum lhasaense A. J. Li et P. K. Hsiao.

Ammonium‐calcium mixed‐cation pentaborate NH4Ca[B5O7(OH)4]·H2O has been synthesized for the first time. Single‐crystal X‐ray diffraction analysis reveals that it crystallizes in the triclinic space group P‐1 with lattice parameters a = 6.7042(3) Å, b = 7.1859(3) Å, c = 10.7447(4) Å, α = 100.304(3), β = 97.774(3), γ = 96.972(3). The structure is characterized by 1D boron–oxygen chains composed of [B5O7(OH)4]3− polyanions that are further interspaced by Ca2+, NH4+ cations, along with lattice water molecules. The phase purity and thermal stability of the as‐synthesized sample were confirmed by XPRD and TG‐DSC analyses. Experimental UV–vis diffuse reflectance spectroscopy coupled with Urbach fitting indicates a direct bandgap of 4.50 eV, contrasting with theoretical calculations that suggest an indirect bandgap of 5.53 eV. Additionally, both theoretical computation and polarized light experimental test indicate that NH4Ca[B5O7(OH)4]·H2O exhibits moderate birefringence. [ABSTRACT FROM AUTHOR]

The Central Asian Orogenic Belt (CAOB) was formed by the aggregation and collage of numerous Paleozoic subduction‐accretion assemblages and Precambrian microcontinental blocks. However, the tectonic nature of the southeastern CAOB remains controversial, which complicates the reconstruction of the Paleo‐Asian Ocean. To address this issue, a deep seismic reflection survey was initiated across the southeastern CAOB and reveals broad gentle sub‐horizontal reflectors in the middle‐lower crust and a relatively transparent zone in the upper crust. Combining with the Precambrian geological outcrops and other geophysical features, we support a microcontinental block, the Xilinhot Block, existed in the Paleo‐Asian domain. Thus, the Paleo‐Asian Ocean was separated into two branches that underwent north‐dipping and double‐dipping oceanic plate subduction, respectively, to form the Hegenshan‐Heihe and Solonker sutures. Multiple relics beneath Hegenshan‐Heihe Suture indicate that multiple sets of unidirectional oceanic subduction‐accretion and magmatism were important mechanisms of continental growth. Plain Language Summary: During the consumption of the Paleo‐Asian Ocean, a great number of Paleozoic subduction‐related accretionary complexes were developed and combined with pre‐existing Precambrian continental fragments to form the Central Asian Orogenic Belt (CAOB). However, research on the tectonic evolution of this area has been limited, and the tectonic nature of the southeastern CAOB remains controversial. A deep seismic reflection survey along the southeastern CAOB shows the crustal architecture in detail. The broad gentle sub‐horizontal reflectors and a relatively transparent zone in the profile reveal a Precambrian continental fragment existed in the North Orogenic Belt of CAOB. The Paleo‐Asian Ocean was further separated into two parts, the fossil subduction zones of which show northward and bidirectional dipping characteristics beneath the Hegenshan‐Heihe and Solonker sutures, respectively. Several relics of the unidirectional subduction beneath the Hegenshan‐Heihe Suture indicate that multiple sets of unidirectional oceanic subduction‐accretion and magmatism were important mechanisms of continental growth. Key Points: A preserved microcontinental block has been revealed in the North Orogenic Belt of Central Asian Orogenic BeltThe Paleo‐Asian Ocean was separated into two branches, which were closed respectively by north‐dipping and double‐dipping subductionMultiple unidirectional subduction‐accretion and oceanic magmatism may contribute to continental growth [ABSTRACT FROM AUTHOR]

Three species of the spider family Philodromidae are reported from the south of China. A new genus, Sinodromus gen. nov., is described from Jiangxi, Fujian, and Hunan Provinces. It can be distinguished from other genera of Philodromidae by the tegular apophysis of the palp and the cymbial process, as well as by its uniquely striped abdomen. The type species, S. fujianensis sp. nov., and a second species, S. perbrevis sp. nov., are described and illustrated; these species occur in bamboo forests in hilly areas. Additionally, the female of Philodromus guiyang Long & Yu, 2022 is described for the first time from Jiangxi and Hunan Provinces. All species are illustrated with SEM micrographs, and their distributions are mapped. [ABSTRACT FROM AUTHOR]