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Early Cretaceous granitic rocks are widely distributed in the Great Xing’an Range, northeast China. However, their precise age and tectonic evolution remain controversial. This study presents new zircon U–Pb, Lu–Hf, and whole-rock geochemical data for the granitic plutons in the Yili area, Xing’an Massif, northern Great Xing’an Range. The aim of this study was to decipher the tectono-thermal history and obtain further understanding of the geodynamic setting of the large-scale Late Mesozoic magmatism in the Great Xing’an Range. Zircon U–Pb age dating indicated that the plutons were emplaced during the Early Cretaceous, with ages of 132.2–130.1 Ma. The plutons showed similar geochemical features, characterized by high concentrations of SiO2 and Na2O + K2O and low concentrations of P2O5, CaO, MgO, and TFe2O3. The plutons were enriched in light rare earth elements and large ion lithophile elements and depleted in heavy earth elements and high-field-strength elements. Such features indicate that the plutons are highly fractionated with I-type granite affinity. These findings, combined with pluton ε Hf(t) values of + 5.25 to + 8.28 and two-stage model ages (t DM2) of 661–855 Ma, indicate that the primary magmas originated from partial melting of juvenile basaltic crustal material accreted during the Neoproterozoic. These results combined with regional geological evolution indicated that the generation of Early Cretaceous plutons in the northern Great Xing’an Range might be closely related to the post-collisional gravitational collapse and subsequent extension resulting from the closure of the Mongolia-Okhotsk Ocean. Their generation also superimposed the back-arc extension resulting from retraction of the Paleo-Pacific subduction plate.

In order to meet the demanding drag reduction requirements of high-speed aircraft, the drag reduction mechanism of array microslit-opposed jets in the passivation leading edge is studied using a numerical method based on the shear stress transfer (SST) k-ω two-path turbulence model. The computations are performed with the commercial CFD solver FLUENT 13.0 code. The interference characteristics of the array jets are analyzed, the influence laws of the microslit array mode and the angle of attack on drag reduction performance are explored, and a prediction method of passivation leading edge drag characteristics based on radial basis function (RBF) neural network is constructed. The research conditions are as follows: the incoming Mach number is 2.0, the angle of attack ranges from 0° to 30°, and the number of microslits is 0 to 5. The results show that when there is interference between microslit jets, the interaction between adjacent reverse reflux regions will change the shape of the reflux regions. When there is a microslit jet in the center line, the position of the detached shock wave is more affected by the angle of attack. The drag characteristics of the leading edge are determined by the location of the detached shock wave and the characteristics of the reflux regions. The mode of microslits determines the drag reduction efficiency and sensitivity to the angle of attack. There may be contradictions in the design of array microslit-opposed jet schemes regarding the overall drag reduction efficiency, local load, and drag reduction stability. The drag prediction model based on the RBF neural network has an accuracy of 5%, which can provide support for the design of array microslit-opposed jets. Practical Applications: The array microslit-opposed jets provide a new technical approach for reducing drag on the passivation leading edge. The paper studies its flow characteristics and laws and provides relevant conclusions. It can serve as a theoretical reference during design. The number of microslits is not the more the better. When designing microslit patterns, many factors need to be considered. [ABSTRACT FROM AUTHOR]

SBA-15@MOF-525 composites were constructed by in situ self-assembly of a metal–organic framework (MOF-525) with mesoporous SBA-15 silica. MOF-525 crystals were confined inside the mesopores as well as grown on the outside surface of SBA-15, under the impact of the structure-directing role of SBA-15, and the composites exhibited both microporous and mesoporous characteristics. In general, the adsorption of tetracycline (TC) on MOF-525 was affected by pH. The adsorption capacity of MOF-525 decreased rapidly, especially in an alkaline environment, due to the collapse of the MOF-525 skeleton. By contrast, incorporating MOF-525 into SBA-15 improved the stability of MOF-525. The adsorption of TC on SBA-15@MOF-525 was almost unaffected by pH. High and stable adsorption capacity over a wide pH range was maintained under acidic, neutral, and alkaline environments. The composites were used effectively for TC adsorption. The maximum adsorption capacity of TC on SBA-15@MOF-525 was 690 mg/g, which is higher than that of most of the reported adsorbents. The great potential of SBA-15@MOF-525 in practical applications was demonstrated by investigating the adsorption of TC in lake water samples. [ABSTRACT FROM AUTHOR]

The redox property of the ultrasmall coinage nanoclusters (with several to tens of Au/Ag atoms) has elucidated the electron-transfer capacity of nanoclusters, and has been successfully utilized in a variety of redox conversions (such as from CO2 to CO). Nevertheless, their biological applications are mainly restricted by the scarcity of atomically precise, water-soluble metal nanoclusters, and the limited application (mainly on the decomposition of H2O2 in these days). Herein, mercaptosuccinic acid (MSA) protected ultrasmall alloy AuAg nanoclusters were prepared, and the main product was determined [Au3Ag5(MSA)3]− by electrospray ionization mass spectrometry (ESI-MS). The clusters can not only mediate the decomposition of H2O2 to generate hydroxyl radicals, but is also able to mediate the reduction of nicotinamide adenine dinucleotide (NAD) to its reduced form of NADH. This is the first time that the atomically precise metal nanoclusters were used to mediate the coenzyme reduction. The preliminary mechanistic insights imply the reaction to be driven by the hydrogen bonding between the carboxylic groups (on the surface of MSA) and the amino N—H bonds (on NAD). In this context, the presence of the carboxylic groups, the sub-nanometer size regime (∼ 1 nm), and the synergistic effect of the Au-Ag clusters are pre-requisite to the NAD reduction. [ABSTRACT FROM AUTHOR]

This paper focuses on the shock wave/boundary layer interaction (SWBLI) at the compression corner. The concept of dynamic microvortex generator (Dy-MVG) is proposed based on the flow control mechanism. A high-precision drive system is used to control the periodic oscillation of the microvortex generator, thereby injecting controllable dynamic disturbances into the boundary layer. Based on the Feng Dong (FD)-06 wind tunnel, the control effect and mechanism of Dy-MVG on SWBLI are investigated by schlieren and pulsating pressure test techniques. The operating conditions are as follows: the incoming Mach number is 2.5 and 3.5, the total temperature is 300 K, and the oscillation frequency of the Dy-MVG is 2–60 Hz. The results show that classical MVG moves the shock foot position downstream and increases the shock angle. Dy-MVG enables dynamic changes in the shock foot position and shock angle over a greater range than classical MVG. Compared with classical MVG, Dy-MVG further weakens the shock intensity in the SWBLI region, and the shock intensity decreases with the increase of excitation frequency. Dy-MVG further increases the pulsating pressure and the energy of low-frequency characteristics in the SWBLI region, resulting in better control of the SWBLI. The Dy-MVG proposed in this paper has better performance than the classical MVG in controlling SWBLI. Due to the adjustable characteristics of Dy-MVG, it can be applied to a wide speed range of aircraft. For example, it can be used for airfoil flow control to improve airfoil characteristics, and it can also be applied to the inlet to improve the inlet performance. The frequency and amplitude can be controlled to meet the requirements of airfoil and inlet under different flight conditions. [ABSTRACT FROM AUTHOR]

An unsteady numerical simulation method was used in order to explore more efficient atomization methods for liquid fuel in scramjet combustors and to study the influence of different shock wave incident positions on the atomization characteristics of kerosene in crossflow. The wedge compression surface was used to generate the incident shock wave, and the incident position of the shock wave on the fuel jet was controlled by changing the angle of the wedge surface. The inlet Mach number was 2.01; the total temperature was 300 K, and the momentum ratio was 12. The research results show that as the incident position of the shock wave moves upstream, the penetration depth of the jet is essentially unchanged, but the inner edge trajectory of the jet is closer to the wall. Because the shock wave affects the Kelvin–Helmholtz instability of the jet, the unsteadiness of the jet root is strengthened, and the unsteadiness downstream of the jet is weakened. The atomization of the jet and the stability of the particle-size distribution are, thus, realized more quickly. The incident shock wave reduces the Sauter mean diameter of the jet section and makes the droplet distribution more uniform. The incident shock wave makes the atomization angle of the jet along the flow direction increase first and then decrease. The changes in the jet characteristics are determined by the changes in the reflux region, momentum transport, and pressure distribution caused by the incident shock wave. [ABSTRACT FROM AUTHOR]

The optical window is an essential channel for optical signal transmission and return of a deep-sea hydrothermal velocimetry system. Due to its unique structural design, the stress concentration of the optical window will occur under the action of deep-sea high pressure, resulting in cracks at the corner of the high-pressure surface of the optical window, which leads to the inaccurate convergence of the optical signal. A pressure self-balancing optical window package structure is designed to solve the problem. The stress at the optical window is numerically analyzed, and the forces of self-balancing and nonpressure self-balancing optical windows under the same seawater pressure are compared. The results show that the maximum stress at the stress concentration can be reduced by 53% using the pressure self-balancing method, and the phenomenon of stress concentration can be effectively eliminated. In addition, to verify the feasibility of the design and the accuracy of the numerical calculation results, the optical window and its encapsulation structure were experimentally studied, and the deep-sea performance test experiment was carried out on the "Jiaolong" submersible, which further verified the accuracy of the results. [ABSTRACT FROM AUTHOR]

MicroRNA plays a crucial part in genesis and development of gastric cancer (GC). We uncovered that microRNA-30c-2-3p was down-regulated in GC tissue and cell lines. Suppression of microRNA-30c-2-3p promoted progression of GC cells in vitro. STRIP2 was confirmed as a target for microRNA-30c-2-3p. MicroRNA-30c-2-3p overexpression remarkably suppressed cell malignant behaviours, while reintroduction of STRIP2 partially restored the anticancer effect of microRNA-30c-2-3p. Taken together, these findings suggested that microRNA-30c-2-3p acted as a candidate tumour suppressor in GC by directly targeting STRIP2. Therefore, microRNA-30c-2-3p can be used as a towardly GC therapeutic target. [ABSTRACT FROM AUTHOR]

In the surface filtration process with pores larger than the particle size, the formation of particle bridges plays a crucial role in the filter cake structure and the filtration efficiency throughout the filtration process. First, to understand the microscopic information required for the bridging mechanism, we use the two-way coupling of computational fluid dynamics (CFD)–discrete element method (DEM) to simulate the deposition characteristics of particles in the pores of ceramic membranes. Next, by dynamically observing the deposition morphology and bridging process of particles, the bridging mechanism was revealed at the level of a single hole. Then, we studied the influence of particle concentration and inlet velocity on the bridge erection process. The results show that the bridging function of particles runs through the clean filtration stage and the transition stage. Particle concentration and inlet flow rate have a crucial influence on the formation of particle bridges and filtration efficiency. [ABSTRACT FROM AUTHOR]

The fundamental reason for the environmental pollution caused by the papermaking industry is the inadequate treatment of the black liquor. How to dispose of the lignin macromolecules, which is the main pollutants in the black liquor, is the key to addressing the environmental pollution. At present, cross-flow membrane filtration is one of the effective ways to retain and recycle lignin macromolecules in black liquor. The paper proposes the adoption of a dynamic blade cross-flow membrane filtration equipment provided by German BOKELA company to treat papermaking black liquor. The experiment shows that when the black liquor is treated with dynamic blade rotation cross-flow, the membrane with a molecular weight cut-off of nanofiltration (NP010) delivers the best retaining effect, with 28 % more lignin in black liquor than that in untreated black liquor. Meanwhile, when the blade rotational speed reaches 300 rpm and the transmembrane pressure is 0.5 or 2 bar, the flux of black liquor through nanofiltration NP010 is relatively desirable. [ABSTRACT FROM AUTHOR]

Visual tracking is still a challenging fundamental task in the field of computer vision, especially in complex scenes such as long-term occlusion, nonrigid deformation and fast movement. In this paper, we presented an RGB-D tracker based on the Siamese Region Proposal Network and Depth Information. First, Siamese Network with shared parameters was constructed to perform feature extraction on the target patch and search area. Second, Region Proposal Network was constructed to estimate the target position in the RGB channels. At the same time, the depth information in the RGB-D video was used to determine the target occlusion state and fine-tune the target position. Finally, the tracker used depth information to achieve occlusion recovery when the target was fully occluded. The experimental result shows that the method has better performance in tracking accuracy and tracking speed on the large-scale Princeton RGB-D Tracking Benchmark (PTB) dataset. [ABSTRACT FROM AUTHOR]

The reaction of volatiles in a coal pyrolysis reactor determines the yield and quality of tar. This paper studies the yield, group composition and radical concentration of tars obtained from pyrolysis of a subbituminous coal, mainly on the effect of the tars' residence time in the pyrolysis reactor and in post-pyrolysis heating. The latter operation simulates the environment of tars, if they were in a large fast pyrolysis reactor. It is found that an increase in the volatiles' residence time in the pyrolysis reactor reduces the yield and increases the radical concentration of tars. The pitch fraction of the tars is mainly responsible for coke formation which occurs significantly at temperatures higher than 420 °C. The tars contain radicals, mainly in their coke and pitch fractions. The coke concentration in the tars increases with increasing heating time, linearly at 420 and 450 °C but in a sigmoidal pattern at higher temperatures. The coking behavior within 10 min can be expressed by the zero-order or zero-order + autocatalytic kinetics with activation energies of 128–138 kJ/mol. [ABSTRACT FROM AUTHOR]

The study about the low-temperature performance of lithium-ion batteries (LIB) is of great significance at extreme temperatures, such as polar scientific research, space exploration, deep-sea exploration, military fields, and so on. In this study, normal devices and symmetrical devices were fabricated by ternary Li(Ni0.5Mn0.3Co0.2)O2 as cathode and graphite as anode at 25 and −20 °C. The results show that the specific discharge capacity of normal device is up to 120 mAh g−1 at 1 C and 25 °C. The specific capacity and energy density at 0.2 C and −20 °C are 106.05 mAh g−1 and 376.53 mWh g−1, respectively, which can reach 92.82% of that at 1 C and 25 °C. The value of activation energy Ea of the interface reaction of the LIB is calculated to be 63.72 kJ/mol by the Arrhenius equation. When the temperature dropped from 25 to −20 °C, the lattice spacing of Li1−x(Ni0.5Mn0.3Co0.2)O2 hardly changed, while the lattice spacing (002) of graphite reduces 0.00248 Å. In addition, some cracks were observed on the charged cathode at −20 °C. We carried out quasi-in situ electrochemical impedance spectroscopy (EIS) when the voltages of normal device discharged to 3.8, 3.6, 3.4, 3.2, and 3.0 V. Unlike the relationship of voltage–resistance at 25 °C, the values of the series resistance (Rs), charge transfer resistance (Rct), and ion transfer resistance (Rit) gradually decrease as the voltage decreases at −20 °C. Compared with the resistance of the symmetrical device based on the anode at 25 °C, the values of Rs and Rit at −20 °C both obviously increase. The main reason of performance degradation for normal device at −20 °C is large ion transfer resistance and the decrease of lattice spacing of the graphite (002). [ABSTRACT FROM AUTHOR]

To better understand the mass transfer behaviors in CaC2 production from CaO and coke, this paper studies the diffusion behaviors of CaO and graphite, with or without ash, at 1500 and 1700 °C. CaO and graphite are pressed into tablets and heated alone or in close contact. Physical and chemical changes in these tablets are analyzed by XRD and SEM+EDX. In some experiments, thin Mo wires are placed between the closely contacted CaO and graphite tablets to identify the diffusion direction. It is found that the diffusion between CaO and low-ash graphite is very limited. SiO2 in a high-ash graphite diffuses into CaO tablet and reacts with CaO to form Ca2SiO4, which then diffuses into the graphite tablet easily and leads to CaC2 formation at 1700 °C. [ABSTRACT FROM AUTHOR]

The Newtonian gravitational constant G, which is one of the earliest fundamental constants introduced by human beings, plays an important role in cosmology, astrophysics, geophysics, metrology, and so on. In spite of the measurement of G having a relative longer history and more than 200 measurement results having been obtained during the past 200 years, G still remains the least precisely known among all fundamental physical constants up to now. Over the past three decades, many experimental physicists devoted themselves to the G measurement with various methods and resulted in a dozen precise values of G. However, the determined results are still in poor agreement with each other. A brief overview of the significance of the gravitational constant G is given herein, followed by an introduction into the history of G measurement. A summary of the five latest precise measurements performed during the past few years is presented. Finally, an outlook of the future development of G measurement is provided. [ABSTRACT FROM AUTHOR]

Solvent extraction of coals has been practiced extensively for various purposes including the determination of coal structure. It is generally assumed that the extraction is mainly a physical process involving little change in covalent bonds. But different opinions were reported. This work studies the behavior of radicals during extraction of 3 low rank bituminous coals using 5 solvents, including hexane, toluene, tetrahydrofuran (THF), 1,2,3,4-tetrahydronaphthalene (THN), and N -methyl-2-pyrrolidinone (NMP), using electron spin resonance (ESR). The extractions are carried out at temperatures from the ambient temperature to temperatures somewhat higher than the boiling points of the solvents, as well as under ultrasound. It is found that the radical concentration of the coals changes during the extraction, and the change is influenced by temperature and varies with the solvent. The decrease in radical concentration in most solvents at temperatures lower than their boiling points is attribute to coupling of free radicals dissolved from the coals, while the increase in radical concentration at high temperatures and in NMP is attributed to the cleavage of weak bonds in coals by the solvents. [ABSTRACT FROM AUTHOR]

The atomic precision of metal nanoclusters and variability of surface ligands pave the way for its rational design and functionalization, whereas the property strengthening in multiple ways has been long challenging. Herein, improved amphiphilicity, chirality, thermostability, and strong CPL (circularly polarized luminescence) properties have been accomplished by facile ligand exchange of [Au23(CHT)16]- with HCapt (HCHT and HCapt denote cyclohexanethiol and captopril). In addition, the obtained chiral [Au23(SR)16]- (short for [Au23(CHT)16-x(Capt)x]-) clusters show specific binding affinity to remote-diamines (such as arginine and single/double strand DNA), originating from the hydrogen bonding and Van der Walls interaction among the surface Capt ligands and the di-amine groups., (© 2024 Wiley‐VCH GmbH.)

The atomic precision of sub-nanometer-sized metal nanoclusters makes it possible to elucidate the kinetics of metal nanomaterials from the molecular level. Herein, the size reduction of an atomically precise [Au 23 (CHT) 16 ] - (HCHT = cyclohexanethiol) cluster upon ligand exchange with HSAdm (1-adamantanethiol) has been reported. During the 16 h conversion of [Au 23 (CHT) 16 ] - to Au 16 (SR) 12 , the neutral 6e Au 21 (SR) 15 , and its 1e-reduction state, i.e. the 5e, cationic radical, [Au 21 (SR) 15 ] + , are active intermediates to account for the formation of thermodynamically stable Au 16 products. The combination of spectroscopic monitoring (with UV-vis and ESI-MS) and DFT calculations indicates the preferential size-reduction on the corner Au atoms on the core surface and the terminal Au atoms on longer Au n S n +1 staples. This study provides a reassessment on the electronic state of the Au 21 structure and highlights the single electron transfer processes in cluster systems and thus the importance of the EPR analysis on the mechanistic issues.

Background: Intervertebral disc degeneration (IDD) is a major cause of low back pain, but the onset and progression of IDD are unknown. Long non-coding RNA (lncRNA) has been validated to play a critical role in IDD, while an increasing number of studies have linked oxidative stress (OS) to the initiation and progression of IDD. We aim to investigate key lncRNAs in IDD through a comprehensive network of competing endogenous RNA (ceRNA) and to identify possible underlying mechanisms. Methods: We downloaded IDD-related gene expression data from the Gene Expression Omnibus (GEO) database and obtained differentially expressed-lncRNAs (DE-lncRNA), -microRNAs (DE-miRNA), and -messenger RNAs (DE-mRNA) by bioinformatics analysis. The OS-related lncRNA-miRNA-mRNA ceRNA interaction axis was constructed and key lncRNAs were identified based on ceRNA theory. We performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses on mRNAs regulated by lncRNAs in the ceRNA network. Single sample gene set enrichment analysis (ssGSEA) was used to reveal the immune landscape. Expression of key lncRNAs in IDD was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results: In this study, 111 DE-mRNAs, 20 DE-lncRNAs, and 502 DE-miRNAs were identified between IDD patients and controls, and 16 OS-related DE-lncRNAs were also identified. The resulting lncRNA-miRNA-mRNA network consisted of eight OS-related DE-lncRNA nodes, 24 DE-miRNA nodes, 70 DE-mRNA nodes, and 183 edges. Functional enrichment analysis suggested that the ceRNA network may be involved in regulating biological processes related to cytokine secretion, lipid, and angiogenesis. We also identified four key lncRNAs, namely lncRNA GNAS-AS1, lncRNA MIR100HG, lncRNA LINC01359, and lncRNA LUCAT1, which were also found to be significantly associated with immune cells. Conclusion: These results provide novel insights into the potential applications of OS-related lncRNAs in patients with IDD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Jiang, Wu, Guo and Song.)