Boletellus is a morphologically distinctive genus within the family Boletaceae, characterized by basidiospores with longitudinally striate ornamentation. Although the species diversity of this genus in China has been well documented in recent years, several historically described species published by early Chinese mycologists have been largely overlooked. To clarify the taxonomic identities of these historic Boletellus species from China, this study applied a genome-skimming approach to perform next-generation sequencing (NGS) on the historical type specimens of B. serpentipileus and B. vulgaris. The integration of NGS data with Sanger sequencing and morphological re-examination enabled a comprehensive taxonomic reassessment, which revealed that B. serpentipileus and B. vulgaris are not members of Boletellus, but belong to Leccinum and Austroboletus, respectively. Accordingly, the new combination Leccinum serpentipileum is proposed, and B. vulgaris is further synonymized with A. fusisporus. These findings resolve long-standing taxonomic uncertainties and contribute to a more accurate understanding of bolete diversity in China.

This work developed an efficient method for fabricating hundred becquerel-level 227Ac radioactive sources. By integrating a refined purification process with an optimized molecular plating technique, a deposition efficiency exceeding 98% was achieved. The prepared source was successfully employed to calibrate the energy and time resolution of the thermochromatography-LEGEND system. The principal novelty of our approach lies in addressing the challenge of impurity control during the deposition of trace amounts of actinide elements, thereby providing a reliable radioactive source for online/offline calibration of the alpha detectors.

Electroextraction of uranium from uranium-containing wastewater requires electrodes with low cost, environmental friendliness, high efficiency, and good antimicrobial activity. Herein, poly(amidoxime) and polyguanidine decorated cotton-derived carbon aerogel (G-CCA/PAO) electrode was directly assembled without adding any adhesive for treating uranium-containing wastewater. Poly(amidoxime) and carbon aerogel derived from raw cotton together endowed G-CCA/PAO with good hydrophilicity while polyguanidine gave G-CCA/PAO with excellent antimicrobial property. The three-dimensional cladding structure and good hydrophilicity of GCCA/PAO facilitated the contact of the functional groups with uranyl ions. As a result, G-CCA/PAO exhibited high electrosorption capacity (719.96 mg/g) and exceptional selectivity (6863.29 mL/g) for U(VI). Most importantly, due to the excellent recyclability, stability, selectivity, and antimicrobial properties, 97.98% of the uranium in real uranium-containing wastewater was electrosorbed by G-CCA/PAO electrode after 12 h. Experimental characterizations and DFT calculations revealed that the amidoxime, carboxyl, and guanidine groups of G-CCA/PAO got involved in U(VI) electrosorption through mutual cooperation. This work provides a facile and eco-friendly strategy to construct hydrophilic and antimicrobial carbon aerogel electrode for efficient U(VI) capture from uranium-containing wastewater.

Thermochromatography is widely used in studying the chemical properties of superheavy elements (SHEs) due to its fast and high efficiency, which requires the detector to accurately measure both the position and energy of charged particles emitted by radioactive elements across a range of temperature distributions. 4H-SiC detectors are conducive to work at high temperature environments due to its unique properties. A 4H-SiC Schottky diode array detector for the detection of Nh (Z = 113) elements by thermochromatography is designed and fabricated in this work. An 80 mu m thick 4H-SiC epitaxial layer with a doping concentration of lowing than 1 x 1014 cm- 3 was designed to achieve a total energy deposition of alpha particles. The leakage current is 82 nA under -200 V at 80 degrees C. By linear fitting, the relationship between the deposition energy and channel number is expressed as y = 4.72x-166.71, with an R-squared value of 0.9984. The detector's energy resolution in air at 80 degrees C is 1.83% @5486 keV, which is consistent with the 1.75%@5486 keV measured at 26 degrees C in air. The energy resolutions of the array detector for 241Am under vacuum ranges from 1.18% to 1.34%, corresponding to a mean spectrum broadening of 69.26 +/- 7.51 keV. 4H-SiC detectors satisfy the thermochromatography requirements for operating temperature, energy resolution, energy linearity, and device uniformity, which will be used for Nh elements study in the following experiments.

Superheavy elements(SHEs), defined as elements with atomic numbers greater than 103, represent a frontier in nuclear and chemical sciences. These elements, which include rutherfordium(Rf) through oganesson(Og), are not exist in nature and currently can only be artificially synthesized using heavy-ion accelerators. The production of SHEs is characterized by extremely low yields, often resulting in only “one-atom-at-a-time” level, and all their isotopes have short half-lives, typically ranging from milliseconds to seconds. These characteristics preclude their detection through conventional chemical analysis techniques, resulting in limited understanding of their chemical properties and behavior. In addition, with the increasing atomic number, relativistic effects become increasingly pronounced, significantly impacting the physical and chemical properties of SHEs. Consequently, the chemical behavior of SHEs deviates markedly from periodicity-based predictions for their lighter homologs. To be precise, the position of a new element in the periodic table can only be definitively assigned after verifying its chemical property. Therefore, investigating the chemical properties of SHEs is a critical research issues in nuclear chemistry. In this case, gas phase chromatography technique was developed as a distinctive and effective method for examining the volatility, adsorption enthalpy, and other essential physicochemical parameters of short-lived SHEs. Through such approaches, researchers can infer the chemical behavior of single atoms of superheavy elements and compare them with predictions from relativistic quantum chemical calculations. This review systematically explores advancements in the gas-phase chemistry of SHEs, encompassing historical developments, experimental methodologies, recent discoveries, status and progress in China. Its objective is to clarify the impact of relativistic effects on their electron configurations and their precise positions within the periodic table. The article reviews the discovery process of SHEs, from the pioneering efforts in the late 20th century until more recent achievements in synthesizing of the heaviest element, and highlights significant technological advancements in their chemical research, including the developments of target preparation and gas chromatography technology. Moreover, the detailed insights into recent experimental methods and results concerning carbonyl complexes of seaborgium(Sg), bohrium(Bh), hassium(Hs), meitnerium(Mt) and their homologues, as well as the chemical properties of copernicium(Cn), nihonium(Nh), flerovium(Fl), and even moscovium(Mc) in their elemental states are presented. Recent studies confirm that, although the chemical properties of SHEs generally follows the periodic trends observed in their lighter homologs, they also exhibit deviations due to the strong relativistic effects on the electron configurations. From a future perspective, anticipated advancements in experimental techniques and theoretical models will further elucidate the underlying principles of the periodic table and enable the exploration of heavier elements.

In the field of superheavy element chemistry, the study of the chemical properties of nihonium (Nh, Z = 113) is currently in the focus. To chemically characterize Nh, fast gas-phase chemistry experiments are essential. Hereto, a new thermochromatographic detection system named LEGEND has been developed for chemistry experiments behind the gas-filled recoil separators SHANS/SHANS2. The presented system will be further developed to higher starting point temperatures of the negative temperature gradient, thereby enabling the investigation of less volatile chemical species. A recoil transfer chamber with a vacuum window acts as an interface between the separator and the thermochromatography detector array, whereas a gas circulation and purification system ensures the required high gas purities. Finally, a state-of-the-art data acquisition system allows for event-by-event alpha-particle and spontaneous fission fragment spectroscopy. The measurement efficiency of detecting alpha-particles adsorbed on the active surface is 89.1%. Using the nuclear fusion-evaporation reactions 169 Tm( 40 Ar, x n) 204-206 Fr and 153 Eu( 40 Ar, x n) 184-185 Tl, short-lived radioisotopes 205 Fr ( t 1 /2 = 3.92 s) and 185 Tl ( t 1/2 = 1.93 s) were produced for first online experiments behind SHANS. The herein presented results render the LEGEND system suitable for gas adsorption chromatography experiments with short-lived 284 Nh ( t 1/2 approximate to 0.77 s).

Present study is the first attempt on the application of ionic liquid (IL) for the extraction of At-211 with the 7.21-h-half-life in targeted alpha-particle therapy. We produced the nuclide to investigate utilities of several ionic liquids, namely, [C(4)mim][Tf2N], [C(6)mim][Tf2N], [C(8)mim][Tf2N], [C(8)mim][PF6], and [C(8)mim][BF4] in solvent extraction and back extraction for the practical application of a Rn-211/At-211 generator. Astatine extraction with ionic liquids was investigated in detail in this study, and the extraction mechanism was elucidated for the first time.

Seawater is a valuable source of uranium (U) resources, and harnessing it effectively can play a crucial role in promoting nuclear energy.

Prussian blue (PB) is an economical material with exceptional sorption capacity and strong selectivity for radiocesium removal, making it a highly promising candidate for wastewater treatment. However, its microcrystalline structure and fine powder form pose challenges to its industrial application. While alginate-based granulation offers a viable method for preparing inorganic ion exchangers, the beads often suffer from insufficient mechanical strength. To overcome this limitation, this study developed novel millimeter-sized composite particles (SA-PB beads) by encapsulating PB within a silica-alginate hybrid matrix, and assessed their cesium removal efficiency through both batch and column experiments. The characterization results revealed that the incorporation of silica significantly enhanced the mechanical strength of the composite material, as compared to adsorbents without silica. Notably, the SA-PB beads containing 25 wt% PB exhibited both excellent mechanical strength and high Cs+ sorption capacity. The uptake of Cs+ on the fabricated beads followed both pseudo-secondorder kinetic model and the Langmuir isotherm. The maximum sorption capacity of the SA-PB beads was determined to be 22.8 mg/g at 25 degrees C, higher than that of most PB-based composites in bead, sponge, or filter forms. Thermodynamic analysis revealed that Cs+ sorption is a spontaneous and endothermic process, while selectivity tests showed strong Cs+ uptake even in the presence of competing ions, with separation factor values exceeding 8.0. Mechanistic studies identified Cs+ binding to cyano groups and immobilization within the lattice spaces of PB crystals. Column studies further demonstrated the practical applicability of the SA-PB beads as a stationary phase for Cs+ removal. This study not only highlights the SA-PB beads as a highly efficient composite for Cs+ uptake, but also provides valuable insights for designing granulated composite materials with high mechanical strength and sorption efficiency.

A gas-phase chemical study of rhenium carbonyls was carried out using short-lived radioisotopes produced at a heavy-ion accelerator. The Re isotopes produced in the nuclear reactions of natGd(23Na,xn)172-177Re were pre-separated with a gas-filled recoil ion separator and their carbonyls were synthesized in a mixture of inert gas and carbon monoxide. Using a low temperature isothermal chromatography apparatus, the adsorption enthalpies of Re carbonyls were derived to be ΔHads = -42 ± 2 kJ mol-1 on a Teflon® surface by fitting the external chromatograms with a Monte Carlo simulation program. A chemical yield of 25% relative to that of the transport yield for Re by a He/KCl gas-jet was achieved. The laser-ablation time-of-flight mass-spectrometric technique was employed to identify the species of Re carbonyls produced in the gas phase. The most stable species was deduced to be Re(CO)5 based on the mass-spectrometric analysis as well as quantum chemistry calculations.

This study utilizes a dynamic mesh technology to investigate the dynamic performance of aerostatic thrust bearings with orifice restrictor, multiple restrictors, and porous restrictor. An experiment, which investigates the bearing static load capacity, was carried out to verify the calculation accuracy of dynamic mesh technology. Further, the impact of incentive amplitude, incentive frequency, axial eccentricity ratio, and non-flatness on the bearing dynamic performance was also studied. The results show incentive amplitude effect can be ignored at the condition of amplitude less than 5% film thickness, while the relationship between dynamic characteristics and incentive frequency presented a strong nonlinear relationship in the whole frequency range. The change law of dynamic stiffness and damping coefficient for porous restrictor was quite different from orifice restrictor and multiple restrictors. The bearing dynamic performance increased significantly with the growth of axial eccentricity ratio, and the surface non-flatness enhanced dynamic performance of aerostatic thrust bearings.

Many researchers concentrate on improving the stiffness and stability of aerostatic bearings, however the contradiction between stiffness and stability is still existed. Therefore, orifice, multiple, and porous restrictors are designed to illustrate the influence of restrictor characteristics on the stability and stiffness of the aerostatic circular pad bearings. Because both the stiffness and stability of aerostatic bearings are determined by the internal pressure distribution, the full Navier-Stokes (N-S) equations are applied to solve internal pressure distribution in bearing film by using computational fluid dynamics (CFD) method. Simulation results present that the stiffness and stability of aerostatic circular pad bearings are influenced significantly by geometrical and material parameters, such as film thickness, orifice diameters, and viscous resistance coefficient. Verified by the experimental data, the micro vibration of orifice restrictor is almost the same as multiple restrictors with amplitude of 0.02 m/s 2 , but it is much stronger than the porous restrictors with acceleration of 0.006 m/s 2 . The optimal stiffness of multiple restrictors increased by 46%, compared to only 30.2 N/μm of orifice restrictor, and the porous restrictors had obvious advantage in the small film thickness less than 6 μm where the optimal stiffness increased to 38.3 N/μm. The numerical and experimental results provide guidance for improving the stiffness and stability of aerostatic bearings.

In this study, a fractal method was applied to calculate the permeability for compressible gas flow through a porous restrictor in aerostatic bearings. A mathematical permeability model without any empirical parameters was established according to the fractal theory, gas conservation equations and Darcy's Law. The box-counting method was applied to determine the pore area fractal dimension and tortuosity fractal dimension. The effects of the scanning magnification and image size on the calculation results of the fractal dimension were also investigated. The porosity characteristics of the scanning images have obvious self-similarity, and the diameters of the maximum pore and minimum pore satisfy the fundamental condition of fractal analysis. Magnification ranges of 50-100x and 1-2kx were appropriate for calculating the permeability of ceramic and graphite porous restrictors, respectively. Image pixels of 512 x 512 were sufficient to ensure the accuracy of permeability calculation. In addition, an experimental platform was constructed to measure the permeability of ceramic and graphite porous restrictors. The differences between the calculation results and the experimental data for both ceramic and graphite porous restrictors were less than 10%, which demonstrated that the permeability for compressible gas flow through a porous restrictor in aerostatic bearings can be accurately predicted by the fractal calculation method. (C) 2018 Elsevier Ltd. All rights reserved.

In ultra-precision machine tool, the running accuracy of aerostatic bearings has a great influence on the machined surface topographies. However, the mechanism of aerostatic bearings running accuracy has not been fully understood. In this paper, a method based on computational fluid dynamic (CFD) method and dynamic mesh technology (DMT) was proposed to quantitatively study the effects of manufacturing errors on the running accuracy of aerostatic porous bearings. The different types of waviness errors and non-flatness errors are modeled based on the actual measurement results of spindle and thrust bearing, respectively. The DMT was applied in CFD method to simultaneously solve the Navier-Stokes (N-S) equations and the Newton's law. The calculation results show that the radial running accuracy of journal bearing can be improved by reducing the waviness amplitude or spatial wavelength, the axial running accuracy of thrust bearing increased with the decrease of non-flatness amplitude. Besides, a nanometer system for measuring the running accuracy of aerostatic porous bearings was constructed based on the Donaldson reversal method. The bearing rotation" movement trajectory of calculation results was very similar with the experiment results, which verified the validity of calculation method proposed in this study. Both the calculation results and experimental data confirmed that the effect of waviness errors on the bearing running accuracy was much more obvious than non-flatness errors, which provide the useful guidance for the design and manufacturing of aerostatic porous bearings.

Numerical and experimental research on the effects of manufacturing errors on the static performance of aerostatic porous journal bearings is presented. The effects of circumferential waviness, taper, concavity, and convexity on the bearing film thickness were modeled based on the experimental results. The effects of amplitude and spatial wave length on the bearing film pressure, load capacity and stiffness were investigated by solving the Darcy-Forchheimer law and Navier-Stokes equations. Both the numerical results and experimental data show that the bearing static characteristics were significantly influenced by the manufacturing errors. Circumferential waviness errors caused the obvious inhomogeneity of the flow field and the transformation of morphology of the high-pressure region, whereas axial errors had a significant impact on the area and location of the high-pressure region. The bearing load capacity and stiffness can be improved by increasing the amplitude of the manufacturing errors, except for the concavity errors. Both the bearing load capacity difference and stiffness difference increased with an increase in the axial errors' amplitude. For the manufacturing errors, the calculation results are close to the measurement data. Therefore, it is necessary to consider the influence of manufacturing errors on the bearing static characteristics in numerical calculations.

The machined surface topography in the ultra-precision machining process was obviously affected by the angular stiffness of aerostatic bearings. In this study, a numerical model was established to investigate the influence of operating conditions, geometric parameters and manufacturing error on the angular stiffness of aerostatic bearings with orifice restrictor. The calculation procedure for bearing angular stiffness was proposed based on the finite element method (FEM) and the proportional division method. The numerical results presented that film pressure distribution was significantly affected by the bearing deflection angle and the manufacturing error. It was confirmed that there was a suitable film thickness corresponding to the maximum angular stiffness, and the suitable film thickness increased with the growth of orifice diameter. The bearing angular stiffness increased with the rise of eccentricity, the thrust bearing angular stiffness can be improved by increasing the amplitude of non flatness error and the thrust eccentricity, which can be used to improve the machining quality of ultra-precision machine tools. Besides, a precision experimental system was constructed to measure the angular stiffness of aerostatic bearings at the different supply pressure. The biggest difference between the experimental data and calculation results was less than 6.7%, which demonstrated the numerical calculation method proposed in this paper can be applied to optimize the angular stiffness of aerostatic bearings.

A series of silica sorbents with different content of amidoxime groups were prepared through co-condensation method and applied to extract uranium from saline lake brine. The optimum amidoxime group content was determined and effects of pH on uranium sorption were investigated. Sorption kinetic and isotherms were also investigated. XPS analysis indicated that the adsorption mechanism of uranium was attributed to the interaction between uranyl ion and N in the amidoxime. Amidoximated silica could efficiently absorb the naturally occurring uranium in the saline lake brine samples from Qinghai, China.

In order to enhance the selectivity of Saccharomyces cerevisiae for uranium, amidoximation of the biomass was performed. The obtained biosorbent was characterized by FTIR and SEM analysis, results showed that amidoxime groups were successfully grafted on the biomass surface. The effects of initial solution pH, time, initial uranium concentration and ion strength on uranium sorption by the amidoximated biomass were studied and the optimal sorption conditions were determined. Furthermore, desorption results revealed that the amidoximated biosorbent can be used at least three times. The uranium sorption kinetics of both amidoximated and raw biomass can be depicted by the nonlinear pseudo-second-order kinetic equation. The nonlinear Langmuir and Freundlich models fitted well with the equilibrium data of amidoximated biomass. Trace uranium sorption from salt lake brine samples suggested that the selectivity of S. cerevisiae was obvious enhanced after amidoximation. The prepared amidoximated biomass can be used as a potential sorbent for selective uranium recovery from salt lake brines.

The sorption of uranium(VI) from aqueous solutions was investigated using synthesized amidoximed silica. Batch experiments were conducted to study the effects of contact time, initial solution pH, solid–liquid ratio, initial uranium concentration and coexisting ions on uranium sorption. The desorbing of uranium was also investigated. The maximum uranium sorption capacity onto amidoximed silicate was estimated to be 156 mg g−1 under the determined optimal experimental conditions. This work suggested that amidoximed silicate can be used as a highly efficient adsorbent for uranium removal from aqueous solutions.