Hydrothermal synthesis of zeolites-calcium silicate hydrate composite from coal fly ash with co-activation of Ca(OH)_(2)-NaOH for aqueous heavy metals removal

Coal fly ash is a typical secondary aluminum/silicon resource.The preparation of zeolite-type absorbent is a potential way for its value-added utilization,while the purity and adsorption property of zeolite are limited due to the occurrence of side reactions in the synthesis process.In this study,a designated composite consisted of crystalline zeolites and amorphous calcium silicate hydrate was selected,which was direct synthesized from fly ash under conditions of a Ca/Si molar ratio of 0.8,an initial NaOH concentration of 0.5 mol/L,a hydrothermal temperature of 170℃and a liquid–solid ratio of 15 mL/g.The results indicated that this composite had superior adsorption property for a variety of heavy metals,which was based on the exchange of calcium and sodium ions in zeolites and calcium silicate hydrate.Its adsorption capacities for Pb^(2+),Ni^(2+),Cd^(2+),Zn^(2+),Cu^(2+)and Cr^(3+)attained 409.4,222.4,147.5,93.2,101.1 and 157.0 mg/g,respectively,in single solution with a pH of 4.5.After regulating the synthesis conditions,the transformation of amorphous calcium silicate hydrate into crystallized tobermorite weakened the adsorption capacity of the composite.Besides,due to the competitive adsorption in a multiple ions solution,the adsorption capacities for these heavy metals had a reduction.

Protein corona mediated liposomal drug delivery for bacterial infection management

Liposomes have been widely investigated as a class of promising antibiotic delivery systems for the treatment of life-threatening bacterial infections.However,the inevitable formation of protein corona on the liposomal surface can heavily impact in vivo performance.A better understanding of the effects of protein corona on liposomal behavior can significantly improve antibacterial liposomal drug development.Here,the critical role of protein corona in mediating liposome-bacteria interactions was elucidated.Adsorption of negatively charged protein on cationic liposome weakened electrostatic attractionenhanced liposomal binding to the bacteria.Cumulative complement deposition on anionic liposome composed of phosphatidylglycerol(DSPG s Lip)contributed to a superior binding affinity of DSPG s Lip to planktonic bacteria and biofilms,which was exploited to enhance bacteria-targeted drug delivery.In both S.aureus-related osteomyelitis and pneumonia mice models,DSPG s Lip was demonstrated as a promising antibiotic nanocarrier for managing MRSA infection,indicating the benefits of lipid composition-based protein corona modulation in liposomal antibiotic delivery for bacterial infection treatment.

Nano-single-crystal-constructed submicron MnCO_(3) hollow spindles enabled by solid precursor transition combined Ostwald ripening in situ on graphene toward exceptional interfacial and capacitive lithium storage

Hollow structuring has been identified as an effective strategy to enhance the cycling stability of electrodes for rechargeable batteries due to the outstanding volume expansion buffering efficiency,which motivates ardent pursuing on the synthetic approaches of hollow materials.Herein,an intriguing route,combining solid precursor transition and Ostwald ripening(SPTOR),is developed to craft nano single-crystal(SC)-constructed MnCO_(3) submicron hollow spindles homogeneously encapsulated in a reduced graphene oxide matrix(MnCO_(3) SMHSs/rGO).It is noteworthy that the H-bonding interaction between Mn_(3)O_(4) nanoparticles(NPs)and oxygen-containing groups on GO promotes uniform anchoring of Mn_(3)O_(4) NPs on GO,mild reductant ascorbic acid triggers the progressive solid-to-solid transition from Mn_(3)O_(4) NPs to MnCO_(3) submicron solid spindles(SMSSs)in situ on GO,and the Ostwald ripening process induces the gradual dissolution of interior polycrystals of MnCO_(3) SMSSs and subsequent recrystallization on surface SCs of MnCO_(3) SMHSs.Remarkably,MnCO_(3) SMHSs/rGO delivers a 500th lithium storage capacity of 2023 mAh g^(-1) at 1000 mAg^(-1),which is 10 times higher than that of MnCO_(3) microspheres/rGO fabricated from a conventional Mn^(2+)salt precursor(202 mAh g^(-1)).The ultrahigh capacity and ultralong lifespan of MnCO_(3) SMHSs/rGO can be primarily attributed to the superior reaction kinetics and reversibility combined with exceptional interfacial and capacitive lithium storage capability,enabled by the fast ion/electron transfer,large specific surface area,and robust electrode pulverization inhibition efficacy.Moreover,fascinating in-depth lithium storage reactions of MnCO_(3) are observed such as the oxidation of Mn^(2+)in MnCO_(3) to Mn^(3+)in charge process after long-term cycles and the further lithiation of Li_(2)CO_(3) in discharge process.As such,the Carbon Energy.SPTOR approach may represent a viable strategy for crafting various hollow functional materials with metastable nanomaterials as precursors.

Implications of Stem Cells and Cancer Stem Cells for Understanding Fomation and Therapy of Cancer

Most cancers are heterogeneous with respect to proliferation and differentiation. There is increasing evidence suggesting that only a minority of cancer cells, tumorigenic or tumor initiating cells, possess the capacity to proliferate extensively and form new hematopoietic cancer or solid tumors. Tumor initiating cells share characteristics required for normal stem cells. The dysregulation of self-renewal and proliferation of stem cells is a likely requirement for cancer development. This review formulates a model for the origin of cancer stem cells and regulating self-renewal which influences the way we study and treat cancer.

Development of Direct Reduced Iron in China:Challenges and Pathways

The steel industry is considered an important basic sector of the national economy,and its high energy consumption and carbon emissions make it a major contributor to climate change,especially in China.The majority of crude steel in China is produced via the energy-and carbon-intensive blast furnace–basic oxygen furnace(BF–BOF)route,which greatly relies on coking coal.In recent years,China’s steel sector has made significant progress in energy conservation and emission reduction,driven by decarbonization policies and regulations.However,due to the huge output of crude steel,the steel sector still produces 15%of the total national CO_(2) emissions.The direct reduced iron(DRI)plus scrap–electric arc furnace(EAF)process is currently considered a good alternative to the conventional route as a means of reducing CO_(2) emissions and the steel industry’s reliance on iron ore and coking coal,since the gas-based DRI plus scrap–EAF route is expected to be more promising than the coal-based one.Unfortunately,almost no DRI is produced in China,seriously restricting the development of the EAF route.Here,we highlight the challenges and pathways of the future development of DRI,with a focus on China.In the short term,replacing natural gas with coke oven gas(COG)and byproduct gas from the integrated refining and chemical sector is a more economically feasible and cleaner way to develop a gas-based route in China.As the energy revolution proceeds,using fossil fuels in combination with carbon capture,utilization,and storage(CCUS)and hydrogen will be a good alternative due to the relatively low cost.In the long term,DRI is expected to be produced using 100%hydrogen from renewable energy.Both the development of deep processing technologies and the invention of a novel binder are required to prepare high-quality pellets for direct reduction(DR),and further research on the one-step gas-based process is necessary.

Pathfinding Pulsar Observations with the CVN Incorporating the FAST

The importance of Very Long Baseline Interferometry(VLBI)for pulsar research is becoming increasingly prominent and receiving more and more attention.We present the pathfinding pulsar observation results with the Chinese VLBI Network(CVN)incorporating the Five-hundred-meter Aperture Spherical radio Telescope(FAST).On MJD 60045(11th April 2023),PSRs B0919+06 and B1133+16 were observed with the phase-referencing mode in the L-band using four radio telescopes(FAST,TianMa,Haoping,and Nanshan)and correlated with the pulsar binning mode of the distributed FX-style software correlator in Shanghai.After further data processing with the NRAO Astronomical Image Processing System(AIPS),we detected these two pulsars and fitted their current positions with accuracy at the milliarcsecond level.By comparison,our results show significantly better agreement with predicted values based on historical VLBI observations than those with previous timing observations,as pulsar astrometry with the VLBI provides a more direct and model-independent method for accurately obtaining related parameters.

Design a Special Fixture for Tractor Lever

Aiming at the problems of long time and poor machining precision in processing the tractor lever workpiece,a special fixture suitable for the tractor lever workpiece is designed by analyzing the processing technology of the lever workpiece,and the workpiece is accurately positioned and tightened under the action of the special fixture.Efficient machining of the workpiece can be achieved by using a drill template.The fixture not only has the advantages of high production efficiency,low cost and high life,but also effectively improves the processing technology of the workpiece,and has certain reference value for the subsequent fixture improvement design.

聚醚酮酮共聚物的结构表征及热分解行为

对聚醚酮酮共聚物的分子结构和热分解行为进行了详细的研究。采用红外光谱、核磁共振氢谱和核磁共振碳谱对聚醚酮酮的结构进行了分析表征,所得结果与聚合物预期分子结构相一致。由于聚醚酮酮苯环上的氢所处环境相似,化学位移相近,出现了部分峰的重叠,导致核磁共振氢谱难以准确地确定对苯和间苯的比例,但通过核磁共振碳谱可确定结构中二者的比例。通过差示扫描量热仪、热重分析和热重-红外-气质联用技术对聚醚酮酮的热分解行为进行了研究。结果表明,随着高温处理时间的延长,聚合物发生了交联,结晶能力减弱、玻璃化转变温度升高、熔点降低。与对苯/间苯的比例无关,聚醚酮酮共聚物的5%失重温度都在559~565℃之间,并且加热至800℃后仍具有较高的残碳量,说明具有较好的热稳定性。最后,对其热分解产物及分解机理进行了探究分析。

Large-Scale Renewable Energy Transmission by HVDC: Challenges and Proposals

Renewable energy transmission by high-voltage direct current(HVDC)has attracted increasing attention for the development and utilization of large-scale renewable energy under the Carbon Peak and Carbon Neutrality Strategy in China.High-penetration power electronic systems(HPPESs)have gradually formed at the sending end of HVDC transmission.The operation of such systems has undergone profound changes compared with traditional power systems dominated by synchronous generators.New stability issues,such as broadband oscillation and transient over-voltage,have emerged,causing tripping accidents in large-scale renewable energy plants.The analysis methods and design principles of traditional power systems are no longer suitable for HPPESs.In this paper,the mechanisms of broadband oscillation and transient over-voltage are revealed,and analytical methods are proposed for HPPESs,including small-signal impedance analysis and electromagnetic transient simulation.Validation of the theoretical research has been accomplished through its application in several practical projects in north,northwest,and northeast region of China.Finally,suggestions for the construction and operation of the future renewable-energy-dominated power system are put forward.

Age and geochemistry of Early Ordovician A-type granites in the Northeastern Songnen Block,NE China

Early Ordovician A-type granites in the northeastern(NE) Songnen Block NE China were studied to better understand the geodynamic settings in this region.This research presents new zircon U–Pb ages and wholerock geochemical data for the Early Ordovician granites in the NE Songnen Block. Zircon U–Pb dating indicates that the granite in the Cuibei, Hongxing, and Meixi areas in the NE Songnen Block formed in the Early Ordovician with ages of 471–479 Ma. The granites show geochemical characteristics of high SiO2 and K2 O compositions and low FeOT, MgO, CaO, and P2 O5 compositions. They belong to a high K calc-alkaline series and display a weak peraluminous featurPe with A/CNK values of 0.98–1.14. The rocks have aREE composition of 249.98–423.94 ppm,and are enriched in LREE with(La/Yb)Nvalues of2.87–9.87, and display obvious Eu anomalies(d Eu =0.01–0.29). Trace elements of the studied granites are characterized by enrichment in Rb, Th, U, Pb, Hf, and Sm,and depletion of Ba, Nb, Ta, and Sr. They display geochemical features of high Zr +Y + Nb+Ce values(324–795 ppm) and Ga/Al ratios consistent with A-type granites. Based on particular geochemical features, such as high Rb/Nb(7.98–24.19) and Y/Nb(1.07–3.43), the studied A-type granites can be further classified as an A2-type subgroup. This research indicates that the Early Ordovician A-type granites were formed by the partial melting of ancient crust in an extensional setting. Lower Sr/Y and(Ho/Yb)Nratios indicate that plagioclase and amphibole are residual in the source, and garnet is absent, implying that the magma was generated at low levels of pressure. By contrast, the contemporaneous granites in the SE Xing'an Block suggest a subduction-related tectonic setting, and its adakitic property indicates a thickened continental crust.We suggest that the Paleo-Asian Ocean plate between the Xing'an and Songnen blocks subducted northward during the Early Ordovician. Meanwhile, the NE Songnen Block was exposed to a passive continental margin tectonic setting.

An integrated and efficient process for borax preparation and magnetite recovery from soda-ash roasted ludwigite ore under CO–CO_(2)–N_(2) atmosphere

To realize the comprehensive utilization of ludwigite ore,an integrated and efficient route for the boron and iron separation was proposed in this work,which via soda-ash roasting under CO–CO_(2)–N_(2) atmosphere followed by grind-leaching,magnetic separation,and CO_(2) carbonation.The effects of roasting temperature,roasting time,CO/(CO+CO_(2))composition,and Na_(2)CO_(3) dosage on the boron and iron separation indices were primarily investigated.Under the optimized conditions of the roasting temperature of 850℃,roasting time of 60 min,soda ash dosage of 20 wt%,and CO/(CO+CO_(2)) of 10 vol%,92%of boron was leached during wet grinding,and 88.6%of iron was recovered during the magnetic separation and magnetic concentrate with a total iron content of 61.51 wt%.Raman spectra and^(11)B NMR results indicated that boron exists asB(OH)_(4)^(-) in the leachate,from which high-purity borax pentahydrate could be prepared by CO_(2) carbonation.

Influencing of students＇ health status and physical education

Schools and parents should pay attention to health education for students＇ health awareness and good health habits, to establish a correct concept of health. School mental health education should be the first place; school should create a positive learning environment for students to get knowledge and skills of exercising. Especially in the nine years of compulsory education stage, we should ensure necessary physical exercise, reasonable arrangements for extracurricular activities to improve students＇ physical fitness. We should improve the school＇ s sports facilities, and create a good campus atmosphere. Schools should actively carry out extra-curricular sports activities, improve the level of quality of physical education teachers, develop students＇ sports consciousness, and improve material conditions for the students to create a good learning environment, meanwhile, we should increase the content of education, and enrich the content of physical education to enable students to select and reach more sports.

Enrichment of Nb and Ti from carbonatite pyrochlore ore via calcining-slaking followed by gravity separation

In this work,a novel process consisting of calcining-slaking followed by gravity separation for the enrichment of niobium(Nb)and titanium(Ti)from carbonatite pyrochlore ore was proposed,validated and compared with the current mainstream flotation method.During calcining of the pyrochlore ore,within which the carbonates were transformed into lime.Subsequently,when the calcined ore was slaked,lime was transformed into hydroxide with fine particles which were amenable to gravity separation.After calcining at 900℃for 60 min,slaking at 90℃for 10 min with a liquid–solid ratio of 3:1(mL/g),approximately 40%of tailings can be removed by gravity separation,the recoveries of Nb and Ti were 94.7%and 91.0%,and the enrichment ratios of Nb and Ti were 1.61 and 1.43,respectively.The new approach exhibits high separation efficiency of carbonate gangue minerals and valuable minerals,satisfactory recoveries of niobium as well as titanium can be achieved.

Dimensionless Variation of Seepage in Porous Media with Cracks Stimulated by Low-Frequency Vibration

Pulse excitation or vibration stimulation was imposed on the low permeable formation with cracks to enhance the production or injection capacity.During that process,a coupling of wave-induced flow and initial flow in dual-porous media was involved.Researchers had done much work on the rule of wave propagation in fractured porous media,whereas attentions on the variation law of flow in developing low permeable formation with cracks under vibration stimulation were not paid.In this study,the effect of low-frequency vibration on the seepage in dual-porous media was examined for the application of wave stimulation technology in developing reservoirs with natural cracks.A model for seepage of single-phase liquid in porous media with cracks under low-frequency vibration excitation was built by combining wave propagating theory for porous media with cracks and dual-porous media seepage mechanics.A governing equation group for the model,which was expressed by dimensionless fluid and solid displacements,was derived and solved with a numerical method.Variable physical properties were simulated to check the applicability of external low-frequency vibration load on dual-porous media and a parametric study for various vibration parameters.Stimulation of low-frequency vibration affected flow velocities of crack and rock matrix fluids.Compared with that in single-porous media,the stimulation effect on the fluid inner matrix of dual-porous media was relatively weakened.Different optimal vibration parameters were needed to increase the channeling flow between the crack and rock matrix or to only promote the flow velocity in the rock matrix.The theoretical study examines wave-coupled seepage field in fractured porous media with results that are applicable for low-frequency stimulation technology.

Molybdenum Concentration and the Risk of Spontaneous Preterm Birth: A Nested Case-Control Study — Beijing Municipality, China, 2018–2020

What is already known about this topic?The level of molybdenum(Mo)in a mother’s urine has been linked to the growth rate of the fetus and the blood pressure levels in children.What is added by this report?We evaluated the variations in maternal plasma Mo concentrations throughout pregnancy and their potential association with the risk of spontaneous preterm birth(SPB).What are the implications for public health practice?Future research must determine the Mo levels in pregnant women across various regions in China.Moreover,particular attention needs to be given to the potential increase in Mo concentration throughout pregnancy and its possible adverse impacts on the health of both the mother and the fetus.

Anti-aging activity and their mechanisms of natural food-derived peptides:current advancements

Recently,there has been a growing focus on researching ways to delay aging and protect against age-related illnesses.Small molecular exogenous peptides,sourced from dietary elements like animals,plants,and microorganisms,have demonstrated considerable potential in exerting anti-aging effects.Notably,natural food-derived peptides have exhibited enhanced stability,safety,absorption efficiency,and heightened biological activity.These attributes position them with a greater potential for mitigating aging-related disorders compared to alternative anti-aging drugs or phytochemicals.This review summarizes the origins,structural attributes,and isolation methods of natural foodderived peptides with anti-aging properties.It also explores how these external peptides improve aging-related conditions such as neurodegenerative diseases,skin aging,and metabolic disorders.The underlying mechanisms dictating their impact on well-conserved signaling pathways—encompassing oxidative stress,inflammation,apoptosis,and collagen synthesis—are meticulously elucidated.This paper engages in an insightful exploration of the key challenges and pivotal trajectories,grounded in ongoing research endeavors.As a result,this review is poised to offer authoritative scientific guidance and invaluable support for the practical implementation of natural food-derived peptides in the realm of anti-aging applications within the food,pharmaceutical,and cosmetic industries.

Modeling and Simulation of Hydrogen Energy Storage System for Power-to-gas and Gas-to-power Systems

By collecting and organizing historical data and typical model characteristics,hydrogen energy storage system(HESS)-based power-to-gas(P2G)and gas-to-power systems are developed using Simulink.The energy transfer mechanisms and numerical modeling methods of the proposed systems are studied in detail.The proposed integrated HESS model covers the following system components:alkaline electrolyzer(AE),highpressure hydrogen storage tank with compressor(CM&H_(2) tank),and proton-exchange membrane fuel cell(PEMFC)stack.The unit models in the HESS are established based on typical U-I curves and equivalent circuit models,which are used to analyze the operating characteristics and charging/discharging behaviors of a typical AE,an ideal CM&H_(2) tank,and a PEMFC stack.The validities of these models are simulated and verified in the MicroGrid system,which is equipped with a wind power generation system,a photovoltaic power generation system,and an auxiliary battery energy storage system(BESS)unit.Simulation results in MATLAB/Simulink show that electrolyzer stack,fuel cell stack and system integration model can operate in different cases.By testing the simulation results of the HESS under different working conditions,the hydrogen production flow,stack voltage,state of charge(SOC)of the BESS,state of hydrogen pressure(SOHP)of the HESS,and HESS energy flow paths are analyzed.The simulation results are consistent with expectations,showing that the integrated HESS model can effectively absorb wind and photovoltaic power.As the wind and photovoltaic power generations increase,the HESS current increases,thereby increasing the amount of hydrogen production to absorb the surplus power.The results show that the HESS responds faster than the traditional BESS in the microgrid,providing a solid theoretical foundation for later wind-photovoltaic-HESS-BESS integration.