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Due to continuous self-sealing and good mechanical properties, the Tamusu clay rock of Inner Mongolia has been identified as the pre-selected site for high-level radioactive waste geological disposal site in China. The study of chemical behaviors related to Tamusu clay rock, such as nuclide migration, will be an important content of the performance assessment and safety assessment of the disposal repository in the future. The diffusion behavior of HTO and Se(IV)/Se(VI) with different compacted column lengths in Tamusu clay rock is discussed by the through-diffusion method. The diffusion coefficient, rock capacity factor, effective porosity, and other diffusion parameters closely related to nuclide migration are calculated, and the mechanism of nuclide diffusion is preliminarily discussed. The results show that D a (6.23 × 10−11∼17.96 × 10−11 m2 s−1), D e (1.62 × 10−11∼4.67 × 10−11 m2 s−1) for HTO increase with the increase of the compacted column length, and it is proposed that the diffusion process of HTO is affected by the change of geometrical factor and path tortuosity. D a (7.29 × 10−13∼1.74 × 10−13 m2 s−1), D e (5.15 × 10−12∼2.15 × 10−12 m2 s−1) for Se(IV), D a (3.11 × 10−12∼1.09 × 10−12 m2 s−1), D e (2.53 × 10−12∼1.09 × 10−12 m2 s−1) for Se(VI), which decrease with the increase of the compacted column length, it is mainly due to the existence of anion repulsion effect.

Modifying natural rubber latex (NRL) and blending it with NRL can improve NRL performance and expand application fields. The performance of co-blended latex will change due to changes in non-rubber components during storage. Therefore, it is important to study the change of properties during the storage of co-blended latexes. In this paper, 30% methyl methacrylate grafted natural rubber (MG30) was synthesized by cumene hydroperoxide/ tetraethylenepentamine (CHPO/TEPA) initiating system, MG30 and NRL were mixed in different proportions to study the morphology and physical and mechanical properties, and the colloidal properties and emulsion properties of co-blended latexes were studied during storage. The results showed that the mechanical stability of NRL and co-blended latexes were high and the viscosity gradually increased during storage. The study of the vulcanization characteristics of the co-blended latexes films and the physical and mechanical properties of the vulcanized latex films showed that the vulcanization time of the co-blended films increased and the torque value increased in comparison to NRL. With the increase of MG30 content, the tensile strength and tear strength of the co-blended latexes vulcanized films showed a trend of increasing and then decreasing, and the co-blended film with 10% MG30 showed the best mechanical properties.

Based on the one-dimensional diffusion theory, the diffusion parameters were obtained from numerical fitting by the Cyclic Initial Value (CIV) program written by MATLAB. Taking the through-diffusion experimental of cesium (stable isotope 133Cs) as an example, on the premise of ensuring accuracy, fitting calculation was used to obtain the diffusion equilibrium time of Cs in different lengths bentonite column. The fitting results of diffusion test for tritium water (HTO) and Cs are both very well. The calculation results of the equilibrium time for Cs diffusion show that the equilibrium time obtained by CIV is less than the experimental period in both groundwater (GW) and seawater (SW). In GW environment, when the sensitivity is at the maximum setting value, the diffusion coefficient of Cs in 1.5 cm bentonite column could be calculated in a shorter period of time. Compared with the experimental period, the time was shortened by 110 days. The main purpose is to verify the feasibility of CIV through the experimental data of Cs in different column lengths. The CIV program can also be used to fit and calculate the experimental data of other ongoing diffusion experiments and get the equilibrium time required for diffusion experiments. It shows that the proposed models offer the advantages of saving experimental time and reducing experimental waste.

Tamusu area is the primary pre-selection site of clayrock disposal repository for high-level radioactive waste (HLW) in China. However, the research on the migration behavior of nuclides in Tamusu clayrock is still in its infancy. For the first time in laboratory, the diffusion behavior of Re(VII) in Tamusu clayrock core was studied by means of through-diffusion method. The effects of pH, ionic strength and humic acid on the diffusion behavior of Re(VII) in clayrock were studied. The effective diffusion coefficient, apparent diffusion coefficient and rock capacity factor value were obtained. All the experimental conditions of Re(VII) diffusion in Tamusu clayrock are compared with other geological samples under the same conditions in literature data. The diffusion mechanism of radionuclide in Tamusu clay is discussed, which can provide experimental data for site selection and safety assessment of high-level radioactive waste repository in China. The experimental results showed an effective application and reference for the countries disposed HLW in mudrocks or clayrocks, such as France, Belgium etc. in Europe. Moreover, this research can provide the original data support for the metallogenic regularity and prospecting prognosis of rare element rhenium in different geological environments.

With the emerging of sustainability, the fabrication of effective and eco-friendly agents for rubber industry has attracted extensive attention. In this study, a novel and nontoxic titanium dioxide-based vulcanization accelerator (xanthate-modified nanotitanium dioxide (TDSX)) with excellent antibacterial performance, for the first time, was synthesized under the catalyst of ceric ammonium nitrate. Notably, the thermal stability of xanthate was greatly enhanced after being grafted on titanium dioxide (TiO2) nanoparticles, in which the activation energy was increased from 6.4 to 92.5 kJ/mol, enabling the obtained TDSX with multiple functions, mainly consisting of fabulous vulcanization-promoting effects, reinforcing effects, antibacterial properties, and anti-ultraviolet aging effects for natural rubber (NR). Simultaneously, the TDSX can be effectively and uniformly dispersed in the rubber matrix along with the developed interface interaction between TDSX particles and rubber matrix. Compared to the traditional accelerators 2-mercaptobenzothiazole (M) system, the tensile strength and the tearing strength of NR/TDSX was improved by 26.3 and 40.4%, respectively. Potentially, our work for preparing green vulcanization accelerator can provide a new design strategy for multifunctional high performance elastomer materials.

Quantitative calculation based on the joint action of anion exclusion and sorption has not been reported. This article studies the diffusion behavior of Se(IV) in MX-80 bentonite fills in different lengths by the through-diffusion method. The anion exclusion and sorption are simultaneously considered and quantitatively calculated. The results show that the effective diffusion coefficient of Se(IV) decreases with the increasing lengths of bentonite plug, because of the joint action of anion exclusion and sorption. On this basis, the anion exclusion and sorption are first quantitatively calculated, then a new theory for calculation is proposed in this article. The calculation results show that the ratio of anion exclusion and sorption. In groundwaterenvironments and seawaterenvironments, the weight of sorption is lower than anion exclusion in diffusion process.

Adsorbents for uranium adsorption from aqueous solutions should possess several key properties, such as sufficient mechanical strength to withstand the impact forces during agitation and anti-biofouling activity to prevent the adhesion of microorganisms to the active sites. Herein, a simple design strategy for the facile construction of tannic acid@high amylose starch/polyvinyl alcohol (TA@HAS/PVA) fibers for efficient uranium adsorption is reported. The sustainable TA@HAS/PVA fibers were synthesized by crosslinking TA on HAS and PVA followed by solution spinning into anhydrous ethanol. The fibers exhibited satisfactory mechanical properties in terms of tensile strength (11.31 MPa) and tensile strain (159.56%), in addition to anti-biofouling activity, good adsorption capacity (86 mg g− 1), and excellent reusability. Furthermore, the adsorption process could be visually indicated by the color of the fibers. The results indicated that TA@HAS/PVA fibers were a promising candidate for industrial uranium adsorption.

Low transformation temperature welding (LTTW) consumables are characterized by a low martensite start temperature and a large fraction of martensite forming in the weld. It can efficiently reduce the tensile residual stress because the volume expansion associated with the martensitic transformation compensates for the thermal contraction during cooling. In this work, a LTTW wire, designated as EH200B, was created for the arc welding of advanced high-strength steel thin plates. In comparison to conventional ER70S-3 wires, this LTTW wire generated an opposite distortion pattern. Neutron diffraction measurements along the center thickness of the welded plates showed the maximum residual stress along the longitudinal direction (LD) in the weld region, and the heat-affected zone (HAZ) immediately adjacent to the weld region was reduced from ~330 MPa to below 240 MPa by using the LTTW wire. A finite element (FE) model was developed to predict the residual stress distributions of the plates welded under these two wires. The simulation results showed reasonable agreement with the volume-average neutron diffraction data. Compressive residual stress in the weld region using the LTTW wire was predicted by the FE method. Electron backscattered diffraction and x-ray diffraction measurements confirmed ~90% martensite was present in the LTTW weld. The fatigue life of DP980 steel lap joint panels using EH200B wire nearly doubled that of ER70S-3 wire. This improvement was attributed to the high strength and low LD residual stress in the weld and HAZ immediately adjacent to the weld.

Xanthate is a class of non-toxic, rapid, and eco-friendly rubber vulcanization accelerator, but it is seldom used in the rubber industry because of its poor thermostability and ease of decomposition. To overcome these drawbacks, silica supported sodium isobutyl xanthate (silica-s-SIBX) was prepared by chemically bonding SIBX onto the silica surface. After loading, the initial degradation temperature (T0), maximum degradation temperature (Tp), and final decomposition temperature (Tf) of silica-s-SIBX were increased by 85.8, 118.9, and 146.9 °C, respectively. Meanwhile, silica-s-SIBX could not only improve the dispersion of fillers in the rubber but also enhance the interfacial interaction between silica and the rubber matrix. Therefore, it may offer new scientific and technological opportunities for preparation of green additives in the rubber industry.

For the first time in laboratory, diffusion parameters of Se(IV) in the clay of Chinese Tamusu region(TMS clay) against compacted density, ionic strength and pH value were obtained by capillary method. Diffusion process can be Simplified by using one-dimensional semi-infinite medium diffusion model. The results show a good similarity with the international literature and meet the internationally recognized range of 10−9–10−12. This work will provide data support and theoretical references for the pre-selection of clay rock sites in China’s high-level radioactive waste deep geological repository.

Thorium is much more abundant than uranium in nature and has become one of the important potential energy sources in the future. It is because that a thorium-232(232Th) nucleus has the ability to produce a uranium-233(233U) nucleus by absorbing a neutron. The aim of this paper is to investigate the extraction and separation of thorium ions and uranyl ions from aqueous solution with N,N’-dimethyl-N,N’-dioctyl-4-oxaheptanediamide (DMDOHA) into ionic liquids of 1-methyl-3-butylimid-azolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]). The results show that the extractant DMDOHA has a good affinity toward thorium ions than uranyl ions in the present system, the maximum value of separation factor SFTh(IV)/U(VI) is 21.9 at pH 2.24. The extraction process of thorium ions and uranyl ions was confirmed to proceed by cation-exchange extraction mechanism. The DMDOHA extractant formed a major 3:1 complex with thorium ion and a major 2:1 complex with uranyl ion based on the relationship between log[DMDOHA] with logD.

Adsorption of Th(IV) on red soil and black soil was studied as a function of ionic strength, pH, solid–liquid ratio, contact time, temperature and initial concentration through batch static tests, and the soils were characterized by SEM, XRD and IR. The results showed that the adsorption reaction was rapidly and greatly affected by pH. The experimental data conformed to the Freudlich model and the pseudo-second-order kinetic model, reflecting nonlinear chemical adsorption. Furthermore, the intra-particle and liquid film diffusion occurred simultaneously during the Th(IV) adsorption on the soils, and adsorption reaction was controlled by cation exchange reactions. According to adsorption thermodynamics in this experiment, the adsorption of Th(IV) on these two soils was found to be a spontaneous and endothermic process. Both soils were good adsorbents; however, the adsorption rate of black soil was faster, and its adsorption capacity was larger.

Through-diffusion experiments with HSeO3− and SeO32− (as a surrogate of 79Se(IV)) in bentonite samples have been performed. The effect of density, magnetite and irradiation on the experimental results have been investigated. It could be shown that the effect diffusion coefficient decreased with the increasing density. In the γ-radiation bentonite and bentonite–magnetite, the diffusion coefficient for SeO32− and HSeO3− were (0.45–4.11) × 10−11 m2/s and (0.95–3.74) × 10−11 m2/s, respectively. While the Kd values were (1.19–4.00) × 10−4 m3/kg and (1.83–4.86) × 10−4 m3/kg, respectively. Moreover, the relationship of De and eacc could be described by Archie’s law. This study reveals that the magnetite has large influence on the diffusion, while the effect of γ radiation on the bentonite is similar.

A method was applied in the separation and determination of trace lithium in uranium products. Separation and enrichment of lithium was carried out through a micro-column packed with activated Al2O3 in an alkaline environment, having the lithium adsorbed while the uranium flowed through the column. And a sulfuric acid solution was adopted to elute lithium. The relative standard deviation were in the range of 4.08–6.72% (n = 5). The accuracy was studied by adding 5 µg lithium to the actual samples and the recoveries were between 99.7 and 100.3%, which indicates that the method is reliable and in good precision.

In this study, nine congeners of polybrominated diphenyl ethers (PBDEs) and sixteen congeners of polycyclic aromatic hydrocarbons (PAHs) were measured in water samples to elucidate their spatial distribution, congener profiles, sources and ecological risks in the Guanlan River during both the dry season (DS) and the wet season (WS). The concentration of Σ9PBDE ranged from 58.40 to 186.35 ng/L with an average of 115.72 ng/L in the DS, and from 8.20 to 37.80 ng/L with an average of 22.15 ng/L in the WS. Meanwhile, the concentration of Σ16PAHs was ranged from 121.80 to 8371.70 ng/L with an average of 3271.18 ng/L in the DS and from 1.85 to 7124.25 ng/L with an average of 908.11 ng/L in the WS. The concentrations of PBDEs and PAHs in the DS were significantly higher than those in the WS, probably due to the dilution of the river during the rainy season. Moreover, the spatial distribution of pollutants revealed decreasing trend in the concentration from upstream to downstream and almost identical pattern was observed during both seasons. The source apportionment suggested that penta-BDE and to some extent octa-BDE commercial products were major sources of PBDEs in the study area. However, the sources of PAHs were mainly comprised of fossil fuels and biomass burning, followed by the petroleum products and their mixtures. The results of the ecological risk assessment indicated PBDEs contamination posed high ecological risks, while PAHs exhibited low or no ecological risks in the study area. Consistent with the environmental levels, the ecological risks of pollutants were relatively lower in the WS, compared to that in the DS. The results from this study would provide valuable baseline data and technical support for policy makers to protect the ecological environment of the Guanlan River.

Banana pseudo-stems fibers were novel extracted via atmospheric liquefaction combined with TEMPO-mediated oxidation. Cellulose nanofibers (CNF) and nanocrystals (CNC) were subsequently obtained by high-intensity ultrasonic treatment and acidolysis, respectively. Liquefied residue content as well as its constituent varied with liquefaction time. Scanning electron microscopy and fourier transform infrared demonstrate that the progressive removal of non-cellulosic impurities. Morphological studies exhibit that CNF present a range of 3∼10 nm in diameter and 140∼690 nm in length, while CNC have average diameter of 3.5 ± 1.6 nm and a length of 93.3 ± 37.6 nm. XRD analysis indicates that the CNCs have a high crystallinity (95.6%). The thermal stability of the fibers was measured by thermogravimetric analysis. The structures and properties of CNF and CNC give it potential to be used in reinforcing polymeric matrix materials.

The extraction behavior and mechanism of uranium(VI) from aqueous solution with the multidentate ligand N,N,N″′,N″′-tetraoctyl-N″,N″-ethidene diglycolamide (TOE-BisDGA) as extractant were investigated. The extraction percentages of uranium(VI) were found to increase with increasing aqueous nitric acid solution. The extraction process was deduced to proceed by neutral extraction mechanism or ion association extraction mechanism, and the TOE-BisDGA extractant formed a major 1:1 complex with uranium(VI) in xylene system. The possible molecular structure of extracted pieces were presumed to be [UO2(NO3)2(TOE-BisDGA)] or [UO2(TOE-BisDGA)](NO3)2 or [UO2(NO3)TOE-BisDGA)](NO3) by ESI–MS and extraction mechanism.

Starch is considered as a cost-effective, abundant, renewable and environmental-friendly filler for rubber reinforcement via proper modification. In the present study, porous starch (PS) was modified by esterification with dodecenyl succinic anhydride (DDSA) for preparation of DDSA-modified porous starch (DDSA-PS). The suitable esterification conditions (e.g., temperature, time and dosage of DDSA) were discussed by single-factor experiments as 40 °C, 8 h, and 8 wt % (based on porous starch dry weight), respectively. Later on, a series of DDSA-PS/carbon black (CB)/natural rubber (NR) composites were prepared from the mixture of carbon black and DDSA-PS/NR compound that was pre-processed by co-coagulation of DDSA-PS and rubber latex. When the total filler dosage is constant as 60 parts per hundred rubber (phr), various properties of DDSA-PS/CB/NR composites were investigated by varying the composition ratio of DDSA-PS/CB. The results showed that when the ratio of DDSA-PS/CB was increased, the Payne effect of rubber compounds was attenuated to a large extent as well as the reduction of mechanical properties of vulcanized rubbers. Notably, the rolling resistance and hysteretic property were improved, reflected as the reduction of heat built-up, by incorporation of modified porous starch into the final NR composites. Therefore, DDSA-PS could be served as a promising filler for rubber industry partially instead of carbon black.

The interlayer cation of bentonite has obviously influence on the diffusion behavior of radionuclides. The diffusion behavior of Re(VII) in Na+- and Ca2+-bentonites was investigated by a through-diffusion method at bulk dry densities from 1000 kg/m3 to 1800 kg/m3. A modified multi-porosity model (APM), which subdivided the porosity into the interlayer porosity (eil), the diffuse double layer porosity (eddl) and free layer porosity (efree) in compacted bentonite, is employed to describe the distribution of the three porosities as a function of the bulk dry density and to explain the lower effective diffusion coefficient (De) and accessible porosity (eacc) of Re(VII) in Na+-bentonite compared to that in Ca2+-bentonite. With increasing bulk dry density, eacc decreased, leading to a decrease of De for Re(VII). eddl and eil are both related to the montmorillonite bulk dry density. Moreover eddl is also related to the external surface area (Aext) and the ionic strength. APM was successful in reproducing trends of eacc data for Re (this work), 35Cl and 125I (data from the literature) as a function of the bulk dry density. Compared to Ca2+-bentonite, Na+-bentonite had higher eil and eddl at the same compaction, indicating a less proportion of large pores. After combing with Archie's law, the dependency of De on bulk dry density was reproduced with a cementation factor of 2.2 and 2.6 for Na+- and Ca2+-bentonites, respectively.

Shading is an important factor affecting the cultivation of American ginseng, as it influences crop quality and yield. Rhizosphere microorganisms are also crucial for normal plant growth and development. However, whether different shade types significantly change American ginseng rhizosphere microorganisms is unknown.This study evaluated the rhizosphere soils of American ginseng under traditional, high flag and high arch shade sheds. High-throughput 16S rRNA gene sequencing determined the change of rhizosphere bacterial communities.The microbial diversity in rhizosphere soils of American ginseng significantly changed under different shading conditions. The bacteria diversity was more abundant in the high arch shade than flat and traditional shades. Different bacterial genera, including

Background The aerial parts of Salvia miltiorrhiza, which was considered to be the waste part and discarded during the root harvest, is rich in protocatechuic aldehyde (PAI). This study investigated the health-promoting effects of extracts and PAI from the aerial parts of Salvia miltiorrhiza, including its anti-inflammatory effects and the underlying mechanisms of action in vitro and in vivo. Method Purification of the sample paste of Salvia miltiorrhiza was accomplished using HPLC analysis. TheMTT (Methylthiazolyldiphenyl-tetrazolium bromide) assay was employed to determine the cell viability. The production of inflammatory factors was detected by ELISA assays. The histopathological analysis was used to analyse the lungs and livers of mice treated with PAI. Western blot was performed to reveal the mechanism of PAI in anti-inflammatory. Results The extracts and PAI from the aerial parts of Salvia miltiorrhiza inhibited TNF-α, IL-6 production and promoted the production of IL-10 in vivo in mice and in vitro in the macrophage cell line RAW264.7. NF-κB and MAPKs kinase phosphorylation were also suppressed by PAI in vivo and in vitro, indicating that PAI exhibited an anti-inflammatory effect. Conclusion These findings suggest that the aerial parts of Salvia miltiorrhiza extract may serve as potential protective agents for inflammatory.

The properties of natural rubber latex coagulated by acid and microorganisms during accelerated storage were contrasted, respectively. The molecular weight, gel content, Mooney viscosity, Wallace initial plasticity and the plasticity retention index of natural rubber latex during the accelerated storage period were analysed. The results indicate that prolonged storage time leads to a gradual increase in the molecular weight, gel content, crosslink density and Wallace initial plasticity, whereas plasticity retention index reduces. Wallace initial plasticity exhibits significant correlation, while plasticity retention index indicates a negative correlation with both molecular weight and gel content, respectively. The molecular structure and properties of natural rubber latex coagulated by microorganisms are significantly different from those of natural rubber coagulated by acid. The molecular weight, gel content and Wallace initial plasticity of natural rubber latex coagulated by microorganisms are higher than those of natural rubber latex coagulated by acid, while plasticity retention index and protein content of natural rubber latex coagulated by microorganisms is lower than that of natural rubber latex coagulated by acid.

The network variations of natural rubber (NR) during the vulcanization process were investigated by 1H chemical shift by liquid-state 1H nuclear magnetic resonance (NMR) spectroscopy. NR latex coagulated by microorganisms (NR-m) was contrasted with NR latex coagulated by acid (NR-a). The influences of the coagulation process on the structures, vulcanization characteristics, and mechanical properties of NR were analyzed. The results show that the cross-link density (XLD) and mass percentage of cross-link network (A(Mc)) can be increased with the increment of the vulcanization time; while the mass percentage of dangling free ends of the hydrocarbon and small molecules (A(T2)), the longitudinal relaxation time (T1), transverse relaxation time (T2), and molecular mass of inter–cross-link chains (Mc) decreased with the prolonging of vulcanization time both NR-m and NR-a. NR-m exhibits shorter scorch times (ts1, ts2) and optimum cure time (t90) and shows higher maximum torque (MH) and minimum torque (ML) than that of NR-a. It is obvious that the higher XLD and A(Mc) and lower A(T2), T1, T2, and Mc values of NR-m result in higher stress, tensile strength, and tear strength of NR compounds.

Al 5083 alloys (5.25 at.% Mg) of different tempers (H131 and H116) were aged at low temperatures (50 and 70 °C) for 41 months. Scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDS), and atom probe tomography (APT) were applied to characterize precipitates formed in the sensitized samples. Experimental results revealed that the size of Mg-rich precipitates increased with aging time at 70 °C for both alloys. APT results showed that Mg-rich precipitates of different Mg concentrations and morphologies formed in Al matrix and on the interface of Al matrix/pre-existing particles. In addition, a model based on local equilibrium of chemical potential and multi-class precipitates number evolution was adopted to predict the multiphase precipitation process in the Al-Mg binary system. The overall trend of precipitate radius and number density predicted by the model matched well with the experimental results. Moreover, modeling results revealed that nucleation and coarsening occurred faster in Al 5083 H131 than in Al 5083 H116 when aged at same temperature. The high density of dislocations and the pipe diffusion mechanism of dislocations can be used to explain such behavior.