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Radioactive isotope decay gives off heat, which is an important basis for calculating the activity of radioactive isotope. In order to measure the heat emitted by tritium decay, the detection limit test, working curve calibration and tritium sample measurement verification of a low detection limit microcalorimeter of μW grade were carried out. The measurement results show that the detection limit of microcalorimeter is 1.28 μW, i.e. 38 mCi tritium. In this paper, the output thermoelectric potential U-input thermal power P of microcalorimeter was calibrated in the range of 165-5063 μW (5-50 Ci tritium), and the calibration relationship obtained is U（μV）=0.141P（μW）, corresponding to the relation between tritium activity and output thermoelectric potential A（Ci）=0.213U（μV）, and the liner correlation coefficient is greater than 0.999. The standard deviation of repeated measurement of tritium samples was 1.14%, and the deviation from PVT method was 2.45%. In order to ensure the consistency of measurement, the calorimeter used in this paper reduces the fluctuation of measurement environment through water bath and vacuum environment. The calibrated calorimeter can measure the activity of tritium samples without damaging their integrity. Compared with other tritium measurement methods, calorimetry is more suitable for the measurement of solid tritium samples and has great engineering application value.

In order to further reduce the tritium abundance of hydrogen isotope exhaust with low tritium content, realize the recovery of tritium efficiently, and reduce the impact of tritium emission sources on the environment, this paper carried out the research of low-abundance tritium recovery process based on thermal cycle adsorption process. When the separation column packed with palladium deposited on kieselguhr (Pd/K) is at low temperature, hydrogen isotope gas is injected from the front end, and then the column is controlled to perform a heating-cooling cycle. After several cycles, the light component argon is enriched at the inlet of the separation column, and the recombinant tritium concentration is concentrated at the outlet. The research showed that the gas with a tritium abundance of 3.2% entered the experimental system, and after 7 cycles, the tritium abundance at the inlet of the separation column is less than 0.01%. A total of 7.55 mol of low-abundance gas is processed in the experiment, and finally 7.42 mol of the exhaust gas with a tritium abundance of less than 0.05% was extracted, as well as 72.31 mmol of tritium gas with an abundance of 98.68% and 0.048 mol of a medium-abundance gas with an average abundance of 29.68%. The system tritium recovery rate reached 99.54%. Experiments have verified that the thermal cycle adsorption optimization process can further reduce the tritium abundance in the exhaust gas and directly obtain high-abundance tritium gas products, greatly increasing the effective extraction of tritium.

Flow mark defects (FMs) worsen surface esthetics and mechanical properties of injection-molded polypropylene (PP). In this work, experiments and dissipative particle dynamic (DPD) simulations were used to investigate the effect of dynamically vulcanized polyolefin elastomer (POE) on FMs of injection-molded PP. Significant FMs reduction was achieved by dynamically vulcanized POE. DPD simulations indicated that POE molecules were randomly distributed in the PP, while dynamic vulcanization led to the formation of elastomeric quasi-clusters, and these quasi-clusters were able to reduce FMs. Both DPD simulations and scanning electron microscopy results showed that more agglomerates with longer and irregular shapes formed with longer vulcanization time and more initiators. The formation of too many agglomerates resulted in different pock surface defects. Dynamically vulcanized POE produced at optimal reaction conditions did not affect the tensile strength, tensile modulus, flexural strength, and flexural modulus, while breaking elongation and notched Izod impact strength of injection-molded PP decreased slightly. This work suggests that the addition of dynamically vulcanized POE may be a promising way to reduce FMs of injection-molded PP. KEYWORDS dissipative particle dynamics, flow mark, polyolefin elastomer, polypropylene, vulcanization, 1 | INTRODUCTION In light of environmental suitability, excellent moldability, lower processing cost, and outstanding mechanical properties, polypropylene (PP) moldings that mainly contain PP, inorganic fillers, and elastomers are widely [...]

We propose a new measure of dependence between a categorical random variable and a random vector with potentially high dimensions, named semi-distance correlation. It is an interesting extension of distance correlation to accommodate the information of the categorical random variable. It equals zero if and only if the categorical random variable and the other random vector are independent. Two important applications of semi-distance correlation are considered. First, we develop a semi-distance independence test between a categorical random variable and a random vector and derive its asymptotic distributions. When the dimension of the random vector tends to infinity, we derive the explicit asymptotic normal distribution of the test statistic under the null hypothesis, which allows us to compute p-values in an efficient and fast way for high dimensional data. Second, we propose to use the semi-distance correlation as a marginal utility between the response and a group of covariates to do groupwise variable screening for ultrahigh dimensional classification problems. The sure screening property has also been established. Monte Carlo simulations and a real data application are presented to demonstrate the excellent finite sample property of the proposed procedures. A new R package semidist is also developed to implement the proposed methods. for this article are available online. [ABSTRACT FROM AUTHOR]

Integrated carbon capture and utilization (ICCU) simplifies the CO2 utilization process by converting chemically combined CO2 molecules into value-added chemicals, leading to a strong energy-saving effect by omitting the CO2 separation process. Two reaction routes for the hydrogenation of amine captured CO2 to methanol over heterogeneous catalysts were summarized: alcoholic hydroxyl groups-promoted CO2 hydrogenation process over Cu or Pd-based catalysts via formate and ester route, and methanol production from the direct hydrogenation of formate over Au-based catalyst. The technical effectiveness of concurrent carbon capture with heterogeneous catalysis toward methanol via alcoholic hydroxyl groups-promoted CO2 hydrogenation is similar to that of the gas-phase CO2 hydrogenation to methanol over heterogeneous catalysts. The sintering of the catalysts, the phase change of the supports, the combination of amines and the catalysts (namely leaching), and the reaction of water with the supports can cause a decrease in the performance of the catalysts. Thus, it is important to rationally design next-generation stable catalysts to achieve amine captured CO2 hydrogenation to methanol while at the same time regenerating amines. The development of heterogeneous catalysts for methanol synthesis in the liquid phase and the development of the CO2 capture process for subsequent conversion(1 ~ 70%) were carefully reviewed. The integration and optimization of multi-pollutant efficient removal technology, selectively coupled CO2 capture technology, and selective routes for methanol synthesis can achieve industrial verification in typical power plants, which is of great significance in promoting energy conservation, emission reduction, and low-carbon footprint. [ABSTRACT FROM AUTHOR]

In the traditional production of acetic esters, water generated in the esterification reaction can form azeotropes with the ester or the unreacted alcohol, which requires subsequent multi-step distillation or extraction to purify the esters. A large number of intermediate streams in the separation process need to consume a lot of steam to obtain high-purity acetic esters, resulting in a high total energy consumption. In this review, a new extraction separation and purification technology, namely the salting-out effect for the purification of acetic esters, was summarized. Different salting-out agents were used to reduce the concentration of water/alcohols in the ester phase and increase the selectivity coefficient of esters to minimize energy consumption. The scaled particle theory provides a clear guideline for the baseline on the separation goal of the alkyl acetate/alcohol/water systems. Extractive distillation, reactive distillation, azeotropic distillation, pervaporation, adsorption, salting-out assisted distillation, and hybrid salting-out-distillation were compared to assess their advantages and disadvantages. Energy-saving production and separation of acetic esters can be achieved with the hybrid salting-out-distillation process because the salting-out agents are cheap, non-toxic, and non-volatile, and the salting-out process can be conducted at room temperature. [ABSTRACT FROM AUTHOR]

Natural drug research is one of the main directions for the discovery and development of new drugs. Underutilized vegetables with a rich source of medicinal value have drawn much attention from scientists in synthesizing new drugs and finding new pharmacological actions. Apigenin is a natural flavonoid with pharmacological effects including anti-inflammatory, anti-tumor, anti-oxidation, anti-radiation, antidepressant effect, cardiovascular protection, regulated glucose and lipid metabolism, protecting the kidneys, neuroprotection, antibacterial, etc. Thus, these pharmacological effects of apigenin and the interaction between apigenin and drugs were mainly reviewed in this paper. The pharmacological actions of apigenin are being elucidated not only on the molecular level but also on the apigenin-receptor interaction, changes in factors, enzymes, proteins, cells, or tissues. The apigenin derivatives and complexes with their pharmacological actions were also summarized, which is expected to provide a reference for the rational development and utilization of apigenin. [ABSTRACT FROM AUTHOR]

Although perovskite solar cells (PSCs) have exhibited a high‐power conversion efficiency, the reproducibility of high‐quality perovskite films is still a big challenge for large‐scale flexible devices. One reason is the super narrow antisolvent dripping window, the other one is the difficulty in controlling the secondary phases. Herein, 18C6 is introduced into the perovskite precursor to achieve a high‐quality and reproducible large‐scale (7 × 7 cm2) flexible perovskite film by enlarging the antisolvent dripping window from 2 to 20 s, with an average efficiency of 13.33% (best 15.80%). Moreover, from the in situ grazing‐incidence wide‐angle X‐ray scattering result, the 2H phase perovskite is highly suppressed with the additive of 18C6. The generality of the approach is also demonstrated in other antisolvents such as ethyl acetate. This finding provides an innovative solution to the realization of repeatable, large‐scale solution fabrication of PSCs. [ABSTRACT FROM AUTHOR]