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In this paper, we study the ancient glass component analysis and category to identify problems, through the establishment of principal component analysis, cluster analysis and multiple regression model mathematical model, using SPSS software, realized by analyzing the chemical composition content on the glass before and after weathering type classification problem and for different categories of the relationship between the chemical composition of glass sample problem solving, According to the change rate, the chemical composition content before weathering is predicted, and the predicted value before weathering is obtained.

Nanocarbons have shown great potential as a sustainable alternative to metal catalysts, but their powder form limits their industrial applications. The preparation of nanocarbon-based monolithic catalysts is a practical approach for overcoming the resulting pressure drop associated with their powder form. In our previous work, a ploycation-mediated approach was used to successfully prepare nanocarbon-containing monoliths. Unfortunately, because there are no macropores in the monolith, it needs to be crashed into millimeter-sized particles before application. Therefore, developing a facile method for preparing mechanically robust nanocarbon-based macroporous monolithic catalysts is vital but still challenging. Herein, evoked by swallows building their nests, we report an approach for successfully preparing a mechanically robust nanodiamond-based macroporous monolith catalyst by plastering melamine sponge (MS) with a slurry composed of nanodiamonds (NDs) and poly(imidazolium-methylene) chloride (PImM) followed by an annealing process. The macroporous monolith catalyst (ND/NC

The rock salt structure of high entropy oxide (HEO) (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O has promising prospects for energy materials. Here, we prepare HEO and calculate the entropy value S m i x ≥ 1.5R (R represents the gas constant), thus proving that HEO is obtained. In addition, we design and obtain HEO@G (HEO@Graphene) through the surface modification of HEO with graphene, which is analysed by X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy to reveal the rock salt structure of HEO@G and the formation of a planar layer architecture on the surface of HEO by graphene. The electrode well design with HEO@G as the anode material for lithium-ion batteries provides a high capacity of 1225 mA h g−1 in the first discharge at 100 mA g−1 and maintains a discharge capacity of ∼950 mA h g−1 after 200 cycles. A reversible cycling capacity of 460 mA h g−1 is obtained under the condition of multiple cycles at high speed. In terms of expansion, electrochemical impedance spectrometry and pseudocapacitance investigations deeply demonstrate that the addition of graphene enhances the diffusion dissemination coefficient of lithium ions in the composite electrode and changes the electrochemical kinetic properties of the composite anode. Such a modification approach for HEO will provide a reference in energy storage applications.

By combining dielectric barrier discharge plasma and external heating, we exploit a two-stage hybrid plasma-thermal system (HPTS), i.e., a plasma stage followed by a thermal stage, for direct non-oxidative coupling of CH4 to C2H4 and H2, yielding a CH4 conversion of ca. 17 %. In the two-stage HPTS, the plasma first converts CH4 into C2H6 and C3H8, which in the thermal stage leads to a high C2H4 selectivity of ca. 63 % by pyrolysis, with H2 selectivity of ca. 64 %.

Li2ZnTi3O8(LZT)-xwt.%Nb2O5 (x = 0, 1, 2, 3, 4) microwave dielectric ceramics were synthesized by the conventional solid-phase sintering method. The effect of Nb2O5 addition on crystal structure, Raman spectra, and dielectric properties were studied. X-ray diffraction results indicated that the maximum crystallinity of LZT ceramics were obtained at 1075 °C, and that Nb5+ diffused into the LZT matrix completely to form a stable solid solution. XRD refinement results demonstrated that the substitution of Nb5+ for Ti4+ caused the cell volume to increase. The microscopic morphology of LZT-xwt.%Nb2O5 (x = 0, 1, 2, 3, 4) ceramics were further investigated by scanning electron microscopy, and results indicated that Nb2O5 could promote the grain growth and sintering of LZT ceramics. Extrinsic and intrinsic dielectric losses were studied through Raman and impedance spectroscopy. The highest value of quality factor × resonant frequency (Q × f) was attributed to the increase in relative density and reduced number of oxygen vacancies ( V O • • ), as well as the decrease in damping behavior. Moreover, the dielectric constant (er) showed the same trend as cell polarization and the temperature coefficient of resonant frequency (τf) was inversely proportional to cell volume. The LZT ceramics with 3 wt% Nb2O5 addition sintered at 1075 °C for 4 h exhibited the optimal microwave properties, i.e., er = 26.52, Q × f = 66 304 GHz, and τf = - 14.2 ppm/°C.

For solvent-free catalytic oxidations, low efficiency resulted from poor mass transfer and insufficient utilization of active centers remains a tough problem. Herein, we demonstrate a novel hybrid core-shell catalyst (TS@PMO) with an amphiphilic shell and a Ti-surface-enriched mesoporous TiO2-SiO2 (TS) core to address this challenge. Such TS@PMO realizes its amphiphilicity via an ex situ formed periodic mesoporous organosilica (PMO) shell. Simultaneously, by a unique etching effect induced by organic precursor growth on [SiO4] tetrahedra in TS core, active Ti sites are facilely enriched in near-surface layer of core and extra mesoporous cavities are introduced for substrate reservation. When applied for solvent-free epoxidation of methyl oleate (MO) with H2O2, TS@PMO exhibits remarkably boosted catalytic activity (X = 90.2%) and epoxide selectivity (S = 70.2%), overwhelming the unmodified titanosilicate (X = 63.7%, S = 49.2%) and Ti-containing organosilica (X = 39.8%, S = 25.0%). Such result benefits from an evidently enhanced interphase mass transfer and sufficiently accessible active Ti sites in TS@PMO. On the one hand, amphiphilic PMO shell can efficiently collect hydrophobic substrate and H2O2, while abundant mesopores in the shell offer open-path for them to access active sites in the core; on the other hand, an increased framework Ti (IV) density and their surface-enrichment in TS core greatly improve the utilization of active Ti sites. This study effectively makes up for the deficiencies of slow mass transfer and insufficient utilization of conventional titanosilicates in biphasic reactions, which paves a new avenue to exploit other hybrid catalysts for high-efficiency solvent-free catalysis.

As deep neural networks (DNNs) are widely used in the field of remote sensing image recognition, there is a model security issue that cannot be ignored. DNNs have been shown to be vulnerable to small perturbations in a large number of studies in the past, and this security risk naturally exists in remote sensing object detection models based on DNNs. The complexity of remote sensing object detection models makes it difficult to implement adversarial attacks on them, resulting in the current lack of systematic research on adversarial examples in the field of remote sensing image recognition. In order to better deal with the adversarial threats that remote sensing image recognition models may confront and to provide an effective means for evaluating the robustness of the models, this paper takes the adversarial examples for remote sensing image recognition as the research goal and systematically studies vanishing attacks against a remote sensing image object detection model. To solve the problem of difficult attack implementation on remote sensing image object detection, adversarial attack adaptation methods based on interpolation scaling and patch perturbation stacking are proposed in this paper, which realizes the adaptation of classical attack algorithms. We propose a hot restart perturbation update strategy and the joint attack of the first and second stages of the two-stage remote sensing object detection model is realized through the design of the attack loss function. For the problem of the modification cost of global pixel attack being too large, a local pixel attack algorithm based on sensitive pixel location is proposed in this paper. By searching the location of the sensitive pixels and constructing the mask of attack area, good local pixel attack effect is achieved. Experimental results show that the average pixel modification rate of the proposed attack method decreases to less than 4% and the vanishing rate can still be maintained above 80%, which effectively achieves the balance between attack effect and attack cost.

Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation. Nevertheless, the elucidation of the structure-performance relationships for these systems remains a scientific challenge. In this work, copper oxide clusters deposited on a high-surface-area silica support were synthesized via a deposition-precipitation approach and exhibited remarkable catalytic reactivity (up to 25.5% conversion and 66.8% selectivity) in the propylene-selective oxidation of acrolein at 300 °C. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy combined with X-ray absorption fine structure measurements of the catalyst before and after the reaction confirmed the transformation of the small-sized copper oxide (CuO) clusters into cuprous oxide (Cu2O) clusters. With the aid of in situ X-ray diffraction and in situ dual beam Fourier transform infrared spectroscopy (DB-FTIR), the allyl intermediate (CH2=CHCH2*) was clearly observed, along with the as-formed Cu2O species. The intermediate can react with oxygen atoms from neighboring Cu2O species to form acrolein during the catalytic process, and the small-sized Cu2O clusters play a crucial role in the generation of acrolein via the selective oxidation of propylene.

A defective HZSM-5 zeolite (SiO2/Al2O3 = 55, crystal size = 300 nm) with a high density of hydroxyl nests and its patched-up counterpart obtained by pretreating the defective zeolite with (NH4)2SiF...

Skin-like sensors that transduce tactile pressures and vibrations with minimal environment variation on performance are crucial in robotic sensing and prosthetic skins. However, sensor performance ...

The gas-phase epoxidation of propylene and hydrogen peroxide (H2O2) vapor to produce propylene oxide (G-HPPO) is a good way to bypass the methanol solvent problem faced by the liquid-phase HPPO pro...

The adsorption removal of indole and quinoline in octane with and without toluene over zeolites NaY and Yttrium Ion-exchanged Y (YY) using batch adsorption experiments was studied at 25 o C and 1 atm. YY was prepared by treating NaY with Y(NO 3 ) 3 solution twice via liquid ion-exchange method. NaY and YY were both characterized by XRD, SEM, N 2 adsorption, XRF, NH 3 -TPD, and pyridine-FTIR techniques. Adsorption isotherms of indole, quinoline and toluene in octane were conducted at 25.0 o C to explain the influence of toluene on nitrogen removal over NaY and YY. The partial destruct of the crystalline structure of NaY was observed after the introduction of yttrium ion , which led to an evident decline in BET surface area and pore volume of YY. Strong Bronsted acidity and medium Lewis acidity were introduced by yttrium ion-exchange. Though the specific surface area and pore volume of YY were much lower than those of NaY, YY exhibited equivalent adsorption capacities for indole and quinoline as NaY in model fuels without toluene. In the presence of 20 vol.% toluene, however, YY exhibited much higher adsorption capacities for indole and quinoline than NaY, especially in the case of quinoline. The improved toluene-tolerant of YY was ascribed to the strong acid-base interaction between YY and quinoline and the decreased adsorption strength between YY and toluene.

Two kinds of bi-functional transition metal doped mesoporous materials (Fe-HMS and Fe-MCM-41) are prepared using one-step hydrothermal method and then treated with hydrochloric acid ethanol solution. The N2 adsorption and HRTEM results show that both of Fe-HMS and Fe-MCM-41 possess mesoporous structure. The UV–vis results suggest that the Fe species are mainly located within the framework. The basicity of as-prepared samples was studied by temperature programmed desorption using CO2 as probe molecule (CO2-TPD). The catalytic performance of Fe-HMS and Fe-MCM-41 in CO2 cycloaddition largely depends on the amount of the accessible basic sites. The acid–base active sites, framework Fe and PDDA species cooperatively catalyze the CO2 cycloaddition for the production of cyclic carbonates under the condition without any co-catalyst. The conversion of epichlorohydrin (ECH) is 97.4% and the selectivity of chloropropene carbonate is 92.9% under optimal conditions. The approximate rate constant of cycloaddition reaction of CO2 with ECH under optimum reaction temperature is calculated. It is worth noting that the Fe-HMS material shows superior reusability than Fe-MCM-41. In addition, this work provides a facile way on the synthesis of bi-functional acid–base heterogeneous catalyst with outstanding catalytic performance for the fixation of CO2.

Owing to the importance of the carbon cycle and the universality of carbon loss in sustainable hydrogen supply systems, Pt-based catalysts were designed carefully for a reversible methylcyclohexane–toluene–hydrogen (MTH) cycle. Through adjusting the activity of the Pt species toward C–H bonds to a middle level, liquid organic hydrogen carriers (LOHCs) with higher selectivity were achieved, making the MTH cycle closer to a closed carbon cycle. Specifically, in the hydrogen generation process, we tried to enhance coking resistance as well as inhibit side-reactions such as disproportionation, de-alkylation and hydro-isomerization via Cu doping in Pt/S-1. Experimentally, the selectivities of H2-rich and H2-lean LOHCs in the MTH cycle reached 99.9% with almost coke free during these two processes. Moreover, Pt-based catalysts exhibited excellent activity and durability in catalyzing the MTH cycle. The hydrogen release rate reached 445.3 mmol gPt−1 min−1 with 92.26% methylcyclohexane (MCH) conversion and a hydrogen storage rate of 1271 mmol gPt−1 min−1 was achieved with greater than 99.9% toluene conversion. Finally, through further investigating the geometric configuration and electronic environment of the Cu and Pt species, we found that the Pt was co-located and interacted with the Cu by forming an alloy. Moreover, the unique electron structure of the Cu–Pt alloy facilitated electron transfer from the Pt to the Cu, decreasing the electron density of the Pt. As a consequence, over-dehydrogenation and hydrogenolysis in the MTH cycle were inhibited.

Side-chain alkylation of toluene with methanol has attracted interest for decades as a one-step alternative pathway to manufacture styrene under mild conditions, and a high performance catalyst is most urgently needed to realize the commercial application of this technology. Herein, we studied the role of boron sites in improving the styrene/ethylbenzene ratio (ST/EB) in the products primarily. It was found that the introduction of boron sites into cesium ion exchanged zeolite X (CsX) is helpful in adsorbing and stabilizing the generated formaldehyde from methanol dehydrogenation over the base sites of CsX, and this mainly accounts for the inhibition of further conversion of styrene into ethylbenzene in the side-chain alkylation products. Moreover, it was found that the catalytic performance of the CsX-based catalyst with boron sites was influenced tremendously by the distance between the boron sites and the base sites of CsX. Introducing boron sites into the CsX-based catalyst by grinding boric acid impregnated SiO2 (B/SiO2) and CsX was an efficient way to greatly improve the ST/EB in the side-chain alkylation products. Finally, based on the above findings, a ternary composite catalyst with a high yield of side-chain alkylation products (styrene and ethylbenzene) and high ST/EB, which were 39.45% and 1.81, respectively, was developed by mixing CsX, cesium oxide modified CsX and B/SiO2 with the grinding route. In addition, the key points for preparing a more efficient catalyst in the future were also discussed and proposed.

Na+ ions in TS-1 influence the results of liquid-phase oxidations of hydrocarbons seriously, and the avoiding of Na+ ion impurity in TS-1 synthesis is crucial for its catalytic application. In this paper, however, the solvent-free gas-phase epoxidation of propylene with H2O2 vapor (G-HPPO) was investigated over TS-1 zeolites with different Na+ ion content. Significant improvement in the performance of G-HPPO process was observed with NaOH solution hydrothermally modified TS-1 which had a Na/Ti ratio of 0.68. The performance of G-HPPO process was further enhanced when the Na/Ti ratio of hydrothermally modified TS-1 was increased to 1.0 via subsequent Na+ ion impregnation. The catalyst showed 16.9% propylene conversion, 97.5% PO selectivity and 79.3% H2O2 utility at a propylene to H2O2 ratio of around 5. On the other hand, when the Na+ ion content of the hydrothermally modified TS-1 was reduced via subsequent NH4+-exchange, the resulted catalyst exhibited a remarkably deteriorated G-HPPO process performance. By Combining the characterizations of UV–Raman, UV–vis and FT-IR with DFT calculation, it is concluded that in the NaOH solution hydrothermally modified TS-1 the Na+ ions served as counter cations of the silicon hydroxyls adjacent to “open” tetra-coordinated framework Ti sites. As a result, the local environment of the “open” Ti sites (with titanium hydroxyls) was adjusted and the Ti sites were properly activated. Whereas, in the case of excess Na+ ions were introduced into the TS-1 (for example Na/Ti ratio more than 1.0), the titanium hydroxyl of the “open” Ti sites would be occupied, to which the deteriorated G-HPPO process performance was ascribed.

This study was related to a solvent-free gas-phase epoxidation of propylene with H2O2 vapor to synthesize propylene oxide (G-HPPO). Focus was given to the hydrothermal modification of TS-1 with NaO...

In this study, an attempt was made to modify Zn/HZSM-5 aromatization catalyst by successively impregnating Sn and Pt. Among prepared catalysts, the Zn6.0Sn0.2Pt0.1/HZSM-5 catalyst exhibited excellent catalytic performances in both activation and aromatics selectivity. Multi-techniques including XRD, nitrogen physisorption, NH3-IR, TEM, HAADF-STEM/EDX and operando dual beam Fourier transform infrared (DB-FT-IR) spectroscopy were applied to study Zn6.0Sn0.2Pt0.1/HZSM-5 catalyst to gain insight into its active sites and collaboration of them. It is concluded that, in the Zn6.0Sn0.2Pt0.1/HZSM-5 catalyst, the aromatization of propane was catalyzed by the cooperation between Bronsted acid sites (bridging hydroxyls)–Lewis acid sites [zinc species and metallic alloy (SnPt nano clusters)]. Sn had crucial mediation effect which remarkably improved metal dispersion and finely tuned metal–metal interactions. Furthermore, the 3000-h fixed-bed propane aromatization stability test indicated that the Zn6.0Sn0.2Pt0.1/HZSM-5 catalyst also had very prominent anti-coking deactivation ability.

The catalytic behaviors of the internal and external Bronsted acid sites on HZSM-5 zeolite were investigated in the alkylation of benzene with methanol (MeOH). The external surface passivated HZSM-...

In this study, solid NMR characterizations including 29Si MAS NMR, 31P MAS NMR, 27Al MAS NMR, and 27 Al MQ MAS NMR were carried out to get insights on the difference of ammonium dihydrogen phosphate (NH4H2PO4) and trimethylphosphate ((CH3)3PO4) modified nano-sized H-ZSM-5 zeolites. Results show that (CH3)3PO4 is more suitable for the phosphorus modification of the H-ZSM-5 zeolite, because it can effectively interact with aluminum species and facilitate the formation of distorted tetra-coordinated framework Al bonded with phosphorous species. This distorted framework Al species can better maintain the acidity of original framework Al during steaming treatment at high temperatures, even up to 800 °C. Relating the NH3-TPD characterization results with the catalytic cracking performance of full range FCC gasoline over the as-prepared P/H-ZSM-5 samples, we found out that the phosphorus-stabilized distorted framework Al sites are highly acidic and active. The (CH3)3PO4-modified H-ZSM-5 zeolite exhibits bright future in the application of important commercial processes operated under severe hydrothermal conditions.

An operando dual-beam Fourier transform infrared spectrometer was developed to identify the transient Bronsted acid sites (BAS) in propene aromatization over acidic HZSM-5 and Zn-modified HZSM-5 catalysts under real reaction conditions. The eliminated signals include gas-phase molecular vibrations and heat irradiation at reaction temperatures. We directly observed that the initial activation of propene over Zn2+ of Zn-modified HZSM-5 generated a substantial number of transient BAS, which serve as active sites for the subsequent aromatization reactions. Moreover, during the propene aromatization process, the desorption of aromatic precursors over the Zn2+ of Zn/HZSM-5 is easier than that over the H+ of HZSM-5, resulting in an enhanced aromatics productivity. A density functional theory calculation certified the priority of the metallic Zn2+ sites over BAS in the competitive activation of propene molecules. The generation of transient BAS is energetically favorable.

Hexamethyleneimine (HMI) is used as the structure-directing agent (SDA) in the conventional synthesis method of MCM-49 zeolite. Cyclohexanine (CA) is less toxic and cheaper than HMI. Hence, in this paper, MCM-49 zeolite was successfully synthesized by using CA as a sole SDA with the aid of seeds. Both the seed and template CA are indispensable for the synthesis of MCM-49 zeolite. The optimum synthesis conditions were obtained. The range of the SiO2/Al2O3 ratio of the initial gel was broadened to 70. The synthesis of MCM-49 followed the liquid-phase crystallization mechanism. The MCM-49 zeolites synthesized by using CA and conventional template hexamethyleneimine (HMI) exhibit similar intrinsic properties, such as morphology, acidity, BET surface area, SiO2/Al2O3, and so on. The MCM-49(CA) exhibite good catalytic activity and product distribution in alkylation of benzene with methanol.

Gelatinous underwater invertebrates such as jellyfish have organs that are transparent, stretchable, touch-sensitive and self-healing, which allow the creatures to navigate, camouflage themselves and, indeed, survive in aquatic environments. Artificial skins that emulate such functionality could be used to develop applications such as aquatic soft robots and water-resistant human–machine interfaces. Here we report a bio-inspired skin-like material that is transparent, electrically conductive and can autonomously self-heal in both dry and wet conditions. The material, which is composed of a fluorocarbon elastomer and a fluorine-rich ionic liquid, has an ionic conductivity that can be tuned to as high as 10−3 S cm−1 and can withstand strains as high as 2,000%. Owing to ion–dipole interactions, it offers fast and repeatable electro-mechanical self-healing in wet, acidic and alkali environments. To illustrate the potential applications of the approach, we used our electronic skins to create touch, pressure and strain sensors. We also show that the material can be printed into soft and pliable ionic circuit boards. A transparent electronic skin, composed of an elastomer and an ionic liquid, can autonomously self-heal in both dry and wet conditions due to ion–dipole interactions.

Highly dispersed Pt–Cu alloy nanoparticles encapsulated in silicalite-1 were prepared by one-pot method. Taking propane dehydrogenation as a probe reaction, it was found that anti-coke ability was improved by encapsulation. Through H2-TPR, CO adsorption DRIFT spectra and X-ray Photoelectron Spectroscopy experiment, enhanced anti-coke ability was ascribed to the electronic environment change of encapsulated metal. And it was further confirmed by in situ coking experiment. Owning to limited acidity, metal encapsulated by silicalite-1 molecular sieve exhibited better anti-coke ability and higher propylene selectivity than that by stronger acidic ZSM-5 molecular sieve. Moreover it was found that the combination of Cu and Pt made better catalytic performance and accelerated dehydrogenation more effectively compared with monometallic catalysts. Therefore, Pt–Cu alloy nanoparticles encapsulated in silicalite-1 molecular sieve core–shell material was a potential coke-resistant catalyst for alkane dehydrogenation reaction.