In the intelligent fault diagnosis of rotating machinery, it is difficult to extract early weak fault impact features of rotating machinery under the interference of strong background noise, which ...makes the accuracy of fault identification low. In order to effectively identify the early faults of rotating machinery, an intelligent fault diagnosis method of rotating machinery based on an optimized adaptive learning dictionary and one-dimensional convolution neural network (1DCNN) is proposed in this paper. First of all, based on the original signal, a redundant dictionary with impact components is constructed by K-singular value decomposition (K-SVD), and the sparse coefficients are solved by an optimized orthogonal matching pursuit (OMP) algorithm. The sparse representation of fault impact features is realized, and the reconstructed signal with a concise fault impact feature structure is obtained. Secondly, the reconstructed signal is normalized, and the experimental dataset is divided into samples. Finally, the training set is input into the 1DCNN model for model training, and the test set is input into the trained model for classification and detection to complete the intelligent fault classification diagnosis of rotating machinery. This method is applied to the fault diagnosis of bearing data of Case Western Reserve University and worm gear reducer data of Shanghai University of Technology. Compared with other methods and models, the results show that the diagnosis method proposed in this paper can achieve higher diagnosis accuracy and better generalization ability than other diagnosis models under different datasets.
Ulinastatin, is a broad-spectrum protease inhibitor purified from human urine, inhibits endogenous proteases such as trypsin, α-chymotrypsin, hyaluronidase, and plasmin. It is widely being used at ...increasingly higher doses for the treatment of acute or chronic pancreatitis, severe infection, and acute organ failure. We aimed to evaluate the safety and tolerability of high-dose ulinastatin in healthy volunteers in our single center, randomized, double-blind, placebo-controlled, single-dose escalation study. Fifty-one healthy Chinese subjects were enrolled in 9 dose cohorts (3×105 U, 6×105 U, 12×105 U, 20×105 U, 30×105 U, 45×105 U, 60×105 U, 70×105 U, or 80×105 U of ulinastatin) and randomized to UTI or matching placebo (n = 1). Each dose cohort was composed of 3-7 subjects. All subjects were required to have 2 h of intravenous infusion. Safety and tolerability were assessed throughout the study via monitoring of vital signs, physical examinations, clinical laboratory tests, 12-lead electrocardiograms, and interviews with the subjects about adverse events. Fifty-one subjects (35 men and 16 women) completed the study. A total of 13 AEs were reported by 10 subjects: 11 adverse events in the ulinastatin groups and 2 adverse events in the placebo group. Twelve of the adverse events were possibly related to the study drug. The most common drug-related adverse events included dizziness, pain at injection site, and a decrease in white blood cell count. All adverse events were of mild severity; none were serious. In conclusion, 2 hours of intravenous infusion of ulinastatin (3×105 to 80×105 U) was well tolerated by healthy Chinese subjects.
The generation of hydroxyl radicals derived from water molecules plays a pivotal role in attacking organic pollutants for the photoelectrocatalytic (PEC) process. To promote the generation efficiency ...of hydroxyl radicals, remarkably efficient transportation of the induced carriers and water molecules is desirable. Here, we implemented a remarkably enhanced photoelectrocatalytic oxidation via cooperative effect of neighboring two different metal oxides, Bi2MoO6 and Sb-doped SnO2 nanosheets, for water remediation. To realize the highly efficient transportation of the induced carriers, the hierarchical architecture Bi2MoO6 wrapped Sb-doped SnO2 nanosheets are rationally designed and synthesized. Density functional theory (DFT) calculations demonstrate that water molecules prefer to be adsorbed on the surface of Sb-doped SnO2 nanosheets, producing hydroxyl radicals (•OH) on the surface of Bi2MoO6. The cooperation action between Bi2MoO6 and Sb-doped SnO2 nanosheets for the generation of hydroxyl radicals by water photoelectrolysis is enforced as follows: the Sb-doped SnO2 nanosheet layer can act as the supply station of water and rapidly transfer the water molecules to neighboring Bi2MoO6 to generate hydroxyl radical. This work may enlighten the design and construction of advanced photoanode materials for future scale-up of cost-effective water purification and environmental remediation.
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•1. A novel isosorbide-based cyclomatrix polyphosphazene (HISP) microsphere was synthesized.•2. The HISP microsphere exhibits a highly selective adsorption ability of cationic dyes ...from aqueous solution.•3. The adsorption behavior of MB follows pseudo-second-order adsorption kinetic model and Langmuir model.•4. The mechanism of adsorption between MB and HISP was revealed by experiment and DFT simulation.•5. The incorporation of isosorbide promotes the cationic dyes adsorption capacity of the HISP microsphere.
A novel bio-based cyclomatrix polyphosphazene microsphere, namely poly(cyclotriphosphazene-co-isosorbide) (HISP), for efficient cationic-dyes adsorption was prepared by solvothermal method using hexachlorocyclotriphosphazene (HCCP) and isosorbide (IS). The chemical structure and morphology of HISP microsphere were characterized by Fourier transform infrared (FTIR), solid-state 31P nuclear magnetic resonance (NMR) spectroscopy, X-Ray photoelectron spectroscopy (XPS), andscanning electron microscope (SEM). The adsorption study towards different organic dyes and their mixtures showed that HISP exhibits an over 850 mg/g adsorption capacity for cationic dyes (e.g., rhodamine B (RhB), methylene blue (MB), and bismarck brown Y (BY)), respectively, and highly selective adsorption ability for MB. Using the adsorption of MB as a model system, the results show that alkaline condition is able to promote the adsorption performance. A high adsorption capacity of 1143.6 mg/g can be obtained towards 200 mg/L MB solution at 25 °C and pH = 10 using 6 mg of HISP. Adsorption kinetics and isotherm studies indicate that the adsorption behavior of HISP can be well described by pseudo-second-order kinetic model and Langmuir isotherm model. Importantly, the adsorption mechanism of HISP was demonstratedto be the electrostatic attractions derived from the numerous electron-rich O atoms in isosorbide, which was clarified by the electrostatic screening experiment and density functional theory (DFT) calculation. This systematic work paves a path to the preparation of highly selective dye adsorbents.
Phototherapies such as photothermal therapy (PTT) and photodynamic therapy (PDT) are considered as alternatives for tumor remedies, because of their advantages of precise spatial orientation, ...minimally invasive, and nonradiative operation. However, most of phototherapeutic agents still suffer from low photothermal conversion efficacy and photodynamic performance, poor biocompatibility, and intratumor accumulation. Herein a biocompatible and target-deliverable PTT-PDT self-synergetic nanoplatform of RGD-BPNS@SMFN based on temperature-dependent catalase (CAT)-like behavior for tumor elimination is presented. The homogeneously dispersible nanoplatform is designed and fabricated through anchoring spherical manganese ferrite nanoparticles (SMFN) to black phosphorus nanosheets (BPNS), followed by arginine-glycine-aspartic acid (RGD) peptide modification. The nanoplatform exhibits excellent targeting ability and enhanced photonic response in comparison to plain BPNS and SMFN in vitro and in vivo. It is found that PTT and PDT have a self-synergetic behavior by means of the dual phototherapy mode interaction. The self-synergetic mechanism is mainly ascribed to PTT-promoted inherent CAT-like activity in the nanoplatform, which remodels the tumor hypoxia microenvironment and further ameliorates the PDT efficiency, providing promising high performance nanoplatform for synergetic dual mode phototherapy, enriching the design for the antitumor nanozyme.
•Beta zeolites with controlled Si / Al ratio and particle size were synthesized and applied in LDPE catalytic cracking.•Gasoline factor (GF) correlating acidity and diffusion was proposed, and the GF ...fits well with experimental data.•M4 multi-dimensional chromatography was applied to analyze the fine composition of gasoline.•A high proportion of cyclo-olefins was discovered in the LDPE cracking gasoline.
Plastics are widely used in daily life and industry. However, the natural degradation of waste plastics is very slow, causing considerable environmental problems. Catalytic cracking is able to convert waste plastics into fuels and chemicals, being an efficient and sustainable utilization route for waste plastics. Zeolites are commonly used as catalysts for this process, with the performance mainly affected by diffusion and acidity properties. It is necessary to elucidate the combinatorial effect of these two factors. Herein, zeolite Beta was used as the model catalyst for the catalytic cracking of low-density polyethylene (LDPE). The synergistic effect of diffusion and acidity on the catalytic performance was explored by systematically controlling the Si/Al ratio (SAR) and particle size of zeolite Beta. By correlating the acidity and pore structure of Beta zeolites with the catalytic performance, a gasoline yield descriptor − gasoline factor (GF) was proposed, and GF fitted well with the gasoline yields of LDPE cracking by Beta zeolites, demonstrating that GF may provide theoretical guidance for the optimized design of zeolite catalysts in the LDPE cracking. Through fine analysis of the gasoline composition with M4 multi-dimensional chromatography, for the first time, a high proportion of cyclo-olefins was discovered in the gasoline products of all zeolite catalysts, which was ascribed to the unique long hydrocarbon chains of LDPE. Considering that cyclo-olefin copolymers possess high thermal stability and excellent chemical resistance, the cyclo-olefin monomers produced by the cracking of LDPE exhibit high potential in commercial applications.
With the continuous development of urbanization, the urban heat island (UHI) phenomenon is becoming increasingly prominent. Especially with the development of various large urban agglomerations and ...the shrinking distance between cities, the regional thermal environment has attracted extensive attention. Therefore, we used Modis land surface temperature (LST) data and employed least squares, standard deviation and spatial autocorrelation analysis methods to analyze the spatiotemporal patterns and characteristics of summer daytime regional urban heat islands (RHI) in the Beijing–Tianjin–Hebei (BTH) urban agglomeration. Our results indicated that the relative land surface temperature (RLST) in the southeastern part of BTH with a relatively high level of urbanization showed a significant and continuous upward trend. With the continuous development of the level of urbanization in the southeast, the center of gravity (GC) of RHI gradually moved to the southeast, and the development direction of RHI changed from northwest–southeast to northeast–southwest. The area transfer of RHI was concentrated in no change and little change, indicating that the evolution trend of RHI was relatively stable. The high-high aggregation areas were mainly located in the more developed areas in the southeast. In addition, the methods and results of this study can provide reasonable and effective insights into the future development and planning of the BTH.
The Sc(OTf)3-catalyzed diastereoselective 3 + 3 cycloaddition of phthalazinium dicyanomethanides with cyclopropane 1,1-diesters proceeded smoothly under mild reaction conditions, affording a variety ...of 3,4-dihydro-1H-pyrido2,1-aphthalazine derivatives in up to 99% yields with excellent diastereoselectivities.
Divergent transformations of allenylethylene carbonates with diboron reagents catalyzed by copper are disclosed. By using CuCl/IPr·HCl as the catalyst, the allenylethylene carbonates react with ...B2hex2 to afford 2,4-dien-1-ols as the product in the presence of Cs2CO3 as the base, i PrOH as the additive, and 1,4-dioxane as the solvent. And they react with B2pin2 to form boronic half acids in the presence of NaO t Bu as the base, water as the additive, and THF as the solvent. The reactions afford corresponding products in good stereoselectivities and yields, and further derivatizations of boronic half acids and study of the mechanism are also demonstrated.
The spoilage bacterium Bacillus licheniformis has been identified as a quick and strong biofilm former in the dairy industry. In our previous study, intra-species variation in bacterial biofilms has ...been observed in diverse B. licheniformis strains from different genetic backgrounds; however, the mechanisms driving the observed heterogeneity of biofilms remain to be determined. In this study, the genotype-phenotype evaluation of the heterogeneity in biofilm formation of four B. licheniformis strains were examined. The heterogeneity in biofilm phenotype was accessed in aspects of bacterial growth and motility, cell viability, biofilm matrix production, and biofilm architectures. The underlying mechanisms of the intra-species variability in biofilms were also explored by whole genome resequencing (WGR). Results from bacterial motility tests showed a diverse motility among the strains, but there was no clear correlation between bacterial motility and biofilm formation. The cell viability results showed a different number of live cells in biofilms at the intra-species level. Analysis of chemical components in biofilm matrix demonstrated the great intra-species differences regarding extracellular matrix composition, and a negative correlation between biofilm formation on stainless steel and the protein: carbohydrate ratio in biofilm matrix was observed. Confocal laser scanning microscopy analysis also revealed the intra-species variability by showing great differences in general properties of B. licheniformis biofilms. WGR results identified important pathways involved in biofilm formation, such as two-component systems, quorum sensing, starch and sucrose metabolism, ABC transporters, glyoxylate and dicarboxylate metabolism, purine metabolism, and a phosphotransferase system. Overall, the above results emphasize the necessity of exploring the intra-species variation in biofilms, and would provide in-depth knowledge for designing efficient biofilm control strategies in the dairy industry.
•Heterogeneity in motility, cell viability, biofilm matrix and structures were observed in four B. licheniformis strains.•A negative correlation between biofilm formation and the protein: carbohydrate ratio in EPS was observed.•Key pathways such as two-component systems and QS, were involved in B. licheniformis biofilm formation.•Whole genome resequencing is a powerful tool to study biofilm heterogeneity.
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![Sc(OTf)3‑Catalyzed [3 + 3] ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1523-7060/small "Sc(OTf)3‑Catalyzed [3 + 3] Cycloaddition of Cyclopropane 1,1-Diesters with Phthalazinium Dicyanomethanides")
