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A series of KF/Mg‐Fe oxides were fabricated via the solid‐state reaction between KF and Mg‐Fe oxides. Especially, when 20 wt % KF was supported on the Mg‐Fe bi‐metal oxides and calcined at 400–600 °C, the solid material with more basic sites than the support itself was obtained. When applied as catalyst to dimethyl carbonate (DMC) synthesis through transesterification of ethylene carbonate (EC) and methanol, this material can afforded up to 88 % yield and 97 % selectivity toward DMC in 2 h under reflux conditions with the molar ratio of methanol to ethylene carbonate set at 8. It is worth noting that the catalyst was easily separated and reused, retaining at least 89 % catalytic activity during the first four recycles. Although an attenuated activity was still observed due to the inevitable filtration loss and dissolution, this solid base can still provide clues to the development recyclable catalyst in green synthesis of DMC. [ABSTRACT FROM AUTHOR]

Monitoring the degradation state of hydraulic pumps is of great significance to the safe and stable operation of equipment. As an important step, feature extraction has always been challenging. The non-stationary and nonlinear characteristics of vibration signals are likely to weaken the performance of traditional features. The two-dimensional image representation of vibration signals can provide more information for feature extraction, but it is challenging to obtain sufficient information based on small-size images. To solve these problems, a method for feature extraction based on modified hierarchical decomposition (MHD) and image processing is proposed in this paper. First, a set of signals decomposed by MHD are converted into gray-scale images. Second, features from accelerated segment test (FAST) algorithm are applied to detecting the feature points of the gray-scale image. Third, the real part of Gabor filter bank is used to convolve the images, and the responses of feature points are used to calculate histograms that are regarded as feature vectors. The method for feature extraction fully acquires the multi-layered texture information of small-size images and removes the redundant information. Furthermore, support vector machine (SVM) and nondominated sorting genetic algorithm II (NSGA-II) are introduced to conduct feature selection and state identification. NSGA-II and SVM can conduct the joint optimization of these two goals. The details of the proposed method are validated using experimental data, and the results show that the highest recognition rate of our proposed method can reach 100%. The results of the comparison among the proposed method, local binary pattern (LBP), and one-dimensional ternary patterns (1D-TPs) certify the superiorities of the proposed method. It obtains the highest classification accuracy (99.7%–98%) and the lowest feature set dimension (13–10). [ABSTRACT FROM AUTHOR]

CO2 valorization into valuable chemicals has attracted much attention, among which carboxylative cyclization represents an appealing transformation strategy to synthesize heterocyclic compounds. Conventionally, the carboxylative cyclization comprises CO2 capture and subsequent nucleophilic attack of the resulting carboxylic anion to an unsaturated bond, by which the monofunctionalization of the unsaturated bond is realized and the heterocyclic compounds, such as 5-/6-membered cyclolactone, cyclocarbonate, and oxazolidinone, are accordingly generated. Nowadays, the CO2-participated multicomponent carboxylative cyclizations have evoked intense interest due to their ability to perform the bifunctionalization of the unsaturated bond in the ring-closing step, thus assembling complex molecules. Up to now, by activating the unsaturated bonds with functionalized reagents and designing cascade reactions of organometallic compounds, substituents including iodine, trifluoromethyl, perfluoroalkyl, alkyl, cyanoalkyl, allyl, aryl, phenoxy, allenyl, selenyl, amino, and phosphonyl groups have been incorporated into the cyclocarbonate or oxazolidinone compounds successfully through the multicomponent carboxylative cyclizations. Given the tremendous utility of this synthetic strategy in heterocyclic compound synthesis, this review summarizes the progress of multicomponent carboxylative cyclizations to spur the further development of this field. [ABSTRACT FROM AUTHOR]

In view of the problem that the actual degradation status of rolling bearing has a poor distinguishing characteristic and strong fuzziness, a rolling bearing degradation state identification method based on multidomain feature fusion and dimension reduction of manifold learning combined with GG clustering is proposed. Firstly, the rolling bearing all-life data is preprocessed by local characteristic-scale decomposition (LCD) and six typical features including relative energy spectrum entropy (LREE), relative singular spectrum entropy (LRSE), two-element multiscale entropy (TMSE), standard deviation (STD), RMS, and root-square amplitude (XR) are extracted and compose the original multidomain feature set. And then, locally preserving projection (LPP) is utilized to reduce dimension of original fusion feature set and genetic algorithm is applied to optimize the process of feature fusion. Finally, fuzzy recognition of rolling bearing degradation state is carried out by GG clustering and the principle of maximum membership degree and excellent performance of the proposed method is validated by comparing the recognition accuracy of LPP and GA-LPP. [ABSTRACT FROM AUTHOR]

The degradation state identification is a key step of the condition based maintenance of hydraulic pump. In this paper, spatial information entropy (SIE) as a novel degradation feature of pump is proposed based on the study of permutation entropy (PE) algorithm. The fundamental principle of SIE is introduced and contrasted with PE. Different parameters used in the calculation of SIE are discussed and meaningful conclusion is gained. The results of simulation analysis not only checked the rationality of SIE but also demonstrated the availability and superiority of adopting SIE as the degradation feature. Based on simulation analysis, SIE and PE are united and used as degradation feature vector of pump. FCM algorithm is employed to diagnose the degradation state of pump. The analysis results of practical signal testified the rationality and availability of the proposed method. [ABSTRACT FROM AUTHOR]

This paper investigates the position regulation problem of permanent magnet synchronous motor (PMSM) subject to parameter uncertainties and external disturbances. A novel fractional second-order nonsingular terminal sliding mode control (F2NTSMC) is proposed and the finite time stability of the closed-loop system is ensured. A sliding mode disturbance observer (SMDO) is developed to estimate and make feedforward compensation for the lumped disturbances of the PMSM system. Moreover, the finite-time convergence of estimation errors can be guaranteed. The control scheme combining F2NTSMC and SMDO can not only improve performance of the closed-loop system and attenuate disturbances, but also reduce chattering effectively. Simulation results show that the proposed control method can obtain satisfactory position tracking performance and strong robustness. [ABSTRACT FROM AUTHOR]

Focuses on a study which explored the singlet-singlet energy transfer between acridine orange and pyronine in vesicle solution, in aqueous solution and in inner and outer immiscible aqueous solutions of vesicle. Results and discussion; Conclusion.

BACKGROUND: Fragrant rice is increasingly popular with the public owing to its fresh aroma, and 2‐acetyl‐1‐pyrroline (2‐AP) is the main characteristic component of the aroma in fragrant rice. Rice–fish co‐culture is an environmentally friendly practice in sustainable agriculture. However, the effect of rice–fish co‐culture on 2‐AP in grains has received little study. A conventional fragrant rice (Meixiangzhan 2) was used, and a related field experiment during three rice growing seasons was conducted to investigate the effects of rice–fish co‐culture on 2‐AP, as well as the rice quality, yield, plant nutrients, and precursors and enzyme activities of 2‐AP biosynthesis in leaves. This study involved three fish stocking density treatments (i.e. 9000 (D1), 15 000 (D2), and 21 000 (D3) fish fries per hectare) and rice monocropping. RESULTS: Rice–fish co‐culture increased the 2‐AP content in grains by 2.5–49.4% over that of the monocropping, with significant increases in the early and late rice seasons of 2020. Rice–fish co‐culture treatments significantly promoted seed‐setting rates by 3.39–7.65%, and improved leaf nutrients and rice quality. Notably, the D2 treatment significantly increased leaf total nitrogen (TN), total phosphorus (TP), and total potassium (TK) contents and the head rice rate at maturity stage, while significantly decreased chalkiness degree. There was no significant difference in rice yield. CONCLUSION: Rice–fish co‐culture had positive effects on 2‐AP synthesis, rice quality, seed‐setting rates, and plant nutrient contents. The better stocking density of field fish for rice–fish co‐culture in this study was 15 000 fish ha−1. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background We investigated risk factors for decreased lung function among Chinese island residents (≥30 years) to determine the relationship between metabolic syndrome (MS) and decreased lung function. Methods From October 17, 2011 to November 1, 2011, 2607 residents aged ≥30 years who lived on the Huangqi Peninsula of Fujian were enlisted by random cluster sampling. They completed a questionnaire designed according to the Burden of Obstructive Lung Disease (BOLD) questionnaire, and underwent physical examination, blood test, and lung function evaluation. We constructed spirometric prediction equations for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), determined the lower limits of normal for FVC, FEV1 and FEV1/FVC, and examined the relationship between lung function and MS. Results Prediction equations for normal island residents were as follows: FVC (L) = −0.023 × age (years) + 0.042 × height (cm) + 0.641 × weight (kg) - 3.607 (males);, FVC (L) = −0.017 × age (years) + 0.030 × height (cm) + 0.009 × weight (kg) - 1.741 (females);, FEV1 (L) = −0.023 × age (years) + 0.040 × height (cm) + 0.010 × weight (kg) - 2.999 (males);, FEV1 (L) = −0.017 × age (years) + 0.026 × height (cm) + 0.007 × weight (kg) −1.135 (females)., The odds ratio for MS for increased risk of decreased FVC was 4.623 (95%CI =3.626-5.894, P<0.001), and for increased risk of decreased FEV1 was 3.043 (95%CI =2.447-3.785, P<0.001). Conclusions MS is a risk factor for decreased lung function in island residents ≥30 years old. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed four-component carboxylative cyclization comprising propargylic amines, aryl iodides, CO2 and CO was developed. By selecting Et3N and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as the base, respectively, both terminal and internal propargylic amines proceeded well facilitated by Pd(PPh3)2Cl2, affording the functionalized 2-oxazolones in moderate yields. This protocol enlarges the product diversity based on CO2 conversion and simultaneously provides a cooperative transformation route for both CO2 and CO. [ABSTRACT FROM AUTHOR]

The thin spray-on liner is an inorganic polymer product that has been widely used to support mine perimeter rock roadways, but it is mainly used in metallic hard rock roadways with high rock strength and is less used in roadways affected by roadway corrosion and weathering in shallowly buried coal seams. Therefore, this study studies the thin spray-on liner support technology under such geological conditions. First, the causes of anchor support failure in this condition are analyzed, and it is concluded that alkaline ionized water corrodes the anchor rods, and chloride ions in the water play a role in accelerating the degree of anchor rod corrosion. Next, microscopic testing was used to determine the content of weathering and swelling minerals contained in the roof rock and the development of tectonic fissures. Third, the loosening circle of the surrounding rock is theoretically calculated and used as a basis to design the anchor mesh rope support parameters for the roadway. Finally, the construction process of a thin spray-on liner anticorrosion and antiweathering support technology is introduced. This technology improves the anchor force environment of anchor rods while incorporating anchor rods (ropes)—rock—metal mesh into the support system to play a coupling support role. On-site monitoring is performed to derive the optimum thickness of the spraying layer in different environments. At the same time, the deformation of the roadway surrounding rock and the anchor force can be improved to meet the requirements of anticorrosion and antiweathering and tighten the roadway surrounding rock. Compared with concrete support technology, the economic and environmental benefits of this support technology are apparent, and it helps to promote the application in shallowly buried coal seam mines. [ABSTRACT FROM AUTHOR]

Photocatalytic synthesis has emerged as an efficient route to transform CO2 into functionalized organic carbamates by photocatalysis. Herein, a catalyst-free carbamoyloxylation of arylacetones with CO2 and amines under visible light was developed for the synthesis of O-β-oxoalkyl carbamates in yields up to 93%. This protocol proceeded smoothly with the assistance of inexpensive carbon tetrabromide at room temperature under atmospheric CO2 pressure, leading to simultaneous construction of C–O and C–N bonds. Mechanism studies suggested the photoinduced hydrogen atom transfer (HAT) pathway followed by radical addition or single electron transfer (SET). [ABSTRACT FROM AUTHOR]

The verification of nuclear test ban necessitates the classification and identification of infrasound events. The accurate and effective classification of seismic and chemical explosion infrasounds can promote the classification and identification of infrasound events. However, overfitting of the signals of seismic and chemical explosion infrasounds easily occurs during training due to the limited amount of data. Thus, to solve this problem, this paper proposes a classification method based on the mixed virtual infrasound data augmentation (MVIDA) algorithm and multiscale squeeze-and-excitation ResNet (MS-SE-ResNet). In this study, the effectiveness of the proposed method is verified through simulation and comparison experiments. The simulation results reveal that the MS-SE-ResNet network can effectively determine the separability of chemical explosion and seismic infrasounds in the frequency domain, and the average classification accuracy on the dataset enhanced by the MVIDA algorithm reaches 81.12%. This value is higher than those of the other four types of comparative classification methods. This work also demonstrates the effectiveness and stability of the augmentation algorithm and classification network in the classification of few-shot infrasound events. [ABSTRACT FROM AUTHOR]

Photocatalytic CO2 reduction to valuable chemicals, especially fuels, is considered as a promising strategy to mitigate CO2 accumulation and tackle the energy crisis, among which photocatalysis is vital to achieve efficient and selective reduction of CO2. In this work, phosphorus-doped hollow polygonal g-C3N4 rods were prepared through phosphoric acid assisted self-assembly under hydrothermal conditions and subsequent thermal polymerization using phosphoric acid as the phosphorus source and melamine as the nitrogen-rich precursor. The resulting phosphorus-doped hollow polygonal g-C3N4 rods feature increased specific surface area, visible light absorption and photogenerated carrier separation and transfer efficiency according to the structure and photoelectric properties characterization. Coupled with an earth abundant metal-based complex, i.e. [Co(bpy)3]Cl2, as a co-catalyst, the phosphorus-doped hollow polygonal g-C3N4 rods deliver a CO evolution rate of up to 447.5 μmol g−1 h−1 with a selectivity of ca. 96%, being much higher compared to the pristine g-C3N4 (67.01 μmol g−1 h−1 with a selectivity of ca. 94%) resulting from the improved light harvesting and charge transfer to the co-catalyst. Remarkably, the phosphorus-doped hollow polygonal g-C3N4 rods can be reused 6 times while retaining constant catalytic activity in the photoreduction reaction. This work presents new insights into photocatalytic CO2 reduction by developing non-metal doping and hollow structural designs for semiconductor photocatalysts. [ABSTRACT FROM AUTHOR]

Background: We investigated the prevalence of and risk factors for small airway obstruction (SAO) among Chinese island residents to establish means to prevent and treat SAO. Methods: From October 17, 2011 to November 1, 2011, a total of 2,873 residents aged >20 years who lived on the Huangqi Peninsula of Fujian were recruited by random cluster sampling. They were asked to complete a Burden of Obstructive Lung Disease (BOLD) questionnaire and underwent physical examinations and lung function evaluations. SAO was defined as a forced expiratory flow at 50% of vital capacity, Vmax50%, of less than 70% of predicted. Risk factors for SAO were assessed from among demographic and anthropometric variables, blood chemistry results, and questionnaire response items. Results: A total of 216 (7.52%) Chinese island residents were identified as having SAO (95 males; 121 females). Their survey and test results were compared with 432 age and sex-matched healthy controls (192 males; 240 females) for SAO risk factors. Among numerous factors investigated, only diabetes mellitus (p = 0.039), smoking index (SI, p<0.001 for SI>600), second hand smoke (p = 0.002), and lack of regular exercise (p<0.001) were significant risk factors for SAO. Conclusions: The risk factors for SAO among Chinese island residents appeared to be similar to those among people who live in high-density urban environments and impoverished rural areas. Public health policies and medical practices directed toward improving respiratory health for island residents should be comparable to those used for urban and rural dwellers. [ABSTRACT FROM AUTHOR]

Abstract: Based on a novel Mach–Zehnder point diffraction interferometer, a real-time method to determinate beam propagation factor M 2 of laser beams is presented. By using the proposed point diffraction interferometer, the intensity profile and wavefront of laser beam are completely extracted from a single interferogram in one-shot measurement. Knowing the complex field of laser beam yields the beam''s propagation parameters such as beam propagation factor M 2 conform to the ISO standard method. The experimental method is simple, fast and operates without movable parts, which is allowed to investigate laser beams in conditions inaccessible using the existing method. [Copyright &y& Elsevier]

Abstract: A nonparametric adaptive filtering approach is proposed in this paper. The algorithm is obtained by exploiting a time-varying step size in the traditional NLMS weight update equation. The step size is adjusted according to the square of a time-averaging estimate of the autocorrelation of a priori and a posteriori error. Therefore, the new algorithm has more effective sense proximity to the optimum solution independent of uncorrelated measurement noise. Moreover, this algorithm has fast convergence at the early stages of adaptation and small final misadjustment at steady-state process. It works reliably and is easy to implement since the update function is nonparametric. Furthermore, the experimental results in system identification applications are presented to illustrate the principle and efficiency of the proposed algorithm. [Copyright &y& Elsevier]

Limb spasms are phenomena of hyperreflexia that occur after spinal cord injury. Currently, the clinical treatment is less than ideal. Our goal is to develop a combination therapy based on individualized medicine to reduce spasticity after spinal cord injury. In this study, rats received a severe contusive injury at the T9 segment of the spinal cord, followed by gene therapy with adenoassociated virus encoding human neurotrophic factor 3 (AAV-NT3) and a 2-week exercise program starting at 4 weeks after injury. We quantified the frequency of spasms during a swimming test at 4 and 6 weeks after injury and confirmed the results of the swimming test by measuring the H-reflex of the plantar muscle. We obtained weekly hind limb exercise scores to assess the effect of the interventions in hind limb motor function improvement. Then, we used immunofluorescence to observe the immunoreactivity of spinal motor neurons, synaptophysin, cholinergic interneurons, and GABAergic interneurons. We also measured the expression of KCC2 in the spinal cord by western blot. We found that AAV-NT3 gene therapy, exercise, and combination therapy all attenuated the frequency of spasms in the swimming test conducted at 6 weeks after spinal cord injury and increased rate-dependent depression of H-reflex. Combination therapy was significantly superior to AAV-NT3 alone in protecting motor neurons. Recovery of KCC2 expression was significantly greater in rats treated with combination therapy than in the exercise group. Combination therapy was also significantly superior to individual therapies in remodeling spinal cord neurons. Our study shows that the combination of AAV-NT3 gene therapy and exercise can alleviate muscle spasm after spinal cord injury by altering the excitability of spinal interneurons and motor neurons. However, combination therapy did not show a significant additive effect, which needs to be improved by adjusting the combined strategy. [ABSTRACT FROM AUTHOR]

Cupric subcarbonate (Cu2(OH)2CO3) was found to be effective for the reductive functionalization of CO2 to produce formamides and methylamines with phenylsilane as reductant. Interestingly, N-formylation and N-methylation were switched on/off by subtly choosing the ligand: DPPB (1,4-bis(diphenylphosphino)butane) promoted N-methylation whereas Ph2CyP (diphenylcyclohexylphosphine) favored for N-formylation. [ABSTRACT FROM AUTHOR]

Abstract: In the last few years, photochemical and electrochemical CO2 transformations have attracted increasing attention in response to topical interest in renewable energy and green chemistry. The present minireview offers an overview about the current approaches for the photochemical and electrochemical carbon dioxide fixation with organic compounds. Valuable products, including carboxylic acids and heterocyclic compounds, are accessible through carboxylation and carboxylative cyclization, respectively. In photochemical and electrochemical processes, photo‐ or electro‐induced radical ions or other high‐energy organic compounds are considered as key intermediates to react with CO2. Besides, activation of CO2 to produce radical anion has also been reported. [ABSTRACT FROM AUTHOR]

[Display omitted] • Benzene ring incorporated g-C 3 N 4 microtubes are fabricated. • This material has improved light harvesting and carrier separation efficiency. • It can be applied in photocatalytic CO 2 reduction with Co(bpy) 3 Cl 2 as co-catalyst. • The catalytic system presents high efficiency and selectivity to CO. • Stability is the most attractive feature for this material. As a promising material for photocatalytic CO 2 reduction, graphitic carbon nitride (CN) and its modification has attracted significant attention. In this work, the in-plane benzene incorporated g-C 3 N 4 microtubes were fabricated via a hydrothermal self-assembly and subsequent thermal polymerization. It is revealed that introducing the π electron-rich benzene ring into the planar structure of g-C 3 N 4 can improve the availability of π electron and create the local asymmetry of heptazine structure. As a result, the separation and transportation of photogenerated charges are improved. Furthermore, the modified g-C 3 N 4 possesses relatively narrow band gap and enhances light absorption. When the in-plane benzene modified g-C 3 N 4 microtubes were applied to photocatalytic CO 2 reduction with Co(bpy) 3 Cl 2 as co-catalyst, a CO yield up to 322.66 μmol·g−1·h−1 was obtained, which was two times in comparison with the pristine g-C 3 N 4. This work confirms the effectiveness of in-plane benzene modification and 1D hollow structure formation in improving the photoelectric performance of g-C 3 N 4. Besides, it provides an efficient photocatalytic CO 2 reduction protocol with nonmetallic semiconductor material and earth-abundant metal co-catalyst. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations were performed for various vancomycin dosage regimens to evaluate the potential for development of vancomycin resistance in meticillin-resistant Staphylococcus aureus (MRSA). When the target of free AUC 24 /MIC ≥ 200 was considered (where AUC 24 is the area under the drug concentration–time curve in a 24-h interval and MIC is the minimum inhibitory concentration), a standard dose regimen (1000 mg every 12 h) yielded unacceptable simulated outcomes in patients with normal renal function; in particular, the probability of target attainment (PTA) was only 30.5% at an MIC of 1 mg/L. For the same dosage regimens and the mutant prevention concentration (MPC)-based pharmacokinetic target (total AUC 24 /MPC > 15), the cumulative fraction of response exceeded 80% for all renal function strata; low values of PTA (<80%) were obtained only for isolates with MPCs of ≥22.4 mg/L, which consisted of all 21 strains of heterogeneous vancomycin-intermediate S. aureus (hVISA) and a handful of non-hVISA strains with MICs of 2 mg/L (32%; 16/50). Based on the current status of vancomycin resistance, we conclude that total AUC 24 /MPC > 15, derived from in vivo experiments, is more suitable to predict the development of vancomycin resistance. In clinical practice, individualised vancomycin therapy should be considered to minimise selection of resistance mutations. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of ricinoleic acid based non-isocyanate polyurethanes were fabricated. • Oligomeric ricinoleic acid (ORA) was designed as the key intermediate. • SnO was developed as an efficient and recyclable catalyst to access the ORA. • The polymerization degree of ORA can be regulated by reaction time. • The properties of polyurethanes can be altered by the polymerization degree of ORA. As a consequence of the great demand and extended application of polyurethanes in various fields, the development of green processes for their production and functional polyurethane materials has received widespread attention. In this regard, the biomass-derived polyurethane via the non-isocyanate route could be promising. In this work, the castor-based polyurethanes were designed and synthesized through a non-isocyanate route by employing ricinoleic acid as the starting material, in which the oligomeric ricinoleic acid (ORA) with variable average polymerization degree was used as the key intermediate. To access the ORA with different average polymerization degree, the solid Lewis acid tin(II) oxide (SnO) was developed as the efficient and recyclable catalyst and the average polymerization degree of ORA was regulated by the reaction time at 210 °C. After sequential esterification, epoxidation, cycloaddition with CO 2 and polyaddition with 1,6-hexamethylene diamine (HMDA) or isophorone diamine (IPDA), a series of polyhydroxyurethanes (PHUs) with different tensile strength and elongation at break as well as the thermal stability and the glass transition temperature were obtained depending on the type of diamine and the average polymerization degree of ORA, indicating the functional role of the polymerization degree of ORA in regulating the mechanical and thermal properties of the resulting materials. This protocol for the castor-based PHUs preparation in this work not only represents a green and sustainable way to produce bio-based material, but also provides a convenient way to change the average polymerization degree of ORA and then alter the properties of resulting polyurethanes. [ABSTRACT FROM AUTHOR]

Inside Back Cover picture shows The carps trying hard to make a successful jump over the Dragon Gate will change into fish‐dragons, which is a legend handed down in China over generations. The back cover picture shows photochemical and electrochemical CO2 transformations with organic compounds through the utilization of solar energy or electric energy, producing a series of valuable products, including carboxylic acids and hetero‐cyclic compounds. The combined utilization of both clean energy and CO2 has attracted increasing attention in sustainable development of renewable energy and green chemistry. Recent advances are summarized by He et al. on page 644–659. [ABSTRACT FROM AUTHOR]