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In recent years, with the increase of wind power generation and the rapid growth of the number of wind turbines installed, the safety monitoring of wind turbine blades has also attracted wide attention. To further study the thermal effect of wind turbine damaged blades under natural excitation in summer in northern China, based on the outdoor infrared non-destructive testing of wind turbine blades, a numerical simulation of wind turbine blades with wear damage is carried out by using the fluid solid heat transfer theory in COMSOL multi-physical field coupling software. The best detection light condition is obtained, in which the detection effect of wear damage is the best when the light intensity reaches 1000W.m− 2 or above at noon. The simulation results are basically in agreement with the experimental results. And compared with the previous physical modeling method using natural convection heat transfer coefficient to replace wind speed, the physical modeling method considering wind speed and air humidity is more consistent with the experimental results, the maximum error value was decreased by 7.46%, which verifies the rationality of the model and the feasibility of the method. Then, the numerical model is used to carry out fluid-heat-solid coupling on the wear-damaged blades, with the increase of wind speed, the temperature on the blade surface gradually decreases and the wind pressure gradually increases. Because the influence of temperature on the stress is greater than that of wind pressure, the stress also shows a gradual downward trend.

In recent years, with the increase of wind power generation and the rapid growth of the number of wind turbines installed, the safety monitoring of wind turbine blades has also attracted wide attention. To further study the thermal effect of wind turbine damaged blades under natural excitation in summer in northern China, based on the outdoor infrared non-destructive testing of wind turbine blades, a numerical simulation of wind turbine blades with wear damage is carried out by using the fluid solid heat transfer theory in COMSOL multi-physical field coupling software. The best detection light condition is obtained, in which the detection effect of wear damage is the best when the light intensity reaches 1000W.m− 2 or above at noon. The simulation results are basically in agreement with the experimental results. And compared with the previous physical modeling method using natural convection heat transfer coefficient to replace wind speed, the physical modeling method considering wind speed and air humidity is more consistent with the experimental results, the maximum error value was decreased by 7.46%, which verifies the rationality of the model and the feasibility of the method. Then, the numerical model is used to carry out fluid-heat-solid coupling on the wear-damaged blades, with the increase of wind speed, the temperature on the blade surface gradually decreases and the wind pressure gradually increases. Because the influence of temperature on the stress is greater than that of wind pressure, the stress also shows a gradual downward trend.

Several environmentally benign graphitic carbon nitride (g-C3N4)-based nanocomposites with Lewis acid–base dual functionalities were developed through the pyrolysis of deep-eutectic solvents (DESs)...

Novel squaramide-based ionic liquids (SAILs) were first presented through properly molecular structure design. They were successfully applied to the cycloaddition of CO2 and epoxide to form cyclic carbonate as single-component catalyst. The catalytic behaviors of SAILs with different structures were thoroughly studied for the cycloaddition reaction. The squaramide groups were easy to form strong hydrogen bonds with oxygen atoms of epoxide, leading to an intensive activation of the epoxide. Under the optimum reaction conditions, good to excellent product yields with satisfactory selectivities were obtained. The structure-designed catalyst was easily recovered and showed excellent reusability with no significant loss of catalytic activity after six cycles. An insight into the synergistic catalytic mechanism deriving from the multiple hydrogen bond donors and bromine anions was proposed. The new strategy helps to solve the problems of cocatalyst/nucleophile leaching and complex separation/purification existed in binary organocatalysts. The multiple hydrogen bond catalysis shows a green and promising alternative to Lewis acid catalysis in the relevant CO2 conversion applications.

CO2 capture and utilization (CCU) have aroused much attention. In this paper, several novel triazolium-based ionic liquids (ILs) were developed for highly efficient transformation of CO2 into quina...

Novel phosphonium-based deep eutectic ionic liquids were well designed and facilely synthesized; their structures and physical properties were studied in detail. As single-component and sustainable...

Multifunctional succinimide-based ionic liquids (SIILs) were well-designed and synthesized, and they were used as a dual solvent–catalyst for efficient transformation of CO2 and 2-aminobenzonitriles into quinazoline-2,4(1H,3H)-diones under mild conditions. The catalytic behaviors, including the effects of anion–cation structures and reaction parameters, catalyst recyclability, and versatility were thoroughly studied. The optimum [HTMG][Suc] comprising a tetramethylguanidine cation and a succinimide anion showed excellent activity toward various substituted 2-aminobenzonitrile substrates. [HTMG][Suc] was easily recyclable with superior structural integrity. The possible pathways of CO2 and 2-aminobenzonitrile activated by [HTMG][Suc] were investigated in depth, which supported the reaction mechanism well. In comparison with reported catalysts, the protocol herein exhibited comparable catalytic performance under milder and greener conditions without any additional organic solvents.

Novel metal-free, dual-ionic ammonium salts catalytic media were developed, and they were used to catalyze the cycloaddition of CO2 and epoxides to yield cyclic carbonate. The effects of catalyst structures and reaction parameters on the catalytic activity were investigated. The optimized [TEA+O2–][Br–][DBUH+] contains hydrogen-bond donor groups (−NH), nucleophilic [Br–] and carboxyl anions, and it shows exceptional catalytic performance with satisfied product yield and selectivity at ambient temperature due to the synergy between the dual cations and anions in the system. The present catalyst exhibits good reusability and can keep excellent activity after five reaction cycles. The catalyst also shows general applicability to other epoxide substrates. Finally, an insight into the dual cation–anions synergetic activation pathway and catalytic mechanism was proposed.

The prevalence of mcr-positive bacteria in 5,169 domestic animal-derived samples collected by USDA Food Safety and Inspection Service between October 2018 and May 2019 was investigated. A procedure including enriched broth culture and real-time PCR targeting mcr-1 to mcr-8 were used for the screening. Fifteen positive isolates were identified, including one plasmid-borne mcr-1-positive Escherichia coli strain, EC2492 (reported elsewhere) and 14 mcr-3/7-positive strains from poultry (1), catfish (2), and chicken rinse (11) samples, resulting in an overall prevalence of mcr-positive bacteria 0.29% in all meat samples tested. Analysis of 16S rRNA and whole genome sequences revealed that all 14 strains belonged to Aeromonas. Data from phylogenetic analysis of seven housekeeping genes, including gyrB, rpoD, gyrA, recA, dnaJ, dnaX, and atpD, indicated that nine strains belonged to Aeromonas hydrophila and five strains belonged to Aeromonas jandaei. Antimicrobial tests showed that almost all mcr-positive strains exhibited high resistance to colistin with MICs ≥ 128mg/L, except for one A. jandaei strain, which showed a borderline resistance with a MIC of 2 mg/L. A segment containing two adjacent mcr-3 and mcr-3-like genes was found in two A. hydrophila and one A. jandaei strains and a variety of IS-like elements were found in the flanking regions of this segment. A mcr-3-related lipid A phosphoethanolamine transferase gene was present in all 14 Aeromonas strains, while an additional mcr-7-related lipid A phosphoethanolamine transferase gene was found in 5 A. jandaei strains only. In addition to mcr genes, other antimicrobial resistance genes, including blaOXA–12/OXA–724, aqu-2, tru-1, cepS, cphA, imiH, ceph-A3, ant(3″)-IIa, aac(3)-Via, and sul1 were observed in chromosomes of some Aeromonas strains. The relative high prevalence of chromosome-borne mcr-3/7 genes and the close proximity of various IS elements to these genes highlights the need for continued vigilance to reduce the mobility of these colistin-resistance genes among food animals.

Aiming at the problems of wrong brand, mixed batch and wrong transmission of electronic parameter information in the production of cut tobacco of different brands in the tobacco industry, a fully intelligent quality error prevention system based on WinCC configuration software and PLC distributed control program is designed. The information of the production and manufacturing execution system in the general control room and the brand, batch and other information stored in the PLC of the bottom electric control cabinet is compared and verified instead of manual self-inspection. If the information is consistent, production is allowed. Otherwise, the equipment locks itself and sends alarm feedback. The design and application of the system realize the automatic error prevention of process equipment and the implementation accuracy of production control parameters, to ensure that the production process meets the requirements of process technology, effectively avoid major quality accidents, and finally guarantee the product quality.

The application of ionic liquids in chemical recycling of waste polycarbonate (PC) via the simple hydrolytic strategy has shown great potential. Herein, a series of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) based ILs were facilely synthesized and characterized, and could efficiently catalyze the hydrolysis of PC in the absence of transition metal and solvent. The catalyst structures and reaction conditions were optimized, and 100% PC conversion with 97% bisphenol A (BPA) yield could be obtained under the conditions of n(H2O)/n(PC) = 3:1, n(Cat.)/n(PC) = 0.1:1, 140 °C for 3.0 h. Based on the experimental results and in-situ FT-IR analysis of the PC residues and BPA product, a feasible molecular activation and catalytic pathway for [HDBU][LAc] catalyzed hydrolysis of PC was proposed.

Polyester wastes have caused a series of environmental issues, and it has became imperative to promote recycling of polyester wastes. Herein, a novel protocol for polyester depolymerization to reco...

The development of efficient and green protocol for recycling of waste plastics is of great significance in terms of “sustainable society” and “green chemistry” concepts. Several ionic liquids (ILs) with different acidity–basicity and structures were one-step synthesized and characterized. They were applied to alcoholysis of polycarbonate (PC) without metal and solvent. The IL structures and reaction conditions were optimized. Moreover, the alcohol scopes and catalyst reusability were evaluated. The results showed that 100% PC conversion and 99% bisphenol A (BPA) yield were obtained by using [HDBU][LAc] catalyst, and the [HDBU][LAc] could keep high-activity after using for six times under the optimized conditions. Finally, the possible reaction mechanism was proposed via the FT-IR and NMR analysis technique.

In this contribution, an efficient and green protocol for alcoholysis of waste polycarbonate (PC) using Lewis acidic ionic liquids (ILs) was first developed under mild and solvent-free conditions. The influence of Lewis acidity and reaction parameters on the catalytic activity were thoroughly studied. It showed that with only 5.0 mol % [Bmim]Cl·2.0FeCl3 loading, 100% PC conversion with 97.2% bisphenol A (BPA) yield was efficiently obtained at 120 °C and n(CH3OH)/n(PC) = 6:1 for 3.0 h. The alcohol scopes for depolymerization of waste PC into BPA monomer were examined, and the moderate to excellent product yields were obtained under the optimized conditions. Also the [Bmim]Cl·2.0FeCl3 catalyst could be reused five successive times without a significant decrease of the catalytic activity. Combining the kinetic study and the in situ FT-IR analysis, a feasible reaction mechanism was proposed.

The male-sterile ms2 mutant has been known for 40 years and has become extremely important in the commercial production of wheat. However, the gene responsible for this phenotype has remained unknown. Here we report the map-based cloning of the Ms2 gene. The Ms2 locus is remarkable in several ways that have implications in basic biology. Beyond having no functional annotation, barely detectable transcription in fertile wild-type wheat plants, and accumulated destructive mutations in Ms2 orthologs, the Ms2 allele in the ms2 mutant has acquired a terminal-repeat retrotransposon in miniature (TRIM) element in its promoter. This TRIM element is responsible for the anther-specific Ms2 activation that confers male sterility. The identification of Ms2 not only unravels the genetic basis of a historically important breeding trait, but also shows an example of how a TRIM element insertion near a gene can contribute to genetic novelty and phenotypic plasticity., The male-sterile ms2 mutant has facilitated commercial production of wheat for over 40 years. Here, Xia et al. map Ms2 and describe how a retrotransposon insertion event in the regulatory element of an orphan gene is associated with expression in anthers and development of male sterility.

This paper describes the results and outcomes of a survey conducted to investigate the presence of mcr-1 in 5169 domestic animal-origin samples collected by the USDA-Food Safety and Inspection Service between October 2018 and May 2019. Samples from chicken rinse (N = 1787), ground beef (N = 1369), beef trim (N = 1057), poultry (N = 363), raw pork (N = 416) and catfish (N = 177) were enriched in non-selective media and transferred to 96 well plates with a selection medium containing CaCl2, colistin and vancomycin. A novel ELISA was used to screen for the mcr-1 gene product (MCR-1). Only a single colistin resistant Escherichia coli carrying a mcr-1 gene was isolated from raw pork with a MIC of 8 mg/L, which resulted in an overall mcr-1 presence in raw pork of 0.24% and less than 0.02% in the total samples tested. This study represents the first large-scale investigation of mcr-1 in the U.S. meat, poultry, and catfish. Further examination of the positive isolate, Escherichia coli 2492 (EC2492), by whole genome sequencing revealed that this strain contained a 4.8 Mb chromosome and six plasmids. The mcr-1 gene was located on an IncI2 type plasmid and other five resistance genes, tetA, tetR, sul2, aph (3”)-Ib and aph (6)-Id identified were located on an IncB/O/K/Z plasmid. In silico analysis assigned EC2492 to ST101 and serotype O54:H21. In conclusion, while the survey results indicated that mcr-1 is rare in the U.S. animal derived foods, that one positive isolate was found suggests that continued vigilance to minimize further spread of mobile colistin resistance is warranted.

Ion beam sputtering has been extensively adopted for optical surface processing. Due to differences between atoms in terms of atomic mass, surface binding energy and surface coverage fraction, the removal characteristics of the solid compound materials will be diverse. This paper first developed a quasi-atomistic model of the binary compound target and simulated ion beam sputtering processes using the Kinetic Monte Carlo (KMC) method. Furthermore, the effect of atomic differences on the removal characteristics was investigated. Finally, contrastive analysis between simulations and experiments of fused silica using an Ar+ ion beam was performed. The simulation results indicated that the competition between two types of preferential sputtering could cause the surface composition, removal amount and removal rate to oscillate in the early stage and to be relatively stable after a period of time. Compared with the fused silica experiments, the stable removal rate error of the KMC model considering the preferential sputtering is 5.9%; however, the stable removal rate error of the KMC model without regard to the preferential sputtering is 12.6%. (C) 2014 Elsevier B.V. All rights reserved.

The wind turbine blade is an elongated structure composed of composite materials. Due to the harsh working environment and the vibration and deformation during operation, the blade is easily damaged, which seriously affects the smooth operation of the wind turbine, and has great potential safety hazards. The finite element software ANSYS is used to study the vibration characteristics under the condition of blade rotation, and different damage modal analysis can be carried out for different positions. The BP neural network is established by MATLAB to quantify the damage degree of the blade. The analysis results show that the damage and damage degree can be recognized by the change of natural frequency before and after the damage of the blade. The damage location can be identified by change rate of strain mode before and after the damage of the blade. The damage degree of the blade can be quantified and judged. The relative error rate is between -4.36% to 2.73%, and the recognition effect is more accurate.

The radius of curvature (ROC) is one of the most important parameters of sphere optic components. In optic fine grinding process, radius of curvature accuracy requires up to 0.1%. We propose a method based on high precision CNC grinding machine, develop ROC online measurement method for fine grinding optics. This rapid method only takes few measurement points based on spiral route path, attaining enough accuracy and reduce the time cost, furthermore, can greatly reduce the repeated installation error. Analyzing the uncertainty sources that affect to the ROC measurement results, calculates the combined standard uncertainty 32.8 micron. Completed comparison experiments with CMM, the standard deviation of the experiment result are about 18 micron that approaches to CMM results.

The evolution of five chromosomes of Brachypodium distachyon from a 12-chromosome ancestor of all grasses by dysploidy raises an interesting question about the fate of redundant centromeres. Three independent but complementary approaches were pursued to study centromeric region homologies among the chromosomes of Brachypodium, wheat, and rice. The genes present in pericentromeres of the basic set of seven chromosomes of wheat and the Triticeae, and the 80 rice centromeric genes spanning the CENH3 binding domain of centromeres 3, 4, 5, 7, and 8 were used as "anchor" markers to identify centromere locations in the B. distachyon chromosomes. A total of 53 B. distachyon bacterial artificial chromosome (BAC) clones anchored by wheat pericentromeric expressed sequence tags (ESTs) were used as probes for BAC-fluorescence in situ hybridization (FISH) analysis of B. distachyon mitotic chromosomes. Integrated sequence alignment and BAC-FISH data were used to determine the approximate positions of active and inactive centromeres in the five B. distachyon chromosomes. The following syntenic relationships of the centromeres for Brachypodium (Bd), rice (R), and wheat (W) were evident: Bd1-R6, Bd2-R5-W1, Bd3-R10, Bd4-R11-W4, and Bd5-R4. Six rice centromeres syntenic to five wheat centromeres were inactive in Brachypodium chromosomes. The conservation of centromere gene synteny among several sets of homologous centromeres of three species indicates that active genes can persist in ancient centromeres with more than 40 million years of shared evolutionary history. Annotation of a BAC contig spanning an inactive centromere in chromosome Bd3 which is syntenic to rice Cen8 and W7 pericentromeres, along with BAC FISH data from inactive centromeres revealed that the centromere inactivation was accompanied by the loss of centromeric retrotransposons and turnover of centromere-specific satellites during Bd chromosome evolution.

The purpose of present study was to evaluate the role of LISS after a large series of patients in whom a fracture around the knee had been treated with this uniform technique. Between April 2004 and September 2006, 210 patients with a total of 216 fractures around the knee were treated with LISS, all at the Affiliated Hospital to Nantong University. Patients were followed for a mean of 27 months (range 12-42 months). 26 patients were excluded from the study. The remaining 184 patients with a total of 189 fractures of either distal femur (85 cases) or proximal tibia (104 cases) were available for analysis. The mean age of these patients was 49 years (range 18-82 years). Immediate postoperative X-rays showed the alignment of bone and joint was satisfactorily maintained with LISS in all cases and an ideal implant position in 176 cases (93%). All cases healed the fracture without non-union. The mean time to union was 15 weeks (range 12-27 weeks) for the femoral and 16 weeks (range 12-27 weeks) for the tibia fractures. Functional assessment was performed using HSS (hospital for special surgery) score. At the time of the latest follow-up, 158 patients (86%) had an excellent or good outcome. Overall, 3 patients were subject to a salvage operative procedure due to implant failure. Three cases underwent secondary bone graft for open fractures. Superficial and deep infection was found each in one patient and both were treated successfully. Hardware prominence irritation was found in 2 patients. LISS was removed in 27 patients after bone healing, and this procedure was neither less invasive nor easy as imagined. The results indicate the LISS system is perfect but by no means unique in the treatment of the fractures around the knee. The fixation is adequate enough to maintain alignment and obtain union with a low incidence of complications even in patients with osteoporotic bone. We firmly believe favourable results can be achieved when this device is combined with correct indications as well as skillful techniques.

Poly(N-isopropylacrylamide)-block-poly{6-[4-(4-methylphenyl-azo) phenoxy] hexylacrylate} (PNIPAM-b-PAzoM) was synthesized by successive reversible addition-fragmentation chain transfer (RAFT) polymerization. In H 2 O/THF mixture, amphiphilic PNIPAM-b-PAzoM self-assembles into giant micro-vesicles. Upon irradiation of light at 365 nm, fusion of the vesicles was observed directly under an optical microscope. The real-time fusion process is presented and the derivation is preliminarily due to the perturbation by the photoinduced trans-to-cis isomerization of azobenzene units in the vesicles.

Ion beam machining has become an important means adopted to high-precision large optical mirror processing. This study has conducted a bitmap-style model, calculation and analysis on low-energy Ar+ ion beam sputtering optical surface, based on Sigmund Theo ry and the CCOS principle. We have obtaine d the relationship of the removal function and the removal rate with major technological parameters of ion beam machining (e.g. dwell time, work distance, ion energy, etc.) also via orthogonal experiments of single point removal. Results indicated that the removal rate of amorphous SiO 2 (fused silica) by Ar + ions with 600~1200 electron volts increases with the increase of ion energy and dwell time at different extents, decreases exponentially with the increase in work distance. On the basis of computational analysis and experimental investigations, we optimized process conditions and further figured the plane mirror with the clear aperture of 130 millimeters, utilizing technologically optimized low-energy Ar+ ion beam machining. Eventually we obtained the high-precision figure shape with the post-machined surface roughness of 0.43~0.44 nm rms and the post-machined figure error of 1 nm rms. Keywords: Ion beam machining, large optical surface, high-precisi on, mechanism, process

Lithography-optics is one of the most complex optical systems. The fine grinding process is the most important step before polishing. Roughness and sub-surface damage (SSD) are essential outputs of fine grinding. We demonstrate the method that use fix abrasive cup tool with CNC grinding machine to complete the fine grinding process, even instead of lapping process. And experiment sample roughness can reach 23.40nm rms and Ra 18.554nm. The SSD estimate is about 2 μm which is also smaller than commercial lapping process. The fine grinding output can satisfy the lithography optic fabrication demands and efficiently reduce the polishing time.

Ion beam Figuring (IBF) is believed to be one of the best ways that can fabricate lenses to surface error less than Root Mean Square (RMS) value 1 nanometer. There are several aspects that will influence the fabricate efficiency and accuracy, for example, stability of ion beam, measuring errors of the lenses’ surfaces, dwell time algorithm, fabrication path, etc. Lots of works have been done and papers are published. Since the ion beam generated from argon plasma is electropositive, the lens’ surface will also be electropositive when it is stroked by the ion particles, so that the fabricating efficiency will be decreased because of the repelling force with the same kind electric charges. To avoid the accumulation of charges on lens’ surface, ion beam is neutralized by electrons excited by electric gun or heated tungsten filament. But sometimes the neutralization is not well done. In this paper, fabricating influence of electrified ion beam was analysed, and experiments were done. First, the shape of ion beam without neutralization was tested by Faraday cup, and its removal volumes with different sputtering time were calculated by subtracting lens’ surface error before and after it were fabricated by the ion beam. Then by adjusting the current of the tungsten filament, the excited electrons’ number was changed and the ion beam was neutralized partly, the shapes of ion beams were recorded and the corresponding removal volumes were also tested. Finally, a lens with diameter about 64mm was fabricated. The results showed that the fabrications were either excessed or not enough when using ion beams that were not neutralized perfectly. When neutralized perfectly, the convergent rate of the fabrication will be very fast, in a single iteration, the initial surface error with RMS value more than 7nm might decrease to less than 1nm.

Hexaploid bread wheat contains A, B, and D three subgenomes with its well-characterized ancestral genomes existed at diploid and tetraploid levels, making the wheat act as a good model species for studying evolutionary genomic dynamics. Here, we performed intra- and inter-species comparative analyses of wheat and related grass genomes to examine the dynamics of homologous regions surrounding Rht-1, a well-known "green revolution" gene. Our results showed that the divergence of the two A genomes in the Rht-1 region from the diploid and tetraploid species is greater than that from the tetraploid and hexaploid wheat. The divergence of D genome between diploid and hexaploid is lower than those of A genome, suggesting that D genome diverged latter than others. The divergence among the A, B and D subgenomes was larger than that among different ploidy levels for each subgenome which mainly resulted from genomic structural variation of insertions and, perhaps deletions, of the repetitive sequences. Meanwhile, the repetitive sequences caused genome expansion further after the divergence of the three subgenomes. However, several conserved non-coding sequences were identified to be shared among the three subgenomes of wheat, suggesting that they may have played an important role to maintain the homolog of three subgenomes. This is a pilot study on evolutionary dynamics across the wheat ploids, subgenomes and differently related grasses. Our results gained new insights into evolutionary dynamics of Rht-1 region at sequence level as well as the evolution of wheat during the plolyploidization process.