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A novel ternary energetic cocrystal composed of 3,4-diamino-furazan (DAF), 3,4-dinitropyrazole (DNP), and H2O in a 1:1:1 stoichiometry with low impact sensitivity is reported. This cocrystal has a predicted detonation velocity higher than DAF and TNT. Preliminary attempts are reported to obtain the even more energetic cocrystals DAF/DNP and DAF/DNP/H2O22 For the latter, an original approach based on the urea/H2O2 cocrystal as a source of H2O2 is described. [ABSTRACT FROM AUTHOR]

Cleavageof lignin-derived 4-O-5 aryl ethers has been conductedover nickel nanoparticles supported on niobic acid-activated carboncomposite under mild conditions. The hydrated niobic acid has beensuccessfully supported and well dispersed on activated carbon. Dueto the coexisting Brönsted and Lewis acid sites on the hydratedniobic oxide, the Ni/xNbAC catalysts exhibited higheractivities for cleavage of C–O ether bonds and dehydrationthan those of the Ni/AC catalyst. With increasing content of niobicacid, a larger amount of O-free alkane is obtained owing to niobicacid-promoted removal of oxygen from lignin-derived aryl ethers. Thecleavage of C–O ether bonds and dehydration of cyclohexanolto cyclohexane are both favored at high temperature. The direct cleavageof the 4-O-5 aryl ether bond can also be achieved under low H2pressure, forming phenol and benzene as intermediates, followedby hydrodeoxygenation of phenol to cyclohexane. [ABSTRACT FROM AUTHOR]

The solubility of newly insensitive energetic material dihydroxylammonium 5,5'-bis(tetrazole)-1,1'-diolate (TKX-50) was measured in ethyl acetate, ethanol, deionized water, dimethyl fumarate (DMF), formic acid, toluene, and dimethyl sulfoxide (DMSO) between 293.15 and 323.15 K at atmospheric pressure by the gravimetric method, which is increased with an increase of temperature. The order of the solubility is ethyl acetate < ethanol < toluene < deionized water < DMF < formic acid < DMSO. The experimental mole fraction solubility data were correlated with a simple Apleblat equation, showing a good fitting between the experimental data and Apleblat equation. [ABSTRACT FROM AUTHOR]

Strong corrosiveness to metals is the main factor restricting the widespread application of the insensitive explosive 3-nitro-1,2,4-triazole-5-one (NTO). Herein, MXene rich in active functional groups was obtained by selective etching of Ti3AlC2, and fine-grained MXene/NTO composites with rod-like morphology were prepared by recrystallization. The incorporation of MXene not only significantly reduced the particle size of explosives from 25 to 8 mm, but also weakened the impact sensitivity from 32% to 20% and friction sensitivity from 28% to 16%. Meanwhile, the enhanced corrosion resistance and thermal stability of the resulting NTO/MXene composites benefited from the introduction of MXene. The corrosiveness of NTO aqueous solution to metals was due to the easy ionization of hydrogen in the molecular structure, MXene with active groups combined with hydrogen atoms in NTO by non-covalent bonds, resulting in difficult hydrogen ionization and corrosion resistance without changing the chemical properties of explosives. The good thermal conductivity of MXene endowed NTO with improved thermal stability and promoted the crystallization of NTO as a nucleating agent. These insensitive explosives with good comprehensive properties would be the mainstay of the upgrading of weapons and equipment. [ABSTRACT FROM AUTHOR]

C4H10BaN8O6, triclinic, P1 (No. 2), a=7.6249(18) Å, b=7.8460(16) Å, c=11.723(3) Å, α=70.520(8)°, β=85.079(10)°, =64.007(7)°, V=592.792 ų, Z=2, Rgt(F)=0.0332, wRref(F²)=0.0734, T=153 K. [ABSTRACT FROM AUTHOR]

C6H6N12O16 . 0.33 H2O, orthorhombic, Pbca (no. 61), a=9.5152(7) Å, b=13.2551(11) Å, c=23.6736(18) Å, V=2985.8(7) ų, Z=4, Rgt(F)=0.0727, wRref(F²)=0.1268, T=293(2) K. [ABSTRACT FROM AUTHOR]

C4H7N8NaO4, monoclinic, C2/c (no. 15), a = 19.42(2) Å, b = 6.514(5) Å, c = 15.38(1) Å, β = 93.23(2)°, V = 1942.9 Ų, Z = 8, Rgt(F) = 0.0631, wRref(F²) = 0.1660, T = 293 K. [ABSTRACT FROM AUTHOR]

Various TiO2, SiO2, Al2O3, and Nb2O5-Al2O3 supported Pt catalysts have been prepared by urea precipitation method for catalytic hydrodeoxygenation (HDO) of diphenyl ether (DPE) as a 4-O-5 aryl-ether lignin model compound. The selectivity toward deoxygenated product cyclohexane increased obviously with Nb2O5·nH2O decorated, owing to the significant promotion effect of NbOx species and acid sites on C-O bond cleavage. At higher pressure (3.0 MPa H2), DPE underwent a HYD route, while direct hydrogenolysis route occurred at low pressure (0.1 MPa H2). In addition, the reaction rate constants and activation energies were obtained in the temperature range from 160 to 220 °C. Based on the Arrhenius law, the activation energy for the cleavage of the C-O bond in DPE was calculated to be 91.22 kJ/mol. It was noteworthy that the Pt/20Nb-Al2O3 showed higher stability than Pt/Al2O3 for hydrodeoxygenation of diphenyl ether, which can be attributed to its water-tolerant Lewis acid sites. [ABSTRACT FROM AUTHOR]

CoSix/CNTs catalysts with different CoSix phases (CoSi, CoSi2) have been rapidly synthesized via a microwave-assisted route and applied for the liquid phase hydrogenation of phthalic anhydride. The synthesized catalysts were analyzed and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy-energy dispersive X-ray spectroscopy, thermogravimetric/derivative thermogravimetric analysis. The reaction progress of cobalt silicides and the ratio of Co:Si were monitored at different microwave irradiation times by XRD, giving insight into the formation mechanism. Compared to the Co/CNTs catalyst, all the prepared CoSix/CNTs catalysts exhibited excellent activity and good selectivity to phthalide under mild reaction conditions (180-220 °C and 4.0 MPa H2). This novel methodology can be applied to the synthesis of other transition metal silicides such as FeSi, Ni2Si, and Cu4Si. [ABSTRACT FROM AUTHOR]

Eliminating the invalid data and locating the doubtful data are realized by using the algorithm of density clustering by referring to the image features of outliers in the rearview from the perspective of manual interactive processing. The MultiBeam EchoSounder (MBES) bathymetric datasets are automatically divided into three types: credible data, doubtful data, and invalid data by the clustering algorithm. The reliable data are retained, invalid data are automatically eliminated, and the doubtful data are judged manually. This kind of automatic outlier cleaning algorithm with partial manual intervention can solve the contradiction between the low reliability of automatic processing algorithms and the low efficiency of manual interactive processing. An example shows that the algorithm improves the reliability of the results obtained from the automatic processing algorithm to a certain extent, and also, the algorithm is of great significance for the realization of high reliability and high-efficiency cleaning of outliers in MBES bathymetric data. As the world continues to explore the ocean, the demand for efficient access to high precision underwater topography is increasing, the accuracy and efficiency of underwater terrain acquisition nowadays will not be able to meet the needs of technology development. As one of the most efficient and precise equipment, the MBES system is widely used worldwide in underwater topography surveys. In recent years, the original MBES data proliferating. However, for a long time, the cleaning of outliers in MBES data with high reliability mainly relies on manual operation, which has an extended processing cycle and dramatically limits data processing efficiency. The automatic processing algorithms that have been proposed improve processing efficiency, but the credibility can not reach that of human processing; it is challenging to apply it in multibeam surveying, especially with nautical charting. Therefore, there is a crucial problem in MBES data processing:how to improve the credibility of the results processed with the automatic algorithm. After years of research, many automatic data cleaning algorithms have been proposed both at home and abroad. The cleaning mechanism can be summarized as follows:Setting up several simple thresholds; Filtering by conditions based on the statistical results;establishing local topography model. The boundary between the recognition and validation of outliers is blurred by most of the existing automatic algorithms, and the MBES soundings are directly divided into two categories according to the specific conditions: credible and ineffective. But in surveying practice, there are usually a few data belonging to the third category, which we call doubtful data. The third category of data has to be verified by professionals, who need to determine with the experience combined with the investigation data of the survey area and instrument characteristics. For example, the causes of a small cluster of points isolated from the central cluster may be suspended solids in water or angular objects, such as stones; the former should be marked as invalid data and eliminated, while the latter should be marked as trusted data to be retained. Most of the existing automatic cleaning algorithms mark the doubtful data as credible data or invalid data across the board, which is the key to the low reliability of the current automatically processing algorithms. Although dubious data accounted for a small percentage, it is crucial because it often represents the characteristics area where the underwater topography changes dramatically or targets unnatural topographic relief. Once been misjudged, it would have a significant influence on the measuring result. Currently, there is no appropriate unartificial solution to validate the doubtful data. Although the doubtful data that need manual validation is rare, manually Screening for doubtful data ping by ping would also take much time. Therefore, it is a feasible program that could improve the credibility and efficiency of data processing, that the doubtful data are located automatically and validated manually. With the matures of the machine learning algorithm, more and more scholars apply it to the cleaning of multibeam outliers, due to its unique advantages in target recognition. Yang Fanlin et al. introduced an erosion and expansion clustering algorithm to realize the automatic cleaning of MBES outliers in the deepwater area(Yang et al., 2007). Xiaolong Chen et al. used the K-Means clustering algorithm to detect outliers based on single pulse-sounding data. In this algorithm, a ping was divided into multiple clustering windows according to the topographic change. With beams in the center of a ping as initial clustering samples, a cluster on behalf of the actual underwater topography was clustered from the central beam to the edge; and the outliers are weed out automatically. This method solves the problem of recognition accuracy, but the K-Means algorithm is sensitive to the noise. As a result, the algorithm may fail when there are large areas of continuous abnormal or missing data. Although the methods above can classify MBES soundings appropriately, they still directly divide the data into two categories: credible and invalid, and the validity of the doubtful data is not isolated; the processing results have the problem of credibility. For this reason, an automatic data cleaning algorithm with partially manual intervention was proposed, Based on the Density Clustering algorithm DBSCAN (Density-based Spatial Clustering of Applications with Noise). DBCSAN algorithm is used to divide the bathymetric data into three categories: credible, doubtful, and invalid, retains the credible data and eliminates the invalid data, and the dubious data submitted to manual validation. The method could effectively improve the credibility of the automatic data cleaning algorithm. Simultaneously, compared with manual processing, the method in this paper still dramatically enhances efficiency. A contradictory problem has been solved, that the automatic processing method has high efficiency but low credibility, while manual processing method has high reliability but low efficiency of this contradiction The main steps of the algorithm include two parts: identification of outliers based on DBSCAN and validation with manual intervention. The first step is to divide the original data into three categories: credible data, invalid data, and doubtful data through the clustering algorithm. The trusted data is retained, the invalid data is eliminated, and the doubtful data is submitted to the manual validation. Finally, the doubtful data will be classified as credible data or invalid data. The concept of 'doubtful data' is introduced into the automatic cleaning of outliers in multibeam bathymetric data, which provides a new idea for the automatic cleaning of outliers. A new automatic cleaning method in multibeam bathymetric data is established, which uses the DBSCAN algorithm to classify bathymetric data and manually validate the doubtful data. This automatic processing algorithm effectively divides raw data into three types: credible data, doubtful data, and invalid data. Retain the credible data and eliminate invalid data. The validation of the dubious data is carried with manual intervention. To a certain extent, this method improves the credibility of the automatic outlier cleaning algorithm and has practical application value. [ABSTRACT FROM AUTHOR]

The internal defects and shape of cyclotrimethylenetrinitramine (RDX) crystal are critical parameters for the preparation of reduced sensitivity RDX (RS-RDX). In the current study, RDX was re-crystallized and spheroidized to form the high-quality RDX that was further characterized by purity, apparent density, size distribution, specific surface area, impact sensitivity, and shock sensitivity. The effects of re-crystallization solvent on the growth morphology of RDX crystal were investigated by both theoretical simulation and experiment test, and consistent results were obtained. The high-quality RDX exhibited a high purity (≥99.90%), high apparent density (≥1.811 g/cm³), spherical shape, and relatively low impact sensitivity (6%). Its specific surface area was reduced more than 30%. Compared with conventional RDXs, the high-quality RDX reduced the shock sensitivities of PBXN-109 and PBXW-115 by more than 30%, indicating that it was a RS-RDX. The reduced sensitivity and good processability of the high-quality RDX would be significant in improving the performances of RDX-based PBXs. [ABSTRACT FROM AUTHOR]

An electrochemical detection biosensor was prepared with the chitosan-immobilizedenzyme (CTS-CAT) and β-cyclodextrin-included-ferrocene (β-CD-FE) complex for the determination of H2O2. Ferrocene (FE) was included in β-cyclodextrin (β-CD) to increase its stability. The structure of the β-CD-FE was characterized. The inclusion amount, inclusion rate, and electrochemical properties of inclusion complexes were determined to optimize the reaction conditions for the inclusion. CTS-CAT was prepared by a step-by-step immobilization method, which overcame the disadvantages of the conventional preparation methods. The immobilization conditions were optimized to obtain the desired enzyme activity. CTS-CAT/β-CD-FE composite electrodes were prepared by compositing the CTS-CAT with the β-CD-FE complex on a glassy carbon electrode and used for the electrochemical detection of H2O2. It was found that the CTS-CAT could produce a strong reduction peak current in response to H2O2 and the β-CD-FE could amplify the current signal. The peak current exhibited a linear relationship with the H2O2 concentration in the range of 1.0 × 10-7-6.0 × 10-3 mol/L. Our work provided a novel method for the construction of electrochemical biosensors with a fast response, good stability, high sensitivity, and a wide linear response range based on the composite of chitosan and cyclodextrin. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) chromosome 3 is evolutionarily conserved across the cultivated cereals and shares large blocks of synteny with maize and sorghum, which diverged from rice more than 50 million years ago. To begin to completely understand this chromosome, we sequenced, finished, and annotated 361 Mb (-97%) from 0. sativa subsp. japonka cv Nipponbare. Annotation features of the chromosome include 5915 genes, of which 913 are related to transposable elements. A putative function could be assigned to 3064 genes, with another 757 genes annotated as expressed, leaving 2094 that encode hypothetical proteins. Similarity searches against the proteome of Arabidopsis thaliana revealed putative homologs for 67% of the chromosome 3 proteins. Further searches of a nonredundant amino acid database, the Pfam domain database, plant Expressed Sequence Tags, and genomic assemblies from sorghum and maize revealed only 853 nontransposable element related proteins from chromosome 3 that lacked similarity to other known sequences. Interestingly, 426 of these have a paralog within the rice genome. A comparative physical map of the wild progenitor species, Oryza nivara, with japonka chromosome 3 revealed a high degree of sequence identity and synteny between these two species, which diverged -10,000 years ago. Although no major rearrangements were detected, the deduced size of the 0. nivara chromosome 3 was 21% smaller than that of japonica. Synteny between rice and other cereals using an integrated maize physical map and wheat genetic map was strikingly high, further supporting the use of rice and, in particular, chromosome 3, as a model for comparative studies among the cereals. [ABSTRACT FROM AUTHOR]

The complete genome of Aeromonas hydrophila ATCC 7966T was sequenced. Aeromonas, a ubiquitous waterborne bacterium, has been placed by the Environmental Protection Agency on the Contaminant Candidate List because of its potential to cause human disease. The 4.7-Mb genome of this emerging pathogen shows a physiologically adroit organism with broad metabolic capabilities and considerable virulence potential. A large array of virulence genes, including some identified in clinical isolates of Aeromonas spp. or Vibrio spp., may confer upon this organism the ability to infect a wide range of hosts. However, two recognized virulence markers, a type III secretion system and a lateral flagellum, that are reported in other A. hydrophila strains are not identified in the sequenced isolate, ATCC 7966T. Given the ubiquity and free-living lifestyle of this organism, there is relatively little evidence of fluidity in terms of mobile elements in the genome of this particular strain. Notable aspects of the metabolic repertoire of A. hydrophila include dissimilatory sulfate reduction and resistance mechanisms (such as thiopurine reductase, arsenate reductase, and phosphonate degradation enzymes) against toxic compounds encountered in polluted waters. These enzymes may have bioremediative as well as industrial potential. Thus, the A. hydrophila genome sequence provides valuable insights into its ability to flourish in both aquatic and host environments. [ABSTRACT FROM AUTHOR]