This paper introduces the background and the status of the development of non toxic mono propellant engines at home and abroad. The physical and chemic characteristic, and the main performance of hydrogen peroxide propellant, HAN based propellant and hydrazine nitrate propellant are listed. These three non toxic engines are contrasted in the principium of work and the character feature. The rule of design in structure, the component of propellant and catalyst are discussed. And their perspectives in application are also estimated.
The comparison of a direct precipitation method (DPM) with a homogeneous precipitation method (HPM) for preparation of nanometer sized zinc oxide is made through discussion in theory and experiment. By using zinc oxide nitrate as the material and urea as the homogeneous precipitate, the particle size of nanometer sized ZnO is much smaller than that by using the direct precipitation method. Moreover, it has a narrow distribution and high dispersion.
Xanthoceras sorbifolium (yellowhorn) is an endemic edible oil crop in China. A novel Neocucurbitaria species associated with dead stems of yellowhorn in Jilin Province (northeast China) is described and illustrated. It is characterized by stromata with 1–5 locules and a subhyaline pycnidial wall under the inner layer. Full morphological details and a comparison with closely related species are also provided. The new species differs from the closely related species N. ribicola, N. rhamni, N. rhamnicola and N. rhamnioides by its distinct conidiogenous cells and conidia. Phylogenetic analysis (maximum likelihood and Bayesian inference method) of combined ITS, LSU, rpb2, tef1-α and tub2 sequence data reveal that two strains of the fungus differ from all other species of Neocucurbitaria (Cucurbitariaceae). Therefore, we introduce N. subribicola as a new species, and this is the first report of the asexual morph of Neocucurbitaria in China
Gold nanoparticles (AuNPs) have recently garnered great interest as potential radiosensitizers in tumor therapy. However, major challenges facing their application in this regard are further enhancement of tumor accumulation of the particles in addition to enhanced permeability retention (EPR) effect and an understanding of the optimal particle size and time for applying radiotherapy after the particle administration. In this study, we fabricated novel cyclic c(RGDyC)-peptide-conjugated, Gd- and 99 mTc-labeled AuNPs (RGD@AuNPs-Gd99 mTc) probes with different sizes (29, 51, and 80 nm) and evaluated their potential as radiosensitization therapy both in vitro and in vivo. We found that these probes have a high specificity for αvβ3 integrin positive cells, which resulted in their high cellular uptake and thereby enhanced radiosensitization. Imaging in vivo with MRI and SPECT/CT directly showed that the RGD@AuNPs-Gd99 mTc probes specifically target tumors and exhibit greater accumulation within tumors than the RAD@AuNPs-Gd99 mTc probes. Interestingly, we found that the 80 nm RGD@AuNPs-Gd99 mTc probes exhibit the greatest effects in vitro; however, the 29 nm RGD@AuNPs-Gd99 mTc probes were clearly most efficient in vivo. As a result, radiotherapy of tumors with the 29 nm probe was the most potent. Our study demonstrates that RGD@AuNPs-Gd99 mTc probes are highly useful radiosensitizers capable of guiding and enhancing radiation therapy of tumors.
The combustion performance of an aerosol fire extinguishing agent (EBM) is studied by the cone calorimeter. Smoking ratio、rate of heat release are analyzed, and the content of CO、CO 2 and O 2 are discussed when aerosol are forming. Experimental results show that the gases of CO、CO 2 and O 2 in burning process are harmless to human being.
Ganoderma tsugae is a significant mushroom with medicinal and dietary properties. However, it has not been used as dishes and fresh-eating food. In order to fully explore this rare mushroom resource, an in-depth investigation was conducted on the dynamic changes in various nutritional and taste indicators of G. tsugae for the first time. This study focused on an analysis of the nutritional components, mineral elements, non-volatile taste compounds, electronic tongue, and texture profile analysis of samples at six different morphogenesis stages (primordia stage, coloration stage, stipe differentiation stage, pileus differentiation stage, spore pre-ejection stage, late stage of spore ejection, respectively). The results indicated that the nutrient and mineral contents in primordia and coloration stage exhibited superior qualities compared to the other treatments. Partial least squares discriminant analysis (PLS-DA) and principal component analysis (PCA) revealed the differences and comprehensive evaluation in taste and nutritional value between different treatments. According to the analysis of the edibility and economic benefit of various samples, it has been determined that the optimal harvest stage for the fresh-eating G. tsugae is coloration stage. This finding serves as a fundamental basis for the development and utilization of fresh culinary lingzhi. It also provides essential data and a comprehensive reference for addressing the issue of raw materials in the production of Ganoderma products.
Elastomeric modified cast double base (EMCDB) propellant, which has good mechanical properties and plateau burning effect, was successfully prepared by granule casting process. The design consideration of EMCDB propellant's compositions, the reasons for the propellant with very low pressure exponent, the characteristics of the propellant's mechanical properties, and the effect of Pb salt and Cu salt on the propellant's mechanical properties were thoroughly analyzed and studied. It was found that the granule casting process has an advantage over silt casting process.
On the basis of investigation of browning spot,the micro-structure of Huangguan pear fruit bagged in white one-layer,three-layer and non-bagged fruit was observed,and microstructure difference between pathological site of browning spot fruit and normal fruit was analyzed.The results showed that browning spot incidence on fruit peel of three-layer bagged mature fruit was 22.5 percent,and the rate of non-bagged mature fruit was just 1.5 percent.The cuticle of non-bagged fruit showed thick and corrugated distribution,and filled in intercellular space of epidermal cells.The change of cuticle thickness was not obvious during fruit development.There was uniform cuticle on bagged fruit surface.The cuticle thickness became thin with fruit development.It was significant thinner than that of non-bagged fruit,and cuticle of fruit bagged in three-layer was the thinnest.The epidermal cell of bagged fruit bagged was rectangle,and its arrangement was obviously more regular and closer than that of non-bagged fruit.Tannins layer number gradually decreased with fruit development,and were not obvious different among different treatment from 90 days after full flowing to fruit mature.The parenchyma cell arrangement of bagged fruit was close,and its intercellular space,stone cells and its density were much smaller than those of non-bagged fruit.The pathological site of browning spot fruit showed blur cuticle,and the thickness of cuticle,epidermal cells and tannins of normal site of browning spot fruit were much thinner than those of normal fruit.The results suggested that variation of surface structure of bagged Huangguan pear fruits may play the important effect in incidence of brown spot.
Several industrial and research nitrate ester plasticized polyether (NEPE) solid propellants with and without N-guanylurea-dinitramide (FOX-12 or GUDN) and ammonium dinitramide (ADN) particles, featuring the same nominal composition, were prepared. The combustion properties (strand burning rate, combustion flame structures, and the associated combustion temperature distribution) of propellants with FOX-12 and ADN were determined and also compared to those propellants without FOX-12 and ADN particles. It turned out that the performed NEPE solid propellants containing dual oxidizer particles (FOX-12 and ADN) can be prepared and cast safely. The addition of ADN particles to the propellant formulation can increase the burning rate and pressure exponent, and affect the combustion behavior, when comparing to the reference propellant. The combustion flame structures of ADN-based NEPE solid propellant with dual oxidizers at various pressures present a multi-flame structure, and the brightness of flame structures increase with an increase in the pressure.
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