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Mixed-mode I–II crack-based fatigue crack propagation (FCPI–II) usually occurs in engineering structures; however, no theoretical formula or effective compliance test methods have been established for FCPI–II to date. For mixed-mode I–II flawed components, based on the principle of mean-value energy equivalence, we propose a theoretical method to describe the relationship between material elastic parameters, geometrical dimensions, load (or displacement), and energy. Based on the maximum circumferential stress criterion, we propose a uniform compliance model for compact tensile shear (CTS) specimens with horizontal cracks deflecting and propagating (flat-folding propagation) under different loading angles, geometries, and materials. Along with an innovative design of the fixture of CTS specimens used for FCPI–II tests, we develop a new compliance-based testing method for FCPI–II. For the 30Cr2Ni4MoV rotor steel, the FCP rates of mode I, mode II, and mixed-mode I–II cracks were obtained via FCP tests using compact tension, Arcan, and CTS specimens, respectively. The obtained da/dN versus ΔJ curves of the FCP rates are close. The loading angle α and dimensionless initial crack length a0/W demonstrated negligible effects on the FCP rates. Hence, the FCP rates of mode I crack can be used to predict the residual life of structural crack propagation.

Residual levels and temporal–spatial distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) in dustfall were studied at the seasonal scale between June 2010 and May 2011 in the fifth largest shallow lake in China. PAHs flux of atmospheric deposition and the impact on the PAHs in the lake water column were estimated. The major sources of PAHs were identified by multiple methods. We found that (1) the seasonal residual levels of 16 priority controlled PAHs (PAH16) were spring (8.89 ± 3.93 μg g−1) > summer (6.68 ± 4.31 μg g−1) > winter (6.06 ± 2.95 μg g−1) > autumn (3.55 ± 2.21 μg g−1). (2) Significant positive correlations were found between the PAH levels in the dustfall and the suspended particle material (SPM) content, as well as between the deposition flux and the PAH content in the water in all four seasons. (3) Vehicle emissions, coal combustion, biomass combustion, and coke ovens were the four major sources in Lake Chaohu, accounting for 12.7%, 40.9%, 14.5%, and 31.9% of the total PAHs, respectively. (4) Compared to long-distance trajectories, short-distance trajectories played a more important role in the external sources of atmospheric PAHs in the region of Lake Chaohu.

This study is to determine the role of the fractional CO2 laser in topical drug delivery and the impact of local immune responses. Experimental rabbit nails were treated with fractionated CO2 laser at varied fluencies of 20 mJ, 25 mJ, and 30 mJ and half of which were coated with rhodamine B (RhB). Histological examination was performed by hematoxylin and eosin staining; the penetration of RhB was assessed by the use of confocal laser scanning microscopy; and the expressions of IFN-γ and IL-4 mRNA in situ were detected by means of qPCR at 12 h, 24 h, 3 days, and 7 days post-laser irritation. The fractional CO2 laser could generate microscopic treatment zones in nail plates, and the depths of these micropores as well as the permeation of RhB in nails increased significantly in an energy-dependent manner. Importantly, the laser irritation led an upregulation of local IFN-γ mRNA expression accompanied by a downregulation of IL-4 mRNA expression. The ultrapulsed ablative fractionated CO2 laser may assist topical drug delivery, and may drive stronger local Th1 responses due to an imbalance of IFN-γ/IL-4 expressions, suggesting that the combination of ablative fractionated CO2 laser with topical agents would be an effective option for the treatment of onychomycosis.

The total synthesis of rebaudioside S, a minor steviol glycoside from the leaves of Stevia rebaudiana, was investigated via a modular strategy, culminating not only in the first and highly efficient synthesis of Reb-S and analogues thereof but also in the revision of the originally proposed structure. The modular strategy dictated the application of C2-branched disaccharide Yu donors to forge C-13 steviol glycosidic linkages, posing considerable challenges in stereoselectivity control. Through systematic investigations, the effect of the internal glycosidic linkage configuration on the glycosylation stereoselectivity of 1,2-linked disaccharide donors was disclosed, and the intensified solvent effect by the 4,6-O-benzylidene protecting group was also observed with glucosyl donors. Through the orchestrated application of these favorable effects, the stereoselectivity problems were exquisitely tackled.

The origin and depositional characteristics of supported conglomerates in the Mahu Sag, Junggar Basin, Xinjiang, China, are examined. Based on the terminological comparison, modern sedimentary survey and core description, the initial connotation and similarities and differences in definition between supported conglomerates and other similar concepts are discussed, the modern sedimentary environment in which supported conglomerates develop is analyzed, and the sedimentological characteristics of supported conglomerates formed in different depositional environments revealed by the cores of Mahu conglomerate oil field in the Junggar Basin are described. The supported conglomerate is similar in texture to grain supported conglomerate and openwork conglomerate but has differences from them, so it is suggested to keep the term “supported conglomerate”, but the formation mechanism of supported conglomerate needs to be re-examined. Through field survey of modern sediments in Baiyanghe alluvial fan, Huangyangquan alluvial fan, and Wulungu Lake in Xinjiang, it is found that supported gravels not only formed by flooding events but also by sieving, avalanching, fluvial sorting as well as wind and wave reworking in the depositional environments such as inter-mountain creek, colluvium fan, gravel channel on gobi and the fan surface, lake beach, delta front, subaerial debris flow and subwater grain-flow etc. Supported gravels could form supported conglomerate after being buried. Supported conglomerates of seven different origins have been recognized in the cores of the Triassic and Permian stratum of Mahu Depression, Junggar Basin, namely, supported conglomerates in gravel channel deposits, in wind reworked channel deposits, in gravel beach bar deposits, in wave reworked delta front deposits, in mouth bar deposits and in debris flow deposits respectively. The study shows the supported conglomerates may be formed by a single depositional event or by multi-events during the post-depositional sedimentary reworking and even in diagenesis stage. Through flume experiment, numerical simulation, empirical model and modern sediment survey, infiltration process of gravelly channel can be reconstructed and the primary pore structure of supported gravel can be estimated. Statistics on physical properties of various types of reservoirs in Triassic Baikouquan Formation of Mahu oilfield show that granule conglomerate and pebbly conglomerate have higher porosity and permeability, while the cobble and coarse pebble conglomerate have lower permeability, which indicates that the supported gravels are easy to be reworked by post depositional filtration and diagenesis, and thus decrease in porosity and permeability. Key words: supported conglomerate, openwork conglomerate, grain supported conglomerate, rock texture, sedimentary environment and facies, reservoir rock, conglomerate reservoir, Mahu depression

An efficient and practical approach for the synthesis of 3-indolyl-C-Δ1,2-glycosides through a palladium-catalyzed annulation/C-glycosylation sequence of o-alkynylanilines with 1-iodoglycals has been developed. This methodology has a wide scope of substrates and gives access to 3-indolyl-C-Δ1,2-glycosides in high yields. Furthermore, the product obtained here exhibits a high utility for further transformations.

The safe-end of a steam generator (SG) nozzle dissimilar metal weld (DMW) for pressurized water reactors (PWRs) is the weakest point of failure which is crucial for the safe operation of a nuclear power station. Related to materials micro-structures, a uniaxial stress–strain relationship is the basic input parameter for nuclear power plant design, safety evaluation, and life management. In this paper, the micro-structure and tensile mechanical properties of a DMW of a European pressurized water reactor (EPR) were studied. Vickers hardness tester, optical microscope, and electron back scatter diffraction were used to analyze the micro-structure of the DMW joint. In addition, the residual strain of the DMW joint base material, heat-affected zone, weld metal, and fusion boundary region were studied. Based on digital image correlation (DIC) technology, tensile mechanical properties of the DMW joint were obtained. The results show that an accurate tensile stress–strain relationship of dissimilar metal welded joints can be obtained by using the DIC technique, the weld is the relatively weak link, and the residual strain is concentrated in the heat-affected zone. This study provides valuable engineering information regarding nuclear power plant design, in-service performance testing, and structural analysis and evaluation of welds containing defects.

The residual levels of 16 priority polycyclic aromatic hydrocarbons (PAHs) in environment media and freshwater fish were collected and measured from Lake Chaohu by using Gas chromatography-mass spectrometry. Potential atmospheric sources were identified by molecular diagnostic ratios and the positive matrix factorization (PMF) method. PAH exposure doses through inhalation, intake of water and freshwater fish ingestion were estimated by the assessment model recommended by US EPA. The carcinogenic risks of PAH exposure were evaluated by probabilistic risk assessment and Monte Carlo simulation. The following results were obtained: (1) The PAH16 levels in gaseous, particulate phase, water and fish muscles were 59.4 ng·m−3, 14.2 ng·m−3, 170 ng·L−1 and 114 ng·g−1, respectively. No significant urban-rural difference was found between two sampling sites except gaseous BaPeq. The relationship between gaseous PAHs and PAH in water was detected by the application of Spearman correlation analysis. (2) Three potential sources were identified by the PMF model. The sources from biomass combustions, coal combustion and vehicle emission accounted for 43.6%, 30.6% and 25.8% of the total PAHs, respectively. (3) Fish intake has the highest lifetime average daily dose (LADD) of 3.01 × 10−6 mg·kg−1·d−1, followed by the particle inhalation with LADD of 2.94 × 10−6 mg·kg−1·d−1. (4) As a result of probabilistic cancer risk assessment, the median ILCRs were 3.1 × 10−5 to 3.3 × 10−5 in urban and rural residents, which were lower than the suggested serious level but higher than the acceptable level. In summary, the result suggests that potential carcinogenic risk exists among residents around Lake Chaohu. Fish ingestion and inhalation are two major PAH exposure pathways.

The Manson–Coffin law for the low-cycle fatigue (LCF) of a representative volume element (RVE) and fatigue crack propagation (FCP) rate of cracked components can characterize material fatigue resistance. This paper proposes an LCF–FCP model for predicting the FCP rate of plane-stress mixed-mode I–II cracks. A semi-analytical model is also proposed for the Je integral of mixed-mode I–II compact tension shear (CTS) specimens based on energy equivalence method. The combination of these two models predicted the FCP rates of CTS specimens made from 30Cr2Ni4MoV rotor steel with mixed-mode I–II cracks and subjected to four different loading angles. The theoretical results were consistent with the experimental results.

The Manson–Coffin law for the low-cycle fatigue of a representative volume element and the fatigue crack propagation rate of a cracked component are crucial for characterizing the fatigue resistance of a material. Using the average plastic-strain-energy density and the average linear damage accumulation in the plastic zone at the crack tip, two fatigue crack growth models for mixed-mode I-II cracks, without artificial parameters, are proposed, based on the low-cycle fatigue properties of a representative volume element under cyclic plastic strain. For 30Cr2Ni4MoV rotor steel, the proposed models are used for theoretically predicting the mixed-mode I–II fatigue crack propagation rates of compact tension shear specimens subjected to loadings at four different loading angles; and the theoretical prediction results are found to be consistent with the experimental ones.