Fabrication and characterization of solution-processed, all-inorganic quantum dots (QDs) light-emitting diodes (QLEDs) incorporating colloidal CdSe/ZnS QDs are presented. Using a simple solvothermal process, Cu-doped NiO nanocrystals were fabricated and applied as a hole transport layer in all inorganic QLEDs. Cu-doped NiO nanocrystals are ascribed to bunsenite cubic structure. The transmittance of the film is more than 81%. The hole-only devices of Au/QDs/Cu–NiO/ITO structures showed that 5% mol Cu doped NiO film obtained the largest hole current. The resulting devices show pure QD electroluminescent emissions with a maximum electroluminescence brightness of 2258 cd/m2 after doping 5% mol Cu in NiO, which is almost 4-fold compared with that of intrinsic NiO due to the enhanced carrier concentration and conductivity. The current efficiency and EQE of the assembled all-inorganic QLED exhibited the maximum values of 1.18 cd/A and 1.223%, respectively.

Rough surfaces have been widely used as an efficient way to enhance the heat-transfer efficiency in turbulent thermal convection. In this paper, however, we show that roughness does not always mean a heat-transfer enhancement, but in some cases it can also reduce the overall heat transport through the system. To reveal this, we carry out numerical investigations of turbulent Rayleigh–Bénard convection over rough conducting plates. Our study includes two-dimensional (2D) simulations over the Rayleigh number range $10^{7}\leqslant Ra\leqslant 10^{11}$ and three-dimensional (3D) simulations at $Ra=10^{8}$ . The Prandtl number is fixed to $Pr=0.7$ for both the 2D and the 3D cases. At a fixed Rayleigh number $Ra$ , reduction of the Nusselt number $Nu$ is observed for small roughness height $h$ , whereas heat-transport enhancement occurs for large $h$ . The crossover between the two regimes yields a critical roughness height $h_{c}$ , which is found to decrease with increasing $Ra$ as $h_{c}\sim Ra^{-0.6}$ . Through dimensional analysis, we provide a physical explanation for this dependence. The physical reason for the $Nu$ reduction is that the hot/cold fluid is trapped and accumulated inside the cavity regions between the rough elements, leading to a much thicker thermal boundary layer and thus impeding the overall heat flux through the system.

The present study examines the characteristics of clay minerals in shale gas reservoirs and their influence on reservoir properties based on X-ray diffraction and scanning electron microscopy. These analyses were combined with optical microscopy observations and core and well-log data to investigate the genesis, distribution characteristics, main controlling factors and pore features of clay minerals of the Lower Silurian Longmaxi Formation in the East Sichuan area, China. The clay mineral assemblage consists of illite + mixed-layer illite-smectite (I-S) + chlorite. This assemblage includes three sources of clay minerals: detrital, authigenic and diagenetic minerals. The lower section of the Longmaxi Formation in the Jiaoshiba area has sealing ability which resulted in abnormal high pressures during hydrocarbon generation which inhibited illitization. Therefore, an anomalous transformation sequence is present in which the mixed-layer I-S content increases with depth. This anomalous transformation sequence can be used to infer the existence of abnormal high pressures. The detrital components of the formation also affect the clay-minerals content indirectly, especially the abundance of K-feldspar. The transformation of mixed-layer I-S to illite is limited due to the limited availability of K+, which determines the extent of transformation. Three types of pores were observed in the shale reservoir rocks of the Longmaxi Formation: interparticle (interP) pores, intraparticle (intraP) pores and organic-matter pores. The clay-mineral content controls the development of intraP pores, which are dominated by pores within clay particles. For a given clay mineral content, smectite and mixed-layer I-S were more conducive to the development of shale-gas reservoirs than other clay minerals.

Excavation of the Han Dynasty chambered tomb at Laoguanshan in Chengdu, south-west China, has provided the earliest known evidence of pattern loom technology. Four model looms, along with accompanying artefacts and figurines relating to the weaving process, give insight into the technique of jin silk production. The discovery is hugely significant as it provides the first direct evidence of pattern-weave textile production in ancient China. Jin silk, made using this method, was both valuable and widely distributed, and the design of the machine influenced the invention of later looms and the spread of technology throughout Eurasia and Europe, representing great technological accomplishment for the second century BC.

High-risk human papillomaviruses (HPVs) are highly prevalent worldwide, and HPV genotype distribution varies regionally. Molecular surveys of HPVs are important for effective HPV control and prevention. Fifteen high-risk HPV strains (16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68) and six low-risk HPV strains (HPV6, 11, 42, 43, 44, CP8304) were detected by cervical cytology from 10 501 subjects. High-risk HPVs, low-risk HPVs, and both high- and low-risk HPVs were detected in 14·5%, 2·8%, and 2·4% of cases, respectively. Of 1782 subjects with high-risk HPV infection, 75·5%, 18·1%, and 6·4% were infected with one, two, and ⩾3 strains of high-risk HPVs, respectively. HPV52, HPV16, and HPV58 were the top three most dominant high-risk HPV genotypes in our population with positivity rates of 23·0%, 17·7% and 16·9%, respectively. Multiple infection was common, with significantly higher co-infection rates of HPV58/HPV33 (12·9%) and HPV58/HPV52 (11·3%). Further data comparisons showed that HPV genotype distribution varied markedly between domestic and international regions. In conclusion, a monolithic vaccination strategy is obviously impractical, and regional HPV surveillance is essential to optimize current HPV control and prevention.

The effects of ion motion on the generation of short-cycle relativistic laser pulses during radiation pressure acceleration are investigated by analytical modeling and particle-in-cell simulations. Studies show that the rear part of the transmitted pulse modulated by ion motion is sharper compared with the case of the electron shutter only. In this study, the ions further modulate the short-cycle pulses transmitted. A 3.9 fs laser pulse with an intensity of $1.33\times 10^{21}\ {\rm W}\ {\rm cm}^{-2}$ is generated by properly controlling the motions of the electron and ion in the simulations. The short-cycle laser pulse source proposed can be applied in the generation of single attosecond pulses and electron acceleration in a small bubble regime.

Experimental studies have suggested that tea consumption could lower the risk of dyslipidaemia. However, epidemiological evidence is limited, especially in southern China, where oolong tea is the most widely consumed beverage. We conducted a population-based case–control study to evaluate the association between consumption of tea, especially oolong tea, and risk of dyslipidaemia in Shantou, southern China, from 2010 to 2011. Information on tea consumption, lifestyle characteristics and food consumption frequency of 1651 patients with newly diagnosed dyslipidaemia and 1390 controls was obtained using a semi-quantitative questionnaire. Anthropometric variables and serum biochemical indices were determined. Drinking more than 600 ml (2 paos) of green, oolong or black tea daily was found to be associated with the lowest odds of dyslipidaemia risk (P< 0·001) when compared with non-consumption, but only oolong tea consumption was found to be associated with low HDL-cholesterol levels. A dose–response relationship between duration of tea consumption and risk of dyslipidaemia (OR 0·10, 95 % CI 0·06, 0·16), as well as that between amount of dried tea leaves brewed and risk of dyslipidaemia (OR 0·34, 95 % CI 0·24, 0·48), was found. Moreover, consumption of oolong tea for the longest duration was found to be associated with 3·22, 11·99 and 6·69 % lower blood total cholesterol, TAG and LDL-cholesterol levels, respectively. In conclusion, the present study indicates that long-term oolong tea consumption may be associated with a lower risk of dyslipidaemia in the population of Shantou in southern China.

Approximately 50 % of patients with inflammatory bowel disease (IBD) suffer from anaemia, with Fe deficiency being the most common cause. CD52 monoclonal antibody (mAb) targets the cell surface CD52 and is effective in depleting lymphocytes through cytolytic effects in vivo. The aim of the present study was to investigate the therapeutic effect of anti-mouse CD52 mAb on Fe-deficient anaemia in IBD. IL-10 knockout mice (IL-10− / −) of 12 weeks with established colitis were treated with anti-mouse CD52 mAb once per week for 2 weeks. Severity of colitis, blood T lymphocytes, blood Hb, haematocrit, plasma erythropoietin (EPO), serum Fe concentration, transferrin saturation, splenic Fe stores, expression of liver hepcidin mRNA, Western blotting of the phosphorylated form of Smad1/5/8 and total Smad1 were measured at the end of the experiment. IL-10− / − mice treated with CD52 mAb showed a reduction in the percentage of CD4+ and CD4+CD45+ T cells in blood and weight loss typically associated with colonic inflammation, serum levels of EPO, the expression of liver hepcidin mRNA and total Smad1 protein, while they showed an increase in Hb concentrations, haematocrit, levels of serum Fe, transferrin saturation and splenic Fe stores. The present results indicated that anti-CD52 therapy may ameliorate Fe-deficient anaemia by reducing colonic inflammation. These findings may open novel horizons in the treatment of patients with IBD by resetting of immunological homeostasis in the gut by depleting the activated T cells in the gut mucosa.

Vanadium-beard bone coal is one of important vanadium resources in China. to extract vanadium tailings from Stone coal is prduced after extracted vanadium from stone coal through the roasting, leaching and other processes. About 120-150 tons of tailings will be produced in extracting 1 ton of vanadium pentoxide. A lot of tailings that are willfully piled up have caused serious environmental pollution and wasting of resources; it is therefore necessary to realize its resource utilization. This study increases the activity of vanadium tailings by means of alkali fusion, and then uses different alkali activators to react with vanadium tailings so that geopolymer with high value added is produced. Sample of geopolymer is acquired from mixture containing vanadium tailings, alkali activators, water and a little sodium aluminate through compression-molding process under 20MPa pressure. After cured in room temperature for three days, the maximum compressive strength of the sample can reach 36.2MPa. XRD analysis indicates: quartz, the major crystal phase in vanadium tailings is decomposed and the activity of vanadium tailings is heightened. FTIR and SEM analyses show: structural change having important impact on the mechanical strength of geopolymer occurred during the process of vanadium tailings generating geopolymer.

The present work proposes a Dugdale type model to theoretically predict the multiple cracks of a residually tensile stressed thin film on a ductile substrate. The results show that there exists a critical value, Rc, of the cracking resistance number, R. When R < R, the film > c cracks and the normalized crack spacing is determined by cracking resistance number and the stress ratio of the residual stress to the yield strength of the substrate.

Vickers indentation tests were carried out at room temperature with a microhardness tester on ZnO thin films deposited on (100) Si wafers. The films with thicknesses ranging from 0.202 to 1.535 νm were tested under indentation loads varying from 50 mN to 2.0 N. The experiments exhibited a film thickness dependent deformation behavior. When the film thickness is smaller than a critical value, only indentation-induced radical cracking occurred and for a given load, the radical crack size decreased with film thickness. On the other hand, indentation-induced delamination was observed if the film thickness was larger than the critical value. In this case, the radial crack, if induced, had a size smaller than the size of delamination or even smaller than the size of indentation impression. Under a same indentation load, the delamination size increased with the film thickness.

This paper reports typical failure modes of polymer microstructures. Polydimethylsiloxane (PDMS) microstructures were fabricated using replication-based methods. The mechanical collapses of these structures were observed using scanning electron microscopy. In this work, we classified the mechanical collapses based on their individual geometries and discussed the mechanism of each failure mode. We also worked on solutions to recover these failed PDMS structures. This work helps to better understand the collapsing mechanism and to facilitate the development of control strategies to enhance the mechanical reliability of polymer microdevices.

This paper reports mechanical properties evolution of polydimethylsiloxane (PDMS) during the crosslinking process. In this work, PDMS crosslinking was induced by mixing base prepolymer and curing agent at certain ratios. The liquid prepolymer was spun coated on a silicon wafer, and the curvature change of the wafer was measured continuously using a curvature measurement system. The relationship between the curvature change and typical mechanical properties was investigated using a bilayer model; and the evolution of the properties was derived, as a function of operational parameters. This work is expected to help better understanding of the crosslinking process and provide practical strategies for controlling the mechanical behavior of the resulting polymer structures, especially those for mechanical sensing applications.

DNA amplification is one of the most routine experiments carried out in biological laboratories. Continuous flow PCR chip releases biologists from their laborious exercises. The use of such chip is, however, hindered by costly expense of the syringe pump, which is used to maintain a constant flow rate. In this paper, we demonstrate a novel pressure indicator which makes up an in-line flow sensor in a continuous flow PCR chip. The pressure of PCR channel is achieved from pattern change in fabricated microstructures, and converted to volume flow rate. A polymeric PCR chip with such pressure indicators is presented. With a much less expense as compared to its conventional peers, this indicator has a wide potential for the use in the laboratories which runs daily activities like sequencing or mutagenesis.

This paper presents a novel approach to create silicon nanostructures with controlled sidewall profiles. The nanostructures are fabricated by alternating the reactive ion etching process and the exposure process to the atmosphere with moisture. The air exposure is believed attributed to the sidewall passivation by facilitating the fast formation of a thin SiO2/SiOxFy layer. Using this approach, three types of representative nanostructures are demonstrated, namely: nanopillars with vertical sidewall, nanopillars with narrowed necks, and suspending nanocantilevers. Without requiring expensive facilities and extensive expertise, this work is expected to provide an alternative for developing nanostructures with a variety of geometric profiles for mechanical sensing applications.

In this work, 4H-SiC substrates intentionally misoriented from the (0001) plane toward [1-100] direction are shown to eliminate rotational twinning in icosahedral boron arsenide (B12As2, abbreviated here as IBA) epitaxial films. Previous studies of IBA on other substrates, including (100), (110), (111) Si and (0001) 6H-SiC, produced polycrystalline and twinned epilayers. Comparisons of IBA on on-axis and off-axis c-plane 4H-SiC by synchrotron white beam x-ray topography (SWBXT), and high resolution transmission electron microscopy (HRTEM) confirm the single crystalline and much higher quality of the films on the latter substrates. Furthermore, no intermediate layer between the epilayer and substrate was observed for IBA on off-axis 4H-SiC. Steps formed on the off-axis 4H-SiC substrate surface before deposition cause the film to adopt a single orientation, a process that is not seen with substrates with either no misorientation, or those tilted toward the [11-20] direction. This work demonstrates that c-plane 4H-SiC with 7° offcut toward (1-100) is potentially a good substrate choice for the growth of high-quality, untwinned B12As2 epilayers for future device applications.

In this paper, a new revolutionary 3D manufacturing approach to rapid processing of 3D microstructures in both soft (SU-8) and rigid (Si) materials is introduced. This technique facilitates very fast prototyping without the need of masks, resulting in a low-cost, short-turnaround flexible fabrication process.