Dependence of Particle Size and Size Distribution on Mechanical Sensitivity and Thermal Stability of Hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine

Two kinds of RDX samples, with broad and narrow particle size distribution, have been fabricated by wet riddling and solvent/non-solvent methods, respectively. By controlling the technical condition, the RDX powders with different particle sizes were obtained for each sample. All samples were characterised by laser granularity measurement and scanning electron microscope (SEM). Using mechanical sensitivity tests, slow cook-off test and differential scanning calorimetry (DSC), the mechanical safety and thermal stability of RDX samples, depending on the particle sizes and size distribution, were studied. Results indicated that, for each kind of RDX particles, the mechanical sensitivity and thermal stability of samples changed according to the particle size. However, although two samples had almost the same average particle size, their safety changed when two particle size distributions differed. Concretely, the mechanical sensitivity of RDX reduced and their thermal stability increased gradually along with the decreasing of particle size. Meanwhile, RDX with broad size distribution had higher mechanical sensitivity and thermal stability than samples with narrow size distribution.Defence Science Journal, 2009, 59(1), pp.37-42, DOI:http://dx.doi.org/10.14429/dsj.59.148

Three new species of the Fannia serena species subgroup from China (Diptera: Fanniidae)

The Fannia serena species group (Diptera: Fanniidae) ismainly distributed in the Holarctic region and comprises four subgroups with a total of 32 species. Three new species of the Fannia serena-subgroup, Fannia aureomarginata Wang et Cheng, sp. n., F. suberemna Wang, sp. n. and F. wui Wang, sp. n., are described from China. An identification key to all known species of the Fannia serena-subgroup is also provided

Temporal compressive edge imaging enabled by a lensless diffuser camera

Lensless imagers based on diffusers or encoding masks enable high-dimensional imaging from a single shot measurement and have been applied in various applications. However, to further extract image information such as edge detection, conventional post-processing filtering operations are needed after the reconstruction of the original object images in the diffuser imaging systems. Here, we present the concept of a temporal compressive edge detection method based on a lensless diffuser camera, which can directly recover a time sequence of edge images of a moving object from a single-shot measurement, without further post-processing steps. Our approach provides higher image quality during edge detection, compared with the conventional post-processing method. We demonstrate the effectiveness of this approach by both numerical simulation and experiments. The proof-of-concept approach can be further developed with other image post-process operations or versatile computer vision assignments toward task-oriented intelligent lensless imaging systems.Comment: 5 pages, 4 figure

Green innovation drives globalization: a longitudinal case study of Angel Yeast’s evolution from a start-up to a world-class manufacturer

In the increasingly competitive global market, emerging market companies, represented by China, have shown mixed performance during their development process. Many companies grow rapidly in the early stages of development but cannot maintain long-term growth. How to achieve sustainable development has become a major challenge for emerging market companies, and green innovation is considered an effective way to address this issue. Based on the resource-based view, this paper conducts a longitudinal case study on Angel Yeast as the research subject, dividing the development process of Angel Yeast into three stages: the start-up period (1986-2000), the growth period (2000-2010), and the maturity period (2010-present), discussing how Angel Yeast has grown from a small start-up company to a world-class manufacturer. The study finds that Angel Yeast has utilized its unique resources at different stages of development for green technology innovation, green product innovation, green management innovation, green marketing innovation, green supply chain management, and green organizational culture construction, enabling Angel Yeast to gain a sustained competitive advantage and grow into a global leader in the yeast industry. This paper expands the research on the evolution of emerging market companies under the resource-based view theory and enriches the understanding of the role of green innovation in the growth process of enterprises

Quantitative and dark field ghost imaging with ultraviolet light

Ultraviolet (UV) imaging enables a diverse array of applications, such as material composition analysis, biological fluorescence imaging, and detecting defects in semiconductor manufacturing. However, scientific-grade UV cameras with high quantum efficiency are expensive and include a complex thermoelectric cooling system. Here, we demonstrate a UV computational ghost imaging (UV-CGI) method to provide a cost-effective UV imaging and detection strategy. By applying spatial-temporal illumination patterns and using a 325 nm laser source, a single-pixel detector is enough to reconstruct the images of objects. To demonstrate its capability for quantitative detection, we use UV-CGI to distinguish four UV-sensitive sunscreen areas with different densities on a sample. Furthermore, we demonstrate dark field UV-CGI in both transmission and reflection schemes. By only collecting the scattered light from objects, we can detect the edges of pure phase objects and small scratches on a compact disc. Our results showcase a feasible low-cost solution for non-destructive UV imaging and detection. By combining it with other imaging techniques, such as hyperspectral imaging or time-resolved imaging, a compact and versatile UV computational imaging platform may be realized for future applications.Comment: 9 pages, 5 figure

Temporal compressive edge imaging enabled by a lensless diffuser camera

Peer reviewe

Psychological Health Status Evaluation of the Public in Different Areas Under the Outbreak of Novel Coronavirus Pneumonia

During the outbreak of novel coronavirus pneumonia, the number of confirmed cases and deaths in Hubei province of China increased sharply, and the situation in Hubei was more severe than that in non-Hubei, so we do a research on psychological health status evaluation of the public in Hubei and non-Hubei areas. In this paper, we adopt textual analysis and contextual analysis using Simplified Chinese Microblog Word Count (SCMBWC), Five-Factors Model (FFM), Semantic Role Labeling (SRL) to interpret and analyze the public perception and psychological personality based on media news. Through the analysis, it was found that there were great differences in public perception to novel coronavirus pneumonia. In Hubei areas, the public perception was mainly reflected in the overall prevention and the treatment of patients, while in non-Hubei areas, the perception was mainly in the orderly promotion of enterprises to return to work. Through contextual analysis, the novel coronavirus pneumonia had a great psychological impact on the public in different regions. The media covered a large number of social process words and cognitive process words, public showed a personality that was inclined to be “open” and “neurotic” in different areas. Furthermore, we find out some reasons like all kinds of rumors, wildlife trade, all kinds of illegal and criminal acts disturbing social order cause this psychology personality through emotional entity mining based on semantic role labeling. This is conducive to the government’s better policies and management in line with local conditions

Nano-Subsidence Assisted Precise Integration of Patterned Two-Dimensional Materials for High-Performance Photodetector Arrays

The spatially precise integration of arrays of micro-patterned two-dimensional (2D) crystals onto three-dimensionally structured Si/SiO$_2$ substrates represents an attractive strategy towards the low-cost system-on-chip integration of extended functions in silicon microelectronics. However, the reliable integration of the arrays of 2D materials on non-flat surfaces has thus far proved extremely challenging due to their poor adhesion to underlying substrates as ruled by weak van der Waals interactions. Here we report on a novel fabrication method based on nano-subsidence which enables the precise and reliable integration of the micro-patterned 2D materials/silicon photodiode arrays exhibiting high uniformity. Our devices display peak sensitivity as high as 0.35 A/W and external quantum efficiency (EQE) of ca. 90%, outperforming most commercial photodiodes. The nano-subsidence technique opens a viable path to on-chip integrate 2D crystals onto silicon for beyond-silicon microelectronics.Comment: 41 pages, 5 figures, with S

In Situ and in Vivo Study of Nasal Absorption of Paeonol in Rats

The objective of this work was to study the in situ and in vivo nasal absorption of paeonol. A novel single pass in situ nasal perfusion technique was applied to examine the rate and extent of nasal absorption of paeonol by rats. Various experimental conditions, such as perfusion rate, pH, osmotic pressure and drug concentration, were investigated. The in situ experiments showed that the nasal absorption of paeonol was not dependent on drug concentration, and fitted a first order process. The absorption rate constant, Ka, increased with an increase in perfusion speed. Paeonol was better absorbed in acidic solutions than in neutral or alkaline solutions. The value of Ka was higher in a hypertonic environment than under isotonic or hypotonic conditions. In vivo studies of paeonol absorption were carried out in rats and the pharmacokinetics parameters of intranasal (i.n.) and intragastric (i.g.) administration were compared with intravenous (i.v.) administration. The bioavailabilities of paeonol were 52.37% and 15.81% for i.n. and i.g, respectively, while Tmax values were 3.05 ± 1.46 min and 6.30 ± 0.70 min. MRT (Mean Residence Time) were 23.19 ± 6.46 min, 41.49 ± 2.96 min and 23.09 ± 5.88 min for i.n., i.g. and i.v. methods, respectively. The results demonstrate that paeonol could be absorbed promptly and thoroughly by i.n. administration in rats