Impact of Through-Hole Defects on the Electro-Explosive Properties of Exploding Foil Transducers.

This study examines the impact of surface defects on the electro-explosive properties of metal explosive foil transducers. Specifically, it focuses on the effects of defects in the bridge foil and their influence on the electrical explosion time and transduction efficiency. To analyze these effects, a current-voltage simulation model is developed to simulate the behavior of a defective bridge foil. The simulation results are validated through experimental current-voltage measurements at both ends of the bridge area. The findings reveal that the presence of through-hole defects on the surface of the bridge foil leads to an advancement in the electrical explosion time and a reduction in the transduction efficiency of the bridge foil. A performance comparison is made between the defective bridge foil and a defect-free copper foil. As observed, a through-hole defect with a radius of 20 µm results in a 1 ns advance in the blast time and a 1.52% decrease in energy conversion efficiency. Similarly, a through-hole defect with a radius of 50 µm causes a 51 ns advancement in the blast time and a 13.96% reduction in the energy conversion efficiency. These findings underscore the detrimental effects of surface defects on the electro-explosive properties, emphasizing the importance of minimizing defects to enhance their performance.

Effect of Dietary Salt Intake on Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Case-Control Studies.

Aim: The effect of dietary salt intake on the risk of gastric cancer is not clear. A meta-analysis was performed to estimate the association between dietary salt intake and the risk of gastric cancer. Methods: Three major databases were searched to retrieve case-control studies published in English before 1 July 2022. Random effects model analysis was used to obtain the pooled odds ratios (ORs) and 95% confidence intervals (CIs) of the association between dietary salt intake and risk of gastric cancer. Subgroup analyses were used to identify possible sources of heterogeneity. Results: Thirty-eight case-control studies were included in this meta-analysis (total population: n = 37,225). The pooled ORs showed a significantly positive association between high salt intake and gastric cancer compared with low salt intake (OR = 1.55, 95% CI (1.45, 1.64); p < 0.001). In subgroup meta-analysis for geographic region, estimation method for dietary salt intake and the source of controls, this association was not changed. Conclusion: Higher dietary salt intake increased the risk of gastric cancer. This study has implications for the prevention of gastric cancer.

Trends in Stroke Mortality Rate - China, 2004-2019.

Introduction: Stroke has been the leading cause of death in China for decades. This study described the trends in stroke mortality in China from 2004 to 2019. Methods: Data was obtained from the National Disease Surveillance Point (DSP) system. A descriptive analysis was conducted. The adjusted mortality rate (AMR) and age-standardized mortality rate (ASMR) of stroke were calculated. Results: From 2004 to 2019, the ASMR substantially decreased, with a reduction of 39.8%, but the AMR stayed relatively stable. The mortality rate of stroke in rural areas was consistently higher than in urban areas. A geographical gradient in mortality of stroke was also apparent, with an increased rate in the western part of China and a decreased rate in the eastern part of China. In central China, the rate remained relatively stable. Conclusions: Although the ASMR of stroke continued to decline in China, the stagnant crude mortality rates suggested that China had not achieved sufficient decline to offset the demographic forces of population growth and ageing. More vigorous and effective prevention and treatment strategies are urgently needed to mitigate the disease burden of stroke in China, especially in areas with high stroke burden and limited resources.

Preparation and Characterization of Mesocarbon Microbeads by the Co-Polycondensation of High-Temperature Coal Tar Pitch and Coal Pyrolytic Extracts.

Mesocarbon microbeads (MCMBs) are a kind of engineering and functional artificial carbon materials generally prepared by the polymerization of polycyclic aromatic hydrocarbons. The physicochemical property of the raw materials plays a key role in the quality of MCMBs. For a detailed analysis of the synergistic effects of the generation of MCMBs, a high-temperature coal tar pitch was used as raw materials, and coal pyrolytic extracts were used as additive to synthesize the MCMBs. The microstructure and morphology of the derived MCMBs were determined by an optical microscope, scanning electron microscope, X-ray diffraction, Raman spectrum, and laser particle size analyzer. In fact, the addition of the coal pyrolytic extracts can adjust the molecular structure of the blending pitch, and the coal pyrolytic extracts can promote the generation of the MCMBs during the co-polycondensation process. The MCMBs obtained by co-polycondensation method have a good degree of sphericity, lower defects in the surface morphology, and a lower charge transfer resistance (Rct) of 4.677 Ω.

Study of the Explosive Bridge Film Using Laser Shaping Technology.

Laser shaping technology and its applications have gained widespread attention in different fields. Using laser repair technology prolongs the service life of micro-explosive products and reduces the production cost, as well as enables the recycling of resources. Although most research mainly focuses on aspheric surface shaping and testing technology, only a few studies on repair technology for micro-explosive products using laser shaping have been reported. To promote the better application of laser shaping technology in the production and repair process of micro-explosive components, this work mainly studied the effect of laser shaping on the repair of an explosive bridge film to enhance the ignition performance and prevent damage. Different processes were used to repair the metal film using laser shaping and non-shaping, respectively. Furthermore, we investigated the similarities and differences of a laser-damaged film surface before and after shaping, and the influence of laser energy parameters on the microstructure and ignition properties of the repaired region. Additionally, we obtained a reasonable repair scheme by analyzing the temperature field variation from the simulation. The results show that the damage caused by the non-shaping and shaping lasers can be repaired using the heat flow and vaporization methods, respectively. By controlling the process parameters, the quality of repair can be improved and the production cost of the bridge film can be reduced.

Ultrasound-assisted extraction of polysaccharide from spent Lentinus edodes substrate: Process optimization, precipitation, structural characterization and antioxidant activity.

Lentinus edodes is the second-most popular and cultivated mushroom worldwide due to its nutritional and health-promoting benefit. However, the mushroom production generates vast amounts of spent L. edodes substrate (SLS) that is generally discharged into the environment, posing a great challenge within mushroom by-product valorization. In this work, SLS polysaccharide (SP) was ultrasonically extracted by optimizing the process conditions with response surface methodology. Using gradient ethanol precipitation, SP was separated into SP40, SP60 and SP80, and their monosaccharide composition, structural properties, and antioxidant potential were further characterized and compared. The results showed the total polysaccharide content reached up to 37.05 ± 0.31 mg/g under the optimal conditions including an extraction temperature of 50 °C, a liquid-solid ratio of 30 mL/g and an ultrasonic power of 120 W. SP and its fractional precipitations were heteropolysaccharides sharing a similar monosaccharide composition including L-rhamnose, D-glucuronic acid, D-galacturonic acid, d-glucose and D-xylose, and a typical infrared spectrum for polysaccharide. These fractions also varied in the surface morphology, where SP80 was looser and more porous than SP40 and SP60. Furthermore, SP and SP80 displayed the strongest antioxidant activities in vitro. This study identified a novel and practical strategy to valorize SLS for valuable polysaccharide.

Exact reconstruction condition for angle-limited computed tomography of chemiluminescence.

Computed tomography of chemiluminescence (CTC) is an effective technique for three-dimensional (3D) combustion diagnostics. It reconstructs the 3D concentrations of intermediate species or 3D images of flame topology by multiple chemiluminescence projections captured from different perspectives. In the previous studies of CTC systems, it was assumed that projections from arbitrary perspectives are available. However, for some practical applications, the range of view angles and the number of projections might be restricted due to the optical access limitation, greatly affecting the reconstruction quality. In this paper, the exact reconstruction condition for angle-limited computed tomography of chemiluminescence was studied based on Mojette transform theories, and it was demonstrated by numerical simulations and experiments. The studies indicate that the object tested within limited angles can be well reconstructed when the number of grids, the number of projections, and the sampling rate of projections satisfy the exact reconstruction condition. By increasing the sampling rate of projections, high-quality tomographic reconstruction can be achieved by a few projections in a small angle range. Although this technique is discussed under combustion diagnostics, it can also be used and adapted for other tomography methods.

Province-specific alcohol-attributable cancer deaths and years of potential life lost in China.

OBJECTIVE: Cancer is a major cause of death in China. As alcohol drinking, a risk factor of cancer, is common in China, we aimed to estimate the alcohol-attributable cancer deaths and years of potential life lost (YPLL) across all provinces in China. METHODS: We estimated the proportion of cancer deaths and YPLL attributable to alcohol consumption at the province level. Population attributable fraction (PAF) was calculated based on: 1) prevalence of alcohol consumption, obtained from the China National Nutrition and Health Survey 2002; 2) dose-response relative risks (RRs) of alcohol consumption and site-specific cancer, extracted from published meta-analyses; 3) cancer mortality data, originated from the National Program of Cancer Registry 2013. RESULTS: We estimated that 98,306 cancer deaths were attributable to alcohol consumption and accounted for 4.56 % of the total cancer deaths in China in 2013. Of these deaths, a total of 919,741.57 person-years premature loss of life was caused. Both overall PAF and average YPLL per 100,000 individuals were much higher in men than that in women (7.01 % vs. 0.33 % and 130.55 vs. 4.45, respectively). At the province level, overall PAF ranged from 2.14 % (95 % CI: 1.40 %-2.87 %) in Shanghai to 6.56 % (95 % CI: 4.06 %-9.05 %) in Anhui and the average YPLL per 100,000 individuals ranged from 10.97 in Tibet to 106.52 in Shandong. CONCLUSIONS: Cancer burden attributable to alcohol consumption varied across provinces in China. Province-level approaches are warranted to decrease alcohol consumption and reduce the alcohol-related cancer burden.

Province-specific smoking-attributable cancer mortality in China 2013.

INTRODUCTION: Province-specific initiatives are at the forefront of tobacco control but limited studies have provided province-specific assessment of smoking-attributable cancer burden in China. METHODS: We estimated the fraction of total and site-specific cancer mortality attributable to tobacco smoking in 31 provinces in mainland China. The population attributable fractions (PAFs) for cancer deaths due to smoking were calculated by Levin's formula using province-specific smoking prevalence data around 1998 (assuming a 15-year latency time) and relative risks from cohort studies and meta-analyses. The 95% confidence intervals (CIs) of PAFs were calculated by a Delta method. Cancer deaths were abstracted from cancer registry data of the 31 provinces in mainland China in 2013. RESULTS: Overall, smoking contributed to a total of 421566 cancer deaths in mainland China in 2013 (19.46% of all cancer deaths), with 400701 of these deaths occurring in men (29.34%) and 20865 (2.61%) in women. The population attributable fractions ranged from 15.56% (95% CI: 9.12-21.82%) in Tibet to 35.09% (95% CI: 25.68-45.83%) in Guizhou among men, and from 0.28% (95% CI: 0.00-0.64%) in Hainan to 10.44% (95% CI: 4.86-16.32%) in Jilin among women. Cancers of lung and liver were the two main smoking-attributable cancers for both men and women. CONCLUSIONS: Tobacco smoking was responsible for nearly 20% of all cancer deaths in mainland China, but the proportion of cancer deaths attributable to smoking varied substantially across provinces. More effective programs and innovative new strategies for local tobacco control are warranted to reduce the future burden of smoking-related cancers in all provinces of mainland China.

Trace metals dramatically boost oxygen electrocatalysis of N-doped coal-derived carbon for zinc-air batteries.

The commercialization of metal-air batteries requires efficient, low-cost, and stable bifunctional electrocatalysts for reversible electrocatalysis of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The modification of natural coal by heteroatoms such as N and S, or metal oxide species, has been demonstrated to form very promising electrocatalysts for the ORR and OER. However, it remains elusive and underexplored as to how the impurity elements in coal may impact the electrocatalytic properties of coal-derived catalysts. Herein, we explore the influence of the presence of various trace metals that are notable impurities in coal, including Al, Si, Ca, K, Fe, Mg, Co, Mn, Ni, and Cu, on the electrochemical performance of the prepared catalysts. The constructed Zn-air batteries are further shown to be able to power green LED lights for more than 80 h. The charge-discharge polarization curves exhibited excellent and durable rechargeability over 500 (ca. 84 h) continuous cycles. The promotional effect of the trace elements is believed to accrue from a combination of electronic structure modification of the active sites, enhancement of the active site density, and formation of a conductive 3-dimensional hierarchical network of carbon nanotubes.

[Compositions and structure characterizations of coal tar refined soft pitch].

High temperature coal tar was used as raw materials, and was distilled to 280 degrees C for getting coal tar soft pitch. Then refined soft pitch was obtained by solvent extracting and subsequent settlement method. Its soft point was 32 degrees C; the group compositions consisted of 53.67% heptane soluble, 39.47% heptane insoluble but toluene soluble, 6.86% toluene insoluble and 0.06% quinoline insoluble. The relative average molecular weight was about 292. Its average molecular formula was C22.22 H16.32 N0.12 S0.06 O0.33; the total content of heteroatom was less than 1. IR analytic results showed that its heteroatom O existed in the R-O-R and Ar-O-R structure; its heteroatom N existed in the R-NH-R and -N=, with the latter being primary. Its average structure was obtained by improved Brown-Lander model: five-membered condensed rings. UV analysis indicated that the majority was linear arrangement, and the minority was surface arrangement; namely, the chemical structure of the samples was mainly the cata-condensed structure, while the minority was peri-condensation.