The concentration distribution of combustible dust determines thermal intensity distribution during an explosion. Current measurements for dust concentration have their particular limitations. ...Targeting this, we proposed an “ultrasonic-electric” hybrid detection system and a fusion model. We deployed 12 of the ultrasonic-electric hybrid systems in orthogonal arrays to comprehensively observe the clouds. First, the ultrasonic-electric hybrid detection systems obtained concentration data in real time, and those data were calculated by fusion model. Then, the clouds and their concentrations changing with time were depicted. We analyzed those trends and found certain patterns in them. Our approach can provide a fast, accurate way to detect concentrations of dynamic and complex dust. Finally, the corresponding relationship between the dust concentration distribution and its explosive heat intensity distribution is obtained. The results show that the thermal distribution of combustible dust at a concentration of 20-120 g/m
3
is proportional to the concentration. This is important for preventing dust explosions and reducing the thermal intensity of explosions.
OBJECTIVE：To determine the clinical effect,treatment times,and rheoencephalogram changes in vertebral artery type cervical spondylosis patients treated with innovative Tuina manipulations.METHODS：One ...hundred and twenty six cervical spondylosis patients（vertebral artery type） were randomly divided into test and control groups.Patients in the test group were treated with innovative Tuina manipulations,while those in the control group were treated with the routine Tuina manipulations according to the textbook of Chinese Massage for Acupuncture and Moxibustion majors.The clinical effects,treatment times,clinical symptoms,and cerebral blood flow were measured.RESULTS：The response to the treatment was 100% in the test group and 88.71% in the control group.Patients in the test group required（7 ± 4） treatments before recovery,while those in the control group required（15 ± 7） treatments before recovery（P〈0.05）.The clinical symptoms exhibited greater improvement in the test group compared to the control group（P〈0.05）.There were no differences in cerebral blood flow between the two groups.CONCLUSION：Both innovative Tuina manipulations and routine Tuina manipulations produced satisfactory therapeutic results in vertebral artery type cervical spondylosis patients.However,the innovative manipulation was more effective in improving the functional symptoms,although there were no changes in the cerebral blood flow.
•Graphite/Silicon@Graphene is synthesized via spray drying and subsequent annealing.•Thermal reduction of graphene oxide was used to obtain graphene.•Graphite and silicon are wrapped by graphene to ...form a spherical structure.•Graphene acts as a carbon matrix to buffer volume effect of silicon particles.•A more stable conductivity network is maintained by graphene.
The Graphite/Silicon@reGO composite was synthesized via spray drying and subsequent annealing. According to XRD, Raman spectroscopy and FT-IR, graphene was demonstrated to be existed in the composite. Moreover, SEM and TEM were also used to illustrate the morphology of Graphite/Silicon@reGO. Used as anode for lithium-ion battery, it exhibited good cyclability with a high reversible charge capacity of 575.1mAhg−1 and showed a capacity retention ratio of 73.1% after 50 cycles at a current density of 50mAg−1. It also presented good rate capability at different rates of 50–1000mAg−1. EIS test showed that the composite electrode had a lower SEI resistance and charge-transfer resistance due to the existence of graphene.
Cement solidification is essential to reduce heavy metal leaching from industrial sludge and make it recyclable. This paper studied the effect of aggregate grading optimized by sludge containing ...heavy metal of different particle sizes on the performance of baking-free sludge bricks, which was mixed with industrial sludge cured by both micro-silica fume and cement. First, the gradation of fine natural aggregates was adjusted according to the Fuller curve. Fine aggregates in baking-free bricks were replaced by artificially processed sludge with particle sizes of 0.15 mm ~0.3 mm and 2.36 mm ~4.75 mm. In this case, a mixed proportion scheme was designed. Then, the strength, water absorption, porosity, and heavy metal leaching were measured. With the help of nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM), the phase and pore structures were observed. The test results showed that: (1) Sludge can replace part of the fine aggregates to make baking-free bricks, resulting in the reduction of the strength of baking-free bricks, but the strength still meets the standard strength requirements of GB/T 21,144-2007. (2) When fine aggregates are partly replaced by sludge with finer particle sizes, baking-free sludge bricks exhibit higher strength, lower water absorption, better pore structures and microphase structure, and stronger solidification of heavy metals, the leaching number of heavy metals meets the standard requirements of GB5085.3-2007, which will be provided support for actual industrial production.
Implications: Cement solidification is an essential means to reduce the heavy metal leaching from industrial sludge and make it recyclable. This paper studied sludge containing heavy metal of different particle sizes on the performance of baking-free sludge bricks. This paper analyzed the compressive strength, porosity and water absorption of baking-free bricks mixed with sludge of different partical sizes, and adopted the NMR to characterize the pores of baking-free bricks, and the SEM to observe the baking-free bricks resultants and the interfacial transition zone (ITZ). The heavy metal leaching test verified the environmental benefits of baking-free bricks mixed with sludge instead of aggregates. There not only make full use of solid wastes, but also thus minimizing pollution to the environment, which provide support for actual industrial production and a reference for studying industrial sludge recycling technology.
Si-based composite with multi-layered structure composed of multicomponent carbon was successfully prepared via a two-step in-situ carbon coating process. The physicochemical properties of the ...composite were characterized by TG-DTA, XPS, XRD, SEM, TEM, Raman and electrochemical measurements. XPS reveals the presence of reduced graphene oxide. SEM and TEM images demonstrate that the nano-Si particles are well dispersed in multi-layered carbon matrix constructed by resin-pyrolyzed carbon and reduced graphene oxide. Used as anode material for lithium-ion batteries, the prepared Si@C@RGO composite exhibits improved electrochemical performance. The electrochemical results indicate that the composite exhibits a high initial charge capacity of 1474.9mAhg−1, with an initial columbic efficiency of 74.57%. The composite also delivered a higher charge capacity at various current densities, and show good rate performance, which is partly attributed to the stable multi-layered structure.
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•A Si@C@RGO composite was prepared by a two-step in-situ carbon coating process.•A carbon matrix was constructed to improve the performance of Si@C@RGO composite.•The composite exhibited stable cycling properties and excellent rate capability.
Exploring high‐efficiency reactive oxygen species (ROS)‐elimination materials is of great importance for combating oxidative stress in diverse diseases, especially stem‐cell‐based biotherapeutics. By ...mimicking the FeN active centers of natural catalase, here, an innovative concept to design ROS‐elimination artificial biocatalysts with Ru catalytic centers for stem‐cell protection is reported. The experimental studies and theoretical calculations have systematically disclosed the activity merits and structure diversities of different Ru sites when serving as ROS‐elimination artificial biocatalysts. Benefiting from the metallic electronic structures and synergetic effects of multiple sites, the artificial biocatalysts with Ru cluster centers present exceptional ROS‐elimination activity; notably, it shows much higher catalytic efficiency per Ru atom on decomposing H2O2 when compared to the isolated single‐atom Ru sites, which is more efficient than that of the natural antioxidants and recently reported state‐of‐the‐art ROS‐scavenging biocatalysts. The systematic stem‐cell protection studies reveal that the catalase‐like artificial biocatalysts can provide efficient rescue ability for survival, adhesion, and differentiation functions of human mesenchymal stem cells in high ROS level conditions. It is suggested that applying these artificial biocatalysts with Ru cluster centers will offer a new pathway for engineering high‐performance ROS‐scavenging materials in stem‐cell‐based therapeutics and many other ROS‐related diseases.
Catalase‐mimetic artificial biocatalysts with Ru catalytic centers are constructed for reactive oxygen species (ROS) elimination. The activity merits and structure diversities of different Ru catalytic sites are systematically disclosed. Notably, the biocatalysts with Ru clusters present exceptional ROS‐elimination activity, thus providing efficient rescue ability for the survival, adhesion, and differentiation of human mesenchymal stem cells in high ROS conditions.
•A modified QuEChERS approach was developed for determination of 26 veterinary drugs in the manure, and it is the first time that Pleuromutilins were included in such study.•Different extraction ...solvents were investigated and modifications to accommodate a variety of target analytes.•It provided a more convenient operation with improved recoveries compared to previous conventional SPE cleanup.•The method is very economical and eco-friendly, especially in the environmental analyse with a large number of samples.
A QuEChERS (quick, easy, cheap, effective, rugged and safe) based methodology was developed for the rapid, simultaneous quantification and identification of 26 veterinary drugs in swine manure by liquid chromatography tandem mass spectrometry. The selected antibiotics included tetracyclines, sulfonamides, macrolides, fluoroquinolones, lincosamides and pleuromutilins. This is the first study to determine pleuromutilin levels in manure. The QuEChERS process involved two simple steps. First, sample extraction with methanol: acetonitrile: 0.1M EDTA-McIlvaine buffer followed by phase separation with MgSO4: NaCl addition. The supernatant was then extracted and cleaned by dispersive solid-phase extraction using a primary-secondary amine (PSA) and octadecylsilane (C18) support. The proposed method provides a linearity in the range of 1–500ngmL-1 and linear regression coefficients (r) were greater than 0.996. MDL and MQL ranged between 0.01–1.86μgkg−1 and 0.05–5.91μgkg−1, respectively. Recoveries ranged from 61.39 to 105.65% with the exception of sulfaquinoxaline (55.7–56.8%) and valnemulin (33.7–37.7%). This method resulted in good precision (repeatability and reproducibility) and relative standard deviations less than 17% within the same day, and lower than 20% between days. The method was then applied to study the swine manure samples collected from Guangdong, China. Chlortetracycline, tetracycline, doxycycline, sulfadimidine and tilmicosin were detected in all samples indicating high residuals in manure. In fact tilmicosin was detected at 14400μgkg−1 suggesting that prudent treatment of manure should be conducted to prevent environmental contamination. In conclusion, this workflow can provide a simpler and more cost-effective alternative to conventional methods and is compatible with processing large sample numbers over a short time period.
Equine infectious anemia (EIA) is a contagious disease of horses caused by the equine infectious anemia virus (EIAV). The clinical signs at the acute phase include intermittent high fever, ...thrombocytopenia, hemorrhage, edema, and anemia. The clinical signs at chronic and relapsing subclinical levels include emaciation and progressive weakness. Surviving horses become lifelong carriers because of the integration of the viral genome into that of the host, and these horses can produce and transmit the virus to other animals. This increases the difficulty of imposing practical control measures to prevent epidemics of this disease. Serological tests measuring the antibodies in equine sera are considered to be a reliable tool for the long-term monitoring of EIA. However, the standard serological tests for EIV either have low sensitivity (e.g., agar gel immunodiffusion test, AGID) or are time consuming to perform (e.g., ELISA and western blotting). The development of a rapid and simple method for detecting the disease is therefore critical to control the spread of EIA. In this study, we designed and developed a colloidal gold immunochromatographic (GICG) test strip to detect antibodies against EIAV based on the double-antigen sandwich. Both the p26 and gp45 proteins were used as the capture antigens, which may help to improve the positive detection rate of the strip. We found that the sensitivity of the test strip was 8 to 16 times higher than those of two commercially available ELISA tests and 128 to 256 times higher than AGID, but 8 to 16 times lower than that of western blotting. The strip has good specificity and stability. When serum samples from experimental horses immunized with the attenuated EIAV vaccine (
n
= 31) were tested, the results of the test strip showed 100% coincidence with those from NECVB-cELISA and 70.97% with AGID. When testing clinical serum samples (
n
= 1014), the test strip surprisingly provided greater sensitivity and a higher number of “true positive” results than other techniques. Therefore, we believe that the GICG test strip has demonstrated great potential in the field trials as a simple and effective tool for the detection of antibodies against EIAV.
Key points
• A colloidal gold immunochromatographic (GICG) fast test strip was developed with good specificity, sensitivity
,
stability, and repeatability
• The test strip can be used in point-of-care testing for the primary screening of EIAV antibodies
• Both the p26 and gp45 proteins were used as the capture antigens, giving a high positive detection rate in the testing of experimentally infected animal and field samples
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•A stable hierarchical Li+/e- conducting shell is constructed on the surface of nano-Si.•Li2SiO3/C shell is self-sacrificially formed via reaction of native oxide layer and Li ...salts.•As-obtained sample shows high capacity and good cycling stability.
The inevitable surface oxidation of nano-Si inhibits its practical application as anode for lithium ion battery. Here, a hierarchical electronic/ionic conducting shell is smartly constructed by self-sacrificing reaction of native oxide layer on Si nanoparticles with lithium species. The morphological observation shows that Si nanoparticles are wrapped by lithium ionic conductor Li2SiO3 and amorphous carbon as the interlayer and outer layer, respectively. Such hierarchical structure not only provides a tight bond between Si and coating layer, but also improves the interfacial stability and conductivity of Si nanoparticles. Theoretical calculations demonstrate that the adsorption of Li2SiO3 on Si (111) and the adsorption of C on Si/Li2SiO3 are exothermic and spontaneous, and that the electron transfer and ionic conductivity at the surface of Si/Li2SiO3/C composite is enhanced. As a result, the as-prepared Si/Li2SiO3/C sample exhibits outstanding cycle stability and rate capability. By optimizing the lithium sources and thickness of native oxide layer, the resulted material exhibits 2106 mAh g−1 at 200 mA g−1, remains 1583 mA g−1 at 3000 mA g−1, and maintains 70.2% of capacity retention after 200 cycles. This work provides a robust strategy to promote the practical applications of Si nanoparticles as anode for lithium ion batteries.
Layered ammonium vanadate materials exhibit significant mass‐specific capacity and ion transport rate due to their small molecular weight and large ionic radius. However, the strong electrostatic ...interactions of Zn2+ and V–O bonds and the fragile ionic bonding of N‐H…O bonds hinder their development. Therefore, this work reports Mg2+ doping NH4V4O10 materials accompanied by flower‐like morphology to lower the migration energy barrier and inhibit amine dissolution. Owing to the 3D‐flower‐like morphology and the combined impact of Mg2+ and structural water, the binding of Zn2+…V‐O is significantly enhanced and additional ion channels were constructed. Pre‐intercalated Mg2+ enhances the structural integrity and prevents irreversible deammoniation from obtaining excellent cyclic stability. Density functional theory (DFT) calculations show that MNVO provides a smoother Zn2+ diffusion path with a lower migration barrier. Benefited from these advantages, the MNVO cathode exhibits a high specific capacity of 410 mAh g−1 at 0.1 A g−1, satisfactory cyclic stability (90.2 % capacity retention at 10 A g−1 after 5000 cycles), and capable rate ability (118 mAh g−1 at 25 A g−1) within 0.4‐1.5 V. Furthermore, the zinc ion storage mechanism in the MNVO cathode is investigated through multiple analyses.
In this work, the synthesis and electrochemical properties of NH4V4O10 and Mg‐doped NH4V4O10 cathodes are demonstrated.
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