Evidence that protons are the primary particles of the hard component

1939 ◽  
Vol 11 (3-4) ◽  
pp. 208-210 ◽  
Author(s):  
Thomas H. Johnson
Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1573
Author(s):  
Aljaž Škrjanc ◽  
Ciara Byrne ◽  
Nataša Zabukovec Logar

The use of green solvents as an alternative to dimethylformamide (DMF) in the synthesis of zeolitic imidazolate framework-90 (ZIF-90) was investigated. Two biobased aprotic dipolar solvents CyreneTM and γ-valerolactone (GVL) proved to successfully replace DMF in the synthesis at room temperature with a high product yield. While the CyreneTM—based product shows reduced porosity after activation, the use of GVL resulted in materials with preserved crystallinity and porosity after activation, without prior solvent exchange and a short treatment at 200 °C. The primary particles of 30 nm to 60 nm in all products further form agglomerates of different size and interparticle mesoporosity, depending on the type and molar ratios of solvents used.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1426
Author(s):  
Tomáš Remiš ◽  
Petr Bělský ◽  
Tomáš Kovářík ◽  
Jaroslav Kadlec ◽  
Mina Ghafouri Azar ◽  
...  

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.


Both the penetrating power of the cosmic rays through material ab­sorbers and their ability to reach the earth in spite of its magnetic field, make it certain that the energy of many of the primary particles must reach at least 10 11 e-volts. However, the energy measurements by Kunze, and by Anderson, using cloud chambers in strong magnetic fields, have extended only to about 5 x 10 9 e-volts. Particles of greater energy were reported, but the curvature of their tracks was too small to be measured with certainty. We have extended these energy measurements to somewhat higher energies, using a large electro-magnet specially built for the purpose and described in Part I. As used in these experiments, the magnet allowed the photography of tracks 17 cm long in a field of about 14,000 gauss. The magnet weighed about 11,000 kilos and used a power of 25 kilowatts.


2021 ◽  
Vol 13 (4) ◽  
pp. 1994
Author(s):  
Muxue Liang ◽  
Hong Liao ◽  
Yue Huang ◽  
Zifang Qiao ◽  
Chenchen Tan ◽  
...  

So far, China’s particulate pollution control is principally focused on primary particles and sulfur dioxide from coal combustion. The contribution of ammonia emissions to particulate matter with an aerodynamic equivalent diameter of less than or equal to 2.5 microns (PM2.5) has been increasingly emphasized. As a world-famous agricultural country with 523 million farmers (2017, National Bureau of Statistics of China), approximately 70.0–90.0% of China’s ammonia emissions come from agriculture. With such a huge population, agriculture industrialization (socioeconomic policies and technology upgrades to reduce ammonia emissions from fertilizers and livestock) has a large potential but is more vulnerable to costs compared to other industries. We need a solution involving both economic benefits and environmental protection. For this purpose, we sent out an anonymous questionnaire consisting of 16 questions to 420 farmers and conducted a field visit survey in a rural area of Jiangsu Province. Through statistical analysis, we found that the use of nitrogen fertilizers in agriculture, which are an important source of ammonia through volatilization, is normal (200/420 × 100% = 47.62% of farmers use such fertilizers). Among the 420 farmers surveyed, 90.71% of them have knowledge of air pollution from agricultural activities and 92.15% of them have certain understanding of agricultural industrialization policies, indicating that coordinated control of ammonia emissions can be achieved together with policy propaganda. Through factor analysis and correlation analysis, we find that the early propaganda of policies can help farmers to be more willing to accept the policies. The correlation coefficient between awareness of pollution and policy approval is 0.94, and that between policy publicity and policy approval is 0.95. Generally speaking, the promotion of policies is worth carrying out during the implementation process.


Author(s):  
Xiaoyan Wang ◽  
Zhiyong Wang ◽  
Xianbo Jin

The size of the primary particles of nanoporous Bi has a great impact on the electrocatalytic performance of Bi for the reduction of CO2 to formate.


2014 ◽  
Vol 937 ◽  
pp. 182-186
Author(s):  
Quan An Li ◽  
Lei Lei Chen ◽  
Wen Chuang Liu ◽  
Xing Yuan Zhang ◽  
Hui Zhen Jiang

The influence of the solution treatment (at the temperature of 500-520°C for 4-12 h) on microstructures and mechanical properties of Mg-Gd-Y-Zr alloy was investigated by means of optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Vickers hardness measurement. The as-cast alloy contains a microstructure consisting of α-Mg matrix, Mg5Gd phase and Mg24Y5phase. With increasing solution temperature and time, the quantity of the primary particles (Mg5Gd and Mg24Y5) in the alloy continually decreased, and the degree of recrystallization gradually increased, which result in the gradual decrease of the Vickers hardness of the solution-treated alloys.


2000 ◽  
Vol 620 ◽  
Author(s):  
R. Lee Penn ◽  
Alan T. Stone ◽  
David R. Veblen

ABSTRACTHigh-Resolution Transmission Electron Microscopy (HRTEM) results show a strong crystal-chemical and defect dependence on the mode of dissolution of synthetic heterogenite (CoOOH) particles. As-synthesized heterogenite particles are micron-size plates (aspect ratio ∼ 1/30) constructed of crystallographically oriented ∼ 3-nm primary particles or are single ∼ 21-nm unattached heterogenite platelets (aspect ratio ∼1/7). Reductive dissolution, using hydroquinone, was examined in order to evaluate morphology evolution as a function of reductant concentration. Two end-member modes of dissolution were observed: 1) non-specific dissolution of macroparticles and 2) preferential dissolution along misoriented boundaries. In the case of non-specific dissolution, average macrocrystal size and morphology are not altered as building block crystals are consumed. The result is web-like particles with similar breadth and shape as undissolved particles. Preferential dissolution involves the formation of channels or holes along boundaries of angular misorientation. Such boundaries involve only a few degrees of tilt, but dissolution occurs almost exclusively at such sites. Energy-Filtered TEM thickness maps show that the thickness of surrounding material is not significantly different from that of undissolved particles. Finally, natural heterogenite from Goodsprings, Nevada, shows morphology and microstructure similar to those of this synthetic heterogenite.


Sign in / Sign up

Export Citation Format

Share Document