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Both dissolved H2 in the Urumqi 04 spring water and the H2 in the soil of the Aksu fault belong to the A-type monitoring points of Xinjiang earthquake monitoring, prediction, and evaluation. This paper takes the two as research objects, and analyzes the dynamic variation characteristics of H2 concentration in different occurrence forms. The R-value scoring method and Molchan chart method were used to test the earthquake-reflecting efficiency of H2 concentration and to extract abnormal indexes. The mechanism of H2 reflecting earthquakes in different occurrence forms is discussed and analyzed. The conclusions are as follows: The concentration of dissolved H2 in the Urumqi 04 spring water is less affected by meteorological factors, while the concentration of H2 in the soil of the Aksu fault is influenced by both air pressure and air temperature, mainly by air temperature. The R-value scoring method and Molchan chart method showed that both monitoring points had good short-term prediction efficiency. The good short-term prediction performance of H2 measurement is due to the stable physical and chemical properties of H2 and its extremely fast migration speed. [ABSTRACT FROM AUTHOR]

In the process of CVD deposition of SiC, the reaction of carrier gas H2 with the surface of the deposited SiC matrix affects the deposition rate and the quality of the deposited products, so it is of great theoretical and practical significance to study these microscopic reaction mechanisms. The adsorption locations, adsorption energies, electronic structures and coverages of H2 on 3C-SiC (111) (above it is the surface of a silicon atom) and 3C-SiC (111) it is the surface of the carbon atom) planes were studied using the first principles based on density functional theory. The results show that the most stable adsorption position of H atom is the OT position (on top) and belongs to chemical adsorption. Upon adsorption H2 spontaneously dissociates into two H atoms which are adsorbed on two adjacent Si atoms in the form of a double top position, thus the electrons of the Si atoms on the surface of the matrix are shifted to H, where the main interaction between the two stems from the overlapping hybridization of the p-orbital of the Si atom and the s-orbital of H. By calculating the coverage of hydrogen on the surface, it is found that the adsorption energy increases with the increase of the coverage, under the low H coverage rate (θH≤4/9 ML), there is a strong attraction between H atoms, with the increase of H coverage (θH＞4/9 ML), the repulsion force between H atoms gradually increases, the adsorption energy increases slowly, and the overall structure tends to be more stable. In the process of CVD deposition of SiC, the reaction of carrier gas H2 with the surface of the deposited SiC matrix affects the deposition rate and the quality of the deposited products, so it is of great theoretical and practical significance to study these microscopic reaction mechanisms. The adsorption locations, adsorption energies, electronic structures and coverages of H2 on 3C-SiC (111) (above it is the surface of a silicon atom) and 3C-SiC (111) it is the surface of the carbon atom) planes were studied using the first principles based on density functional theory. The results show that the most stable adsorption position of H atom is the OT position (on top) and belongs to chemical adsorption. Upon adsorption H2 spontaneously dissociates into two H atoms which are adsorbed on two adjacent Si atoms in the form of a double top position, thus the electrons of the Si atoms on the surface of the matrix are shifted to H, where the main interaction between the two stems from the overlapping hybridization of the p-orbital of the Si atom and the s-orbital of H. By calculating the coverage of hydrogen on the surface, it is found that the adsorption energy increases with the increase of the coverage, under the low H coverage rate (θH≤4/9 ML), there is a strong attraction between H atoms, with the increase of H coverage (θH＞4/9 ML), the repulsion force between H atoms gradually increases, the adsorption energy increases slowly, and the overall structure tends to be more stable. [ABSTRACT FROM AUTHOR]

Copyright of Journal of East China University of Science & Technology is the property of Journal of East China University of Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective The aim is to recycle C3+ and H2 in refinery fuel gas to improve economic benefits. Methods Through the analysis and comparison of the fuel gas from different sources, the hydrogen-rich and high-level C3+ fuel gas are found out. Then the process of H2 recycling is optimized and the area of dehydrogenation membrane is increased so as to improve the amount of H2 recovery. The absorption and stabilization system of catalytic unit and coking unit is used to recover C3+ in fuel gas. Results The total investment of technological transformation is 3.2 million yuan, this can recover 12. 3×10³ tons of C3+ components per year, increase the benefits by 30 million yuan per year, recover H2 10, 5X 106 m³ per year, and reduce the cost of H2 production by 12 million yuan per year. Conclusions This scheme makes full use of the existing absorption and stabilization system and the existing dehydrogenation system of the refinery to expand the capacity, it has the advantages of less investment, good benefit and quick efficiency, and great significance for the high-quality development of Yumen Refining and Chemical Plant. [ABSTRACT FROM AUTHOR]

Structural stability, thermodynamic stability and chemical reactivity of the bimetallic Cu12 Fe clusters were investigated based on the framework of the relativistic density functional theory. It was calculated that Ih - core cluster was thermodynamically more stable than Ih - shell clusters. To explore the most stable adsorption configuration, the adsorption behavior of one CO or H2 molecule on three types of bimetallic Cu12 Fe cluster was studied via analyzing the adsorption energy. The calculation results indicate that the CO molecule is preferably adsorbed on corner site in Cu12Fe cluster, in which the adsorption configuration is the most stable, that the H2 molecule tends to break the H - H bond and form a two - facet adsorption structure. Finally, the orbital informations of the adsorption structures are obtained by the frontier orbitals. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Engineering education professional certification requires students to have the ability to solve complex engineering problems, and curriculum experiment is an important part of cultivating students' ability. In this paper, taking the photocatalytic H2 production experiment as an example, the teaching reform method of material experiment course for engineering education professional certification is proposed from the aspects of experiment content design, material preparation, phenomenon observation and result analysis. In this experiment, semiconductor nanomaterial ZnIn2S4 was synthesized by onestep hydrothermal methods, and the effect of thermal treatment temperature on the aquatic H2 production rate under visible light irradiation was studied. The results show that ZnIn2S4 has the best visible light H2 production performance when the heat treatment temperature is 300 ℃, and the H2 production rate is 591.3 μmol/h. The content of this experiment is closely related to the frontier and hot spot of photocatalysis technology, which covers a lot of knowledge in classroom teaching and meets the requirement of solving complex engineering problems. It is helpful for students to consolidate basic theoretical knowledge, cultivate students'innovation and scientific research interest, and improve their scientific research literacy. [ABSTRACT FROM AUTHOR]

Copyright of Energy Chemical Industry is the property of Energy Chemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Methanol in propylene of DCC unit of CNOOC Dongfang Petrochemical Co., Ltd. exceeds the standard. Through analysis, it is found that the main reason is that oxygen-containing substances such as CO, CO2 and O2 are brought into the regeneration inclined pipe of DCC unit to produce methanol under the action of the reaction system and catalyst. Measures such as maintaining the stable fluidization of the two reactors, replacing non purified air with low-pressure steam and increasing the degassing of the regenerated catalyst are taken. It can effectively reduce the methanol content in propylene from 0.018%% to less than 0.010%%, and ensure that the quality of propylene is qualified. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Petrochemical Universities / Shiyou Huagong Gaodeng Xuexiao Xuebao is the property of Journal Editorial Department Of Liaoning Shihua University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

After a refinery was overhauled in 2019, the contents of hydrogen and liquefied gas above C3 in gas system changed greatly. The hydrogen and hydrocarbon enriched components were sent to high pressure gas system. The hydrogen and liquefied gas components were not fully recovered and used as fuel gas of heating furnace, which caused the waste of hydrogen and liquefied gas resources. By optimizing the flow and operation parameters of the feed gas and the flow of the light hydrocarbon recovery, adjusting initial distillation tower pressure of atmospheric vacuum unit, the monthly total economic benefit increased 1.27 million yuan, which achieved good economic. At the same time, the optimization directions at the next step were put forward:(1) The hydrogen-rich gas flow of S Zorb was further optimized; (2) The adsorbent of aromatic and hydrogen production PSA was replaced to increase processing load and increase output of hydrogen; (3) Optimal operation of diesel hydrotreating unit to decrease the emission of hydrocarbon-rich gas; (4) The gas compressor of coking unit in high load was operated to increase the recovery of hydrocarbon-rich gas and increase the yield of liquefied gas. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of the Chinese Society of Rare Earths is the property of Editorial Department of Journal of the Chinese Society of Rare Earths and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The national standard Quality Requirements for Gases Entering Long-distance Transportation Gas Pipeline is drafted in consistency of latest modified national standard GB 17820 “Natural gas”, and this draft will rule the gas quality entering long-distance transportation gas pipeline. The great progress exhibits on the criterion of calorific value and total sulfur etc in this standard will make great influence on natural gas treatment and analysis. Especially change by order of magnitude will fit the environmental need of the people. Moreover, the criterion of hydrogen and carbon monoxide will expand the application scope of this standard to all the type of gas entering longdistance transportation gas pipeline. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper aims to provide an approach to obtain a lower bound of H∞ control performance in state space. It is not involved in algebraic manipulation of Riccati equation and only concerned with the solution to the standard H2 Riccati equation. As a consequence, the approach can help one to narrow the optimal Ho performance search via bisection method to a smaller range and considerably reduce the search cost. In addition, the approach enables us to have an insight into not only the link and difference between the optimal performance and the H∞ performance including the optimal control and H∞ control performance, the optimal estimation and the H∞ estimation, but also the impact of the multiple-channel disturbances or previewable disturbance on the H, control performance. [ABSTRACT FROM AUTHOR]