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Throughout his over 60-year career, professor Xu Zhonglin demonstrated through words and actions that fostering virtue is a teacher's duty, educating is a teacher's foundation, practicing what one preaches is a teacher's way, ideals and beliefs are the basis of a teacher's self-cultivation, morality is the path to a teacher's success, solid knowledge is a teacher's root, and love is a teacher's enduring virtue. On the other hand, through diligence and exploration, he gained valuable insights into teaching wisdom, such as the integration of being "a teacher of books" and "a teacher of human beings", the mutual enhancement of research and teaching, and the balance between "self-improvement" and "helping others". These qualities and wisdom collectively constitute Professor Xu's unique spirit as an educator, showcasing the demeanor of "a Great Master" of the times.

In this paper, an embedded mobile air curtain machine is designed on the sliding window of the suction cabinet to reduce the harm to the environment and workers caused by the leakage of harmful gases produced by the volatilization of waste liquid during the suction process of laboratory waste liquid. The air curtain machine is embedded and installed at the bottom of the sliding window, which can move up and down with the sliding window to generate a variable air curtain. In this paper, the working principle of the sliding window embedded mobile air curtain machine is described. The process of air curtain formation under various working conditions is analyzed by Fluent simulation. The reliability and uniformity of the mobile air curtain barrier are verified by prototype trial and test. The movable air curtain machine can effectively block the air flow inside and outside the suction cabinet, prevent the leakage of harmful gases, and ensure the safety and environmental protection of the whole process of waste liquid suction. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 Zhejiang Electric Power is the property of Zhejiang Electric Power 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.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

The contradiction between humans and land is prominent in the karst area of Southwest China. Human destruction of vegetation eventually leads to serious water loss and soil erosion, resulting in a large number of rocky desertification. In order to control the expansion of rocky desertification, the Chinese government has carried out a series of projects, such as returning farmland to forest, natural forest protection and Yangtze River shelterbelt projects, which have caused corresponding changes in land use and vegetation cover. As one of the most important types of rocky desertification control in China, karst graben basins are usually characterized by drastic changes in basin-mountain topography, great climate contrast, severe soil flow/loss, poor vegetation site conditions, and the slow recovery of community ecosystem. Therefore, the study on the comprehensive control of rocky desertification at the karst graben basin became urgent. The ecological stoichiometry is a state-of-the-art science that analyzes the regional circulation patterns of biogeochemical elements from the perspective of element metrology, which provides a new insight to solve the problem of nutrient supply/demand and circulation in ecosystems. It has important application value in the study of soil nutrient circulation and balance mechanism, and is one of the hot spots in current ecological research. However, domestic studies on ecological stoichiometry mainly select desert steppe, Loess Plateau and Minjiang River estuary as research areas in recent years. There is a paucity of systematic studies on soil metrology characteristics in different stages of vegetation succession at karst graben basins, and the response of soil nutrients and ecological stoichiometry to different types of vegetation restoration is still unclear. In order to elucidate the content and stoichiometric ratios of C, N and P elements in the soils in different stages of vegetation succession at karst graben basins, Santang, located in Xiaojiang karst basin, Luxi county, Yunnan Province, was selected as a study area. This area is dominated by a subtropical monsoon climate, with the average annual temperature of 15.2 °C, the average annual sunshine of 2,122 h, and the average annual precipitation of 1,000 mm. The main tree species in the study area include Platycladus orientalis (L.) Franco, sticky alder, Yunnan pine, and so on. In January 2018, by the "space for time" approach, the soils from 5 different stages of vegetation succession (corn land, grassland, shrub land, planted forest and primary forest) were collected from different soil depths (0--10 cm and 10--20 cm) according to the sampling method of profile excavation. The soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) contents were determined by potassium dichromate oxidation with an external heating method, Kjeldahl method, and molybdenum antimony anti-colorimetric method. Excel 2019 software was used for data statistics. One-Way ANOVA, Duncan's new multiple range test method (LSD), Pearson correlation and Two-way ANOVA in SPSS 25.0 software were used to study the variance and correlations of soil ecological stoichiometric characteristics. The study results are expected to further reveal nutrient restriction and nutrient change patterns in the vegetation succession process, meanwhile, providing the scientific basis for vegetation restoration management and rational use of land resources in karst graben basins. There were significant differences in soil nutrient contents in different succession stages, mainly manifested in the 0--10 cm soil layer. SOC and TN contents showed an overall increasing trend with the increase of succession years, while TP content fluctuated and showed no obvious change pattern. Soil C and N contents differed significantly among soil layers. Specifically, SOC and TN contents in 0--10 cm soil layer were higher than those in 10--20 cm soil layer at each succession stage. Compared with C and N contents, soil P content did not differ significantly among soil layers at each succession stage, except for the content in the primary forest. In 0--10 cm soil layer, C/N, C/P and N/P showed significantly positive correlations with SOC content; C/P and N/P indicated significantly positive correlations with TN content; soil TP content was not significantly correlated with C/N, C/P and N/P. There was no significant correlation between soil physicochemical properties and soil stoichiometric ratio in the 10--20 cm soil layer. In the present study, the N/P ratios of 0--10 cm soil in different succession stages were between 2.71 and 5.93, and those of 10--20 cm soil were between 3.11 and 4.92. Essentially, all of the N/P ratios of soil at different depths were lower than 10, indicating that vegetation growth in the study area was more likely to be limited by N. However, given the fact that P content in karst soil is relatively low, vegetation growth should be first limited by P rather than N. Moreover, vegetation types and soil depths significantly affected SOC, TN and TP contents and their stoichiometric ratios in the study area. In summary, soil nutrient and stoichiometric ratios at karst graben basins change significantly with vegetation restoration chronosequence, and soil physicochemical properties have an important impact on soil stoichiometric ratios. These results are of great significance for further research on soil nutrient balance and limiting factors in karst graben basins. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation 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 Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

Copyright of Mountain Research (10082786) is the property of Mountain Research 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.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

Copyright of Journal of Data Acquisition & Processing / Shu Ju Cai Ji Yu Chu Li is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics 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 Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research 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.)

In order to obtain the law of the impact of fuel injection pulse width and injection pressure change on the discharge coefficient and understand the causes of this law, this article designed and completed the experiment with commonly used fuel injection pulse width (1 000-2 500 μs) and large scope of injection pressure (40-180 MPa). The momentum method was adopted to measure the fuel injection law in experiment, and the fuel injection quantity in different periods of injection process could be figured out at the same time, with the purpose of calculating the maximum discharge coefficient which corresponded to the duration of needle valve open completely, and the average discharge coefficient in the fuel injection duration in all conditions. The two parameters were used to explore the law of their own variation when the fuel injection pulse width and the injection pressure changed and to find their relationship and difference. With the purpose of obtaining more general results, the ratio of the duration of valve open fully and the injection duration was introduced as a dimensionless parameter τ, through which we could easily know the deviation value of discharge coefficient according to the curve of the mean discharge coefficient deviating from the maximum discharge coefficient. A lot of research has been made on discharge coefficient change in terms of external cause at home and abroad. But most of these studies were based on fluid simulation, or through Nurick simplified model to analyze, or just discussed the impacts of some physical parameters such as nozzle geometry, needle valve lift, Reynolds number and surface roughness inside the nozzle, fuel density and viscosity on discharge coefficient. Just discussing how much effect the conditions would have on the discharge coefficient was not enough, we must study why. This paper introduced the theory of flow loss analysis of nozzle discharge coefficient. Changes of discharge coefficient with the fuel injection pulse width and injection pressure were obtained by experiment. Then we could explain those changes in the law with the method based on the theory of flow loss, which was different from the conventional research methods of discharge coefficient analysis, for our method not only focused attention on how much impact the change of the fuel injection pulse width and injection pressure will cause on the discharge coefficient, but also attempted to explain why. The method confirmed the influence factors of discharge coefficient, namely the local loss and equivalent linear loss. The local loss was associated with shrunk stream and cavitation, and the equivalent linear loss in the direct ratio to a power of -0.25 of flow velocity. The experimental results showed that: When the injection pressure was over 160 MPa and the increment of injection pulse width was 500 μs, the variation of the average discharge coefficient was no more than 5.9%; when the injection duration was greater than 1.78 ms, the injection pulse width had no influence on the maximum discharge coefficient in principle; when the ratio of the duration of valve open fully and the injection duration was about 0.85, the difference rate between the average discharge coefficient and maximum flow coefficient under the condition of injection pressure below 180 MPa was less than 7.5%; when the injection pressure was greater than 140 MPa, the discharge coefficient tended to be stable and was lower than the value corresponding to injection pressure less than 90 MPa. The method that analyzes the effect of fuel injection pulse width and injection pressure on the discharge coefficient from the angle of flow loss can preferably explain the experimental results, which proves that the method is relatively accurate. This paper can provide a reference for the optimization of injection and the further study of discharge coefficient. [ABSTRACT FROM AUTHOR]