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直流断路器是多端直流输电系统可靠性控制的关键设备，实际工程中不同区域、不同设备的故障各有特点，对直流系统的影响也不尽相同。基于一种具有限流功能的混合式直流断路器，首先描述了该直流断路器的分断和限流控制原理，而后针对实际工程中不同情形下的瞬时性故障和永久性故障，提出一种差异化可靠性控制策略，能够有效避免系统因瞬时故障而造成不必要的停运，在永久故障下也可以为其他设备动作以及控制策略的进行争取时间，增强系统运行的可靠性和稳定性。最后通过PSCAD/EMTDC仿真分析，验证了该控制策略对短路电流的有效控制和不同故障类型的处理效果。

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute 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 Objectives of this study are to estimate the effects of throughfall exclusion (drought) on the sap flow in a Populus deltoides plantations and to enhance our understanding of the response of poplar plantations to changes in global precipitation patterns. [Methods] The study was conducted from September 2018 to November 2020 in a 10-year old poplar plantation in Dongtai Forest Farm. There were three treatments in this study, including CK (control), D1 (30% throughfall exclusion）, and D2 (50% throughfall exclusion）. The sap flow density and environmental factors were continuously measured by thermal diffusion probe technology and the Micro Weather Monitoring System to evaluatethe response of the poplar plantation to environmental factors. [Results] (1) In three treatments, the annual variation of sap flow in poplar plantations showed a single peak, similar to the interannual variation of vapor pressure deficit and photosynthetic active radiation. The sap flow rate reached its peak in summer, and then gradually decreased over time. In the dormant period, the sap flow density approached zero. (2) In the drought treatment, the sap flow decreased with the increasing throughfall exclusion. The average sap flow density in the growth seasons of D1 and D2 were 39.61 and 31.85 g/ (m² s）, respectively, which were significantly reduced by 24% to 39% compared to the control (p＜0.05）. (3) The mixed effect model showed that the vapor pressure deficit and soil temperature were extremely significantly correlated with sap flow (p＜0.01）, while air temperature, rainfall, and soil temperature were significantly correlated with sap flow (p＜0.05）. [Conclusion] In D1 treatment, the power of explanation of environmental factors to sap flow increased, and the sensitivity sap flow to environmental changes could be increased in drought treatments. Among them, soil temperature was significantly correlated with sap flow. Further exploration of the response of tree traits to the environment is needed in the future. [ABSTRACT FROM AUTHOR]

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Copyright of Food Research & Development is the property of Food Research & Development 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.)

Based on the phenomenon that rhodamine derivatives（4-N-acrylamide-（3'，6'-bis（diethylamino）- spiro［isobenzofuran-1，9'-xanthene］-3-one）（AM-RhB）will open the lactone ring to display color or emit fluorescence under moderate acidic conditions（4. 425%） and fluorescence intensity modulation （>700） before and after stimulating with water ，and good reversibility （> 5 times）. This work will provide a promising way for the development of new hydrochromic materials. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Shanghai Jiaotong University (Medical Science) is the property of Journal of Shanghai Jiaotong University (Medical Science) 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 Food Research & Development is the property of Food Research & Development 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 Food Research & Development is the property of Food Research & Development 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 Food Research & Development is the property of Food Research & Development 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.)

Lithocarpus polystachyus is a kind of precious natural wild medicinal plants, and can develop health food pigment and natural medicinal drugs. There are rich plant resources in Guangxi. To provide certain reference for early selecting the superior germplasm, seeds from such four origins as Bama, Napo, Debao and Tianlin County were collected and sowed through ascertain difference of leaf morphology index and growth index in seedling plants between different origins of L. polystachyus in Guangxi, for nursing seedlings respectively,and tracking to survey and determine the leaf traits and growth of seedlings aged one,and then compared the degree of variation of leaf area, leaf length, leaf width, leaf thickness, vein spacing, leaf fresh weight, leaf dry matter content, specific leaf area, leaf tissue density, the relative contents of chlorophyll, leaf water retention, plant height, ground diameter, dry weight per plant, taproot length,root dry weight per plant,leaf dry weight per plant between different origins of plants, and further to analyze the correlation between leaf traits and growth of seedling. The results were as follows:(1) There were a lot of differences in leaf traits and seedling growth among different origins, in which the length, width, LAI (leaf-area-index), veins distance, fresh weight, dry weight, tissue density of leaves and mean height, diameter, whole dry weight, root length, root dry weight of individual seedling from Bama were significantly higher than those from Napo, Debao and Tianlin. Mean biomass of individual seedling from Bama was one to two times as much as those from other three origins. Analysis from leaf water holding ability and net growth rate showed that the drought tolerance of seedlings from Bama were higher than those from three other origins. In conclusion, Bama could be considered as a superior provenance on a preliminary basis;(2) The growth peak of L. polystachyus was in August in Guangxi, the plant height and the ground diameter growed significantly at this time. In order to obtain the largest accumulation of seedling growth,some proposal that strengthen the water management, adjust the suitable conditions of field water, and as far as possible to prolong rapid growth of seedlings should be put forward;(3) Correlation analysis indicated that LAI had extremely positive correlation with seedling height, diameter, individual whole dry weight, root length, individual root dry weight and individual leaf dry weight, The veins distance and SPAD value both had positive correlation with seedling height and individual seedling whole dry weight, while SLA (specific leaf area) had negative correlation with seedling height and diameter. Therefore, during the phenotype selection in the future, priorities should go to the seedlings with mature thick-green leaves of broad leaf area and veins distance. [ABSTRACT FROM AUTHOR]