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传统基于锁相环（phase lock loop，PLL）电网跟踪型控制在电网短路比（short circuit ratio，SCR）较低或PLL带宽较高情况时，给电力系统引入负阻尼导致系统不稳定。为此，提出了一种不依赖PLL的用于区域间电网互联的新型电压源换流器（voltage source converter，VSC）虚拟同步控制。首先，构造VSC直流电压与受端系统频率间的下垂特性，当受端电网受扰后，受端换流器可为系统提供惯量支撑。其次，测量送端电压波动与直流电流波动可计算受端交流系统的频率扰动，通过模拟同步机的一次调频特性，在受端电网受扰时，送端电网可不依赖通信为受端电网提供频率支撑。与传统控制相比，在系统受扰时，利用电容储能及送端电网的调频能力为其提供频率支撑。基于PSCAD/EMTDC仿真算例验证了受端系统弱SCR场景、负荷变化场景下所提控制策略的有效性。

The goals and functions of universities are constantly evolving, yet talent cultivation as the core task of universities has remained unchanged. University libraries play an important role in this endeavor by offering robust academic resource support, promoting knowledge dissemination and innovation, and improving students' independent learning and research capacities. The advent of artificial intelligence, particularly Large Language Model (LLM) technology, offers the potential to refine and restructure academic resources based on personalized needs. This innovation can go beyond the traditional paradigm of academic resource use, make learning materials more diverse, change the way resources are presented, and improve the efficiency of library resource utilization and student learning outcomes. This paper analyzes the shortcomings of contemporary university libraries in supporting student learning. including limited course-related resources, lack of initiative in library learning support services, inaccurate student learning profiles affecting the accuracy of personalized resource recommendations, imperfect resource organization models that cannot meet students' learning needs, and lack of effective cognitive learning theory integration in resource organization. In response to the above problems, a personalized learning support service system based on artificial intelligence technology is proposed. This system is predicated on students' learning and growth, synergizes with the vast academic resources of libraries, and aligns with the evolution and application trajectories of new generation information technologies such as artificial intelligence. It is anchored in the mission of university libraries to underpin talent cultivation, places students' learning at the core, and emphasizes effectiveness of learning and development as the driving force. This system is based on large language model technology, structured within a "knowledge ability literacy" framework, supported by cognitive learning theory, and guided by cognitive hierarchy models. Its goal is to facilitate personalized, autonomous, and efficient learning. The system utilizes self- constructed learning resources, library academic literature, reliable internet sources, and resources generated by large language models to form a diverse and multimodal academic resource base. By considering the needs of individual courses, students, teachers, majors, and topics as entry points, the system broadens the scope and depth of learning services. It also enhances the construction of learning support connotations, making learning support services more precise, efficient, and personalized. This personalized learning support service system is expected to change the library's service model, the organization model and use model of academic resources, thereby supporting the evolution of students' learning methods. [ABSTRACT FROM AUTHOR]

Copyright of Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica 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 Hubei Open Vocational College is the property of Journal of Hubei Open Vocational College 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 effects of different treatments of whole-plant corn silage in dairy cows' diet on the production performance, milk quality, rumen fermentation parameters, and serum biochemical indexes were studied. Sixty Holstein cows with similar parity, lactation period and milk yield were divided into four treatment groups according to a single factor design, with five replicates in each group and three cows in each replicate. Dairy cows in the control group were fed a whole-plant corn silage without any additives, dairy cows in the test group 1 were fed a whole-plant corn silage treated with probiotic preparation, dairy cows in the test group 2 were fed a whole-plant corn silage treated with enzyme preparation, and dairy cows in the test group 3 were fed a whole-plant corn silage treated with bacteria-enzyme compound preparation. The pre-feeding period was one week, and the formal trial period was eight weeks. The results showed that compared with the control group, the average daily dry matter intake of cows in the test group 3 significantly increased (P<0.05). The milk yield of dairy cows in the test group 1, group 2 and group 3 significantly increased (P<0.05). The milk protein rate in the test group 3 significantly increased (P<0.05), and the somatic cell number in the test group 1, group 2 and group 3 significantly decreased (P<0.05). The rumen acetic acid, total volatile fatty acid, and bacterial protein levels in the test group 3 significantly increased (P<0.05). The serum total protein level in the test group 3 significantly increased (P<0.05), the serum glucose level in the test group 1, test group 2 and test group 3 significantly increased (P<0.05), and the urea nitrogen level significantly decreased (P<0.05). The result shows that the whole-plant corn silage treated with additives can improve the production performance, milk quality, rumen fermentation function and some serum biochemical indexes of dairy cows, and the whole-plant corn silage treated with bacteriaenzyme compound preparation had a better effect. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhengzhou University (Natural Science Edition) is the property of Journal of Zhengzhou University (Natural Science Edition) 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 Geodesy & Geodynamics (1671-5942) is the property of Editorial Board Journal of Geodesy & Geodynamics 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 Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering Technology 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 To investigate the mechanism of miR-338-5p regulating the proliferation, migration and invasion of bladder cancer cells by targeting TSHZ3. Methods The expression of miR-338-5p in 33 samples of bladder cancer tissue and paracancerous tissue was detected by qRT-PCR. Bladder cancer T24 and UM-UC-3 cells were transfected with mimics-NC, miR-338-5p mimics, inhibitor-NC and miR-338-5p inhibitor, and the transfection efficiency was detected by qRT-PCR. CCK-8 assay was used to detect the effect of overexpression or knockdown of miR-338-5p on the proliferation of bladder cancer cells. Transwell assay was used to detect the effect of miR-338-5p on migration and invasion of bladder cancer cells. The potential target genes of miR-338-5p were predicted by TargetScan, miRDB and Targetminer databases, and TSHZ3 was chosen for the target gene. The targeting relationship between miR-338-5p and TSHZ3 was verified by dual-luciferase reporter gene assay and Western blot assay. miR-338-5p mimics and TSHZ3 overexpression plasmids were co-transfected in bladder cancer cells, and the proliferation, migration and invasion of cells were detected by CCK-8 and Transwell assays. Western blot assay was used to detect the overexpression of miR-338-5p or TSHZ3 against Wnt/ β-catenin signaling pathway. Results miR-338-5p was significantly upregulated in bladder cancer (P＜0.05). Overexpression of miR-338-5p increased the proliferation, migration and invasion of bladder cancer cells (P＜ 0.05), while transfection of miR-338-5p inhibitor decreased the proliferation, migration and invasion of bladder cancer cells (P＜0.05). Bioinformatics analysis and the dual-luciferase reporter gene assay showed that there was a targeting relationship between miR-338-5p and TSHZ3. The rescue experiment showed that co-transfection of miR-338-5p mimics and TSHZ3 overexpression plasmid partially eliminated the promoting effect of overexpression of miR-338-5p on the proliferation, migration and invasion of bladder cancer cells (P＜0.05). Western blot results showed that overexpression of miR-338-5p significantly decreased the expression level of TSHZ3 protein and increased Wnt3a and β-catenin protein expression levels (P＜0.05). In addition, overexpression of TSHZ3 reduced Wnt3a and β -catenin protein expression levels (P＜0.05). Conclusion miR-338-5p is upregulated in bladder cancer, and promotes the proliferation, migration and invasion of bladder cancer by targeting TSHZ3 expression. The mechanism may be related to the activation of Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Refrigeration Technology is the property of Shanghai Society of Refrigeration 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.)

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Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen 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.)

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Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water 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.)

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Copyright of Journal of Signal Processing is the property of Journal of Signal Processing 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 Acta Agronomica Sinica is the property of Crop Science Society of China 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 Guilin University of Technology is the property of Journal of Guilin University of 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.)

Copyright of Journal of Zhengzhou University: Engineering Science is the property of Editorial Office of Journal of Zhengzhou University: Engineering 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 Journal of Tiangong University is the property of Journal of Tianjin Polytechnic 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.)

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China 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.)

目的 介绍锁骨上动脉岛状皮瓣的血供方式以及该皮瓣在下咽癌手术中的应用特点。方法 自 2019 年 1 月至 2021 年 12 月，辽宁省肿瘤医院甲状腺头颈外科收治 2 例下咽癌患者，采用锁骨上动脉岛状皮瓣修复下咽癌根治切除后下咽缺 损。结果 2 例患者皮瓣成活良好。其中 1 例出现较小咽瘘，经 2 周换药后痊愈。术后分别随访 26、32 个月，患者肿瘤无复发， 疗效满意。结论 明确锁骨上动脉岛状皮瓣的血供方式能够有效促使皮瓣成活。锁骨上动脉岛状皮瓣可以完成下咽癌手术的修 复，损伤小的梨状窝癌患者还可保留喉功能，具有良好的临床实用价值。 [ABSTRACT FROM AUTHOR]

In the uncertain nuclear environment, the manual door opening is dangerous. This paper proposed an adaptive opening and screwing method of manipulator based on force sense guidance. The six-dimensional force sensor could obtain the force and moment information at the end of the manipulator. It input the difference between the actual force or torque and the expected force or torque into deep deterministic policy gradient algorithm, output actions at the same time . This method used the function relationship between the two direction forces at the end of the manipulator to set the basic reward function and used the expected movement direction of the manipulator to set the guided reward function, for the manipulator could automatically adapt to the change of the moment and the stress, and completed the task of screwing the door handle. The experimental results show that the self-adaptive rotation method based on force guidance can achieve convergence in a shorter time and complete the task of rotating the door handle. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tiangong University is the property of Journal of Tianjin Polytechnic 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.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science 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 Jilin University (Science Edition) / Jilin Daxue Xuebao (Lixue Ban) is the property of Zhongguo Xue shu qi Kan (Guang Pan Ban) Dian zi Za zhi She 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.)

Aiming at the problem of batch breaking of bolts at the blade root of wind turbine in a wind farm, to analyze whether the fracture was caused by fatigue damage, the method of finite element simulation and field test was used. The stiffness behavior of the blade bolt connection system and fatigue life of the blade bolt were studied. The fatigue life calculation results of blade bolts were combined with the fracture analysis of blade bolts to confirm that the fracture of blade bolt was caused by fatigue damage. A method of reducing the stiffness of blade bolts to improve their fatigue life was proposed, and the optimization scheme of fine bolt was designed, implemented and verified on site. The results show that the fatigue fracture location of blade bolt is mainly within ± 45 degrees of leading edge, which is consistent with the simulation results. The improved fine-rod bolt scheme reduces the stress amplitude of the blade bolt by about 13%, which improves the fracture of blade bolt obviously in the field application. [ABSTRACT FROM AUTHOR]

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Copyright of Electronic Science & Technology is the property of Electronic 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.)