Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：数字媒体是一种当代的新兴媒体,它具有双面性、多样性、及时性。在传播方式上也有着很大的不同,相比于传统的传播模式来讲,数字媒体可以收集以及传输大量信息,并且有着不可替代的作用。而在另一方面,现在的省级电视台新闻类节目正处于瓶颈时期,在播出时间、播出内容以及播出形式上都需要进行颠覆性的改革。本文结合了数字媒体的特点,以及电视新闻类节目的传统优势,以省级电视台新闻节目的瓶颈为出发点,从更新观念、增加直播报道的途径、提高网络平台互动三个层面着重加以阐述及说明。
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：网络分析就是通过对网络数据的全面监控分析,对网络中传输的数据包进行解码、检测、分析、诊断,排除各种网络应用行为造成的网络故障和问题,准确并快速地定位网络病症,规避网络安全风险,提高网络性能,增强网络可用性。本文介绍了网络分析的位置、数据的筛选、统计方法、分析方法,使用网络分析解决性能评价、网络资源管理和决策,以及识别网络中的安全威胁等进行了详细阐述,通过实例讲解网络分析在实践中的重要作用。
Subjects: Psychology >> Developmental Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： Autobiographical Memory is the memory of personal experiences. Attachment theory provides an important framework for understanding autobiographical memory. Based on the differences in individual attachment styles and the Self-Memory System of Conway and Pearce’s, this article concludes that attachment system plays the role of target director, defensive exclusion and emotion regulation in autobiographical memory retrieval. Studies have found that secure individuals have advantages over insecure ones in the quantity, specificity, accuracy, accessibility, emotional intensity and arousal of memory retrieval. Future research can be carried out on the effects of attachment activation, the differences in specific components of memory retrieval between anxious and avoidant attachment styles, the relationship between attachment and retrieval of involuntary autobiographical memory.
Subjects: Library Science，Information Science >> Information Science submitted time 2017-11-05 Cooperative journals: 《智库理论与实践》
Abstract： [Purpose/significance] This article is written from the perspective of organic intellectuals to explore the new type of think tanks about how to construct itself and serve the local development. In the transition period of China, there are many grassroots problems. For think tanks, the use of professional and organic intellectuals to serve the local development is one of the paths. Therefore, how to build a new type of think tanks has become a problem. On the one hand, the positioning of the think tank is closely related to the need of the local development. On the other hand, the development of the think tank should be combined with the organic intellectuals. [Method/process] In this article, we chose “the think tank for China rural policies” as a case study and analyzed the think tank construction points, intellectual effective participation and local development needs. [Result/conclusion] It is found that the new type of think tanks should emphasize the talents introduction, and propose organic countermeasures based on government requirements to provide organic solutions to better serve the local development.
Subjects: Library Science，Information Science >> Information Science submitted time 2017-07-13 Cooperative journals: 《智库理论与实践》
Abstract：[目的/意义]本文主要从有机知识分子的角度来探讨新型智库该如何进行自我建设,以服务地方发展。在转型期的中国,基层的问题可谓繁多。对智库而言,利用有机知识分子的专业性与有机性,来服务地方发展是路径之一,而如何建设新型智库就成为了一个难题。一方面,智库的定位与地方发展的需要应紧密结合;另一方面,智库的发展与知识分子的有机性要结合起来。[方法/过程]本文择取了"中国农村智库发展平台"作为研究个案,以分析智库建设的要点、知识分子有效参与和地方发展需要等问题。[结果/结论 ]研究发现:新型智库要在人才引入上面下足功夫;要有针对性地依据政府要求,提供有机性的对策,以更好地服务地方发展。
Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2023-11-29
Abstract： With the development of renewable energy, the voltage support strength of renewable energy multi-infeed systems is gradually decreasing, and there is an urgent need for strength evaluation methods. If considering that converters are all at the rated operating conditions, accurate quantification of strength can be achieved by utilizing existing power grid strength indices and threshold; However, the actual operating conditions are diverse and complex, which disrupts the existing criteria for defining indices and leads to the failure of existing methods. Therefore, this paper focuses on the quantification of voltage support strength under actual operating conditions. Firstly, the mapping relationship between the dynamic characteristics of grid-following converters, operating conditions, and parameters is discovered. Secondly, based on the perturbation theory of characteristics subspaces, an equivalent single-infeed system that can approximate the stability of the actual system is solved. On this basis, the operational generalized short circuit ratio(OgSCR) are defined. A rigorous method for quantifying voltage support strength can be formed based on the OgSCR and the device critical operational short-circuit ratio (OSCR0). In addition, this paper reveals the effect of actual operating conditions on strength. Finally, a numerical example is used to verify the feasibility of the proposed method
Peer Review Status:
Awaiting Review
Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2023-12-20
Abstract： With the large-scale integration of renewable energy and power electronic devices, system voltage support strength decreases, thus threatening the system's safe and stable operation. In the homogeneous scenario where power electronic devices integrated into the system have the same dynamics, a theoretically rigorous and highly stable quantitative method for quantifying system voltage support strength can be formed based on the generalized short-circuit ratio(gSCR) and the device critical short-circuit ratio(SCR0) In the heterogeneous scenario where power electronic devices integrated into the system have weakly different dynamics, system voltage support strength can be quantified by the first-order approximation of gSCR and SCR0, based on some special dynamic characteristics of devices and power grid. However, there is a lack of unified calculation principles at the theoretical level. To this end, this paper focuses on quantifying system voltage support strength under small-signal stability and discovers that the multi-infeed system can be approximately decoupled into multiple low-dimensional systems. On this basis, this paper proposes the concept and approximate calculation method of eigen-subsystems and interprets their physical significance. Based on the concept of eigen-subsystems, the general calculation principle of gSCR and SCR0 were unified, which achieves strength quantification of heterogeneous multi-infeed systems. Additionally, the specific calculation methods for gSCR and SCR0 are provided in typical scenarios, such as grid-following converters under non-rated operating conditions, reverse active power output, and considering grid-forming devices. Finally, the effectiveness of the calculation principles and methods is verified in several cases.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2021-05-08 Cooperative journals: 《天文研究与技术》
Abstract：嫦娥四号低频射电频谱仪放置在月球背面，其天然观测条件得天独厚。然而，嫦娥四号平台存在约10-15W/(m2*Hz)级别的强干扰，并且干扰在每道时域数据中都存在明显的差异，这大大削弱了低频射电频谱仪的天文观测灵敏度。为此，本论文从两组信号的相关性出发，提出基于CLEAN算法，借助互相关功率谱、傅立叶级数展开等工具，把低频射电频谱仪A、B、C天线的时域观测数据切分为强相关的CLEAN模型信号和部分相关的残余信号两个部分。其中CLEAN模型信号主要由平台干扰信号和可能的低频强射电爆发组成；残余信号由接收机噪声、未扣除干净的平台干扰信号和常规的低频射电信号组成。将该方法应用到实际数据中，结果表明嫦娥四号低频射电频谱仪的未积分灵敏度可以提高约8个数量级，达到10-23W/(m2*Hz)水平。在此基础上，基于对平台干扰信号中确定性成分和宽带随机成分的分别处理，再借助低频射电爆发信号和平台干扰信号在功率谱上不同的表现，以及常规低频射电天文信号受月球自转调制等信息，将来科学分析工作的重点是进一步处理CLEAN模型信号和残余信号，以期发现低频强射电天文爆发信号，乃至对全天区进行粗略的成像。
Subjects: Psychology >> Social Psychology submitted time 2019-01-28
Abstract： Although previous studies have found that a conformity effect exists widely, whether people are affected by groups in the evaluation of creative products, the new products with the basic characteristics of novelty and practicability, remains a question to be studied. Compared to artistic products, such products are closely related to real life, reflecting actual creativity, and they are typical creative products in life. Although such products reveal new perspectives for consumers, they also promote a sense of uncertainty. Research shows that when faced with uncertainty, participants are more likely to follow others. Almost all studies on this subject have involved the evaluation of creativity, yet novelty and practicability are two important aspects of creativity. Researchers have studied the characteristics of creativity or creative products; however, creative products can be divided into innovative products and renovative products according to their originality. Therefore, we plan to compare the conformity effect of the two kinds of creative products in the evaluation of novelty and practicability in this study. An “initial evaluation–conformity induced–delay re-evaluation” paradigm was used in Experiment 1, in which participants were first asked to evaluate the practicability (or novelty) of creative products; then the 200 undergraduates' average rating and the participants' own ratings were revealed. The group rating would be revealed as higher or lower than or similar to the participants' rating. Thirty-minutes later, participants evaluated the task again were entirely unexpected. To further analyze the difference in conformity degree between the two types of creative products, the subjects were required to make a certainty judgment on the novelty and practicality of the product in Experiment 2. Experiment 1 revealed that participants had decreased their practicability (or novelty) ratings when the group rating was lower than their first rating, increased their practicability (or novelty) ratings when the group rating was higher than their first rating, and did not change their ratings significantly when the group rating was comparable to their first rating. In the evaluation of practicability, it was found that the conformity of variation (the second rating–the first rating) of innovative products was significantly higher than that of renovative products. Nevertheless, in the evaluation of novelty, the two types of creative products had the same conformity of variation. Similarly, Experiment 2 found that the uncertainty of the evaluation of the practicability of the innovative product was greater than that of the renovative product. In the evaluation of the novelty of the two kinds of products, the degree of uncertainty was the same. In summary, both the evaluation of novelty and the practicability of creative products had a conformity effect. In the practicality evaluation of innovative products, it was easier for respondents to follow others, which might be caused by the greater uncertainty in the practical evaluation of innovative products than in that of renovative products. Nevertheless, in the absence of knowledge of new things, blindly following the crowd is likely to have unimaginable consequences. For long-term development, we should fully understand that innovative products are practical and decide what to do the next. "
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-27 Cooperative journals: 《南方医科大学学报》
Abstract： Objective To observe the effect of parathyroid hormone (PTH)(1-34) on the expression of matrix Gla protein (MGP) and Wnt/β-catenin signaling pathway and elucidate the possible molecular mechanism of PTH (1-34) in the prevention and treatment of osteoporosis. Methods MG63 cells treated with PTH (1-34) at 10-9, 10-8, and 10-7 mol/L, alone or in combination with Wnt/beta-catenin signaling pathway inhibitors DKK-1 (200 ng/ml) were examined for mRNA and protein expressions related with Wnt/β-catenin signaling with real-time PCR and Western blotting. The cell differentiation after the treatment was assessed with alkaline phosphatase (ALP) staining and cell viability assay. Results PTH (1-34) significantly increased the expression of MGP in a dose-dependent manner in MG63 cells (P<0.05 or P<0.01). PTH treatment obviously enhanced ALP activity in the cells, and this effect was suppressed by DKK-1. Combined treatment with DKK-1 partially blocked PTH-induced enhancement of ALP activity (P<0.05). PTH promoted the expression of MGP and enhanced LRP5, β-catenin, and Runx2 expressions in Wnt/β-catenin signaling pathway at both protein and mRNA levels (P<0.05 or P<0.01). DKK-1 partially blocked the effect of PTH (1-34) on Wnt/β-catenin signaling pathway (P<0.05) without affecting MGP expression. Conclusion PTH (1-34) significantly increases the expressions of MGP and proteins in the Wnt/β-catenin signaling pathway. Wnt/β-catenin signaling pathway and MGP mediate the regulation of osteogenosis by PTH.
Subjects: Psychology >> Cognitive Psychology submitted time 2023-11-20
Abstract： Serial dependence refers to the phenomenon where current perception is influenced not only by the current stimulus input but also by preceding events in recent history. This effect plays a crucial role in the establishment of relatively stable perceptions in dynamically changing environments. Previous studies have shown that the degree and direction of serial dependence are related to the task relevance of stimulus features. It is still unclear, though, if task relevance in linearly distributed features affects this impact, given that the majority of these researches have mostly focused on experiments using circularly distributed features. The current study investigated the impact of task relevance of linearly distributed features on serial dependence by using estimation tasks with dot arrays as stimulus materials, which were transformed orthogonally in two dimensions: number/area (Experiment 1) or number/size (Experiment 2).
The study employed a 7 (number of dots) × 7 (dot array area in Exp 1/average dot size in Exp 2) × 2 (task relevance: relevant vs. irrelevant feature) block design. All subjects were exposed to all experimental conditions. In the area estimation task, subjects were asked to pay attention to the area of the dot array, where the area is a task-relevant feature and the number of dots is a task-irrelevant feature. The order of the two tasks was balanced between subjects. The dependent variable of the experiment was the subject's estimate of the task-relevant feature. The visual stimuli were presented by a monitor with a 59 Hz refresh frequency. Following the fixation screen, which lasted for 1350–1450 ms, the stimulus image appeared in the center of the screen for 250 ms, one dot array at a time. Then the task instruction was presented at the top of the screen, and a number axis was presented below the instruction, with "5" and "40" scales at each end of the axis. After the subject clicked the mouse on the number axis, a white scale appeared at the clicked position, and the corresponding value was displayed below the scale. The subject had a 15-second response time, and if the subject did not press the Enter key within 15 seconds, the program automatically advanced to the next trial, recording the subject's response as "N/A".
We found that the influence of a feature from the previous trial on current perception was consistently opposite to that of the same feature in the current trial, regardless of the feature's task relevance. Serial dependence effects from task-relevant features of the previous trial were always repulsive. For task-irrelevant features, however, whether the serial dependence induced by the feature in the previous trial was an attraction or a repulsion effect depended on the feature itself. The effect of task relevance on serial dependence was mainly reflected in the reduction of the effect magnitude.
These findings suggest that both task relevance and feature characteristics have an impact on the serial dependence of linearly distributed features, and the persistence of the serial dependence in irrelevant features implies that serial dependence can also arise at the object level.
Subjects: Psychology >> Social Psychology submitted time 2023-03-27 Cooperative journals: 《心理学报》
Abstract： People can infer personal traits from names and, thus, the impressions of an individual can be influenced by how others perceive his or her name. Previous research has found that people have a distinctive perception of masculine and feminine names. This raises an interesting question: How do people evaluate individuals with opposite gender-oriented names, and how will this evaluation affect interpersonal interaction based on the main two dimensions of social cognition (i.e., warmth and competence). To answer these questions, the first aim of this study was to evaluate the perception of warmth and competence of names within the Chinese context and examine the effects of an individual’s gender and name-gender orientation on impression formation. The second aim was to explore the behavioral aftereffects of evaluation of impressions based on individual’s names.Four studies were conducted to explore the research questions. In Study 1, a total of 100 masculine and feminine names were presented to 176 undergraduate students who were asked to rate these names according to four traits: two traits for each dimension of warmth and competence. In Study 2, 121 undergraduate participants were presented with information about target genders and names. Participants were asked to rate these targets based on warmth and competence. In Study 3a, 136 undergraduate participants were presented with two targets that had masculine or feminine names within the context of imagining going on a trip with them. Furthermore, in Study 3b, 131 undergraduate participants were asked to imagine that they would meet two individuals with different names within the context of finishing a difficult task. Participants in Study 3a and Study 3b were then asked to evaluate these individuals based on their warmth and competence traits and choose one of them as their partner to complete the corresponding activities.The results were as follows: (1) Feminine names were rated higher on warmth than masculine names, and masculine names were rated higher on competence than feminine names; (2) Individuals with gender-consistent names were considered to have the typical characteristics of their gender: women with feminine names were perceived as warmer than women with masculine names, and men with masculine names were perceived more competent than men with feminine names; (3) Individuals with gender-inconsistent names were considered to have the characteristics of the opposite sex: men with feminine names were perceived less competent than women with masculine names, whereas women with masculine names were perceived less warm than men with feminine names; (4) Participants intended to make friends with women whose names were consistent with their gender, and the perception of warmth completely mediated the effect of name-gender orientation on willingness to interact; and 5) Participants preferred to finish difficult tasks with men whose names were consistent with their gender, and the perception of competence completely mediated the effect of name gender orientation on willingness to cooperate. This is the first study to explore how gender and name gender orientation affect individuals’ impressions by applying stereotype content in China. We examined the influence of name gender orientation on individuals’ perceptions about others, as well as their behavior intention and mechanism, from the perspective of the perceiver’s motivation. This study provides new theoretical explanations and empirical support for impression evaluation and interpersonal interaction based on names, and has important implications for future research on the social cognition of names. Further studies should explore the content of gender-ambiguous names and their effects on individuals’ impressions and behavioral aftereffects. The effects of emotional and cognitive processes on names and interpersonal interaction should also be assessed.
Subjects: Psychology >> Social Psychology submitted time 2020-12-23
Abstract： People can infer personal traits from names, and impressions of individual can be influenced by names. It is estimated that male-oriented names and female-oriented names have difference on the perception of the big two fundamental traits: warmth and competence. It raises an interesting question: how people evaluate individuals with opposite gender-oriented names, and what effect does the name have on the individual's interpersonal interaction. To answer these questions, the first aim of the current study was to test the content of gender-oriented names in Chinese context, and examine the effects of name-gender orientation and gender on individual’s impression formation. The second aim of the study was to explore the behavioral aftereffects of names and its evaluation-behavior mechanism. Four studies were carried out to explore this problem. In Study 1, 176 undergraduate participants were presented with 100 gender orientation names, participants were asked to rate names on 4 traits (2 on warmth dimension, 2 on competence dimension). In Study 2, 121 undergraduate participants were presented with information about two subjects, two subjects are of the same sex but different gender orientation names. Participants were asked to rate two subjects on warmth and competence dimension. In Study 3a, 136 undergraduate participants were presented with introductions, which describe two person with different gender orientation names in the context of trip. In Study 3b, 131 undergraduate participants were imagined that they would meet two person with different names in the context of finishing task. Participants in Study 3a and Study 3b were then asked to evaluate subjects on 6 traits (3 on warmth dimension, 3 on competence dimension), and choose one as partner to complete corresponding activities. The results showed that: (1) Female-oriented names were higher on warmth than male-oriented names, male-oriented names were higher on competence than female-oriented names; (2) Individuals with gender-consistent names were considered to have the characteristic of typical male or female: female with female-oriented names were perceived more warmth than female with male-oriented names, and male with male-oriented names were perceived more competence than man with female-oriented names; (3) Individuals with gender-inconsistent names were considered to have the characteristics of the opposite sex: male with female-oriented names were perceived more warm than female with male-oriented names, female with male-oriented names were perceived more competence than male with female-oriented names; (4) Participants intended to make friends with female subjects whose name is consistent with gender, and trait warmth totally mediated the impact of gender-oriented names on willingness to interact; Participants intended to finish task with male whose name is consistent with gender, and trait competence totally mediated the impact of gender-oriented names on willingness to cooperate. In conclusion, the current study is the first to explore gender-oriented names and gender on impression of name owners by applying the content of stereotype, and examines the influence of gender-oriented names on individual impression and behavior intention and its mechanism from the perspective of social motivation. This study provides new theoretical basis and empirical support for impression evaluation and interpersonal interaction based on names, and has important implications for the future research about name social cognition. Future research should explore the content of gender-ambiguous names and its’ effects on individual’s impression and behavior aftereffects, and combine emotion and cognition to examine the influence of names on interpersonal interaction. "
Peer Review Status:Awaiting Review
Subjects: Computer Science >> Computer Application Technology submitted time 2017-03-10
Abstract：在传统服务计算研究工作中往往忽视数据共享和数据流，为了在企业应用集成系统升级时更好地支持数据资源共享和应用协同，本文将着重讨论云计算环境下的数据资源接入、以用户为中心的数据资源集成、数据驱动的业务协同等问题。研究成果可用于跨管理域、基于云资源中心的多信息系统的逻辑集成和 信息共享、综合集成类系统特征数据的提取和实时呈现等。
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2020-04-09 Cooperative journals: 《天文研究与技术》
Abstract： 对月球以及更远天体或者空间环境的探测是人类航天活动的重要方向。开展月球和深空探测任务有利于研究太阳系起源、演化与现状，以及生命起源与演变等重大科学问题，有利于催生基础性、前瞻性的学科与技术。相比光学等探测方法，雷达具有强穿透性、极化特性以及不受光照限制等优势，是探测天体特性的有效手段之一，在人类的月球和深空探测任务中发挥了重要作用。电磁波能够穿透几米到几千米的次表层，可用于探测月球和深空目标的表层介电常数、次表层结构、电离层及水冰等。按照探测方式的不同，表层穿透雷达探测主要包括地基雷达、环绕器雷达及巡视器雷达三种方式。针对不同的科学目标，不同的探测方式具有各自的优势和不足。本文回顾了表层穿透雷达在月球、火星以及小行星等探测中的科学应用，总结了已经投入使用的以及计划中的各种雷达科学载荷的探测任务、参数设计、工作原理和探测结果，展望了在未来利用表层穿透雷达进行月球和深空探测的发展趋势。
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2023-08-31 Cooperative journals: 《中国全科医学》
Abstract：背景 抗生素滥用导致的耐药问题已成全球重大公共卫生议题，减少公众上呼吸道感染的抗生素不合理使用是我国治理抗生素滥用的重要策略，识别上呼吸道感染疾病病症特点及其对抗生素不合理使用行为的影响有助于临床医生设计更为精准的干预政策。目的 定量分析公众上呼吸道感染症状的潜在模式，探究其对抗生素使用行为的影响。方法 本研究采用整群随机抽样调查，于 2022-07-2008-02 选取重庆市三个县（区）的公众作为调查对象。调查公众上呼吸道感染疾病症状、公众上呼吸道感染抗生素使用行为、公众抗生素使用知识及人口学特征。采用潜在类别分析方法鉴别公众上呼吸道感染疾病症状的潜在模式，采用多因素 Logistic 回归分析探索不同潜在症状模式对抗生素使用行为的影响。结果 815 位公众参与本研究。其中，30.06%（245/815）受访者存在无处方从药店购买抗生素，14.72%（120/815）受访者使用过抗生素自我药疗以应对上呼吸道感染。公众抗生素合理使用知识水平较低〔（2.31.7）分〕。上呼吸道感染疾病发病模式方面，潜在类别分析共识别 4 种症状模式，包括多样症状组 39 例（11.41%）、全身症状组 124 例（15.21%）、鼻咽症状组 282 例（34.60%）和轻微症状组 316 例（38.77%）。多因素 Logistic 回归分析显示：相较于轻微症状组，鼻咽症状组出现无处方购买抗生素行为的概率更高（OR=1.538，P<0.05），结果在调整知识与人口学变量后仍显著。除个体疾病症状潜在模式外，年龄和医保类型也对公众无处方抗生素购药行为有显著影响（P<0.05）。抗生素使用知识水平对抗生素自我药疗行为有显著影响（OR=0.869，P<0.05），对公众无处方抗生素购药行为也有显著影响（OR=1.155，P<0.05）。结论 公众上呼吸道感染症状存在 4 种潜在模式，疾病病症模式显著影响公众抗生素的合理使用，应着重关注出现鼻咽症状患者的抗生素不合理使用行为。
Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2023-06-06
Abstract： System strength is generally used to describe the voltage response performance under a disturbance and quantify the stability margin. The system strength indicated by short-circuit ratio (SCR) has provided a simple and intuitive reference for grid operators. However, the existing SCR-based methods rely on the premise that synchronous generators provide short-circuit capacity and voltage support. Due to this premise, these methods are unsuitable for renewables delivery systems with voltage source converter-based high voltage direct current (VSC-HVDC), where all apparatuses are power-electronic interfaces. This paper aims to respond the system strength evaluation problem in terms of small-disturbance analysis. Firstly, the sensitivity transfer function matrix of the bus voltage to the renewables multi-feed current is derived and the relationship between the voltage performance and stability is illustrated; Secondly, the generalized short-circuit ratio is extended into the renewables VSC-HVDC delivery system based on the voltage-source equivalent modeling of VSC-HVDC; Then, by combing the apparatus critical SCR and generalized short-circuit ratio, a source-grid separation method can be further proposed to quantify the system strength of such a system. The proposed method can assess the static voltage stability margin or small-disturbance synchronous stability margin at the operating point and determine the critical bus of system strength and the optimization path of system strength improvement. Finally, the proposed method is verified by simulation in multiple wind plants with VSC-HVDC.
Peer Review Status:Awaiting Review
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-05-24 Cooperative journals: 《工程热物理学报》
Abstract：本文基于预混滞止弱旋火焰系统，以溶于水或乙醇的廉价硝酸盐为前驱物，采用“一步”的雾化火焰方法来合成铜基催化剂纳米颗粒。采用TEM、XRD等分析了合成颗粒的形貌及物相态，进而考察了该催化剂在甲烷催化氧化反应中的催化活性。根据TEM结果，发现乙醇做溶剂时所合成的氧化铜颗粒具有颗粒直径小且结晶度较好的特点。实验结果表明，10 nm氧化铜颗粒体现出良好的甲烷催化性能，但掺杂氧化铝后，铜基催化剂对甲烷的催化性能有所下降，其原因可归结为氧化铝对氧化铜的覆盖作用导致其有效比表面积降低。
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2023-08-29 Cooperative journals: 《中国全科医学》
Abstract： Background The effects of childhood experiences on the health of middle-aged and older adults has become a research hotspot. However，the effects and pathways of childhood experiences on cognitive function in middle-aged and older adults still remain unclear. Objective To analyze the effect of childhood socioeconomic status on cognitive function in middle-aged and older adults from a whole life cycle perspective，and explore promotion strategies for cognitive function in middle-aged and older adults. Methods The China Family Panel Studies（CFPS） for 2010，2012，and 2020 was used to construct a multiple mediated-effects model to investigate the mediating pathways of the effect of childhood socioeconomic status on cognitive function in middle-aged and older adults. Results A total of 1 034 middle-aged and older adults with an average age of 62.33 years were included in this study. The childhood socioeconomic status score was（0.000±0.797），education level score was（1.970±1.111），social participation score was（1.150±0.967），depression status score was（5.960±4.681）， and cognitive score was（0.000±1.000）. Childhood socioeconomic status was positively correlated with education level，social participation，and cognitive function in middle-aged and older adults（P<0.05），and negatively correlated with depressive status（P<0.05）. The results of regression analysis showed that childhood socioeconomic status had no significant direct effects on cognitive function of middle-aged and older adults（β=0.054，t=1.400，P=0.162），education level，social participation， and depression status significantly affected cognitive function in middle-aged and older adults（β=0.335，t=11.622，P<0.05； β=0.064，t=2.166，P<0.05；β=-0.019，t=-3.154，P<0.05）when controlled of age，gender，urban/rural，chronic disease prevalence，and medical service utilization. The results of the mediation effect test showed that education level and social participation significantly affected cognitive function in the middle-aged and older adults（95%CI=0.141-0.223；95%CI=0.001-0.019）. There was a statistically significant chain mediated effect of education level and social participation（95%CI=0.001-0.017）， as well as education level and depression status（95%CI=0.001-0.008）. Conclusion Education level is the resource pathway through which childhood socioeconomic status affects cognitive function in middle-aged and older adults；social participation is a conditional path through which childhood socioeconomic status affects cognitive function in the middle-aged and older adults； depression is a risk factor affecting cognitive function in middle-aged and older adults. Based on the life course theory，attention should be paid to the effect of childhood socioeconomic status from multiple levels of individual，family，and society，to develop cognitive function promotion strategies for the middle-aged and older adults.
Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2024-03-07
Abstract： The large-scale integration of renewable energy into the power grid leads to the decrease of short circuit ratio (SCR) and system voltage support strength, which results in stability issues such as static voltage stability problems and sub/super synchronous oscillation. Grid-forming (GFM) converters have effective voltage support capacity and equipping renewable energy stations with a certain proportion of GFM converters can improve the stability of the system. However, the analytical relationship between the capacity of GFM converters and the stability margin is unclear, which is difficult to estimate the required proportions of GFM converters theoretically. Therefore, from the perspective of small signal stability, this paper discusses the estimation method and typical values of the capacity ratios between GFM converters and grid-following (GFL) converters. Firstly, based on the voltage-source equivalent analysis of GFM converters, the influence of the capacity ratios on the system strength and stability margin is analyzed through the generalized short circuit ratio (gSCR) index. Secondly, considering changing some of the wind turbines into GFM control and installing new GFM converters, the typical values of the capacity ratios in practical engineering are discussed based on typical parameters of step-up transformers and using relevant industry standards as boundary conditions. The validity of the conclusion is verified by simulation results of the multi-wind-farm system.
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