排序方式： 共有9条查询结果，搜索用时 15 毫秒
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集成运放广泛用于模拟信号的产生和处理电路中。用集成运放构成的电压比较器设计的太阳能光伏庭院灯控制器具有简单可靠、维护方便、成本低、功耗低及安全性好等特点。 相似文献
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论述了建筑物用光伏集成系统 (BIPV )在中国用于太阳能发电的潜力和前景 .为了保护环境 ,减少矿物能源的消耗 ,并满足人们对电力的需求 ,BIPV被认为是最经济的利用可再生能源的技术 .计算了中国 14个城市的太阳能资源 ,估算了建筑物用光伏集成系统的发电潜力 ,分析了 BIPV技术应用的经济性 .研究表明中国的 BIPV市场潜力是巨大的 ,政府对这项技术的发展应发挥重要作用 相似文献
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介绍了一种与建筑一体化的光伏发电系统,提出固定的二次反射多平面镜聚光系统,可成倍地增大太阳电池的输出功率,大幅度降低系统成本。在金数龙仿真物理实验室仿真软件设计的基础上,经过分析,得出下方与上方反射镜的数据;实验表明,太阳光线能够均匀地聚光在太阳电池上,达到二倍光强的效果。系统功能完善,安装简单而且抗风能力强,有很好的应用前景。 相似文献
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Mahmood H. Shubbak 《Research Policy》2019,48(4):993-1015
This research paper studies the Chinese technological system of production and innovation in the field of photovoltaics (PV). It contributes to a better understanding of the emergence and development of the system by utilizing three levels of analysis: the institutional framework of the system, the market dynamics of production and deployment, and the composition of innovation-related activities. The analysis demonstrates the interrelated roles of transnational factors, local government policies, and research and development (R&D) activities undertaken by the main actors in shaping the system dynamics. Tracking the relative position of China in the global PV manufacturing, installation and technological development, the analysis shows a gap between the growth of China’s market share and its modest share of transnational patent applications. This suggests a puzzle, which the paper attempts to answer by inspecting the individual companies in the system against four aspects. First, the dynamic development of their size and performance. Second, the nature of their international involvement through foreign direct investment and mergers and acquisition deals. Third, their technological specialization within the PV value chain over time. Fourth, the spatial scope of their patenting protection endeavours. The analysis recognises four periods of system development driven jointly by market dynamics and government plans. Behind the continuous growth of the system, there were different driving and moderating factors in each period. 相似文献
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This study explores the dynamics of a government sponsored collaboration network concerning the development of solar photovoltaics (PV) technologies in China, and investigates the effect of network evolution on the subsequent innovation performance of network actors. Network structure characteristics and attribute proximity variables are jointly examined through a bibliometric methodology based on scientific publication and patent data. In addressing the evolution of the government sponsored collaboration network, this study has identified that actors are more likely to engage in collaboration with prior partners, partners of direct & indirect partners, and partners with similar attributes. These collaboration patterns, in turn, negatively impact direct ties and network efficiency, and increase the attribute proximity of an actor’s network. On the other hand, the estimation results indicate that direct ties have an inverted U-shaped effect on innovation performance, while indirect ties are found to be positively related to innovation performance. As expected, a positive effect of network efficiency is found on innovation performance. The results of attribute proximity variables suggest geographical proximity is negatively related to innovation performance. Taken together, the collaboration patterns in the government sponsored network might have a negative impact on innovation performance of network actors. The empirical findings extend the network literature that collaboration network matters differently in different research contexts, and it is no longer appropriate to simply assume that collaboration is purely a good thing. As such, special attention should be paid to the network structure and composition in further policy design. 相似文献
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Petros J. Axaopoulos Konstantinos N. Moutsopoulos Michael P. Theodoridis 《European Journal of Engineering Education》2012,37(1):39-48
An experiment using real hardware and under real test conditions can be remotely conducted by engineering students and other interested individuals in the world via the Internet and with the capability of live video streaming from the test site. The presentation of this innovative experiment refers to the determination of the current voltage characteristic curve of a photovoltaic panel installed on the roof of a laboratory, facing south and with the ability to alter its tilt angle, using a closed loop servo motor mounted on the horizontal axis of the panel. The user has the sense of a direct contact with the system since they can intervene and alter the tilt of the panel and get a live visual feedback besides the remote instrumentation panel. The whole procedure takes a few seconds to complete and the characteristic curve is displayed in a chart giving the student and anyone else interested the chance to analyse the results and understand the respective theory; meanwhile, the test data are stored in a file for future use. This type of remote experiment could be used for distance education, training, part-time study and to help students with disabilities to participate in a laboratory environment. 相似文献
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Domain walls (DWs) in ferroelectrics are atomically sharp and can be created, erased, and reconfigured within the same physical volume of ferroelectric matrix by external electric fields. They possess a myriad of novel properties and functionalities that are absent in the bulk of the domains, and thus could become an essential element in next-generation nanodevices based on ferroelectrics. The knowledge about the structure and properties of ferroelectric DWs not only advances the fundamental understanding of ferroelectrics, but also provides guidance for the design of ferroelectric-based devices. In this article, we provide a review of structures and properties of DWs in one of the most widely studied ferroelectric systems, BiFeO3 thin films. We correlate their conductivity and photovoltaic properties to the atomic-scale structure and dynamic behaviors of DWs. 相似文献
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The impact of technology-push and demand-pull policies on technical change - Does the locus of policies matter? 总被引：1，自引：0，他引：1
Michael Peters Malte SchneiderTobias Griesshaber Volker H. Hoffmann 《Research Policy》2012,41(8):1296-1308
How to foster technical change is a highly relevant and intricate question in the arena of policymaking. Various studies have shown that technology-push and demand-pull policies induce innovation. However, there is a lack of work that distinguishes between the loci of policy support when assessing the policy-innovation relationship. We address this gap by shedding light on the question how the innovation effects of domestic and foreign demand-pull and technology-push policies differ. Using solar photovoltaic modules as a research case we conduct a panel analysis on 15 OECD countries over the period 1978 through 2005 with patent data. Three key findings emerged: First, our analyses find no evidence that domestic technology-push policies foster innovative output outside of national borders. Second, both domestic and foreign demand-pull policies trigger innovative output in a country. Third, we detect no indication that market growth induced by domestic demand-pull policies leads to more national innovative output than market growth induced by foreign demand-pull policies. Consequently, demand-pull policies create significant country-level innovation spillovers, which could disincentivize national policymakers to engage in domestic market creation. Based on these findings we discuss the need to establish supranational demand-pull policy schemes in order to address the spillover issue. 相似文献
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Xiaoling Ma Anping Zeng Jinhua Gao Zhenghao Hu Chunyu Xu Jae Hoon Son Sang Young Jeong Caixia Zhang Mengyang Li Kai Wang He Yan Zaifei Ma Yongsheng Wang Han Young Woo Fujun Zhang 《国家科学评论(英文版)》2021,8(8)
A series of ternary organic photovoltaics (OPVs) are fabricated with one wide bandgap polymer D18-Cl as donor, and well compatible Y6 and Y6-1O as acceptor. The open-circuit-voltage (VOC) of ternary OPVs is monotonously increased along with the incorporation of Y6-1O, indicating that the alloy state should be formed between Y6 and Y6-1O due to their excellent compatibility. The energy loss can be minimized by incorporating Y6-1O, leading to the VOC improvement of ternary OPVs. By finely adjusting the Y6-1O content, a power conversion efficiency of 17.91% is achieved in the optimal ternary OPVs with 30 wt% Y6-1O in acceptors, resulting from synchronously improved short-circuit-current density (JSC) of 25.87 mA cm−2, fill factor (FF) of 76.92% and VOC of 0.900 V in comparison with those of D18-Cl : Y6 binary OPVs. The JSC and FF improvement of ternary OPVs should be ascribed to comprehensively optimal photon harvesting, exciton dissociation and charge transport in ternary active layers. The more efficient charge separation and transport process in ternary active layers can be confirmed by the magneto-photocurrent and impedance spectroscopy experimental results, respectively. This work provides new insight into constructing highly efficient ternary OPVs with well compatible Y6 and its derivative as acceptor. 相似文献
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