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自然吸气式CNG发动机主充模型的研究
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作者 张鹏 石凯凯 毛功平 《内燃机》 2020年第3期42-46,共5页
为了准确预测自然吸气式压缩天然气(Compressed Natural Gas,CNG)发动机的空气流量,基于汽油机进气系统平均值模型,构建了CNG发动机的主充模型。根据CNG发动机进气系统的实际工作环境,引入了温度修正系数、体积修正系数、燃气量修正系... 为了准确预测自然吸气式压缩天然气(Compressed Natural Gas,CNG)发动机的空气流量,基于汽油机进气系统平均值模型,构建了CNG发动机的主充模型。根据CNG发动机进气系统的实际工作环境,引入了温度修正系数、体积修正系数、燃气量修正系数等参数,计算了不同工况下CNG发动机的空气流量。通过CNG发动机台架试验,测量了不同转速、不同进气歧管压力下的空气流量;对比分析了空气流量的计算值和试验值的方法,评估了模型的预测性能。结果表明,所建立的主充模型能较好的预测不同转速下空气流量随CNG发动机进气歧管压力的变化规律,空气流量的预测值与实验值的最大误差小于3%,模型具有较高的预测精度。 展开更多
关键词 CNG发动机 进气系统 主充模型 进气歧管压力 空气流量
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补肾中药调控骨髓间充质干细胞防治多发性硬化的机制探索
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作者 李春雨 王蕾 《环球中医药》 CAS 2024年第9期1713-1718,共6页
髓鞘再生障碍是脱髓鞘疾病如多发性硬化(multiple sclerosis,MS)的重要病理环节,而中医药具有促进髓鞘再生的潜在优势。中医学认为,肾藏精,精化髓,髓上行充脑。MS患者的基本病机为肾精亏虚,脑髓失养,损伤的轴突再髓鞘化困难,从而导致神... 髓鞘再生障碍是脱髓鞘疾病如多发性硬化(multiple sclerosis,MS)的重要病理环节,而中医药具有促进髓鞘再生的潜在优势。中医学认为,肾藏精,精化髓,髓上行充脑。MS患者的基本病机为肾精亏虚,脑髓失养,损伤的轴突再髓鞘化困难,从而导致神经功能障碍。因此补肾生髓为其根本治法,补肾中药治疗MS疗效显著。研究发现,骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)是一类具有强大分化潜能的多能干细胞,其分泌的外泌体可透过血脑屏障,其功能特点与中医肾藏精主骨生髓充脑的理论具有高度相关性,且BMSCs对MS也有良好的治疗作用。研究还证实,补肾中药可促进BMSCs增殖分化、定向迁移和调节自噬与凋亡。因此推测补肾中药调控BMSCs可能是其防治MS的机制之一。本研究为中医药防治MS等脱髓鞘疾病提供了新思路。 展开更多
关键词 多发性硬化 骨生髓 骨髓间质干细胞 补肾中药 髓鞘再生 机制
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主变空充励磁涌流造成差动保护动作的分析 被引量:1
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作者 闫新兰 王国金 《江西电力》 2008年第5期38-40,共3页
针对主变空充时励磁涌流引起微机差动保护误动这一情况,从保护装置原理、整定计算及主变性能等方面分析微机差动保护误动的原因,提出了减少该类事件的建议,同时还提出如何识别空投变压器是否存在故障的方法,以避免延误主变的恢复送电。
关键词 差动保护 励磁涌流 误动
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汇源发电公司#4主变充氮灭火装置误动放油故障及处理经过
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作者 周桂冉 郭守贤 《安徽电力科技信息》 2002年第4期6-8,共3页
关键词 发电公司 氮灭火 误动放油故障
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空充主变时保护误跳闸原因分析及改进措施 被引量:1
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作者 吴英豪 《广东输电与变电技术》 2004年第6期48-51,共4页
经常发生空充主变时差动保护误动作跳闸。针对空充主变时保护误跳闸现状,本文从分析保护装置原理、整 定计算、主变性能出发提出改进措施。
关键词 误跳 改进措施
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蓄电池充电系统性能分析 被引量:1
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作者 崔秀兰 《科技与企业》 2013年第24期430-430,共1页
通过对新旧充电系统的对比,分析我们ΚΠ—1高压变电所继电保护和操作系统直流电源蓄电池充电系统的性能。
关键词 蓄电池 模糊控制 无源PFC技术 脉宽调制技术 主充
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高水固化充填材料的注浆性能研究 被引量:4
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作者 陈永利 霍广新 +1 位作者 吴献 冯戈 《黄金》 CAS 北大核心 1998年第4期20-23,共4页
本文所指的高水固化充填材料是一种新型特种水泥混合材料。通过在实验室内对高水固化充填材料按注浆材料的要求,对其性能进行了检测及现场试验研究。分析表明,将其应用到注浆工程中,使它具有普通水泥所不具备的高水灰比、较好的流动... 本文所指的高水固化充填材料是一种新型特种水泥混合材料。通过在实验室内对高水固化充填材料按注浆材料的要求,对其性能进行了检测及现场试验研究。分析表明,将其应用到注浆工程中,使它具有普通水泥所不具备的高水灰比、较好的流动性和良好的稳定性、凝结时间的可调性,并能准确控制凝结时间、微膨胀、结石率高、初期强度增长快,且胶砂体强度高、抗渗性能好等优点,完全可将其作为注浆材料应用到注浆加固与堵漏防渗工程中。 展开更多
关键词 水固化 注浆 防渗 注浆材料
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陶瓷砖压机中充液阀的结构分析与计算 被引量:2
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作者 李良光 冯长印 《佛山陶瓷》 2007年第12期27-30,共4页
本文主要对比分析了国外陶瓷砖自动液压机中常见的几种充液阀结构及控制油路,阐明了充液阀通流面积和阀芯复位弹簧的计算方法。
关键词 缸外置式液阀 缸内置式液阀 无复位弹簧式液阀
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陶瓷砖压机中充液阀的结构分析与计算
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作者 李良光 冯长印 《山东陶瓷》 CAS 2007年第6期15-18,共4页
主要对比分析了国外陶瓷自动液压机中常见的几种充液阀结构及控制油路,阐明了充液阀通流面积和阀芯复位弹簧的计算方法。
关键词 缸外置式液阀 缸内置式液阀 无复位弹簧式液阀
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微机型国产主变保护防励磁涌流功能比较与分析
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作者 柏强 《江苏科技信息》 2014年第9期40-42,共3页
文章针对国产主变保护在主变空充时对励磁涌流进行制动的情况,从保护装置的设计原理及动作实例进行功能比较,分析不同原理的保护装置动作情况是否正确,并提出建议。
关键词 变空 励磁涌流 二次谐波制动
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陶瓷砖压砖机中充液阀的结构分析与计算
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作者 李良光 《陶瓷》 CAS 2007年第6期34-38,共5页
主要对比分析了国外陶瓷砖自动液压压砖机中常见的几种充液阀结构及控制油路,阐明了充液阀通流面积和阀芯复位弹簧的计算方法。
关键词 缸外置式液阀 缸内置式液阀 无复位弹簧式液阀
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Design of dense gap-graded friction course mixture 被引量:2
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作者 吴旷怀 张肖宁 《Journal of Southeast University(English Edition)》 EI CAS 2006年第1期101-105,共5页
The design procedure of a dense gap-graded friction course(DGGFC) with coarse aggregate void filling method is presented. Testing results show that a DGGFC mixture possesses a dense stone-matrix structure, good stab... The design procedure of a dense gap-graded friction course(DGGFC) with coarse aggregate void filling method is presented. Testing results show that a DGGFC mixture possesses a dense stone-matrix structure, good stability and almost the same texture depth as stone matrix asphalt (SMA). It also has a coarse and even surface after paving and has no separation during construction. It is durable and impermeable. It balances and improves the inherent inconsistency of asphalt mixture between the large texture depth for skid resistance and the impermeability for durability. The actual application in the Nanning-Liuzhou Expressway also shows that the performance of the DGGFC is as excellent as that of SMA, while the DGGFC mixture is cheaper than SMA. The DGGFC mixture is good for wearing course of pavement. Further research on DGGFC can be helpful for improving the surface skid resistance, prolonging the life-span period and reducing the construction costs of asphalt pavement. 展开更多
关键词 dense gap-graded friction course (DGGFC) coarse aggregate void filling method dense stonematrix structure pavement performance
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一种变压器差动保护相位补偿的新方法
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作者 陈绍亮 陈晓彬 《广东科技》 2007年第11X期25-26,共2页
本文通过对不同相位补偿方法的比较,阐述了采用新相位补偿方法在主变空充时的优点。
关键词 相位补偿 差动保护 变压器 励磁涌流
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空分设备节能运行的优化 被引量:1
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作者 兰振强 《南钢科技与管理》 2017年第4期34-39,共6页
提高空分设备的利用率,减少放散损失,降低制造成本,确保空分设备节能运行,一直是钢铁企业制氧厂研究的重要课题。讲述了空分设备开车过程中,可结合主冷液氧液位高度与参与精馏的冷量富裕情况,通过液化装置对主冷返充液氧,来提高空分设... 提高空分设备的利用率,减少放散损失,降低制造成本,确保空分设备节能运行,一直是钢铁企业制氧厂研究的重要课题。讲述了空分设备开车过程中,可结合主冷液氧液位高度与参与精馏的冷量富裕情况,通过液化装置对主冷返充液氧,来提高空分设备的开车效率。介绍了水循环能耗控制所采取的诸多优化措施,并达到了节水降耗的效果。根据制氧厂现有设备配置特点,对氮气和氧气产品的增产实施创新改造。 展开更多
关键词 空分设备 水循环 增氮 增氧
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Completeness of Eigenfunction Systems for Off-Diagonal Infinite-Dimensional Hamiltonian Operators 被引量:15
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作者 侯国林 阿拉坦仓 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第2期237-241,共5页
For the off-diagonal infinite dimensional Hamiltonian operators, which have at most countable eigenvalues, a necessary and sufficient condition of the eigenfunction systems to be complete in the sense of Cauchy princi... For the off-diagonal infinite dimensional Hamiltonian operators, which have at most countable eigenvalues, a necessary and sufficient condition of the eigenfunction systems to be complete in the sense of Cauchy principal value is presented by using the spectral symmetry and new orthogonal relationship of the operators. Moreover, the above result is extended to a more general case. At last, the completeness of eigenfunction systems for the operators arising from the isotropic plane magnetoelectroelastic solids is described to illustrate the effectiveness of the criterion. The whole results offer theoretical guarantee for separation of variables in Hamiltonian system for some mechanics equations. 展开更多
关键词 Hamiltonian system infinite dimensional Hamiltonian operator COMPLETENESS Cauchy principalvalue magnetoelectroelastic solid
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Green House in Semi-arid Regions of Mexico
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作者 Maria de los Angeles Rechy Carvajal Emil von Roth Jose Alberto Murillo Rodriguez 《Journal of Environmental Science and Engineering(B)》 2016年第5期224-227,共4页
The subject structure was consisted of a proto-type house with plan dimensions of 8 m ×4 m. A variety of materials was used to the construction, with special emphasis on using environmentally friendly non-toxic m... The subject structure was consisted of a proto-type house with plan dimensions of 8 m ×4 m. A variety of materials was used to the construction, with special emphasis on using environmentally friendly non-toxic materials. The structure's core consisted of reinforced concrete frames with masonry infill walls. Inside faces of the walls and the roof's outside face were covered with proprietary composite panels, which are manufactured with a mixture of cement, volcanic ash, and local sawmill waste. These panels were analyzed for their physical and chemical properties, as well as for their resistance to decay and insects when subjected to extreme conditions for 15 years. The panels have also shown to provide thermal insulation and nonflammable when in direct contact with fire. The roof surface was further covered with a blend of local drought-resistant succulents and cacti. This study provides a detailed review of the construction process and materials employed. 展开更多
关键词 Prototype house thermal insulation non-combustible resistant to decay.
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Comparison of human amniotic fluid-derived and umbilical cord Wharton's Jelly-derived mesenchymal stromal cells: Characterization and myocardial differentiation capacity 被引量:9
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作者 Jing Bai Yuan Hu +4 位作者 Yi-Ru Wang Li-Feng Liu Jie Chen Shao-Ping Su Yu Wang 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2012年第2期166-171,共6页
Objective To compare the characterization and myocardial differentiation capacity of arnniotic fluid-derived mesenchymal stromal cells (AF MSCs) and umbilical cord Wharton's Jelly-derived mesenchymal stromal cells ... Objective To compare the characterization and myocardial differentiation capacity of arnniotic fluid-derived mesenchymal stromal cells (AF MSCs) and umbilical cord Wharton's Jelly-derived mesenchymal stromal cells (WJ MSCs). Methods The human AF MSCs were cultured from amniotic fluid samples obtained by amniocentesis. The umbilical cord WJ MSCs were obtained from Wharton's Jelly of umbilical cords of infants delivered full-term by normal labor. The morphology, growth curves, and analyses by flow cytometry of cell surface markers were compared between the two types of cells. Myocardial genes (GATA-4, c-TnT, a-actin, and Cx43) were detected by real-time PCR and the corresponding protein expressions were detected by Western blot analysis after myocardial induced in AF MSCs and WJ MSCs. Results Our findings revealed AF MSCs and WJ MSCs shared similar morphological characteristics of the fibroblastoid shape. The AF MSCs were easily obtained than the WJ MSCs and had a shorter time to reach adherence of 2.7 ± 1.6 days to WJ MSCs of 6.5 ± 1.8 days. The growth curves by MTT cytotoxic assay showed the AF MSCs had a similar proliferative capacity at passage 5 and passage 10. However, the proliferative capacities ofWJ MSCs were decreased at 5 passage relative to 10 passage. Both AF stem cells and WJ stem cells had the characteristics of mesenchymal stromal cells with some characteristics of embryonic stem cells. They express CD29 and CD105, but not CD34. They were positive for Class I major histocompatibility (MHC I) antigens (HLA-ABC), and were negative, or mildly positive, for MHC Class II (HLA-DR) antigen. Oct-4 was positive in all the two cells types. Both AF MSCs and WJ MSCs could differentiate along myocardium. The differentiation capacities were detected by the expression of GATA-4, c-TnT, a-actin, Cx43 after myocardial induction. Conclusions Both AF MSCs and WJ MSCs have the potential clinical application for myogenesis in cardiac regenerative therapy. 展开更多
关键词 Human amniotic fluid-derived ceUs Wharton's Jelly-derived cells Myocardial differentiation Mesenchymal stromal cells
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Projective Synchronization Between Two Nonidentical Variable Time Delayed Systems
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作者 冯存芳 汪映海 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第3期395-399,共5页
In this paper, we propose a method for the projective synchronization between two different chaotic systems with variable time delays. Using active control approach, the suitable controller is constructed to make the ... In this paper, we propose a method for the projective synchronization between two different chaotic systems with variable time delays. Using active control approach, the suitable controller is constructed to make the states of two different diverse time delayed systems asymptotically synchronize up to the desired scaling factor. Based on the Lyapunov stability theory, the sufficient condition for the projective synchronization is calculated theoretically. Numerical simulations of the projective synchronization between Maekey-Glass system and Ikeda system with variable time delays are shown to validate the effectiveness of the proposed algorithm. 展开更多
关键词 projective synchronization different time-delayed chaotic systems variable time delays
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