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| 1 | 国内MOOC研究现状的文献分析显示文摘MOOC(Massive Open Online Course)即'大规模在线开放课程',因其大规模和开放性等特点,已成为国内外互联网上的热点,与之相关的非正式言论和正式的学术研究纷至沓来。对MOOC实践和研究的深入分析既是MOOC现实发展的需要,也是其可持续发展的要求。国内MOOC的发展已然将成燎原之势,在相关实践中亮点与不足并存,与之对应的是,国内对MOOC的学术研究状况既有亮点,亦有较大的上升空间。本文试图在全球MOOC发展热潮的背景下,参照国外MOOC相关研究成果,梳理国内MOOC相关的学术和非学术文献,综合国内MOOC相关学术会议情况,探讨国内MOOC研究的特点和值得关注的问题。 | 郝丹 | 2013 | 中国远程教育2013，，21： | 398 |
| 2 | Origin of ore-forming fluids of the Dachang Sn-polymetallic ore deposit: Evidence from helium isotopes显示文摘The ore genesis model for the Dachang Sn-polymetallic ore deposit has long been in dispute, and the major debate focuses on whether the stratiform and massive orebodies formed during the Yanshanian magmatic-hydro-thermal event or they were products of Devonian syn-sedi-mentary exhalative-hydrothermal event. This note presents new helium isotope data from fluid inclusions of four pyrites and one fluorite. The pyrites were collected from the stratiform and massive orebodies in the deposit, and their 3He/4He ratios are significantly higher than 1, ranging from 1.7 to 2.5 Ra, which indicates a mantle component in the responsible hydrothermal fluids. It is suggested that the ore-forming fluids were a mixture of deep circulating seawater and a mantle-derived fluid, which are similar to many of those modern submarine hydrothermal fluids. In contrast, the fluorite, collected from a granite-related hydrothermal vein in the deposit, shows a low 3He/4He ratio of 0.7 Ra, which indicates no mantle component | Kuidong Zhao Shaoyong Jiang Hongquan Xiao Pei Ni | 2002 | Chinese Science Bulletin2002，47，12： | 28 |
| 3 | Prototype for 5G New Air Interface Technology SCMA and Performance Evaluation显示文摘Sparse code multiple access(SCMA) is a novel non-orthogonal multiple access scheme proposed to meet the challenging demand of the future 5G communications, especially in support of the massive connections. The coded bits from each data stream will be directly mapped as multi-dimensional SCMA codeword in complex domain and then spread onto the physical resource elements in a sparse manner. The number of codewords that can be nonorthogonally multiplexed in one SCMA block can be made much larger than the number of orthogonal resource elements therein, resulting in an overloaded system. The sparsity in the spreading pattern and the design in the multidimensional modulator jointly ensure the SCMA codewords can be robustly decoded with low complexity. In this paper, we focus on the low complexity receiver design and verified the superior of an SCMA system via simulations and real-time prototyping. Lab tests and field tests all show that SCMA is a promising candidate for 5G non-orthogonal multiple access which can provide up to 300% overloading that triples the whole system throughput while still enjoying the link performance close to orthogonal transmissions. | LU Lei CHEN Yan GUO Wenting YANG Huilian WU Yiqun XING Shuangshuang | 2015 | China Communications2015，12，S1： | 15 |
| 4 | Effective solutions to a global 3D visual system in networking environments显示文摘The development of Web-based global 3D visual system has made progresses. However, there exist few mature and effective ways for managing, transmitting and visualizing massive spatial data. Based on the related work, the paper illustrates the ellipsoidal quadtree technique for rapid access multi-scale and multiple level geographical data, integrates the streaming with level-of-detail rendering method for transmitting the data on the network, and im-plements large-scale terrain surface simplification using M-band wavelet transforms and mul-tiresolution triangulations. We fulfil a web-based global terrain visual system using COM com-ponents on the basis of the above techniques. The system has a good prospect in the military simulation and city plans. | ZHANG Liqiang1,2, ZHANG Yan3, YANG Chongjun2, LIU Suhong1, REN Yingchao2, RUI Xiaoping2 & LIU Donglin2 1. State Key Laboratory of Remote Sensing Sciences, School of Geography and Remote Sensing, Beijing Normal University, Beijing 100875, China 2. State Key Laboratory of Remote Sensing Sciences, Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 101001, China 3. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 101001, China | 2005 | Science China Earth Sciences2005，48，11： | 13 |
| 5 | 大型开放式网络课程与医学统计学教学改革显示文摘MOOC简介大型开放式网络课程(massive open online course,M OOC)是近年来在开放教育领域新出现的一种课程模式,具有大规模(massive)、开放性(open)和在线自主学习(online)等特点[1]。MOOC起源于开放教育资源运动。2008年,加拿大阿萨巴斯卡大学的George Siemens和加拿大国家研究委员会的Stephen Downes共同开设了第一门MOOC‘Connectivism and ConnectiveKnowledge(CCK08)’,课程上线后很快便吸引了超过2200名学员免费学习[2-3]。 | 陈雯 郝元涛 中山大学公共卫生学院医学统计学慕课团队 | 2015 | 中国卫生统计2015，32，5： | 13 |
| 6 | Massive presacral bleeding during rectal surgery: From anatomy to clinical practice显示文摘AIM: To investigate control of two different types of massive presacral bleeding according to the anatomy of the presacral venous system. METHODS: A retrospective review was performed in 1628 patients with middle or low rectal carcinoma who were treated surgically in the Department of Colorectal Surgery, Changhai Hospital, Shanghai, China from January 2008 to December 2012. In four of these patients, the presacral venous plexus (n = 2) or basivertebral veins (n = 2) were injured with massive presacral bleeding during mobilization of the rectum. The first two patients with low rectal carcinoma were operated upon by a junior associate professor and the source of bleeding was the presacral venous plexus. The other two patients with recurrent rectal carcinoma were both women and the source of bleeding was the basivertebral veins.RESULTS: Two different techniques were used to con-trol the bleeding. In the first two patients with massive bleeding from the presacral venous plexus, we used suture ligation around the venous plexus in the area with intact presacral fascia that communicated with the site of bleeding (surrounding suture ligation). In the second two patients with massive bleeding from the basivertebral veins, the pelvis was packed with gauze, which resulted in recurrent bleeding as soon as it was removed. Following this, we used electrocautery applied through one epiploic appendix pressed with a long Kelly clamp over the bleeding sacral neural foramen where was felt like a pit Electrocautery adjusted to the highest setting was then applied to the clamp to 'weld' closed the bleeding point. Postoperatively, the blood loss was minimal and the drain tube was removed on days 4-7. CONCLUSION: Surrounding suture ligation and epiploic appendices welding are effective techniques for controlling massive presacral bleeding from presacral venous plexus and sacral neural foramen, respectively. | Zheng Lou Wei Zhang Rong-Gui Meng Chuan-Gang Fu | 2013 | World Journal of Gastroenterology2013，19，25： | 11 |
| 7 | Massive haemorrhage in liver transplantation:Consequences,prediction and management显示文摘From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity(need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both proand anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shownimprovements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss. | Stuart Cleland Carlos Corredor Jia Jia Ye Coimbatore Srinivas Stuart A Mc Cluskey | 2016 | World Journal of Transplantation2016，6，2： | 11 |
| 8 | 5G通信测试技术挑战显示文摘第5代移动通信(5G)采用的大规模天线阵列、新型多址技术、全频谱接入、超密集组网、新型网络架构等关键技术给测试带来了巨大的挑战,为便于进一步的开展具体测试方案研究,本文从测试的角度提出了第5代移动通信测试技术体系结构,结合5G通信新的网络架构、新的空口要求,重点对5G通信的无线信道模拟与评估测试、Massive MIMO系统测试、新波形和多址方案测试、业务和系统级集中测试等测试技术的难点和挑战进行了论述。 | 詹建 | 2017 | 国外电子测量技术2017，36，5： | 11 |
| 9 | Antenna Selection and Power Allocation Design for 5G Massive MIMO Uplink Networks显示文摘Massive MIMO is one of the key technologies in future 5G communications which can satisfy the requirement of high speed and large capacity. This paper considers antenna selection and power allocation design to promote energy conservation then provide good quality of service(QoS) for the whole massive MIMO uplink network. Unlike previous related works, hardware impairment, transmission efficiency, and energy consumption at the circuit and antennas are involved in massive MIMO networks. In order to ensure the QoS, we consider the minimum rate constraint for each user and the system, which increases the complexity of power allocation problem for maximizing energy and spectral efficiency in massive MIMO system. To this end, a quantum-inspired social emotional optimization(QSEO) algorithm is proposed to obtain the optimal power control strategy in massive MIMO uplink networks. Simulation results assess the great advantages of QSEO which previous strategies do not have. | Hongyuan Gao Yumeng Su Shibo Zhang Ming Diao | 2019 | China Communications2019，16，4： | 10 |
| 10 | 基于TDM的大规模多天线信道测量系统的射频切换模块设计显示文摘传统大规模多天线(Massive MIMO)信道测量系统采用的是虚拟大规模多天线阵列,测量周期较长,测试环境要求静止,同步要求高并且需要修正天线阵元间互耦特性。针对于传统测量系统的不足构建了真实Massive MIMO信道测量系统,该系统相对于传统信道测量系统的不同在于TDM的射频切换模块和相应的天线阵列。射频切换模块主要包括时钟控制单元和射频切换单元,时钟控制单元产生控制矢量信号发生器的触发信号和控制射频切换单元的控制信号,射频切换单元则根据输入的控制信号快速切换不同的天线阵元。实验表明,该套设备大大缩短了测量时间,减轻了人力测试强度,降低了对测试环境和同步的要求并且测量结果包含天线之间的互耦影响,极大的增加了信道建模的准确性。 | 吴钰浩 陶成 刘留 雷勇 刘妍 | 2018 | 电子测量与仪器学报2018，32，3： | 10 |
| 11 | 5G MASSIVE MIMO技术显示文摘本文介绍了5G系统中MassiveMIMO技术的信道估计、预编码技术、信号检测算法,研究了不同算法的适用场景,分析了MassiveMIMO技术发展中存在的问题,重点阐述了导频污染产生的原因并提供了减少导频污染的思路,分析了信道模型设计中需要关注的问题、算法优化的方向等。 | 伍株仪 | 2019 | 电子技术与软件工程2019，，8： | 9 |
| 12 | Disruption of interstitial cells of Cajal networks after massive small bowel resection显示文摘AIM: To investigate the disruptions of interstitial cells of Cajal (ICC) in the remaining bowel in rats after massive small bowel resection (mSBR). METHODS: Thirty male Sprague-Dawley rats fitting entry criteria were divided randomly into three experimental groups (n = 10 each): Group A rats underwent bowel transection and re-anastomosis (sham) and tissue samples were harvested at day 7 post-surgery. Group B and C rats underwent 80% small bowel resection with tissue harvested from Group B rats at day 7 post-surgery, and from Group C rats at day 14 postsurgery. The distribution of ICC at the site of the resid-ual small bowel was evaluated by immunohistochemical analysis of small intestine samples. The ultrastructural changes of ICC in the remnant ileum of model rats 7 and 14 d after mSBR were analyzed by transmission electron microscopy. Intracellular recordings of slow wave oscillations were used to evaluate electrical pacemaking. The protein expression of c-kit, ICC phenotypic markers, and membrane-bound stem cell factor (mSCF) in intestinal smooth muscle of each group were detected by Western blotting. RESULTS: After mSBR, immunohistochemical analysis indicated that the number of c-kit-positive cells was dramatically decreased in Group B rats compared with sham tissues. Significant ultrastructural changes in ICC with associated smooth muscle hypertrophy were also observed. Disordered spontaneous rhythmic contractions with reduced amplitude (8.5 ± 1.4 mV vs 24.8 ± 1.3 mV, P = 0.037) and increased slow wave frequency (39.5 ± 2.1 cycles/min vs 33.0 ± 1.3 cycles/min, P = 0.044) were found in the residual intestinal smooth muscle 7 d post mSBR. The contractile function and electrical activity of intestinal circular smooth muscle returned to normal levels at 14 d post mSBR (amplitude, 14.9 ± 1.6 mV vs 24.8 ± 1.3 mV; frequency, 30.7 ± 1.7 cycles/min vs 33.0 ± 1.3 cycles/min). The expression of Mscf and c-kit protein was decreased at 7 d (P = 0.026), but gradually returned to normal levels at 14 d. The ICC and associated neural networks were disrupted, which was associated with the phenotype alterations of ICC. CONCLUSION: Massive small bowel resection in rats triggered damage to ICC networks and decreased the number of ICC leading to disordered intestinal rhythmicity. The mSCF/c-kit signaling pathway plays a role in the regulation and maintenance of ICC phenotypes. | Jie Chen Lei Du Yong-Tao Xiao Wei Cai | 2013 | World Journal of Gastroenterology2013，19，22： | 9 |
| 13 | Massive MIMO关键技术和应用部署策略初探显示文摘从移动通信技术的发展与业务发展的需求展开对5G的Massive MIMO技术讨论,主要介绍5G新型无线技术Massive MIMO技术原理,基于当前的研究进展讨论Massive MIMO的关键技术,并从理论性能展开分析,结合Massive MIMO试验数据,给出Massive MIMO的性能评估。最后通过Massive MIMO技术特点发展讨论当前无线网络应用Massive MIMO技术的部署场景、部署策略及演进分析。 | 韩玉楠 李轶群 李福昌 张香云 | 2016 | 邮电设计技术2016，，7： | 9 |
| 14 | Arthroscopic treatment options for irreparable rotator cuff tears of the shoulder显示文摘The management of patients with irreparable rotator cuff tears remains a challenge for orthopaedic surgeons with the final treatment option in many algorithms being either a reverse shoulder arthroplasty or a tendon transfer. The long term results of these procedures are however still widely debated, especially in younger patients. A variety of arthroscopic treatment options have been proposed for patients with an irreparable rotator cuff tear without the presence of arthritis of the glenohumeral joint. These include a simple debridement with or without a biceps tenotomy, partial rotator cuff repair with or without an interval slide, tuberplasty, graft interposition of the rotator cuff, suprascapular nerve ablation, superior capsule reconstruction and insertion of a biodegradable spacer(Inspace) to depress the humeral head. These options should be considered as part of the treatment algorithm in patients with an irreparable rotator cuff and could be used as either as an interim procedure, delaying the need for more invasive surgery in the physiologically young and active, or as potential definitive procedures in the medically unfit.The aim of this review is to highlight and summarise arthroscopic procedures and the results thereof currently utilised in the management of these challenging patients. | Cameron M Anley Samuel KL Chan Martyn Snow | 2014 | World Journal of Orthopedics2014，5，5： | 8 |
| 15 | 基于Massive MIMO的5G安全通信技术研究显示文摘随着现代信息安全和无线通信技术的高速发展,对于有广泛数据业务量的5G移动通信系统来说,将会有大量的机密、敏感信息在其通信系统中进行传输,所以安全问题越来越引起人们的关注,提供安全传输服务显得尤为重要。随着计算机不断增强的计算能力,传统的基于计算复杂度的加解密算法和密钥协商机制已经不能满足人们对于未来无线通信安全性的要求,而基于信号调制的方向调制技术因其无需考虑窃听者的计算能力,通过扰乱非期望方向上的信号星座图来实现安全传输的目的,成为了5G系统的重要研究点。在简单介绍了波束赋形的原理及其不足的基础上引出方向调制技术,并着重阐述了在大规模天线阵的前提下,基于天线子集选择和混合阵的方向调制技术实现安全传输目标的方法,并且从理论的角度说明了安全性能的提高。 | 吴敏 吴蒙 | 2017 | 计算机技术与发展2017，27，4： | 7 |
| 16 | A mouse model for SARS-CoV-2 infection by exogenous delivery of hACE2 using alphavirus replicon particles显示文摘Dear Editor,Since the outbreak of a novel coronavirus disease(COVID-19)in late 2019,it has spread rapidly and developed into a global pandemic.As of August 12,2020,more than 215 countries and territories around the world have reported more than 20.5 million confirmed COVID-19 cases with over 745,693 deaths(https://www.worldometers.info/coronavirus/#countries).Such harsh conditions urged scientists across the world to gear up to develop vaccines and antiviral drugs against COVID-19,which also lead to massive requirement for experimental animals. | Ya-Nan Zhang Xiao-Dan Li Zhe-Rui Zhang Hong-Qing Zhang Na Li Jing Liu Jia-Qi Li Hua-Jun Zhang Ze-Jun Wang Shuo Shen Zheng-Li Shi Hong-Ping Wei Zhi-Ming Yuan Han-Qing Ye Bo Zhang | 2020 | Cell Research2020，30，11： | 7 |
| 17 | User Assisted Cooperative Relaying in Beamspace Massive MIMO NOMA Based Systems for Millimeter Wave Communications显示文摘A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy efficiency for millimeter wave(mmWave)communications.A downlink system for M users,where base station(BS)is equipped with beamforming lens antenna structure having NRF radio frequency(RF)chains,has been considered.A dynamic cluster of users is formed within a beam and the intermediate users(in that cluster)between beam source and destination(user)act as relaying stations.By the use of successive interference cancellation(SIC)technique of NOMA within a cluster,the relaying stations relay the symbols with improved power to the destination.For maximizing achievable sum rate,transmit precoding and dynamic power allocation for both intra and inter beam power optimization are implemented.Simulations for performance evaluation are carried out to validate that the proposed system outperforms the conventional beamspace M-MIMO NOMA system for mmWave communications in terms of spectrum and energy efficiency. | Jaipreet Kaur Maninder Lal Singh | 2019 | China Communications2019，16，6： | 6 |
| 18 | Hybrid Precoding for mm Wave Massive MIMO Systems with Different Antenna Arrays显示文摘In this paper, the performance of hybrid precoding is investigated for mmWave massive MIMO systems with different antenna arrays. The hybrid precoding with partially connected architecture (PCA) is adopted. The spectral efficiency (SE) and received energy efficiency (EE) are investigated by considering four types of antenna arrays, including uniform linear array (ULA), uniform rectangular planar array (URPA), uniform hexagonal planar array (UHPA), and uniform circular planar array (UCPA), respectively. We focus on analysis at the antenna response vector and utilize the idea of orthogonal matching pursuit algorithm to seek the optimal hybrid precoder. Furthermore, the trade-off of precoding architectures is studied between SE and received EE. Simulation results show that if the uniform planar array antenna is more concentrated, the SE and receive EE will be higher. Considering SE and received EE, the performance of planar arrays outperform linear array. There exist different optimal radio-frequency chain numbers to maximize the SE for planar array and linear array. In addition, the PCA can achieve relatively higher received EE while the SE is close to the fully connected architecture and the full digital architecture. | Qingfeng Ding Yuqian Deng Xinpeng Gao Mengxia Liu | 2019 | China Communications2019，16，10： | 6 |
| 19 | 5G关键技术Massive MIMO及NOMA技术综述显示文摘随着移动通信的快速发展,移动互联网对网络性能提出了新的要求,4G网络已经无法满足移动通信网络业务发展需求,制定统一的5G标准已经成为共识,5G关键技术已经成为全球研发的焦点。本文总结了5G网络的性能指标和标准制定进展,介绍了国内外5G网络的商用计划,重点分析了富有前景的大规模MIMO天线、非正交多址技术(NOMA)两项潜在的5G关键技术的优势及目前所面临的挑战。 | 邢金柱 芦翔 | 2018 | 电子世界2018，0，2： | 6 |
| 20 | The“Double First Class”Initiative under Top-Level Design显示文摘In 2017,Chinese government launched a massive higher education initiative targeting at developing selected universities and disciplines into the world first-class universities as well as first-class disciplines in the world(abbreviated as the“Double First Class”initiative).The initiative was an ambitious higher education project following the existing“985”and“211”key projects. | Xiao Liu | 2018 | ECNU Review of Education2018，1，1： | 6 |
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