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| 1 | 5G承载网的需求、架构和解决方案显示文摘认为5G承载面临超大带宽、低时延、灵活连接、网络切片和超高精度时间同步等诸多挑战。分析了中兴通讯在5G承载技术方面的研究和创新,包括:基于FlexE的大带宽、低时延和业务隔离技术、满足5G泛在灵活连接的Segment Routing路由优化技术、基于网络切片的软件定义网络(SDN)架构和控制技术、超高精度时间同步技术等。 | 李光 赵福川 王延松 | 2017 | 中兴通讯技术2017，23，5： | 32 |
| 2 | Differences in symptoms and pre-hospital delay among acute myocardial infarction patients according to ST-segment elevation on electrocardiogram: an analysis of China Acute Myocardial Infarction (CAMI) registry显示文摘Background: Approximately 70% patients with acute myocardial infarction (AMI) presented without ST-segment elevation on electrocardiogram. Patients with non-ST segment elevation myocardial infarction (NSTEMI) often presented with atypical symptoms, which may be related to pre-hospital delay and increased risk of mortality. However, up to date few studies reported detailed symptomatology of NSTEMI, particularly among Asian patients. The objective of this study was to describe and compare symptoms and presenting characteristics of NSTEMI vs. STEMI patients. Methods: We enrolled 21,994 patients diagnosed with AMI from China Acute Myocardial Infarction (CAMI) Registry between January 2013 and September 2014. Patients were divided into 2 groups according to ST-segment elevation: ST-segment elevation (STEMI) group and NSTEMI group. We extracted data on patients' characteristics and detailed symptomatology and compared these variables between two groups. Results: Compared with patients with STEMI (N=16,315), those with NSTEMI (N=5679) were older, more often females and more often have comorbidities. Patients with NSTEMI were less likely to present with persistent chest pain (54.3% vs.71.4%), diaphoresis (48.6% vs.70.0%), radiation pain (26.4% vs.33.8%), and more likely to have chest distress (42.4% vs.38.3%) than STEMI patients (all P<0.0001). Patients with NSTEMI were also had longer time to hospital. In multivariable analysis, NSTEMI was independent predictor of presentation without chest pain (odds ratio: 1.974, 95% confidence interval:1.849-2.107). Conclusions: Patients with NSTEMI were more likely to present with chest distress and pre-hospital patient delay compared with patients with STEMI. It is necessary for both clinicians and patients to learn more about atypical symptoms of NSTEMI in order to rapidly recognize myocardial infarction. | Rui Fu Chen-Xi Song Ke-Fei Dou Jin-Gang Yang Hai-Yan Xu Xiao-Jin Gao Qian-Qian Liu Han Xu Yue-Jin Yang | 2019 | Chinese Medical Journal2019，，5： | 29 |
| 3 | Central hepatectomy for centrally located malignant liver tumors: A systematic review显示文摘AIM: To study whether central hepatectomy(CH) canachieve similar overall patient survival and disease-freesurvival rates as conventional major hepatectomies ornot.METHODS: A systematic literature search was per-formed in MEDLINE for articles published from January1983 to June 2013 to evaluate the evidence for andagainst CH in the management of central hepatic malig-nancies and to compare the perioperative variables andoutcomes of CH to lobar/extended hemihepatectomy. RESULTS: A total of 895 patients were included from21 relevant studies. Most of these patients who un-derwent CH were a sub-cohort of larger liver resectionstudies. Only 4 studies directly compared Central vshemi-/extended hepatectomies. The range of opera-tive time for CH was reported to be 115 to 627 min andPringle's maneuver was used for vascular control in themajority of studies. The mean intraoperative blood lossduring CH ranged from 380 to 2450 mL. The reportedmorbidity rates ranged from 5.1% to 61.1%, the most common surgical complication was bile leakage and the most common cause of mortality was liver failure. Mor-tality ranged from 0.0% to 7.1% with an overall mor-tality of 2.3% following CH. The 1-year overall survival(OS) for patients underwent CH for hepatocellular car-cinoma ranged from 67% to 94%; with the 3-year and 5-year OS having a reported range of 44% to 66.8%, and 31.7% to 66.8% respectively. CONCLUSION: Based on current literature, CH is a promising option for anatomical parenchymal-preserv-ing procedure in patients with centrally located liver malignancies; it appears to be safe and comparable in both perioperative, early and long term outcomes when compared to patients undergoing hemi-/extended hepatectomy. More prospective studies are awaited to further define its role. | Ser Yee Lee | 2014 | World Journal of Hepatology2014，6，5： | 15 |
| 4 | Plantlet regeneration of adult Pinus massoniana Lamb. trees using explants collected in March and thidiazuron in culture medium显示文摘A protocol for micropropagation using nodal explants from mature Pinus massoniana trees has been developed. Time of explant collection is crucial for the initial success of aseptic culture. Explants collected in early March gave the highest percentage of explant survival(64.5%) and shoot-forming percentage(52.3%). Thidiazuron(TDZ) concentration significantly influenced shoot formation; 4 μM TDZ was optimum, with 4.8 shoots produced per explant with a mean length of 7.1 cm after 120 days of culture. Regenerated shoots rooted for 60 days in basic medium with 1μM NAA were ready for growth in pots. This is the first report on plantlet regeneration in vitro from mature trees of P. massoniana that provides a reliable method for propagating selected elites. | Yin Wang Ruiling Yao | 2017 | Journal of Forestry Research2017，28，6： | 12 |
| 5 | 单目视觉下结构化车道实时检测显示文摘车道检测是高级驾驶员辅助系统的重要组成部分。本文对视频进行实时处理,实现对结构化车道线的实时检测。首先使用行方向的Sobel算子对处理区域进行边缘增强,接着在处理后的区域使用LSD(Line Segment Detector)进行线段提取,提取的线段集合包含代表车道线的线段。最后通过线段倾角以及相对位置过滤线段集合,并结合线段稳定帧数来筛选出最佳候选车道线。 | 胡忠闯 陈杰 顾兆伦 钱沄涛 | 2017 | 信号处理2017，33，4： | 8 |
| 6 | Segment Routing技术及其应用分析显示文摘SDN技术在未来网络重构中具有较明显的优势。Segment Routing作为IP路由技术的继承和创新,与SDN架构有机结合后能够很好地解决因为网络规模过大造成的控制层面压力过大问题。文中介绍Segment Routing技术的产生背景、技术优势和基本原理,并探讨其在通信网络中典型的应用场景。 | 刘强 石磊 | 2017 | 电信技术2017，，12： | 8 |
| 7 | Discovery of khondalite series from the western segment of Altyn Tagh and their petrological and geochronological studies显示文摘The khondalite series, which are characterized by aluminum-rich gneisses (schists) consisting of sillimanite-garnet-biotite-monzonite gneiss, garnet-biotite-monzonite gneiss, graphite-sillimanite-biotite schist, and garnet-amphibole two-pyroxene granulites occurring as lenses and layers within gneisses (schists), were discovered in Tula area of western segment of Altyn Tagh. The petrology and geochemistry indicate that the protoliths of aluminum-rich gneisses (schists) are aluminum-rich pelitic and pelitic arenaceous sedimentary rocks, the protoliths of basic granulites are continental tholeiitic basalts. Therefore, the khondalite series may be produced at continental margin. They had suffered granulitic facies metamorphism with peak temperatures of 700-850℃ and pressures of 0.8-1.2 GPa. The U-Pb and Pb-Pb isotopic dating of zircons provided the ages of 447-462 Ma representing the ages of peak granulitic metamorphism. The U-Pb dating of detrital zircons from aluminum-rich gneisses yielded older upper | 张建新 张泽明 许志琴 杨经绥 崔军文 | 2000 | Science China Earth Sciences2000，43，3： | 8 |
| 8 | ST-segment elevation: Distinguishing ST elevation myocardial infarction from ST elevation secondary to nonischemic etiologies显示文摘The benefits of early perfusion in ST elevation myocardial infarctions(STEMI) are established; howeverearly perfusion of non-ST elevation myocardial infarctions has not been shown to be beneficial. In additionST elevation(STE) caused by conditions other thanacute ischemia is common. Non-ischemic STE may beconfused as STEMI, but can also mask STEMI on electrocardiogram(ECG). As a result, activating the primarypercutaneous coronary intervention(pPCI) protocooften depends on determining which ST elevation patterns reflect transmural infarction due to acute coronary artery thrombosis. Coordination of interpreting theECG in its clinical context and appropriately activatingthe pPCI protocol has proved a difficult task in borderline cases. But its importance cannot be ignored, asreflected in the 2013 American College of CardiologyFoundation/American Heart Association guidelines concerning the treatment of ST elevation myocardial infarction. Multiples strategies have been tested and studiedand are currently being further perfected. No mattethe strategy, at the heart of delivering the best care lies rapid and accurate interpretation of the ECG. Here, we present the different patterns of non-ischemic STE and methods of distinguishing between them. In writing this paper, we hope for quicker and better stratification of patients with STE on ECG, which will lead to be bet-ter outcomes. | Alok Deshpande Yochai Birnbaum | 2014 | World Journal of Cardiology2014，6，10： | 7 |
| 9 | Risk stratification for ST segment elevation myocardial infarction in the era of primary percutaneous coronary intervention显示文摘Acute coronary syndromes presenting with ST elevation are usually treated with emergency reperfusion/revascularisation therapy. In contrast current evidence and national guidelines recommend risk stratification for non ST segment elevation myocardial infarction(NSTEMI) with the decision on revascularisation dependent on perceived clinical risk. Risk stratification for STEMI has no recommendation. Statistical risk scoring techniques in NSTEMI have been demonstrated to improve outcomes however their uptake has been poor perhaps due to questions over their discrimination and concern for application to individuals who may not have been adequately represented in clinical trials. STEMI is perceived to carry sufficient risk to warrant emergency coronary intervention [by primary percutaneous coronary intervention(PPCI)] even if this results in a delay to reperfusion with immediate thrombolysis. Immediate thrombolysis may be as effective in patients presenting early, or at low risk, but physicians are poor at assessing clinical and procedural risks and currently are not required to consider this. Inadequate data on risk stratification in STEMI inhibits the option of immediate fibrinolysis, which may be cost-effective. Currently the mode of reperfusion for STEMI defaults to emergency angiography and percutaneous coronary intervention ignoring alternative strategies. This review article examines the current risk scores and evidence base for risk stratification for STEMI patients. The requirements for an ideal STEMI risk score are discussed. | Richard A Brogan Christopher J Malkin Philip D Batin Alexander D Simms James M McLenachan Christopher P Gale | 2014 | World Journal of Cardiology2014，6，8： | 6 |
| 10 | Average recurrence intervals of strong earthquakes and potential risky segments along the Taiyuan-Linfen portion of the Shanxi graben system显示文摘Since the great 1303 Hongtong, Shanxi, earthquake of magnitude 8, 700 years have elapsed. To analyze the long-term seismic potential, this paper divides the Taiyuan-Linfen portion of the Shanxi graben system into 5 seismogenic segments. Based on data of historical earthquakes and GPS observation, the authors estimate mean seismic-moment rates and average recurrence intervals of strong earthquakes for the individual segments, and further analyze relative levels of current stress cumulation on the segments based on mapping b-values along the graben system by using the network seismic data for the recent over 30 years. The main result shows that the Linfen basin segment has an estimated mean seismic-moment rate of 2.21×1016 N·m/a to 3.03×1016 N·m/a, and its average recurrence interval for M=7.5 earthquake is estimated to be between 1 560 and 2 140 years. For the Lingshi-Hongtong segment, the estimated average recurrence interval for M=8 earthquakes is between 4 300 and 5 100 years, equivalent to having a mean moment-rate of 2.58×1016 N·m/a to 3.10×1016 N·m/a. The contour map of b-values shows that the two segments of Lingshi-Hongtong and Linfen basin have been being at low or relatively low stress levels, reflecting that since the 1303 M=8 and the 1695 M=7.5 earthquake ruptures, the fault-plane's strengths of the both segments have not been resumed yet. And the other two segments, the Houma and the Jiexiu-Fenyang, have relatively high stress levels, and have been already identified as potential risky segments for the coming earthquakes from the analysis combining with the estimated average recurrence intervals of earthquakes on the both segments. | 易桂喜 闻学泽 徐锡伟 | 2004 | Acta Seismologica Sinica(English Edition)2004，17，4： | 6 |
| 11 | Transfer of small chromosome fragments of Agropyron elongatum to wheat chromosome via asymmetric somatic hybridization显示文摘The chromosome constitution of hybrids and chromation patterns of Agropyro-nelelongatum(Host)Neviski in F5 somatic hybrid lines Ⅱ -1-3 and l-1-9 between Triticum aesti-vum L.and A.elongatum were analyzed.Based on the statistic data of pollen omther cells,F5 l-1-9 and Ⅱ-1-3 had 20—21 bivalents with a frequency of 84.66% and 85.28%,of which,89.83% and 89.57% were ring bivalents.The result indicated that both hybrid lines were basically stable in the chromosome constitution and behavior.RAPD analysis showed that the two hybrids contained biparental and integrated DNA.GISH(Genome in situ hybridization)revealed that in the form of small chromosome segments,A.elongatum chromatin was scattered on 4—6 wheat chromo-somes near by the region of centromere and telomere in the two hybrid lines.SSR analysis in-dicated that A.elongatum DAN segments were distributed on the 2A,5B,6B and 2D wheat chromosomes in the hybrids,which was in accordance with the GISH results that small-segments intercalated poly-site. | WANG Jing,XIANG Fengning,XIA Guangmin & CHEN Huimin School of Life Sciences,Shandong University,Jinan 250100,China | 2004 | Science China(Life Sciences)2004，47，5： | 5 |
| 12 | The diversity effect of inductive reasoning under segment manipulation of complex cognition显示文摘The present study proposed the idea of segment manipulation of complex cognition (SMCC), and technically made it possible the quantitative treatment and systematical manipula-tion on the premise diversity. The segment manipulation of complex cognition divides the previ-ous inductive strengths judgment task into three distinct steps, attempting to particularly distin-guish the psychological processes and their rules. The results in Experiment 1 showed that compared with the traditional method, the quantitative treatment and systematical manipulation of SMCC on the diversity did not change the task’s nature, and remain rational and a good measurement of inductive strength judgment. The results in Experiment 2 showed that the par-ticipants’ response rules in the triple-step task were expected from our proposal, and that in Step 2 the “feeling of surprise” (FOS), which seems implausible but predicted from the diversity premises, was measured, and its component might be the critical part that produced the diversity effect. The “feeling of surprise” may reflect the impact of emotion on cognition, representing a strong revision to premise probability principle of pure rational hypothesis proposed by Lo et al., and its roles in the diversity effect are worthy of further research. In this regards were discussed the mistakes that the premise probability principle makes when it takes posterity probability as prior probability. | CHEN Antao LI Hong FENG Tingyong GAO Xuemei ZHANG Zhongming LI Fuhong YANG Dong | 2005 | Science China(Life Sciences)2005，48，6： | 5 |
| 13 | K-Ar dating of extensional fault gouge from the Yi-Shu segment of the Tan-Lu fault zone显示文摘Two grabens were developed in the Yi-Shu segment of the Tan-Lu fault zone (TLFZ) during its exten-sional activities, and are now confined by four major NNE-trending normal faults and filled with Creta-ceous sediments. These faults were developed due to their reactivities, containing gouge and cutting the graben sediments. Detailed fieldwork demonstrates that the faults experienced sinistral transten-sional moment related to regional NE-SW extension during the reactivity. X-ray diffraction (XRD) analysis of the finest gouge samples gives illite crystallinity values higher than 0.42o?2θ, indicating temperatures experienced by the gouge samples were less than 150℃ . From the relation between K-Ar data and proportions of detrital illite in different size fractions of the gouge samples, we conclude that refaulting for the western boundary fault of the TLFZ, abbreviated to F4, took place at ca. 90 Ma and for the eastern boundary fault, abbreviated to F1, happened from 70 to 60 Ma. During the two phases of reactivity imposed by the same NE-SW extension, the TLFZ experienced uplifting and no sediments were deposited in the two grabens. It is suggested that the TLFZ experienced extension during the Late Cretaceous, which supports the inference that lithospheric thinning was still undergoing in the east of the North China Craton during the Late Cretaceous magmatic hiatus. | WANG YongSheng ZHU Guang HU ZhaoQi ZHANG BiLong XIANG BiWei XIE ChengLong | 2009 | Science China Earth Sciences2009，52，4： | 5 |
| 14 | Geochemical characteristics of the metapelites from the Xingxingxia group in the Eastern Segment of the Central Tianshan:Implications for the provenance and paleoweathering显示文摘Metapelites from the Mesoproterozoic Xingxingxia group in the Eastern Segment of the Central Tianshan, Northwestern China, were analyzed for major and trace elements, includ-ing rare earth elements. Compared with post-Archean shales, the metapelites are enriched in Sr, Hf and Zr. The other elements are similar to the compositions of the Phanerozoic North American Shale Composite and the Post-Archean Australian average Shale (PAAS). The characteristics of Al2O3/TiO2, Cr/Zr, Cr/Th, Th/Sc and high Zr concentration suggest that these pelites could be derived from a significant proportion of felsic and a few proportion of participation of mafic mate-rials in nature. These rocks display highly fractionated REE patterns, and average (La/Yb)n = 18.6. Several samples have slightly negative Eu anomalies (Eu/Eu* = 0.7―0.84) in comparison with PAAS (Eu/Eu* = 0.65), indicating contribution from young immature materials. The low K2O/Al2O3 values of these metapelites suggest that their source materials could contain minimal alkali feldspar. In the A-CN-K triangular diagram, the sample data array intersects the feldspar join, indicating that the source had a plagioclase: K-feldspar ratio of approximately 5:1, repre-senting weathered products from components that could approximately correspond to granodio-rites and tonalites. The low Chemical Index of Alteration (CIA) and high Index of Compositional Variability (ICV) values suggest low degrees of weathering of the source and low compositional maturity of the sediments, respectively. The geochemical characteristics of the metapelites from the Xingxingxia group also demonstrate that these sediments were deposited in a back-arc background within a continental-arc system. | LI Qiugen LIU Shuwen HAN Baofu WANG Yueran DANG Qingning | 2005 | Science China Earth Sciences2005，48，10： | 4 |
| 15 | FPN在高速列车接触网定位器检测应用显示文摘高速列车接触网的定位器夹持导线,在保证受电弓的受流质量方面发挥着关键的作用。近年来随着计算机视觉技术和硬件的快速发展,采用高清摄像头对接触网进行图像监测越来越普遍。特征网络金字塔(feature pyramid networks,FPN)可以将包含更加抽象、更多语义的深层卷积特征和更高分辨率、更多细节信息的浅层卷积特征融合,能够有效解决高速列车的接触网定位器因目标较小而导致检测效果较差的问题。首先研究了Faster R-CNN的目标检测算法,然后结合FPN算法思想对Faster R-CNN进行改进,提出了基于FPN+Faster R-CNN的高速列车接触网定位器检测模型。整个检测系统流程包含2步:首先利用FPN+Faster R-CNN对定位器关键区域进行初定位,然后在获得的关键区域内采用LSD(line segment detector)直线检测算法对定位器做精确检测。通过高速列车4C监测系统对列车某线路接触网采集的图像数据集实验分析,采用的基于FPN+Faster R-CNN定位器检测模型在检测精确率和回召率方面得到了很大程度的提高,同时具有较高的实时性。这对实现高速列车的接触网定位器快速而又准确的检测以及保障列车安全行驶具有重要的意义。 | 崔宵洋 林建辉 陈春俊 杨劼立 徐刚 | 2019 | 电子测量技术2019，42，15： | 4 |
| 16 | Strength behaviour of a model rock intersected by non-persistent joint显示文摘Several constructions in the field of civil engineering quite often need to deal with rocks.Strength behaviour of rock intersected by a discontinuity or a set of discontinuities has been a topic of keen interest for engineering community.The popular attributes of discontinuities that have been given due importance are their frequency,orientation and surface characteristics.Non-persistency,however,has been given little attention.This article presents an experimental study wherein focus has been made on the effect of non-persistency of the joint on the uniaxial compressive strength(UCS)of a model rock for various geometries such as orientation,discontinuity length ratio and number of joint segments.The applicability of single plane of weakness theory(SPWT)to assess the strength of jointed specimens has also been evaluated.It has been noticed that SPWT captures the strength behaviour only for a narrow range of discontinuity orientations.As an improvement,an approach is suggested by extending concepts of degree of persistence and joint factor to have a better understanding towards strength behaviour of rocks intersected by non-persistent joints. | Divya Shaunik Mahendra Singh | 2019 | Journal of Rock Mechanics and Geotechnical Engineering2019，11，6： | 4 |
| 17 | Sugar Starvation Enhances Leaf Senescence and Genes Involved in Sugar Signaling Pathways Regulate Early Leaf Senescence in Mutant Rice显示文摘To clarify the complex regulatory relationship between changes in sugar content and leaf senescence during the grain-filling stage of rice,genotype-dependent differences in sugar content and the temporal transcriptional patterns of genes involved in sugar signaling pathways were determined in mutant rice exhibiting early leaf senescence and its wild type Zhefu 142.The effects of exogenous glucose or sucrose on the senescence of detached leaves under dark conditions were also investigated.Chlorophyll,soluble sugar,sucrose and fructose contents decreased,whereas electrolytic leakage and malondialdehyde levels increased in mutant leaves at the grain-filling stage.These results suggested that sugar starvation is positively correlated with the early leaf senescence of mutant plants.Detached leaf segments incubated in exogenous sugar solutions under dark conditions exhibited delayed senescence.The high expression of Hxk1 in leaves of mutant plants at the initial grain-filling stage suggested that Hxk1 is involved in the hexose-sensing process at the early stage of leaf senescence.The low expression levels of Hxk2 and Frk1 in the senescing leaves of mutant rice during the grain-filling stage are indicative of weakened hexose phosphorylation.In addition,the high expression levels of Su Sy1,Su Sy2 and Su Sy4 in leaves of mutant plants at the initial grain-filling stage are accompanied by the high transcript levels of SUT1,which favor sucrose translocation and remobilization from the early senescing leaves of mutant rice.The relatively reduced transcript levels of ch FBP,cy FBP,SPS1,SPS2 and SPS6 indicated that during the grain-filling stage,sucrose biosynthesis is weakened in the senescing leaves of mutant rice. | LI Zhaowei ZHAO Qian CHENG Fangmin | 2020 | Rice science2020，27，3： | 4 |
| 18 | Left jackknife position:a novel position for laparoscopic hepatectomy显示文摘Background: Laparoscopic hepatectomy for hepatocellular carcinoma(HCC) located in segment Ⅵ, Ⅶ, or Ⅷ of the liver is usually difficult because of poor operative exposure, due to the unique anatomical structure. In this study, we evaluated the practice of laparoscopic hepatectomy with the left jackknife position for patients with HCC located in segment Ⅵ, Ⅶ, or Ⅷ.Methods: A total of 10 patients were enrolled to undergo laparoscopic hepatectomy with the left jackknife position.Tumors located in segment Ⅵ, Ⅶ, or Ⅷ were assessed by preoperative dynamic computed tomography or magnetic resonance imaging. Operation time, intraoperative blood loss, postoperative fasting time, postoperative drainage time, major postoperative complications, and duration of postoperative hospital stay were recorded.Results: All surgeries were successfully completed. None of the patients required conversion to open surgery during the procedure, and no serious postoperative complications were observed.The median tumor size was 31 mm(range 23-41 mm) in diameter, the mean operation time was 166 ± 38 min, the mean intraoperative blood loss was220 ± 135 mL, and the median postoperative hospital stay was 4 days(range 2-7 days).Conclusions: For HCC located in segment Ⅵ, Ⅶ, or Ⅷ, laparoscopic hepatectomy with this novel position—the left jackknife position—is safe and effective during tumor resection by exposing a sufficient operating field.Trial registration ClinicalTrials.gov ID: | Jian-Cong Chen Rong-Xin Zhang Min-Shan Chen Li Xu Jin-Bin Chen Ke-Li Yang Yao-Jun Zhang Zhong-Guo Zhou | 2017 | Chinese Journal of Cancer2017，36，8： | 4 |
| 19 | A sparse matrix model-based optical proximity correction algorithm with model-based mapping between segments and control sites显示文摘Optical proximity correction (OPC) is a key step in modern integrated circuit (IC) manufacturing.The quality of model-based OPC (MB-OPC) is directly determined by segment offsets after OPC processing.However,in conventional MB-OPC,the intensity of a control site is adjusted only by the movement of its corresponding segment;this scheme is no longer accurate enough as the lithography process advances.On the other hand,matrix MB-OPC is too time-consuming to become practical.In this paper,we propose a new sparse matrix MB-OPC algorithm with model-based mapping between segments and control sites.We put forward the concept of 'sensitive area'.When the Jacobian matrix used in the matrix MB-OPC is evaluated,only the elements that correspond to the segments in the sensitive area of every control site need to be calculated,while the others can be set to 0.The new algorithm can effectively improve the sparsity of the Jacobian matrix,and hence reduce the computations.Both theoretical analysis and experiments show that the sparse matrix MB-OPC with model-based mapping is more accurate than conventional MB-OPC,and much faster than matrix MB-OPC while maintaining high accuracy. | Bin LIN Xiao-lang YAN Zheng SHI Yi-wei YANG | 2011 | Journal of Zhejiang University-Science C(Computers and Electronics)2011，12，5： | 4 |
| 20 | Synthesis of waterborne polyurethane using snow as dispersant:Structures and properties controlled by polyols utilization显示文摘waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively characterized in terms of thermal, mechanical properties, hydrophilic behavior and morphology. Snowwas chosen as dispersant instead of comm only used water. Preparation param eters such as intrinsic properties and molecular weight of polyols were discussed systematically. A chain structure was confirmed by Fourier transform infrared (FT-IR) spectroscopy. when com paring the nature of the polyols (PPG, PEG and PNA, 2000g/mol) of this study, as-synthesized polyether waterborne polyurethane provided higher solid content, viscosity and water-resistance. However, polyester waterborne polyurethane perform ed differently and it exhibited higher therm al stability and crystallinity. When com paring the samples (WPU-N210, WPU-N220, WPU-N230 and WPU-N240) with different molecular weight of the same polyol (PPG) used as soft segment, the emulsion WPU-N220 with molecular weight of 2000g/mol PPG provided the highest solid content and lowest viscosity. It was observed th at particle size was uniform and highly dispersed for all sam ples from TEM images. Therm ogravim etric, differential scanning calorim etry (DSC) and X-ray diffraction results dem onstrated that the emulsion WPU-N230 with m olecular weight of 3000 g/mol PPG possessed higher therm al stability and crystallinity than the other samples. The reason was that the Tg and thermal stability were increased with increasing molecular weight. when molecular weight increased, the arrangem ent of soft segm ent became more regular and so did the regularity of the molecular chains. This work demonstrated that different polyols as soft segment applied could lead to great differences in the structure and property of the resulting WPU. | Changqing Fang Shaofei Pan Zhen Wang Xing Zhou Wanqing Lei Youliang Cheng | 2019 | Journal of Materials Science & Technology2019，35，7： | 4 |
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