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大偏角短引渠侧向进水泵站流场流态优化
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作者 奚斌 王欣昱 +7 位作者 张雄伟 徐健 陈志刚 沈世煊 陈叶欣 宋梓豪 连延续 吉睿 《中国农村水利水电》 北大核心 2024年第9期115-122,129,共9页
为了改善大偏角短引渠侧向进水泵站前池、进水池内偏流、回流和漩涡等不良流态,以某大型大偏角短引渠侧向进水泵站工程为研究对象,采用物理模型试验和数值模拟相结合的方式对初步设计方案下的前池、进水池流态进行分析,提出流速偏差系... 为了改善大偏角短引渠侧向进水泵站前池、进水池内偏流、回流和漩涡等不良流态,以某大型大偏角短引渠侧向进水泵站工程为研究对象,采用物理模型试验和数值模拟相结合的方式对初步设计方案下的前池、进水池流态进行分析,提出流速偏差系数λ作为评价指标,对工程进行优化,探讨前池的结构性改造对水流的整流效果,得出“弧形隔墩+改变底坡坡度+开设消涡孔”的组合方案为推荐整流方案,有效解决了前池及进水池内原设计存在的不良流态。研究结果表明,该整流方案使各个机组进水池偏差系数分别下降了37.03%、12.99%、22.29%、22.04%,显著改善了前池,进水池流态。研究结果可为类似大偏角短引渠侧向进水泵站前池及进水池流场流态优化提供参考,也可为类似短引渠泵站工程和进水建筑物的设计提供参考。 展开更多
关键词 大偏角短引 侧向进水泵站 整流 前池 数值模拟
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奶牛子宫角细短引起不孕1例
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作者 王伟红 《畜牧与兽医》 北大核心 2003年第4期46-46,共1页
关键词 不孕症 症状 剖检变化 治疗 奶牛 子宫角细短引
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短套管二元引射喷管设计及气动与红外特性数值研究 被引量:6
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作者 刘福城 吉洪湖 +1 位作者 斯仁 刘常春 《红外技术》 CSCD 北大核心 2013年第10期623-628,664,共7页
数值模拟的方法研究了短套管二元引射喷管几何参数(LW、LN和间距比)变化对推力特性的影响,优选出了短套管二元引射喷管几何参数的选取范围,并计算了优选结构下短套管二元引射喷管在3~5 m波段的红外辐射特性,且与轴对称喷管、二元喷管... 数值模拟的方法研究了短套管二元引射喷管几何参数(LW、LN和间距比)变化对推力特性的影响,优选出了短套管二元引射喷管几何参数的选取范围,并计算了优选结构下短套管二元引射喷管在3~5 m波段的红外辐射特性,且与轴对称喷管、二元喷管和长套管二元引射喷管进行了对比。排气系统的流场采用了商用软件计算,红外辐射特征采用了自主开发的软件(NUAA-IR)进行计算。结果表明:短套管二元引射喷管相对长套管二元引射喷管具有更好的推力特性和红外抑制效果。 展开更多
关键词 套管二元射喷管 推力特性 红外辐射特性 几何参数
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新氢缓冲罐引压上短管开裂原因分析 被引量:1
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作者 严子韬 《化工机械》 CAS 2019年第2期213-215,221,共4页
为查明新氢缓冲罐引压上短管开裂的原因,对开裂的引压上短管进行了检验分析。结果表明:短管在焊接过程中热输入较大,导致焊缝热影响区产生了大量的魏氏体,晶粒粗大,材料脆化;短管长时间带压运行,内壁在氢气和应力的共同作用下产生微裂纹... 为查明新氢缓冲罐引压上短管开裂的原因,对开裂的引压上短管进行了检验分析。结果表明:短管在焊接过程中热输入较大,导致焊缝热影响区产生了大量的魏氏体,晶粒粗大,材料脆化;短管长时间带压运行,内壁在氢气和应力的共同作用下产生微裂纹,裂纹不断扩展,最终开裂。 展开更多
关键词 缓冲罐 压上 魏氏体 氢致开裂
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高速舰用燃气轮机超短型排气引射装置的研究与应用 被引量:7
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作者 王小玲 《船舶》 2005年第5期35-40,共6页
在研制我国首制舰用燃气轮机超短型排气引射装置的过程中,作者通过理论研究和大量的模型试验,成功设计了超短型排气引射装置。本文阐述了超短型排气引射装置成功设计的要领,并给出实艇应用实例。对燃气轮机舰用化发展起到了推动作用。
关键词 高速舰用燃气轮机 常规排气射装置 型排气射装置
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Factors relating to the short term effectiveness of percutaneous biliary drainage for hilar cholangiocarcinoma 被引量:4
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作者 Hong-Ming Tsai Chiao-Hsiung Chuang +1 位作者 Xi-Zhang Lin Chiung-Yu Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第41期5206-5210,共5页
AIM: To identify factors that were related to the short term effectiveness of percutaneous transhepatic biliary drainage in cholangiocarcinoma patients and to evaluate the impact of palliative drainage on their surviv... AIM: To identify factors that were related to the short term effectiveness of percutaneous transhepatic biliary drainage in cholangiocarcinoma patients and to evaluate the impact of palliative drainage on their survival. METHODS: Seventy-four patients with hilar cholangiocarcinoma who underwent percutaneous biliary drainage were enrolled in the study. The demographic and laboratory data as well as the imaging characteristics were retrospectively analyzed to correlate with the bile output and reduction rate of serum bilirubin 1 wk after drainage.RESULTS: Patients with more bile duct visualized on percutaneous transhepatic cholangiography or absence of multiple liver metastases on imaging studies had more bile output after biliary drainage [odds ratio (OR): 8.471, P = 0.010 and OR: 1.959, P = 0.022, respectively]. Patients with prolonged prothrombin time had a slow decrease in serum bilirubin (OR: 0.437, P = 0.005). The median survival time was not signif icantly different in patients with low or high bile output (75 d vs 125 d, P = 0.573) or in patients with slow or rapid reduction of serum bilirubin (88 d vs 94 d, P = 0.576). CONCLUSION: The short term effectiveness of percutaneous biliary drainage was related to patient's prothrombin time or the extent of tumor involvement. It, however, had no impact on survival. 展开更多
关键词 CHOLANGIOCARCINOMA Percutaneous biliary drainage Treatment effectiveness
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Effects of rainfall regime and its character indices on soil loss at loessial hillslope with ephemeral gully 被引量:5
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作者 HAN Yong ZHENG Fen-li XU Xi-meng 《Journal of Mountain Science》 SCIE CSCD 2017年第3期527-538,共12页
Understanding the relationship between hillslope soil loss with ephemeral gully and rainfall regime is important for soil loss prediction and erosion control. Based on 12-year field observation data, this paper quanti... Understanding the relationship between hillslope soil loss with ephemeral gully and rainfall regime is important for soil loss prediction and erosion control. Based on 12-year field observation data, this paper quantified the rainfall regime impacts on soil loss at loessial hillslope with ephemeral gully. According to three rainfall parameters including precipitation (P), rainfall duration (t), and maximum 30-minute rainfall intensity (I30), 115 rainfall events were classified by using K-mean clustering method and Discriminant Analysis. The results showed that 115 rainfall events could be divided into three rainfall regimes. Rainfall Regime 1 (RR1) had large I30 values with low precipitation and short duration, while the three rainfall parameters of Rainfall Regime 3 (RR3) were inversely different compared with those of RR1; for Rainfall Regime 2 (RR2), the precipitation, duration and Iso values were all between those of RR1 and RR3. Compared with RR2 and RR3, RR1 was the dominant rainfall regime for causing soil loss at the loessial hillslope with ephemeral gully, especially for causing extreme soil loss events. PI30 (Product of P and Izo) was selected as the key index of rainfall characteristics to fit soil loss equations. Two sets of linear regression equations between soil loss and Plzo with and without rainfall regime classification were fitted. Compared with the equation without rainfall regime classification, the cross validation results of the equations with rainfall regime classification was satisfactory. These results indicated that rainfall regime classification could not only depict rainfall characteristics precisely, but also improve soil loss equation prediction accuracy at loessial hillslope with ephemeral gully. 展开更多
关键词 Rainfall regime Soil loss Rainfall character indices Loessial hillslope Ephemeral gully
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Is spleen circulation impaired in systemic sclerosis and what is the role of liver fibrosis? 被引量:1
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作者 Giovanni Tarantino Angelo Spanò +5 位作者 Gabriella Loi Anna Parisi Marianna Tarantino Giuseppina Brancaccio Giovanni Battista Gaeta Antonio Riccio 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第12期1606-1613,共8页
AIM:To investigate the spleen vascular involvement and the presence of liver fibrosis in a population of subjects with established systemic sclerosis(SSc).METHODS:In a cross-sectional fashion,17 patients with SSc were... AIM:To investigate the spleen vascular involvement and the presence of liver fibrosis in a population of subjects with established systemic sclerosis(SSc).METHODS:In a cross-sectional fashion,17 patients with SSc were compared with 18 patients suffering from hepatitis C virus(HCV) -related liver cirrhosis,grade A and B Child-Pugh classification.Eighteen non elderly subjects,apparently healthy,were used as the control group.Splenic artery resistivity index(SARI) at doppler ultraSound,transient elastography of liver and nailfold capillaroscopy were the main outcomes.RESULTS:Transient elastography values of SSc patients were similar to those of controls;5.2±1.1 vs 4.5 ±1,(P=0.07).Median Alanine amino transferase(ALT) concentrations of cirrhotic patients were greater than those of controls and SSc patients,i.e.66.5(36-89) U/L vs 29(22-34) U/L and 31(22-41) U/L,respectively,(P =0.005).SARI determinations in cirrhotic patients,although significantly higher than those found in controls and SSc patients,showed some degree of overlap with SSc patients,i.e.0.59 vs 0.52 and 0.57,respectively,(P =0.04).Mean systolic blood pressure was significantly higher in SSc patients than in cirrhotics and controls,i.e.142 mmHg vs 128.2 mmHg and 127 mmHg,respectively,(P=0.005).Mean diastolic blood pressure behaved in a similar fashion,i.e.84 mmHg vs 72.2 mmHg and 76.9 mmHg(P=0.005).Nailfold Capillaroscopy grades and diastolic blood pressure values correlated well with SARI results.CONCLUSION:An enhanced resistivity of the splenic artery was found in patients suffering from SSc;they did not have evidence of splenomegaly as well as no liver fibrosis or any other form of liver damage. 展开更多
关键词 Splenic artery resistivity index Doppler ultrasound Transient elastography Nailfold capillaroscopy Systemic sclerosis Liver fibrosis
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Thermal Energy of Confined Gravitons can Vary Cold Geodesic Curves
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作者 Igor E. Bulyzhenkov 《Journal of Physical Science and Application》 2014年第7期468-474,共7页
Internal energy of real warm bodies can change their kinetic-potential energy balance on Keplerian orbits and relativistic geodesic. Chiral nature of the mass results in chirality of gravitons and their energy confine... Internal energy of real warm bodies can change their kinetic-potential energy balance on Keplerian orbits and relativistic geodesic. Chiral nature of the mass results in chirality of gravitons and their energy confinement within the constant energy charge of a moving thermodynamical body. Zero energy-momentum gravitons provide dissipative self-heating and spiral fall of massive stars on gravitating centers. Computed self-heating of the pulsar PSR B1913+16 quantitatively describes its period decay without an outward emission of metric waves in question. Deviation of warm bodies from geodesic trajectories of cold point matter complies with Einstein's directives toward pure field physics of material space plenum without metric singularities. 展开更多
关键词 Zero particles chiral graviton SELF-HEATING thermal time evolution.
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鸦衔孤寂短,雁引明空长
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作者 文远 《读写月报(初中版)》 2011年第3期10-11,共2页
【注释】天净沙:曲牌名。残霞:晚霞。寒鸦:天寒归林的乌鸦。飞鸿影下:雁影掠过。
关键词 中学 课外阅读 阅读材料 《鸦衔孤寂 明空长》
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氨氧化炉常见问题分析及处理措施
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作者 李苏军 《中氮肥》 2020年第1期17-19,共3页
重庆飞华环保科技有限责任公司270kt/a双加压法稀硝酸装置作为BASF重庆MDI一体化项目系列生产装置之一,其生产情况较为特殊,几乎每月都要开停车1次,由此造成氨氧化炉运行中出现了各类事故。着重介绍2015年1月装置投产以来氨氧化炉运行... 重庆飞华环保科技有限责任公司270kt/a双加压法稀硝酸装置作为BASF重庆MDI一体化项目系列生产装置之一,其生产情况较为特殊,几乎每月都要开停车1次,由此造成氨氧化炉运行中出现了各类事故。着重介绍2015年1月装置投产以来氨氧化炉运行中出现的各类事故--过热盘管出口与出口集箱焊缝频繁出现裂纹、氧化炉温度探头环形切断、氧化炉催化剂筐严重弯曲变形、氧化炉引压短管出现腐蚀,分析与探究出现上述事故的原因,并阐述所采取的应对措施。 展开更多
关键词 氨氧化炉 焊缝裂纹 温度探头切断 催化剂筐变形 管腐蚀 问题描述 原因分析 解决方案
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Beasts of the Devil, Perishables, and the Natura Morta
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作者 Gregory Chan 《Journal of Literature and Art Studies》 2013年第6期391-394,共4页
Bugs have long embodied that from which we seek protection. Whether a mild irritant (a "fly in the ointment"), a costly pest to gardeners ("bug of W"), or a destructive force of Biblical proportions (a swarm ... Bugs have long embodied that from which we seek protection. Whether a mild irritant (a "fly in the ointment"), a costly pest to gardeners ("bug of W"), or a destructive force of Biblical proportions (a swarm of locusts), bugs are nature's warning of approaching death. This paper investigates the natura morta canvas during the Golden Age of Dutch art, focusing on how these symbols of natural evil work to enliven the visual rhetoric of the still-life as they invite spiritual contemplation. In religious-themed art, we intuitively recognize these morbid creatures as symbols of decay encroaching on domestic scenes filled with food and cut flowers. Emphasizing the short life of these perishables, bugs embody a classic tension and its dichotomous variations: the corporeal vs. the spiritual, earth vs. heaven, and sin vs. redemption. Though ostensibly a peripheral feature of the natura morta, bugs are a decidedly central motif that reflects the viewer's struggle with sin: Is it repellent, attractive, or repellently attractive? This study will concern the visual rhetoric of flies, dragonflies, and bees in the works of Osias Beert, Ambrosius Bosschaert, and Georg Flegel, with an emphasis on the beasts of the devil as icons of Dutch art. 展开更多
关键词 still-life Dutch paintings religious art DEATH
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Clinical role of non-invasive assessment of portal hypertension 被引量:12
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作者 Massimo Bolognesi Marco Di Pascoli David Sacerdoti 《World Journal of Gastroenterology》 SCIE CAS 2017年第1期1-10,共10页
Measurement of portal pressure is pivotal in the evaluation of patients with liver cirrhosis. The measurement of the hepatic venous pressure gradient represents the reference method by which portal pressure is estimat... Measurement of portal pressure is pivotal in the evaluation of patients with liver cirrhosis. The measurement of the hepatic venous pressure gradient represents the reference method by which portal pressure is estimated. However, it is an invasive procedure that requires significant hospital resources, including experienced staff, and is associated with considerable cost. Non-invasive methods that can be reliably used to estimate the presence and the degree of portal hypertension are urgently needed in clinical practice. Biochemical and morphological parameters have been proposed for this purpose, but have shown disappointing results overall. Splanchnic Doppler ultrasonography and the analysis of microbubble contrast agent kinetics with contrast-enhanced ultrasonography have shown better accuracy for the evaluation of patients with portal hypertension. A key advancement in the non-invasive evaluation of portal hypertension has been the introduction in clinical practice of methods able to measure stiffness in the liver, as well as stiffness/congestion in the spleen. According to the data published to date, it appears to be possible to rule out clinically significant portal hypertension in patients with cirrhosis (i.e., hepatic venous pressure gradient &#x02265; 10 mmHg) with a level of clinically-acceptable accuracy by combining measurements of liver stiffness and spleen stiffness along with Doppler ultrasound evaluation. It is probable that the combination of these methods may also allow for the identification of patients with the most serious degree of portal hypertension, and ongoing research is helping to ensure progress in this field. 展开更多
关键词 Portal hypertension Splenic stiffness Liver stiffness Splenic arterial resistance indices SONOGRAPHY Doppler ultrasound CIRRHOSIS Transient elastography Esophageal varices
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34例奶牛顽固性瓣胃阻塞的诊治 被引量:1
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作者 李忠显 《畜牧与兽医》 北大核心 2016年第7期142-143,共2页
奶牛瓣胃阻塞是因前胃迟缓,瓣胃收缩力减弱,瓣胃内容物滞留,水分被吸收而干涸,致使瓣胃秘结和扩张的一种疾病。对慢性不完全阻塞病例,采用增强前胃运动机能,促进瓣胃内容物软化与排出等保守疗法,经过1~2周的治疗多数可治愈。但顽固性... 奶牛瓣胃阻塞是因前胃迟缓,瓣胃收缩力减弱,瓣胃内容物滞留,水分被吸收而干涸,致使瓣胃秘结和扩张的一种疾病。对慢性不完全阻塞病例,采用增强前胃运动机能,促进瓣胃内容物软化与排出等保守疗法,经过1~2周的治疗多数可治愈。但顽固性完全阻塞病例,常发病急、病情重、病程短引起瓣小叶坏死及败血症,5~8 d后卧地不起,陷入昏迷。 展开更多
关键词 瓣胃阻塞 前胃迟缓 胃内容物 短引 运动机能 蠕动音 传导麻醉 兽医院 收缩力 酸臭味
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人民币币值何去何从?
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作者 黄有光 《上海企业》 2014年第8期44-44,共1页
由于人民币在升值多年后,连接几个月对美元下跌,共约3%左右,引发人们对人民币是否可能继续贬值的热议。在此"恭疏短引",为一己之见。根据笔者对中国经济的认识与对报道的阅读,认为这次的升值,是中国央行(中国人民银行)为了减少热钱... 由于人民币在升值多年后,连接几个月对美元下跌,共约3%左右,引发人们对人民币是否可能继续贬值的热议。在此"恭疏短引",为一己之见。根据笔者对中国经济的认识与对报道的阅读,认为这次的升值,是中国央行(中国人民银行)为了减少热钱进入,故意使人民币贬值,以改变人们对人民币单向升值的预期。当然,也不否定,在贬值后,可能有市场投机者担心人民币进一步贬值,而加大贬值的市场压力。 展开更多
关键词 一己之见 短引 升值空间 双向波动 出口产品 成长率 财富分配 数据显示 十年
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全城向上看 上上酒吧济南店
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《城色》 2012年第9期13-13,共1页
上上酒吧是全国著名的酒吧连锁企业,酒吧宽敞明亮风格独特,是中外文化与时尚完美结合,上上酒吧秉承了工业区颓废与华丽、个性与自由、张扬与艺术等特点,酒吧内后工业时代与新古典主义完美结合的装修风格。时尚跳动的欧美音乐,上上酒吧... 上上酒吧是全国著名的酒吧连锁企业,酒吧宽敞明亮风格独特,是中外文化与时尚完美结合,上上酒吧秉承了工业区颓废与华丽、个性与自由、张扬与艺术等特点,酒吧内后工业时代与新古典主义完美结合的装修风格。时尚跳动的欧美音乐,上上酒吧以充满个性,健康阳光,崇尚艺术,独特的音乐文化得到社会各界的认可装修风格前卫,每一处细节都可看出独具匠心的设计,干净且舒适。酒柜里的酒,品种齐全。专业DJ师,让你很快融入明快的音乐中,闻歌起舞。严谨规范的管理模式,成就了贴心服务,让您倍感舒心。劲爆的音乐,靓丽的美女,绝对的帅哥,保证让你度过开心、难忘的一夜! 展开更多
关键词 装修风格 卿实 目脚 中外文化 名时 短引 管理模式
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贴片元器件知识问答(下)
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作者 刘伟 《家电检修技术》 2014年第11期63-64,共2页
问3:什么是贴片元器件以及它的分类是怎样的?(续) 答:(1)贴片元器件的判断贴片元器件的判断贴片元器件的判断,只看"个头儿"不够,还得看"引脚与焊盘的关系应是表面组装"、"引脚是无引线或短引线"的才是贴片元器件。贴片集... 问3:什么是贴片元器件以及它的分类是怎样的?(续) 答:(1)贴片元器件的判断贴片元器件的判断贴片元器件的判断,只看"个头儿"不够,还得看"引脚与焊盘的关系应是表面组装"、"引脚是无引线或短引线"的才是贴片元器件。贴片集成电路"个头儿"不小就是一个很好的例子。 展开更多
关键词 有源器件 知识问答 无源元件 短引 尺寸规格 线或 行输出变压器 封装尺寸 彩色显像管 计量单位
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Existence of Global Attractor for LS Type Equations
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作者 张瑞凤 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2006年第4期708-714,共7页
The global attractor problem of the long-short wave equations with periodic boundary condition was studied. The existence of global attractor of this problem was proved by means of a uniform a priori estimate for time.
关键词 long-short wave equations a priori estimate global attractor.
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