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Evolution of associating liver partition and portal vein ligation for staged hepatectomy: Simpler, safer and equally effective methods 被引量:14
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作者 Shu-You Peng Xu-An Wang +4 位作者 Cong-Yun Huang You-Yong Zhang Jiang-Tao Li De-Fei Hong Xiu-Jun Cai 《World Journal of Gastroenterology》 SCIE CAS 2017年第23期4140-4145,共6页
Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS) has been recently demonstrated as a method to induce rapid and extensive hypertrophy within a short time and has been employed for a v... Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS) has been recently demonstrated as a method to induce rapid and extensive hypertrophy within a short time and has been employed for a variety of primary and metastatic liver tumors. However, controversies remain due to its high morbidity and mortality. To enable safer surgery, liver surgeons have searched for better technical modifications, such as partial ALPPS, mini-ALPPS, minimally invasive ALPPS, and Terminal branches portal vein Embolization Liver Partition for Planned hepatectomy(TELPP). It seems that TELPP is very promising, because it has the main advantage of ALPPS-the rapid increase of future liver remnant volume, but the morbidity and mortality are much lower because only one surgical operation is required. 展开更多
关键词 Associating liver partition and portal vein ligation for staged hepatectomy Terminal branches portal vein embolization Terminal branches portal vein embolization liver partition for planned hepatectomy Transarterial chemoembolization
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Asymptotic Behavior of Super Brownian Motion
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作者 阎国军 马建国 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第3期9-17,共9页
Generally, super Brownian motion will not c on verge vaguely to 0 if the initial measure is sufficiet large, so it is very inte resting to get asymptotic estimation for super Brownian motion. In this paper, w e will p... Generally, super Brownian motion will not c on verge vaguely to 0 if the initial measure is sufficiet large, so it is very inte resting to get asymptotic estimation for super Brownian motion. In this paper, w e will prove two asymptotic for super Brownian motion with general critical bran ching mechanism. 展开更多
关键词 super Brownian motion super martingale inequality cr itical branching mechanism
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Strength and deformation behaviors of bedded rock mass under bolt reinforcement 被引量:9
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作者 Wenxin Zhu Hongwen Jing +2 位作者 Lijun Yang Bing Pan Haijian Su 《International Journal of Mining Science and Technology》 EI CSCD 2018年第4期591-597,共7页
The mechanism of bolt support is an important topic in mining engineering and slope treatment. The artificial material and loading system were self-developed to study the influence of bedding cohesion and bolt number ... The mechanism of bolt support is an important topic in mining engineering and slope treatment. The artificial material and loading system were self-developed to study the influence of bedding cohesion and bolt number on the anchoring behavior of bedded rock mass. The results show that, both peak strength and elasticity modulus increase gradually with the increase of bedding cohesion and bolt number. The axial stress–strain curve of bedded rock mass under the reinforcement of bolts presents the features of strain-softening and secondary strengthening. Finally, anchoring behavior of bedded rock mass with different bolt numbers was simulated by using FLAC3 D numerical program and the results were compared with the experimental results. This study can provide certain bases to the stability control and support design of bedded rock mass in roadway. 展开更多
关键词 Bedded rock mass Anchoring behavior Peak strength Bedding cohesion Secondary strengthening
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Analyzing on the Characteristics of Several Typical Financial Behavior of Loss Listed Companies in China
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作者 Du Yong Chen Jianying 《Chinese Business Review》 2013年第3期204-216,共13页
In combination with socio-economic development of China's current status, this article analyzes the characteristics of several typical financial behavior of loss listed companies in China. Among them, the debt financ... In combination with socio-economic development of China's current status, this article analyzes the characteristics of several typical financial behavior of loss listed companies in China. Among them, the debt financing behavior have a high level, a single means, a short-term structured and other characteristics, the corporate governance behavior have a goal of collaborative, several forms, and a complex environment, the earnings management behavior have diverse motives, many types of means, bigger range and other features, the asset restructuring behavior have a passive subject, methods of differentiation, performance-oriented features such as myopia. 展开更多
关键词 LOSS financial behavior debt financing asset restructuring corporate governance earnings management
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Study on how to elevate the discriminating ability of the discriminating model of the financial statement fraud
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作者 CHEN Qing-jie ZHAO Hong-jin 《Chinese Business Review》 2010年第12期60-65,共6页
By summarizing the factor of the financial statement fraud in existing research outcome, the paper confirms the discriminating characteristic of the financial statement fraud and sets up a theoretic model to discrimin... By summarizing the factor of the financial statement fraud in existing research outcome, the paper confirms the discriminating characteristic of the financial statement fraud and sets up a theoretic model to discriminate the financial statement fraud. Using radial basis function neural network, regarding to the swatch that the listed company that is punished by the Securities Regulatory Commission or the Ministry of Finance, and according to the clustering elements, validating across by set one aside, the paper verifies respectively the 22 characteristics and 31 characteristics of discriminating model. According to the clustering elements, validating across by set one aside, the paper verifies respectively the 31 characteristics and 8 characteristics selected by Fisher-ratio of discriminating model. The research outcome indicates the discriminating ability of the model including 8 characteristics is better elevated than the traditional model including 31 characteristics by comparing the disciplinary error and the forecast precision. 展开更多
关键词 Fisher-ratio the discriminating ability financial statement fraud
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Arab Uprising, African Youth, and the Burden of History: Hegemony or Revolution?
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作者 Browne Onuoha 《Sociology Study》 2012年第8期591-604,共14页
Youth in Africa must be put in context: from colonialism to post-colonial politics underpinned by ethnic rivalry, tribalism, dictatorship, or the rule of strongmen. The context also included the more than one generat... Youth in Africa must be put in context: from colonialism to post-colonial politics underpinned by ethnic rivalry, tribalism, dictatorship, or the rule of strongmen. The context also included the more than one generation of perverse military rule. In each of the historical epochs, no African leadership built the youth; there was no ideology or a value system transmitted to the youth. Accordingly it becomes increasingly difficult in the twenty-first century attempting to mobilize the African youth as meaningful change agents. The possible exception to these failures was the Ghana Young Pioneers. The manifestation of this neglect in most parts of sub-Saharan Africa is the hoard of jobless youth involved in crime and other deviant behaviors. Thus to build the youth who will develop the society, African states will necessarily have to invest in the youth, evolve an ideology and an African world view, which will be transmitted to the youth, and which will constitute a driving force for their mobilization as critical agents of change. 展开更多
关键词 Africa YOUTH values IDEOLOGY change
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Comparative study on pullout behaviour of pressure grouted soil nails from field and laboratory tests 被引量:3
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作者 HONG Cheng-yu YIN Jian-hua PEI Hua-fu 《Journal of Central South University》 SCIE EI CAS 2013年第8期2285-2292,共8页
Pullout resistance of a soil nail is a critical parameter in design and analysis for geotechnical engineers. Due to the complexity of field conditions, the pullout behaviour of cement grouted soil nail in field is not... Pullout resistance of a soil nail is a critical parameter in design and analysis for geotechnical engineers. Due to the complexity of field conditions, the pullout behaviour of cement grouted soil nail in field is not well investigated. In this work, a number of field pullout tests of pressure grouted soil nails were conducted to estimate the pullout resistance of soil nails. The effective bond lengths of field soil nails were accurately controlled by a new grouting packer system. Typical field test results and the related comparison with typical laboratory test results reveal that the apparent coefficient of friction (ACF) decreases with the increase of overburden soil pressure when grouting pressure is constant, but increases almost linearly with the increase of grouting pressure when overburden pressure (soil depth) is unchanged. Water contents of soil samples at soil nail surfaces show obvious reductions compared with the results of soil samples from drillholes. After soil nails were completely pulled out of the ground, surface conditions of the soil nails and surrounding soil were examined. It is found that the water content values of the soil at the soil/nail interfaces decrease substantially compared with those of soil samples extracted from drillholes. In addition, all soil nails expand significantly in the diametrical direction after being pulled out of ground, indicating that the pressurized cement grout compacts the soil and penetrates into soil voids, leading to a corresponding shift of failure surface into surrounding soil mass significantly. 展开更多
关键词 soil nail apparent coefficient of friction overburden soil pressure grouting pressure
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Development of a Test Program for Assessing the SCC, Pitting and Crevice Corrosion Behaviour of Selected Corrosion Resistant Alloy Liner Materials for Clad Pipe for Offshore Applications 被引量:1
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作者 Barry Gideon Liam Ward 《Journal of Mechanics Engineering and Automation》 2013年第12期778-784,共7页
The development of an offshore gas field involves production of oil and gas from subsea wells. Design considerations for a particular subsea system have identified the maximum temperature for operations which is great... The development of an offshore gas field involves production of oil and gas from subsea wells. Design considerations for a particular subsea system have identified the maximum temperature for operations which is greater than 130 ~C. Consequently, for large diameter flowlines, this precludes the use of duplex stainless steels as CRA's (corrosion resistant alloys) for service under the expected operating conditions. Attention has therefore focused on alternative CRA's such as austenitic stainless steels and Ni based alloys as mechanically clad or lined clad pipe for carbon steel subsea gas flowlines. One design concern is the recognized temperature limit for CRA materials, such as 316L stainless steel and similar alloys in production fluids is taken to be 120 ~C. This then raises concerns surrounding their suitability for providing sufficient corrosion resistance/stress corrosion cracking resistance in gas environments containing COz and H2S at temperatures higher than 130 ~C. It was recommended that specific testing should be completed at temperatures greater than 133 ~C to establish that candidate materials are still corrosion resistant. The focus of this study was to develop, implement and assess a testing program that would predict the suitability of a series of CPA's alloys for use in mechanical clad/lined subsea gas flowlines, with respect to pitting corrosion, crevice corrosion and stress corrosion cracking. This paper will present the rationale adopted for this testing program to simulate the stringent operating conditions, the results from these findings and the overall assessment/integrity of the candidate alloys selected. 展开更多
关键词 Stress corrosion cracking crevice corrosion pitting corrosion corrosion resistant alloy.
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Hydrodynamic Behavior of a Single Bubble Rising in Viscous Liquids 被引量:7
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作者 CAI Ziqi BAO Yuyun GAO Zhengming 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第6期923-930,共8页
The rising behavior of single bubbles has been investigated in six systems with different viscosity and Morton number(Mo) from 3.21×10-11 to 163. Bubbles with maximum equivalent diameter of up to 16 mm were inves... The rising behavior of single bubbles has been investigated in six systems with different viscosity and Morton number(Mo) from 3.21×10-11 to 163. Bubbles with maximum equivalent diameter of up to 16 mm were investigated. The bubble Reynolds number(Re) ranged from 0.02 to 1200 covering 3 regimes in which two func-tions are obtained relating the drag coefficient,CD,with Re and Mo. It has been found that in the high Reynolds number regime the drag coefficient increases until the Reynolds number of about 1200. The classic expression of Jamialahmadi(1994) is improved and extended to high viscosity liquids. A new relationship for the aspect ratio of deformed bubbles in terms of Re,the Etvs number and Mo,applicable to a wide range of system properties,espe-cially in high viscosity liquids,is also suggested. 展开更多
关键词 BUBBLE rising velocity viscous liquid drag coefficient DEFORMATION
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STUDY ON HIV/STDS KNOWLEDGE AND RISK BEHAVIORS RELATED FACTORS AMONG FEMALE SEX WORKERS IN SHANGHAI,CHINA
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作者 蔡泳 施榕 +4 位作者 沈恬 裴蓓 蒋雪琴 黄红 商美丽 《Medical Bulletin of Shanghai Jiaotong University》 CAS 2010年第2期71-76,共6页
Objective To assess the HIV/STDs knowledge and risk behaviors related factors among female sex workers(FSWs)in Shanghai,China.Methods A cross-sectional study was conducted in 5 districts(including 3 suburbs and 2 urba... Objective To assess the HIV/STDs knowledge and risk behaviors related factors among female sex workers(FSWs)in Shanghai,China.Methods A cross-sectional study was conducted in 5 districts(including 3 suburbs and 2 urban districts).A total of 324 FSWs from 88 massage parlors and hair-beauty salons participated in the survey.An interviewer-administrated questionnaire was used to collect information.Results The average score of HIV/STDs knowledge was 15.2±3.9.Multivariate analyses indicated that limited education [odds ratio(OR):8.6,95% confidence interval(CI):2.9-25.6],coming from suburbs [odds ratio(OR):3.7,95% confidence interval(CI):2.0-6.8],monthly income less than 1500 RMB(220 US$)[odds ratio(OR):3.9,95% confidence interval(CI):1.9-8.1],without HIV/STDs-related education experience(OR:5.2,95% CI:2.8-9.5),and coming from provinces of low epidemic(OR:2.7,95% CI:1.1-6.6)were significant predictors of lower HIV/STDs knowledge.And 29.5% FSWs had sex without a condom when clients paid much more money,and 46.3% had the experience of condom broke or slipped during commercial sexual intercourse.Conclusion Health promotion should be conducted to enhance HIV/STDs knowledge and reduce risk behaviors among FSWs from suburbs with limited education in Shanghai especially. 展开更多
关键词 HIV/AIDS risk behavior female sex workers China
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Molecular dynamics simulation of water transport through graphene-based nanopores: Flow behavior and structure characteristics 被引量:4
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作者 杨雪平 杨晓宁 刘淑延 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第10期1587-1592,共6页
The flow behavior of pressure-driven water infiltration through graphene-based slit nanopores has been studied by molecular simulation.The simulated flow rate is close to the experimental values,which demonstrates the... The flow behavior of pressure-driven water infiltration through graphene-based slit nanopores has been studied by molecular simulation.The simulated flow rate is close to the experimental values,which demonstrates the reasonability of simulation results.Water molecules can spontaneously infiltrate into the nanopores,but an external driving force is generally required to pass through the whole pores.The exit of nanopore has a large obstruction on the water effusion.The flow velocity within the graphene nanochannels does not display monotonous dependence upon the pore width,indicating that the flow is related to the microscopic structures of water confined in the nanopores.Extensive structures of confined water are characterized in order to understand the flow behavior.This simulation improves the understanding of graphene-based nanofluidics,which helps in developing a new type of membrane separation technique. 展开更多
关键词 GRAPHENE NANOPORES Flow behavior MEMBRANE Molecular simulation
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Serum uric acid as an index of impaired renal function in congestive heart failure 被引量:9
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作者 Yu Tian Ying Chen +11 位作者 Bao Deng Gang Liu Zhen-Guo Ji Qing-Zhen Zhao Yu-Zhi Zhen Yan-Qiu Gao Li Tian Le Wang Li-Shuang Ji Guo-Ping Ma Kun-Shen Liu Chao Liu 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2012年第2期137-142,共6页
Background Hyperuricemia is frequently present in patients with heart failure. Many pathological conditions, such as tissue ischemia, renal function impairment, cardiac function impairment, metabolic syndrome, and inf... Background Hyperuricemia is frequently present in patients with heart failure. Many pathological conditions, such as tissue ischemia, renal function impairment, cardiac function impairment, metabolic syndrome, and inflammatory status, may impact uric acid (UA) metabolism. This study was to assess their potential relations to UA metabolism in heart failure. Methods We retrospectively assessed clinical charac- teristics, echocardiological, renal, metabolic and inflammatory variables selected on the basis of previous evidence of their involvement in cardiovascular diseases and UA metabolism in a large cohort of randomly selected adults with congestive heart failure (n = 553). By clustering of indices, those variables were explored using factor analysis. Results In factor analysis, serum uric acid (SUA) formed part of a principal cluster of renal functional variables which included serum creatinine (SCr) and blood urea nitrogen (BUN). Univariate correlation coefficients between variables of patients with congestive heart failure showed that the strongest correlations for SUA were with BUN (r = 0.48, P 〈 0.001) and SCr (r = 0.47, P 〈 0.001). Conclusions There was an inverse relationship between SUA levels and measures of renal function in patients with congestive heart failure. The strong correlation between SUA and SCr and BUN levels suggests that elevated SUA concentrations reflect an impairment of renal function in heart failure. 展开更多
关键词 Serum uric acid Heart failure Renal function impairment Factor analysis
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The state of the Mind in a Revolutionary state of the State
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作者 Nditsheni Emmanuel Tshikwatamba 《Sociology Study》 2014年第1期69-84,共16页
The article epitomises its foundations by providing definitional and explanative dichotomy among the State, Nation, and Nation State. It affords a depiction of the centrality of the mind, the interface of the body and... The article epitomises its foundations by providing definitional and explanative dichotomy among the State, Nation, and Nation State. It affords a depiction of the centrality of the mind, the interface of the body and mind in behavioural manifestations. It furthermore acknowledges that nothing occurs in a vacuum but in the context of the fullness of the mind. The visible manifestations of human behaviour are contended to be informed by the noiselessness invisible aspects of the mind. The same noiseless mind that informs the behavioural visibility that becomes somewhat active and busier in its conspicuousness. The dual existence of things and events in a revolutionary context that transcends to other behavioural undertones is discoursed. In the context application of the revolutionary mapping, the mind is presented as a culprit revolutionarist that wages revolutions without fear of external threats through arrests, danger, pain, terror, dread, apprehension, detentions, and any other similar means including death. The article settles that the mind is the determinant factor of human behaviours and it therefore defines the state of the State in any revolutionary circumstance. It denotes a functional separatism of the mind from the brain which is an organ of the body thereby equally accepting that the brain functionalises the mind. The equal essential role of the mind in post revolution construction to establish and promote an acceptable system of government that responds to socio-economic factors is detailed herein the manuscript. A deliberate attempt is made not to be suggestive and prescriptive on the shape and form of such a post revolution system of government. 展开更多
关键词 Revolutionary mind DUALISM State(s) CONSTRUCTS
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Phosphorus Behavior at Sediment-Water Interface in Coastal Wetland 被引量:1
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作者 Xueping LI Jialiang LI 《Agricultural Science & Technology》 CAS 2016年第1期194-196,共3页
[Objective] The aim was to explore the role of coastal wetlands in phosphorus fixation in the Yellow River Delta.[Method] The research analyzed phosphorus behavior at sediment-water interface by static water column te... [Objective] The aim was to explore the role of coastal wetlands in phosphorus fixation in the Yellow River Delta.[Method] The research analyzed phosphorus behavior at sediment-water interface by static water column test. [Result] The research concluded that phosphorus concentration was in the range of 0.051-0.322 mg/L in overlying water, and phosphorus was effectively removed by degradation and adsorption. The static water column test has demonstrated that phosphorus concentration of coastal wetlands plays the role of accumulation when phosphorus concentration is lower than 7 mg/L in overlying water of coastal wetlands. It is notable that substrates of overlying water all perform well in adsorption, and the adsorption reaches saturation if the concentration goes up to 10 mg/L. [Conclusion] Coastal wetlands would significantly adsorb and degrade phosphorus in overlying water, controlling phosphorus within a lower range. 展开更多
关键词 Coastal wetlands PHOSPHORUS Sink-source function
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Development of an oil spill forecast system for offshore China 被引量:2
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作者 王永刚 魏泽勋 安伟 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第4期859-870,共12页
An oil spill forecast system for of fshore China was developed based on Visual C++. The oil spill forecast system includes an ocean environmental forecast model and an oil spill model. The ocean environmental forecast... An oil spill forecast system for of fshore China was developed based on Visual C++. The oil spill forecast system includes an ocean environmental forecast model and an oil spill model. The ocean environmental forecast model was designed to include timesaving methods, and comprised a parametrical wind wave forecast model and a sea surface current forecast model. The oil spill model was based on the "particle method" and fulfi lls the prediction of oil particle behavior by considering the drifting, evaporation and emulsifi cation processes. A specifi c database was embedded into the oil spill forecast system, which contained fundamental information, such as the properties of oil, reserve of emergency equipment and distribution of marine petroleum platform. The oil spill forecast system was successfully applied as part of an oil spill emergency exercise, and provides an operational service in the Research and Development Center for Off shore Oil Safety and Environmental Technology. 展开更多
关键词 oil spill China offshore particle method emergency service
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A Study on the Behavior of Large Stock Dividends and Stock Splits Among Chinese Listed Companies: A Case Study on Zoomlion's 2010 Middle-Term Stock Dividend Plan
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作者 Qi Yongjun 《Journal of Modern Accounting and Auditing》 2012年第3期374-380,共7页
This paper takes Zoomlion (Changsha Zoomlion Heavy Industry Science and Technology Development Co., Ltd) as an example and illustrates the reasons why traditional theories of stock dividends and stock splits cannot ... This paper takes Zoomlion (Changsha Zoomlion Heavy Industry Science and Technology Development Co., Ltd) as an example and illustrates the reasons why traditional theories of stock dividends and stock splits cannot rationally explain the large stock dividend and stock split behavior among Chinese listed companies. The paper offers the following points after analyzing the current situation of China's capital market: As many investors seek after the stocks with large stock dividends and stock splits and form a "herd effect", it greatly pushes up the price of these stocks. Thus, companies' managers can cater these investors' irrational behavior, and help their companies get more funds from secondary equity offerings, or help their large shareholders and institutional investors to obtain more returns after lifting the sell restriction on their shares. 展开更多
关键词 large stock dividend and stock split herd effect catering theory
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Anaphora's Creating Irony by the Aid of Context
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作者 LIU Yan-chun 《Sino-US English Teaching》 2015年第9期647-653,共7页
The core function of anaphora is to serve as a substitute for a certain linguistic component in texts, but it actually has other missions such as creating the rhetorical effect--irony. However, anaphora alone cannot c... The core function of anaphora is to serve as a substitute for a certain linguistic component in texts, but it actually has other missions such as creating the rhetorical effect--irony. However, anaphora alone cannot contribute to ironic effect, and only by resorting to other resources like contextual information, can anaphora generate irony. Therefore, Yus' s classification of contextual sources is employed to analyze with examples how anaphora creates irony by the aid of context. Ultimately, the conclusion has been drawn that anaphora is able to produce irony with the help of six groups of contextual information classified by Yus except the category--speaker's nonverbal behavior and anapbora sometimes has to interact with several groups of contextual information in order to create irony. 展开更多
关键词 ANAPHORA IRONY contextual information
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Analytical Behavior of Fura-2 and Its Determination of [Ca2+]i in Lymphocytes Treated with Cefotaxime
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作者 双少敏 乔晓娜 +4 位作者 王丹丹 樊丽 芦冬涛 慕丽晓 周叶红 《Journal of Measurement Science and Instrumentation》 CAS 2010年第4期395-400,共6页
The interaction of Fura-2 with Ca^2+ is studied using steady fluorescence technique. The effect of pH on the spectra behavior of Fura-2 in the presence of Ca^2+ is investigated, the excitation maxima (340 nm) and ... The interaction of Fura-2 with Ca^2+ is studied using steady fluorescence technique. The effect of pH on the spectra behavior of Fura-2 in the presence of Ca^2+ is investigated, the excitation maxima (340 nm) and the isobestic point (360 nm) for the fluorescence spectra of Fura-2 depend on pH. At different temperatures the apparent dissociation constants ( Kd ) of Fura-2-Ca^2+ complex are examined, Kd is found to decrease with increasing temperatures (20 ℃, 37 ℃, 50 ℃ ) and △His calculated to be 21.16 kJ/mol by using the Van' t Hoff equation at pH 7.4 for all the temperatures tested. The determination of intracellular Ca^2+ concentration ( [Ca^2+ ] i ) in lymphocyte is developed by using Fura-2 as a fluorescence probe in the presence of Cefotaxime at 37 ℃ and pH 7.4. 展开更多
关键词 FURA-2 pH temperature [Ca^2+]i CEFOTAXIME
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The Impact of Debt Financing on Corporate R & D Investment Behavior in China ——Based on the Empirical Evidence of Listed Companies from 2004 to 2011
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作者 Shengqiang LIU Dandan CHANG 《International English Education Research》 2015年第11期59-63,共5页
Base on panel data of manufacturing and high-tech industry companies which discoursed R & D expenditure in financial statements from 2004 to 2011, this paper studies the relationship between debt financing and corpor... Base on panel data of manufacturing and high-tech industry companies which discoursed R & D expenditure in financial statements from 2004 to 2011, this paper studies the relationship between debt financing and corporate R & D expenditure under different grow opportunities by using the robust fixed effects that Daniel Hoechle proposed m 2007. The results show that there is not a "increasing first, decreasing later" non-linear relationship but a "double negative" relationship between debt level and corporate R & D expenditure. And the "double negative" relationship has a different mechanism in different growth companies. 展开更多
关键词 Debt Financing R D Investment Fixed Effects
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On the Lateral Behavior of the Backfill of a Skew Abutment
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作者 Ali Nojoumi Tadeh Zirakian 《Journal of Civil Engineering and Architecture》 2018年第1期22-38,共17页
It is generally accepted that the interaction between a bridge and its abutment's backfill soil is highly nonlinear, especially under a strong earthquake loading that contains a velocity pulse. For bridges with skew ... It is generally accepted that the interaction between a bridge and its abutment's backfill soil is highly nonlinear, especially under a strong earthquake loading that contains a velocity pulse. For bridges with skew abutments, the superstructure-abutment interaction can dominate the overall bridge performance. This study puts forth a new approach for predicting the lateral capacity of a skew abutment using verified high-fidelity three-dimensional continuum finite element (FE) models. The core idea is that the lateral capacity of a straight abutment is bounded from above and below by that of the abutment of a skew bridge that has the same deck-width, and that of another skew bridge (with the same angle) that has the same backwall length as the original/straight bridge, respectively. This postulation is then used in reverse to estimate the lateral capacity of a skew abutment, given the capacity of a straight but otherwise identical one with an arbitrary length. In prior research, the latter information had already been obtained in closed-form expressions that use physical parameters, such as backfill cohesion, internal friction angle and density, backwall height, and backwall-backfill friction angle. The approach presented here is constrained by the assumption that bridge deck will not rotate during loading. While this assumption is generally violated in a strong earthquake--because a skew bridge will tend to rotate, especially if its in-plane torsional rigidity is low, the model presented does serve as an anchor for parameterizing more advanced (e.g., macro-element plasticity) models that allow rotation, and also as fully parametric lateral response models for torsionally stiff (ile., multi-span, multi-bent) skew bridges. 展开更多
关键词 Soil-structure interaction non-rotating abutment walls numerical simulation.
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