A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transf...A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transfer (LET) with a tilted ion beam at the 130?nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40?MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained.展开更多
This paper presents two approaches to perform the electronic device heating during radiation hardness assurance tests.Commonly used conductive heating approach is compared with contactless laser-based approach,charact...This paper presents two approaches to perform the electronic device heating during radiation hardness assurance tests.Commonly used conductive heating approach is compared with contactless laser-based approach,characteristics and limitations of these methods are described.Experimental results for temperature dependence of single-event latchup(SEL)cross-section during heavy ion irradiation along with some aspects of physics-based numerical simulation of heat transfer processes are presented.展开更多
The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment po...The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.展开更多
[Objective] To screen the optimal fertilizer formula, and to lay foundation for the research on special fertilizer for Sagittaria sagittifolia production. [Method] Based on the "3414" fertilization design, the yield...[Objective] To screen the optimal fertilizer formula, and to lay foundation for the research on special fertilizer for Sagittaria sagittifolia production. [Method] Based on the "3414" fertilization design, the yield of S. sagittifolia in each treatment was determined, and the effects of N, P and K treatments on the yield and eco- nomic benefit of S. sagittifolia were investigated, obtaining the optimal fertilizer appli- cation ratio. [Result] N, P and K had relatively good effects on the yield of S. sagittifolia. Treatment of N2P2K3 showed the optimal fertilizer application ratio, with the yield of 18 397.80 kg/hm2, yield increasing rate of 104.77%, and net income in- crease of 80 317.35 Yuan/hm2. N fertilizer had the greatest impacts on the yield of S. sagittifolia, followed with K fertilizer; while P fertilizer showed the poorest impacts. [Conclusion] To achieve the highest yield of S. sagittifolia, the fertilizer application was as follows: N of 446.70 kg/hm2, P20 of 568.10 kg/hm2, K2O of 534.90 kg/hm2, when the highest yield was 18 612.75 kg/hm2. Fertilizer application for the optimal economic benefit was N of 420.60 kg/hm2, P2O5 of 70.50 kg/hm2, K2O of 492.15 kg/hm2, when the optimal yield was 18 579.00 kg/hm2.展开更多
This study was aimed to develop the Chinese herbal formula with dysentery arresting and antidiarrheal effect. [Method] The Chinese herbal for-mulation was used to carry out the clinical curative effect test and pharma...This study was aimed to develop the Chinese herbal formula with dysentery arresting and antidiarrheal effect. [Method] The Chinese herbal for-mulation was used to carry out the clinical curative effect test and pharmacological test for il livestock. [Results] Curative effect test showed that the formula had good effect on abdominal pain, diarrhea and fecal changes of livestock, and the cure rate reached up to 92%. Pharmacological experiments showed that the formula had sig-nificant inhibitory effect on the gastrointestinal motility of the tested animals, and the diarrhea arresting and dysentery treating effect of the formula was also extremely significant. In addition, the formula was safe for tested animals, proving to be reli-able. [Conclusion] The formula has distinct curative effect on treating white scour of piglets, yel ow scour of piglets, livestock gastroenteritis and lienteric diarrhea, and it can also be used in veterinary clinic, as wel as be used as feed additive.展开更多
The size and shape of the effective test area are crucial to consider when short-crested waves are created by segmented wavemakers. The range of the effective test area of short-crested waves simulated by two-sided se...The size and shape of the effective test area are crucial to consider when short-crested waves are created by segmented wavemakers. The range of the effective test area of short-crested waves simulated by two-sided segmented wavemakers is analyzed in this paper. The experimental investigation on the wave field distribution of short-crested waves generated by two-sided segmented wavemakers is conducted by using an array of wave gauges. Wave spectra and directional spreading function are analyzed and the results show that when the main direction is at a certain angle with the normal line of wave generators, the wave field of 3D short-crested waves generated by two-sided segmented wavemakers has good spatial uniformity within the model test area. The effective test area can provide good wave environments for seakeeping model tests of various ocean engineering structures in the deep ocean engineering basin.展开更多
Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings ...Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings have seldom been studied so far due to the huge workload involved in experiments and data processing.In this paper,mean and dynamic force/response interference effects and peak wind pressure interference effects of two and three tall buildings,especially the three-building configuration,are investigated through a series of wind tunnel tests on typical tall building models using high frequency force balance technique and wind pressure measurements.Furthermore,the present paper focuses on the effects of parameters,including breadth ratio and height ratio of the buildings and terrain category,on the interference factors and derives relevant regression results for the interference factors.展开更多
Various field investigations of earthquake disaster cases have confirmed that earthquake-induced liquefaction is a main factor causing significant damage to dyke,research on seismic performances of dyke is thus of gre...Various field investigations of earthquake disaster cases have confirmed that earthquake-induced liquefaction is a main factor causing significant damage to dyke,research on seismic performances of dyke is thus of great importance.In this paper,seismic responses of dyke on liquefiable soils were investigated by means of dynamic centrifuge model tests and three-dimensional(3D) effective stress analysis method which is based on a multiple shear mechanism model and a liquefaction front.For the prototype scale centrifuge tests,sine wave input motions with peak accelerations 0.806 m/s2,1.790 m/s2 and 3.133 m/s2 of varied amplitudes were adopted to study the seismic performances of dyke on the saturated soil layer foundation with relative density of approximately 30%.Then,corresponding numerical simulations were conducted to investigate the distribution and variations of deformation,acceleration,excess pore-water pressure(EPWP),and behaviors of shear dilatancy in the dyke and the liquefiable soil foundation.Moreover,detailed discussions and comparisons between numerical simulations and centrifuge tests were also presented.It is concluded that the computed results have a good agreement with the measured results by centrifuge tests.The physical and numerical models both indicate that the dyke hosted on liquefiable soils subjected to earthquake motions has exhibited larger settlement and lateral spread:the stronger the motion is,the larger the dyke deformation is.Compared to soils in the deep ground under the dyke and the free field,the EPWP ratio is much smaller in the shallow liquefiable soil beneath the dyke in spite of large deformation produced.For the same overburden depth soil from free site and the liquefiable foundation beneath dyke,the characteristics of effective stress path and stress-strain relations are different.All these results may be of theoretical and practical significance for seismic design of the dyke on liquefiable soils.展开更多
Tailings impoundments can potentially collapse due to damage caused by earthquakes,which has frequently occurred around the world.This study takes the proposed valley type tailings impoundment in Yunnan as the researc...Tailings impoundments can potentially collapse due to damage caused by earthquakes,which has frequently occurred around the world.This study takes the proposed valley type tailings impoundment in Yunnan as the research object to analyze the dynamic response behavior under earthquake action with both numerical simulation and physical model test(1:300).The results of both tests show that the dynamic response of the valley type tailings impoundment is characterized by"medium stiffness effect",in other words,in a certain range,the"softer"the unsaturated tailings sand is,the more energy it can dissipate,which leads the decrease of the value of the acceleration amplification factor.In addition,the peak acceleration of the monitoring points increases with the vertical elevation,which indicates that the"elevation amplification effect"exists in the tailings impoundment dynamic response.The middle part of the outer side of the raised embankment reacts more sensitive than the crest,which is similar to the slope dynamic response.The starter dam reacts sensitively under the earthquake excitation,which should be given more attention during the seismic design.The dynamic response rules reflected by the numerical simulation are consistent with the results monitored on the physical model test,although there are some differences between their values.The dynamic response rules of the valley type tailings impoundment can provide basis for the design of the similar projects in this region.展开更多
A human K562 leukaemia call and acute adult leudaemia patient samples have been used to test the efficacy of antineoplastic agents with MTT assay.All 18 drugs were invoved.According to the purpose of experiment these...A human K562 leukaemia call and acute adult leudaemia patient samples have been used to test the efficacy of antineoplastic agents with MTT assay.All 18 drugs were invoved.According to the purpose of experiment these durgs were applied at different opportunities or combinations.The drug efficacy has been observed and summarized as four different conditions:1.the change of the time(△ T )closely related with drug effacacy, during the duration the change of drug concentration(△ C) at certain extent has almost no influence; 2the △ C closely related with the efficacy, the △ T has no influence;3. The △ C and △ T effect the results together;and 4.the △ C and △ T effect not the result. And then draw a conclution that the process or drug effacacy has a multiple function with flat distrtct.展开更多
Ion photon emission microscopy (IPEM) is a new ion-induced emission microscopy. It employs a broad ion beam with high energy and low fluence rate impinging on a sample. The position of a single ion is detected by an...Ion photon emission microscopy (IPEM) is a new ion-induced emission microscopy. It employs a broad ion beam with high energy and low fluence rate impinging on a sample. The position of a single ion is detected by an optical system with objective lens, prism, microscope tube and charge coupled device (CCD). A thin ZnS film doped with Ag ions is used as a luminescent material. Generation efficiency and transmission efficiency of photons in the ZnS(Ag) film created by irradiated Cl ions are calculated. A single Cl ion optical microscopic image is observed by high quantum efficiency CCD. The resolution of a single Cl ion given in this IPEM system is 6μm. Several factors influencing the resolution are discussed. A silicon diode is used to collect the electrical signals caused by the incident ions. Effective and accidental coincidence of optical images and electronic signals are illustrated. A two-dimensional map of single event effect is drawn out according to the data of effective coincidence.展开更多
[Objective] The aim was to study the obtaining method of meticulous climate forecast product and test its forecast effect. [Method] Based on the national standard surface observation data and secondary data bank obtai...[Objective] The aim was to study the obtaining method of meticulous climate forecast product and test its forecast effect. [Method] Based on the national standard surface observation data and secondary data bank obtained by means of distance weight interpolation method, the model of climate forecast was established, and the timing, fixed-point and quantitative meticulous climate forecast of meteorological elements was obtained by using many forecast methods and artificial revision, finally the forecast effect was tested. [Result] At present, meticulous climate forecast system was used to predict the daily, five-day, ten-day, monthly, seasonal and annual variation of six meteorological elements (including average temperature, maximum temperature, minimum temperature, precipitation, average pressure and sunshine) in 10 meteorological stations in Guangzhou City. The forecast effect of meteorological elements in 10 stations in Guangzhou City from 2006 to 2010 was tested, and the average scores of monthly precipitation, average temperature, maximum temperature and minimum temperature were 75.0, 94.5, 98.6 and 88.9, respectively, while the scores of five-day meteorological elements were 77.1, 90.6, 90.1 and 82.8, which met the requirement of objective management of Guangdong Meteorological Observatory. [Conclusion] Meticulous climate forecast system could be widely used in the forecast of agricultural meteorological disasters and fixed-point forecast in large reservoir, new airport and nuclear power station.展开更多
Many experiments have been conducted on accidents and transients of pressurized water reactor (PWR) employing the rig of safety assessment/large-scale test facility (ROSA/LSTF). Recent research activities concerned wi...Many experiments have been conducted on accidents and transients of pressurized water reactor (PWR) employing the rig of safety assessment/large-scale test facility (ROSA/LSTF). Recent research activities concerned with the OECD/NEA international joint projects included experimental investigation via the ROSA and ROSA-2 Projects, and counterpart testing with thermal-hydraulic integral test facilities under collaboration of the PKL-2, PKL-3, ATLAS, and ATLAS-2 Projects. Major results of the related integral effect tests (IETs) with the LSTF were reviewed to experimentally identify thermal-hydraulic phenomena involved, regarding the PWR accident sequences in accordance with the new regulatory requirements for the Japanese light-water nuclear power plants. Future separate effect test using the LSTF is planned to simulate loss of emergency core cooling system (ECCS) recirculation functions in a large-break loss-of-coolant accident (LOCA). Key results of the recent IETs utilizing the LSTF and future plans were presented relevant to multiple steam generator tube rupture accident with recovery operation, small-break LOCA with accident management measure on core exit temperature reliability, and small-break LOCA with thermal stratification under cold water injection from ECCS into cold legs. Also, main outcomes of the LSTF IETs were indicated for wide spectrum LOCA with core uncovery and anticipated transient without scram following small-break LOCA under totally failed high-pressure injection system.展开更多
In a wood processing factory, the measured air concentration of birchen dust was 1. 26 ±0. 41 mg/m3, and the micronucleus frequency of peripheral blood lymphocytes in 83 workersexposed to wood dust was 1. 13 ...In a wood processing factory, the measured air concentration of birchen dust was 1. 26 ±0. 41 mg/m3, and the micronucleus frequency of peripheral blood lymphocytes in 83 workersexposed to wood dust was 1. 13 ± 2. 83%, which was significantly higher (P < 0.01 ) thanthat of control group (0. 51 ± 1. 41% ). The number of exposed workers with positive mi-cronucleus test was 9. 6 %, which was higher than that of control group (4. 5 % ), but thedifference was not significant (P >0. 05 ). The micronucleus test in mice treated with waterextracts of unsteamed and unbaked birchen dust showed that the micronucleus frequencies inall treated groups were significantly higher than that of contro group (P < 0. 01 ) and therewas also a doseresponse correlation (r = 0. 96, P < 0. 0005 ). The results of steamed andbaked birchen dust extracts were significantly lower than those of the unsteamed and unbakedones at the same doses (P< 0. 001 ). This suggests that when the birchen dust is steamed atthe temperature of 100℃ for 24h or baked at the temperature of 80℃, its inducing effect inmicronucleus test could be lowered展开更多
Traditionally, timing and the failure rate are the only two factors considered in software reliability formula, which is actually incomplete. Reliability should be redefined as a function of software complexity, test ...Traditionally, timing and the failure rate are the only two factors considered in software reliability formula, which is actually incomplete. Reliability should be redefined as a function of software complexity, test effectiveness, and operating environment. This paper focuses on software complexity with its relation to the soft- ware reliability. Today, many software complexity measurements have been proposed, but most of them treat the reliability model incompletely. This paper proposes a new method which considers a relatively complete view of software reliability including its complexity and test effectiveness of the software being tested.展开更多
Although mutation testing is one of the practical ways of enhancing test effectiveness in software testing, it could be sometimes infeasible in practical work for a large scale software so that the mutation testing be...Although mutation testing is one of the practical ways of enhancing test effectiveness in software testing, it could be sometimes infeasible in practical work for a large scale software so that the mutation testing becomes time-consuming and even in prohibited time. Therefore, the number of faults assumed to exist in the software under test should be reduced so as to be able to confine the time complexity of test within a reasonable period of time. This paper utilizes the concept of fault dominance and equivalence, which has long been employed in hardware testing, for revealing a novel way of reducing the number of faults assumed to hide in software systems. Once the number of faults assumed in software is decreased sharply, the effectiveness of mutation testing will be greatly enhanced and become a feasible way of software testing. Examples and experimental results are presented to illustrate the effectiveness and the helpfulness of the technology proposed in the paper.展开更多
The production-oriented approach (POA) has been developed over a decade. It is driven by the need to improve English classroom instruction for university students in China (Wen, 2016). It is also motivated by the ...The production-oriented approach (POA) has been developed over a decade. It is driven by the need to improve English classroom instruction for university students in China (Wen, 2016). It is also motivated by the aspiration to enhance the quality of foreign language education in other similar pedagogical contexts outside China. A volume of research has been done by Wen Qiufang and her research team, to formulate the theory of POA and to test its effectiveness in classroom pedagogy (e.g. Wen, 2016, 2015; Yang, 2015; Zhang, 2015). At the moment, the POA is still at an early stage of theory building and almost all empirical research is done in the Chinese context. In order to improve the quality of this theory and to make it intelligible to the international academic community, a one-day symposium was held in Beijing Foreign Studies University on May 15, 2017. The symposium was entitled 'The first international forum on innovative foreign language education in China: Appraisal of the POA'. In the forum, leading experts in applied linguistics were invited to discuss the strengths and weaknesses of the POA and the directions for its future development. The symposium was the first attempt for the POA research team to discuss its latest work with international scholars. This Viewpoint section collects the responses of four experts who participated in the symposium, listed in alphabetical order. The collection of articles covers three topics related to the POA: its pedagogical application, its use for teacher training, and its research. Alister Cumming is Professor Emeritus and the former Head of the Centre for Educational Research on Languages and Literacies, University of Toronto, Canada. His article focuses primarily on POA research as an exemplary case of design-based research. Rod Ellis is Research Professor in the School of Education at Curtin University, Australia. He discusses POA in terms of pedagogy, teacher training and research, with both critiques and constructive suggestions. Paul Kei Matsuda is Professor of English and Director of Second Language Writing at Arizona State University, the writed states. He responds to POA from the perspective of an expert researcher and teacher of L2 writing. Charlene Polio is Professor and Associate Chair in the Department of Linguistics & Germanic, Slavic, Asian & African Languages atMichigan State University, the writed states. She conceptualises POA as a useful method to address some issues in pre-service teacher development. Overall, the articles in this section are insightful and reader-friendly. They are not only useful for the development of POA in particular, but may also be valuable to a broad range of researchers as they touch upon pertaining issues, as well as emerging topics, in the field of applied linguistics. We therefore find it necessary to make them accessible to a wide readership.展开更多
基金Supported by the Key Laboratory of Microsatellites,Chinese Academy of Sciences
文摘A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transfer (LET) with a tilted ion beam at the 130?nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40?MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained.
文摘This paper presents two approaches to perform the electronic device heating during radiation hardness assurance tests.Commonly used conductive heating approach is compared with contactless laser-based approach,characteristics and limitations of these methods are described.Experimental results for temperature dependence of single-event latchup(SEL)cross-section during heavy ion irradiation along with some aspects of physics-based numerical simulation of heat transfer processes are presented.
文摘The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.
基金Supported by the Test Station Program of Sagittaria sagittifolia as the Feature Crop of Pingle,Guangxi Province(Gui TS201409)~~
文摘[Objective] To screen the optimal fertilizer formula, and to lay foundation for the research on special fertilizer for Sagittaria sagittifolia production. [Method] Based on the "3414" fertilization design, the yield of S. sagittifolia in each treatment was determined, and the effects of N, P and K treatments on the yield and eco- nomic benefit of S. sagittifolia were investigated, obtaining the optimal fertilizer appli- cation ratio. [Result] N, P and K had relatively good effects on the yield of S. sagittifolia. Treatment of N2P2K3 showed the optimal fertilizer application ratio, with the yield of 18 397.80 kg/hm2, yield increasing rate of 104.77%, and net income in- crease of 80 317.35 Yuan/hm2. N fertilizer had the greatest impacts on the yield of S. sagittifolia, followed with K fertilizer; while P fertilizer showed the poorest impacts. [Conclusion] To achieve the highest yield of S. sagittifolia, the fertilizer application was as follows: N of 446.70 kg/hm2, P20 of 568.10 kg/hm2, K2O of 534.90 kg/hm2, when the highest yield was 18 612.75 kg/hm2. Fertilizer application for the optimal economic benefit was N of 420.60 kg/hm2, P2O5 of 70.50 kg/hm2, K2O of 492.15 kg/hm2, when the optimal yield was 18 579.00 kg/hm2.
基金Supported by the Science and Technology Major Project of Guizhou Province(Qiankehe Major Special Projects(2007)6013)~~
文摘This study was aimed to develop the Chinese herbal formula with dysentery arresting and antidiarrheal effect. [Method] The Chinese herbal for-mulation was used to carry out the clinical curative effect test and pharmacological test for il livestock. [Results] Curative effect test showed that the formula had good effect on abdominal pain, diarrhea and fecal changes of livestock, and the cure rate reached up to 92%. Pharmacological experiments showed that the formula had sig-nificant inhibitory effect on the gastrointestinal motility of the tested animals, and the diarrhea arresting and dysentery treating effect of the formula was also extremely significant. In addition, the formula was safe for tested animals, proving to be reli-able. [Conclusion] The formula has distinct curative effect on treating white scour of piglets, yel ow scour of piglets, livestock gastroenteritis and lienteric diarrhea, and it can also be used in veterinary clinic, as wel as be used as feed additive.
基金financially supported by the National Natural Science Foundation of China(Grant No.51239007)
文摘The size and shape of the effective test area are crucial to consider when short-crested waves are created by segmented wavemakers. The range of the effective test area of short-crested waves simulated by two-sided segmented wavemakers is analyzed in this paper. The experimental investigation on the wave field distribution of short-crested waves generated by two-sided segmented wavemakers is conducted by using an array of wave gauges. Wave spectra and directional spreading function are analyzed and the results show that when the main direction is at a certain angle with the normal line of wave generators, the wave field of 3D short-crested waves generated by two-sided segmented wavemakers has good spatial uniformity within the model test area. The effective test area can provide good wave environments for seakeeping model tests of various ocean engineering structures in the deep ocean engineering basin.
基金supported by the National Natural Science Foundation of China (90715040)
文摘Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings have seldom been studied so far due to the huge workload involved in experiments and data processing.In this paper,mean and dynamic force/response interference effects and peak wind pressure interference effects of two and three tall buildings,especially the three-building configuration,are investigated through a series of wind tunnel tests on typical tall building models using high frequency force balance technique and wind pressure measurements.Furthermore,the present paper focuses on the effects of parameters,including breadth ratio and height ratio of the buildings and terrain category,on the interference factors and derives relevant regression results for the interference factors.
基金Financial supports provided by Science and Technological Fund of Anhui Province for Outstanding Youth(No.08040106830)National Natural Sciences Foundation of China(No.41172274)
文摘Various field investigations of earthquake disaster cases have confirmed that earthquake-induced liquefaction is a main factor causing significant damage to dyke,research on seismic performances of dyke is thus of great importance.In this paper,seismic responses of dyke on liquefiable soils were investigated by means of dynamic centrifuge model tests and three-dimensional(3D) effective stress analysis method which is based on a multiple shear mechanism model and a liquefaction front.For the prototype scale centrifuge tests,sine wave input motions with peak accelerations 0.806 m/s2,1.790 m/s2 and 3.133 m/s2 of varied amplitudes were adopted to study the seismic performances of dyke on the saturated soil layer foundation with relative density of approximately 30%.Then,corresponding numerical simulations were conducted to investigate the distribution and variations of deformation,acceleration,excess pore-water pressure(EPWP),and behaviors of shear dilatancy in the dyke and the liquefiable soil foundation.Moreover,detailed discussions and comparisons between numerical simulations and centrifuge tests were also presented.It is concluded that the computed results have a good agreement with the measured results by centrifuge tests.The physical and numerical models both indicate that the dyke hosted on liquefiable soils subjected to earthquake motions has exhibited larger settlement and lateral spread:the stronger the motion is,the larger the dyke deformation is.Compared to soils in the deep ground under the dyke and the free field,the EPWP ratio is much smaller in the shallow liquefiable soil beneath the dyke in spite of large deformation produced.For the same overburden depth soil from free site and the liquefiable foundation beneath dyke,the characteristics of effective stress path and stress-strain relations are different.All these results may be of theoretical and practical significance for seismic design of the dyke on liquefiable soils.
基金financially supported by project (Grant NO. U1502232, U1033601)-National Science Foundation of China-Yunnan Joint Fundproject (Grant NO. 20135314110005)-Research Fund for the Doctoral Program of Higher Education of China
文摘Tailings impoundments can potentially collapse due to damage caused by earthquakes,which has frequently occurred around the world.This study takes the proposed valley type tailings impoundment in Yunnan as the research object to analyze the dynamic response behavior under earthquake action with both numerical simulation and physical model test(1:300).The results of both tests show that the dynamic response of the valley type tailings impoundment is characterized by"medium stiffness effect",in other words,in a certain range,the"softer"the unsaturated tailings sand is,the more energy it can dissipate,which leads the decrease of the value of the acceleration amplification factor.In addition,the peak acceleration of the monitoring points increases with the vertical elevation,which indicates that the"elevation amplification effect"exists in the tailings impoundment dynamic response.The middle part of the outer side of the raised embankment reacts more sensitive than the crest,which is similar to the slope dynamic response.The starter dam reacts sensitively under the earthquake excitation,which should be given more attention during the seismic design.The dynamic response rules reflected by the numerical simulation are consistent with the results monitored on the physical model test,although there are some differences between their values.The dynamic response rules of the valley type tailings impoundment can provide basis for the design of the similar projects in this region.
文摘A human K562 leukaemia call and acute adult leudaemia patient samples have been used to test the efficacy of antineoplastic agents with MTT assay.All 18 drugs were invoved.According to the purpose of experiment these durgs were applied at different opportunities or combinations.The drug efficacy has been observed and summarized as four different conditions:1.the change of the time(△ T )closely related with drug effacacy, during the duration the change of drug concentration(△ C) at certain extent has almost no influence; 2the △ C closely related with the efficacy, the △ T has no influence;3. The △ C and △ T effect the results together;and 4.the △ C and △ T effect not the result. And then draw a conclution that the process or drug effacacy has a multiple function with flat distrtct.
基金Supported by the National Natural Science Foundation of China under Grant No 11690044
文摘Ion photon emission microscopy (IPEM) is a new ion-induced emission microscopy. It employs a broad ion beam with high energy and low fluence rate impinging on a sample. The position of a single ion is detected by an optical system with objective lens, prism, microscope tube and charge coupled device (CCD). A thin ZnS film doped with Ag ions is used as a luminescent material. Generation efficiency and transmission efficiency of photons in the ZnS(Ag) film created by irradiated Cl ions are calculated. A single Cl ion optical microscopic image is observed by high quantum efficiency CCD. The resolution of a single Cl ion given in this IPEM system is 6μm. Several factors influencing the resolution are discussed. A silicon diode is used to collect the electrical signals caused by the incident ions. Effective and accidental coincidence of optical images and electronic signals are illustrated. A two-dimensional map of single event effect is drawn out according to the data of effective coincidence.
文摘[Objective] The aim was to study the obtaining method of meticulous climate forecast product and test its forecast effect. [Method] Based on the national standard surface observation data and secondary data bank obtained by means of distance weight interpolation method, the model of climate forecast was established, and the timing, fixed-point and quantitative meticulous climate forecast of meteorological elements was obtained by using many forecast methods and artificial revision, finally the forecast effect was tested. [Result] At present, meticulous climate forecast system was used to predict the daily, five-day, ten-day, monthly, seasonal and annual variation of six meteorological elements (including average temperature, maximum temperature, minimum temperature, precipitation, average pressure and sunshine) in 10 meteorological stations in Guangzhou City. The forecast effect of meteorological elements in 10 stations in Guangzhou City from 2006 to 2010 was tested, and the average scores of monthly precipitation, average temperature, maximum temperature and minimum temperature were 75.0, 94.5, 98.6 and 88.9, respectively, while the scores of five-day meteorological elements were 77.1, 90.6, 90.1 and 82.8, which met the requirement of objective management of Guangdong Meteorological Observatory. [Conclusion] Meticulous climate forecast system could be widely used in the forecast of agricultural meteorological disasters and fixed-point forecast in large reservoir, new airport and nuclear power station.
文摘Many experiments have been conducted on accidents and transients of pressurized water reactor (PWR) employing the rig of safety assessment/large-scale test facility (ROSA/LSTF). Recent research activities concerned with the OECD/NEA international joint projects included experimental investigation via the ROSA and ROSA-2 Projects, and counterpart testing with thermal-hydraulic integral test facilities under collaboration of the PKL-2, PKL-3, ATLAS, and ATLAS-2 Projects. Major results of the related integral effect tests (IETs) with the LSTF were reviewed to experimentally identify thermal-hydraulic phenomena involved, regarding the PWR accident sequences in accordance with the new regulatory requirements for the Japanese light-water nuclear power plants. Future separate effect test using the LSTF is planned to simulate loss of emergency core cooling system (ECCS) recirculation functions in a large-break loss-of-coolant accident (LOCA). Key results of the recent IETs utilizing the LSTF and future plans were presented relevant to multiple steam generator tube rupture accident with recovery operation, small-break LOCA with accident management measure on core exit temperature reliability, and small-break LOCA with thermal stratification under cold water injection from ECCS into cold legs. Also, main outcomes of the LSTF IETs were indicated for wide spectrum LOCA with core uncovery and anticipated transient without scram following small-break LOCA under totally failed high-pressure injection system.
文摘In a wood processing factory, the measured air concentration of birchen dust was 1. 26 ±0. 41 mg/m3, and the micronucleus frequency of peripheral blood lymphocytes in 83 workersexposed to wood dust was 1. 13 ± 2. 83%, which was significantly higher (P < 0.01 ) thanthat of control group (0. 51 ± 1. 41% ). The number of exposed workers with positive mi-cronucleus test was 9. 6 %, which was higher than that of control group (4. 5 % ), but thedifference was not significant (P >0. 05 ). The micronucleus test in mice treated with waterextracts of unsteamed and unbaked birchen dust showed that the micronucleus frequencies inall treated groups were significantly higher than that of contro group (P < 0. 01 ) and therewas also a doseresponse correlation (r = 0. 96, P < 0. 0005 ). The results of steamed andbaked birchen dust extracts were significantly lower than those of the unsteamed and unbakedones at the same doses (P< 0. 001 ). This suggests that when the birchen dust is steamed atthe temperature of 100℃ for 24h or baked at the temperature of 80℃, its inducing effect inmicronucleus test could be lowered
基金the National Natural Science Foundation of China (Nos. 60473033 and 60173029)
文摘Traditionally, timing and the failure rate are the only two factors considered in software reliability formula, which is actually incomplete. Reliability should be redefined as a function of software complexity, test effectiveness, and operating environment. This paper focuses on software complexity with its relation to the soft- ware reliability. Today, many software complexity measurements have been proposed, but most of them treat the reliability model incompletely. This paper proposes a new method which considers a relatively complete view of software reliability including its complexity and test effectiveness of the software being tested.
基金the National Natural Science Foundation of China (No. 60473033)
文摘Although mutation testing is one of the practical ways of enhancing test effectiveness in software testing, it could be sometimes infeasible in practical work for a large scale software so that the mutation testing becomes time-consuming and even in prohibited time. Therefore, the number of faults assumed to exist in the software under test should be reduced so as to be able to confine the time complexity of test within a reasonable period of time. This paper utilizes the concept of fault dominance and equivalence, which has long been employed in hardware testing, for revealing a novel way of reducing the number of faults assumed to hide in software systems. Once the number of faults assumed in software is decreased sharply, the effectiveness of mutation testing will be greatly enhanced and become a feasible way of software testing. Examples and experimental results are presented to illustrate the effectiveness and the helpfulness of the technology proposed in the paper.
文摘The production-oriented approach (POA) has been developed over a decade. It is driven by the need to improve English classroom instruction for university students in China (Wen, 2016). It is also motivated by the aspiration to enhance the quality of foreign language education in other similar pedagogical contexts outside China. A volume of research has been done by Wen Qiufang and her research team, to formulate the theory of POA and to test its effectiveness in classroom pedagogy (e.g. Wen, 2016, 2015; Yang, 2015; Zhang, 2015). At the moment, the POA is still at an early stage of theory building and almost all empirical research is done in the Chinese context. In order to improve the quality of this theory and to make it intelligible to the international academic community, a one-day symposium was held in Beijing Foreign Studies University on May 15, 2017. The symposium was entitled 'The first international forum on innovative foreign language education in China: Appraisal of the POA'. In the forum, leading experts in applied linguistics were invited to discuss the strengths and weaknesses of the POA and the directions for its future development. The symposium was the first attempt for the POA research team to discuss its latest work with international scholars. This Viewpoint section collects the responses of four experts who participated in the symposium, listed in alphabetical order. The collection of articles covers three topics related to the POA: its pedagogical application, its use for teacher training, and its research. Alister Cumming is Professor Emeritus and the former Head of the Centre for Educational Research on Languages and Literacies, University of Toronto, Canada. His article focuses primarily on POA research as an exemplary case of design-based research. Rod Ellis is Research Professor in the School of Education at Curtin University, Australia. He discusses POA in terms of pedagogy, teacher training and research, with both critiques and constructive suggestions. Paul Kei Matsuda is Professor of English and Director of Second Language Writing at Arizona State University, the writed states. He responds to POA from the perspective of an expert researcher and teacher of L2 writing. Charlene Polio is Professor and Associate Chair in the Department of Linguistics & Germanic, Slavic, Asian & African Languages atMichigan State University, the writed states. She conceptualises POA as a useful method to address some issues in pre-service teacher development. Overall, the articles in this section are insightful and reader-friendly. They are not only useful for the development of POA in particular, but may also be valuable to a broad range of researchers as they touch upon pertaining issues, as well as emerging topics, in the field of applied linguistics. We therefore find it necessary to make them accessible to a wide readership.