Two deficiencies in traditional iterative closest pointsimultaneous localization and mapping( ICP-SLAM) usually result in poor real-time performance. On one hand, relative position between current scan frame and globa...Two deficiencies in traditional iterative closest pointsimultaneous localization and mapping( ICP-SLAM) usually result in poor real-time performance. On one hand, relative position between current scan frame and global map cannot be previously known. As a result, ICP algorithm will take much amount of iterations to reach convergence. On the other hand,establishment of correspondence is done by global searching, which requires enormous computational time. To overcome the two problems,a fast ICP-SLAM with rough alignment and narrowing-scale nearby searching is proposed. As for the decrease of iterative times,rough alignment based on initial pose matrix is proposed. In detail,initial pose matrix is obtained by micro-electro-mechanical system( MEMS) magnetometer and global landmarks. Then rough alignment will be applied between current scan frame and global map at the beginning of ICP algorithm with initial pose matrix. As for accelerating the establishment of correspondence, narrowingscale nearby searching with dynamic threshold is proposed,where match-points are found within a progressively constrictive range.Compared to traditional ICP-SLAM,the experimental results show that the amount of iteration for ICP algorithm to reach convergence reduces to 92. 34% and ICP algorithm runtime reduces to 98. 86% on average. In addition,computational cost is kept in a stable level due to the eliminating of the accumulation of computational consumption. Moreover,great improvement can also been achieved in SLAM quality and robustness.展开更多
An analysis was performed of the turbulent data obtained from Yucheng experimental station in the Shandong Province in 1984. [t is shown that at variant wind speed, the spectra of streamwise velocity remain similar an...An analysis was performed of the turbulent data obtained from Yucheng experimental station in the Shandong Province in 1984. [t is shown that at variant wind speed, the spectra of streamwise velocity remain similar and the intensity of wind fluctuations is proportional to wind speed in the downwind area of shelter belt. Therefore, we may decide the similarity of wind fluctuations by a speed scale and a length scale which is not correlated with stability, σu /V0 = F(X / H). The -5/3 power range of temperature spectra extends to lower frequency. The variation of ratio σ0 /T. with stability becomes σ0 / T . = C(X / H)( - Z / L)-1/3 . There is not such an extension of -5 / 3 power range in the humidity spectra.展开更多
We observed the nearby galaxy M31 in the 〔C II〕158 μm emission line. An extended component was detected over the central 1 5 kpc region with a line-to-continuum ratio of 〔C II〕/〔40-120μm〕6×10 -3 . This ra...We observed the nearby galaxy M31 in the 〔C II〕158 μm emission line. An extended component was detected over the central 1 5 kpc region with a line-to-continuum ratio of 〔C II〕/〔40-120μm〕6×10 -3 . This ratio is 3 times larger than that of the Galactic counterpart and is comparable to that in the general Galactic Plane. We expect that the difference between the two central regions are due to different gas densities; the self-shielding of CO molecules decreases the C + abundance at the higher density in the Galactic case.展开更多
Abundance of total bacteria, heterotrophic bacteria, coliform and oil degradable bacteria and their relations with salinity and suspended matter in the frontal waters in the Hangzhou Bay are described. The results obt...Abundance of total bacteria, heterotrophic bacteria, coliform and oil degradable bacteria and their relations with salinity and suspended matter in the frontal waters in the Hangzhou Bay are described. The results obtained show that the highest abundances of total bacteria , heterotrophic bacteria are encountered around the front and near the northern shore of the Hangzhou Bay, where a positive correlation ( r =0. 70) between the total bacteria abundance and the total suspended matter (TSM) is persent. Moreover,the abundance of oil degradable bacteria being an indicator of oil pollution, is also high in that region.展开更多
The pointed observations of NGC3077 are analyzed by position sensitive proportional counter (PSPC) on board the ROSAT satellite on 1991-04-18, 1991, finding out that the X-ray emission range of M81 galaxy has, in the ...The pointed observations of NGC3077 are analyzed by position sensitive proportional counter (PSPC) on board the ROSAT satellite on 1991-04-18, 1991, finding out that the X-ray emission range of M81 galaxy has, in the softer and more sensitive ROSAT PSPC band (0. 2-2. 4 keV), extended by 40% larger than ever observed by image proportional counter (IPC) on board the Einstein satellite, which shows that M81 galaxy has a larger X-ray corona. And by the aid of the timing analysis, it is concluded that M81 nucleus has no variabilities on time scale of a few minutes; hence the possibility of M81 nucleus having the marginal variability over time scale of about 2 min that Fabbiano (1988) found from the Einstein IPC observation is ruled out.展开更多
In this paper,we consider the families of nearby singular diffeomorphism and the measure of a set in the parameter space,such that for each point of the set the corresponding diffeomorphism possesses strange attractor...In this paper,we consider the families of nearby singular diffeomorphism and the measure of a set in the parameter space,such that for each point of the set the corresponding diffeomorphism possesses strange attractor.For some families of one-dimensional mapping satisfying certain transversality condition,we prove that there is a positive measure set in the parameter space, such that the system in the corresponding families of nearly singular diffeomorphism has strange attractor.Furthermore,we study the dynamics of this type of strange attractor.展开更多
2015年11月26日,《加拿大岩土工程学报》（Canadian Geotechnical Journal）发表文章《针对流体注入诱发地震活动及激活断层的离散单元模型》（Discrete element modeling of fluid injection-induced seismicity and activation of nea...2015年11月26日,《加拿大岩土工程学报》（Canadian Geotechnical Journal）发表文章《针对流体注入诱发地震活动及激活断层的离散单元模型》（Discrete element modeling of fluid injection-induced seismicity and activation of nearby fault）,展开更多
This paper uses the fifth and sixth census data and 2018 demographic statistics to analyze the spatiotemporal evolution of the urbanization of county in China and the factors that influence the evolution.The paper rev...This paper uses the fifth and sixth census data and 2018 demographic statistics to analyze the spatiotemporal evolution of the urbanization of county in China and the factors that influence the evolution.The paper reveals that the urbanization level of counties is a weak area in China’s overall urbanization.During the period from 2000 to 2010,the spatial patterns of the urbanization level of counties remained stable.Counties with high-level urbanization were concentrated in the coastal areas of the eastern region,while counties that experienced rapid urbanization were mainly located in the central and western regions.Regression analyses indicate that harsh natural endowments that constrain economic development are the most important factors that hinder the urbanization of county;these factors include marginalized locations far away from center cities,high altitudes,and a population with a low education level.This paper also compares two theoretical modes of new-type urbanization,nearby urbanization and remote urbanization,and argues that the new-type urbanization of county is the main form of nearby urbanization and provides an example of urbanization for developing countries worldwide.展开更多
China has entered a new stage of high-quality urbanization.Therefore,it is critical to grasp the latest population distribution and dynamics.Using mean-variance grading,Moran’s index,and the Theil index,this study co...China has entered a new stage of high-quality urbanization.Therefore,it is critical to grasp the latest population distribution and dynamics.Using mean-variance grading,Moran’s index,and the Theil index,this study compared the differences in population changes between 2010–2020 and 2000–2010 at the prefecture-level city scale based on census data to analyze the new trends in population evolution.We found that:(1)New growth poles of the population are inland provincial capitals,forming rapid-growing zones together with coastal urban agglomerations.Population growth in over 60%of the cities in the northern coastal urban agglomeration has slowed.(2)The scope of population loss in inland areas is constantly expanding.In the northeastern part of China,92.7%of the cities have lost population,making this a typical population loss area.(3)Population shrinkage in the northeastern region and growth in the Pearl River Delta urban agglomeration show diffusion characteristics,while population patterns around the provincial capital are in a polarized stage.(4)The Theil index of population distribution increased,with 83.91%of differences coming from between groups,indicating that the gap between cities of different sizes has further expanded.This study provides scientific support for the coordinated promotion of nearby and remote urbanization.展开更多
The video compression sensing method based onmulti hypothesis has attracted extensive attention in the research of video codec with limited resources.However,the formation of high-quality prediction blocks in the mult...The video compression sensing method based onmulti hypothesis has attracted extensive attention in the research of video codec with limited resources.However,the formation of high-quality prediction blocks in the multi hypothesis prediction stage is a challenging task.To resolve this problem,this paper constructs a novel compressed sensing-based high-quality adaptive video reconstruction optimizationmethod.Itmainly includes the optimization of prediction blocks(OPBS),the selection of searchwindows and the use of neighborhood information.Specifically,the OPBS consists of two parts:the selection of blocks and the optimization of prediction blocks.We combine the high-quality optimization reconstruction of foreground block with the residual reconstruction of the background block to improve the overall reconstruction effect of the video sequence.In addition,most of the existing methods based on predictive residual reconstruction ignore the impact of search windows and reference frames on performance.Therefore,Block-level search window(BSW)is constructed to cover the position of the optimal hypothesis block as much as possible.To maximize the availability of reference frames,Nearby reference frame information(NRFI)is designed to reconstruct the current block.The proposed method effectively suppresses the influence of the fluctuation of the prediction block on reconstruction and improves the reconstruction performance.Experimental results showthat the proposed compressed sensing-based high-quality adaptive video reconstruction optimization method significantly improves the reconstruction performance in both objective and supervisor quality.展开更多
Sum frequency generation spectroscopy（SFG） has been widely used to study the interfacial chemistry of aqueous salt solutions of biological or environmental importance. Most of the SFG data analysis used the same bul...Sum frequency generation spectroscopy（SFG） has been widely used to study the interfacial chemistry of aqueous salt solutions of biological or environmental importance. Most of the SFG data analysis used the same bulk refractive index for different salt concentrations despite of the variations of the refractive indices. Here we systematically investigate the influence of the refractive index on the SFG intensities at various experimental conditions. It is discovered that the SFG intensities are the most sensitive to the refractive index at solid/liquid interfaces nearby the total internal reflection geometries. At air/liquid interfaces, the effect of the refractive indices is also nonegligible. Consequently some important SFG results, such as the response of water structures to the ionic strength at the SiO2/aqueous interfaces, are necessary to be reevaluated. These conclusions on the effect of the small variations of the refractive index are generally useful for the common practice of SFG data analysis.展开更多
To ascertain whether the gene expression is altered byexposure of living organisms to strong magnetic field,4-7 days old males of fruit fly Drosophila melanogasterwere exposed to 10,000 G static magnetic field
The cavitation dynamics and mechanical stress in viscoelastic tissues, as the primary mechanisms of some ultrasound therapies, are extremely complex due to the interactions of cavitation bubble with adjacent bubbles a...The cavitation dynamics and mechanical stress in viscoelastic tissues, as the primary mechanisms of some ultrasound therapies, are extremely complex due to the interactions of cavitation bubble with adjacent bubbles and surrounding tissues.Therefore, the cavitation dynamics and resultant mechanical stress of two-interacting bubbles in the viscoelastic tissues are numerically investigated, especially focusing on the effects of the adjacent bubble. The results demonstrate that the mechanical stress is highly dependent on the bubble dynamics. The compressive stress and tensile stress are generated at the stage of bubble expansion and collapse stage, respectively. Furthermore, within the initial parameters examined in this paper, the effects of the adjacent bubble will distinctly suppress the radial expansion of the small bubble and consequently lead its associated stresses to decrease. Owing to the superimposition of two stress fields, the mechanical stresses surrounding the small bubble in the direction of the neighboring bubble are smaller than those in other directions. For two interacting cavitation bubbles, the suppression effects of the nearby bubble on both the cavitation dynamics and the stresses surrounding the small bubble increase as the ultrasound amplitude and the initial radius of the large bubble increase, whereas they decrease with the inter-bubble distance increasing. Moreover, increasing the tissue viscoelasticity will reduce the suppression effects of the nearby bubble, except in instances where the compressive stress and tensile stress first increase and then decrease with the tissue elasticity and viscosity increasing respectively. This study can provide a further understanding of the mechanisms of cavitation-associated mechanical damage to the adjacent tissues or cells.展开更多
"Wesincerely hope that not only Mercedes Benz can realize an increase in car sales volume in China for35 months in line,but also Geely will get popular in Europe;not only can we go to Carrefour after work,but als..."Wesincerely hope that not only Mercedes Benz can realize an increase in car sales volume in China for35 months in line,but also Geely will get popular in Europe;not only can we go to Carrefour after work,but also these Europeans can shop in a Wangfujing Department Store nearby,"said Jiang Zengwei,Chairman of China Council for the Promotion of International Trade(CCPIT),at the symposium展开更多
The 28-year-old had spent six years working at night whileshe attended university during the day.“I always wanted to be ateacher,”she says,“and I worked hard to earn my degree.When Ifinally graduated.I was very opt...The 28-year-old had spent six years working at night whileshe attended university during the day.“I always wanted to be ateacher,”she says,“and I worked hard to earn my degree.When Ifinally graduated.I was very optimistic.”She had her eye on ateaching position at a nearby primary school.展开更多
During the war, a fighter pilot was injured. Fortunately, he wassaved by a group-of nuns from a nearby convent. He had beenvery weak, and lost his sense When he came to, he was astonished t^find a woman beside him. It...During the war, a fighter pilot was injured. Fortunately, he wassaved by a group-of nuns from a nearby convent. He had beenvery weak, and lost his sense When he came to, he was astonished t^find a woman beside him. It was Sister Mary, the nun in charge. She said to the pilot,'This convent is a teaching hospital. We have many young girls here,learning to be nurses. We will hide you here as long as possible,展开更多
hand作为名词时,常与不同的介词搭配.表示不同的意义。常见的有atband、in hand,on band,by hand,to bud等.如果不弄清楚它们各自的意义、用法,在使用时就很容易出现错误。现将它们的用法比较如下: (1)at hand表示“在时间、空间上临近...hand作为名词时,常与不同的介词搭配.表示不同的意义。常见的有atband、in hand,on band,by hand,to bud等.如果不弄清楚它们各自的意义、用法,在使用时就很容易出现错误。现将它们的用法比较如下: (1)at hand表示“在时间、空间上临近”或”在手头”.包含有“即可使用”之意,相当于nearby;near;coming:ready for use ①The summer vacation is at hand.暑假马上就到了。②It is easy to find him.He lives close at hand. 要找到他很容易,他就住在附近. ③I didn’t buy the coat because I had no money at hand. 因为手里没钱,我没有买那件外套.展开更多
文摘Two deficiencies in traditional iterative closest pointsimultaneous localization and mapping( ICP-SLAM) usually result in poor real-time performance. On one hand, relative position between current scan frame and global map cannot be previously known. As a result, ICP algorithm will take much amount of iterations to reach convergence. On the other hand,establishment of correspondence is done by global searching, which requires enormous computational time. To overcome the two problems,a fast ICP-SLAM with rough alignment and narrowing-scale nearby searching is proposed. As for the decrease of iterative times,rough alignment based on initial pose matrix is proposed. In detail,initial pose matrix is obtained by micro-electro-mechanical system( MEMS) magnetometer and global landmarks. Then rough alignment will be applied between current scan frame and global map at the beginning of ICP algorithm with initial pose matrix. As for accelerating the establishment of correspondence, narrowingscale nearby searching with dynamic threshold is proposed,where match-points are found within a progressively constrictive range.Compared to traditional ICP-SLAM,the experimental results show that the amount of iteration for ICP algorithm to reach convergence reduces to 92. 34% and ICP algorithm runtime reduces to 98. 86% on average. In addition,computational cost is kept in a stable level due to the eliminating of the accumulation of computational consumption. Moreover,great improvement can also been achieved in SLAM quality and robustness.
文摘An analysis was performed of the turbulent data obtained from Yucheng experimental station in the Shandong Province in 1984. [t is shown that at variant wind speed, the spectra of streamwise velocity remain similar and the intensity of wind fluctuations is proportional to wind speed in the downwind area of shelter belt. Therefore, we may decide the similarity of wind fluctuations by a speed scale and a length scale which is not correlated with stability, σu /V0 = F(X / H). The -5/3 power range of temperature spectra extends to lower frequency. The variation of ratio σ0 /T. with stability becomes σ0 / T . = C(X / H)( - Z / L)-1/3 . There is not such an extension of -5 / 3 power range in the humidity spectra.
文摘We observed the nearby galaxy M31 in the 〔C II〕158 μm emission line. An extended component was detected over the central 1 5 kpc region with a line-to-continuum ratio of 〔C II〕/〔40-120μm〕6×10 -3 . This ratio is 3 times larger than that of the Galactic counterpart and is comparable to that in the general Galactic Plane. We expect that the difference between the two central regions are due to different gas densities; the self-shielding of CO molecules decreases the C + abundance at the higher density in the Galactic case.
文摘Abundance of total bacteria, heterotrophic bacteria, coliform and oil degradable bacteria and their relations with salinity and suspended matter in the frontal waters in the Hangzhou Bay are described. The results obtained show that the highest abundances of total bacteria , heterotrophic bacteria are encountered around the front and near the northern shore of the Hangzhou Bay, where a positive correlation ( r =0. 70) between the total bacteria abundance and the total suspended matter (TSM) is persent. Moreover,the abundance of oil degradable bacteria being an indicator of oil pollution, is also high in that region.
文摘The pointed observations of NGC3077 are analyzed by position sensitive proportional counter (PSPC) on board the ROSAT satellite on 1991-04-18, 1991, finding out that the X-ray emission range of M81 galaxy has, in the softer and more sensitive ROSAT PSPC band (0. 2-2. 4 keV), extended by 40% larger than ever observed by image proportional counter (IPC) on board the Einstein satellite, which shows that M81 galaxy has a larger X-ray corona. And by the aid of the timing analysis, it is concluded that M81 nucleus has no variabilities on time scale of a few minutes; hence the possibility of M81 nucleus having the marginal variability over time scale of about 2 min that Fabbiano (1988) found from the Einstein IPC observation is ruled out.
基金Project Supported by Fund of National Science of China
文摘In this paper,we consider the families of nearby singular diffeomorphism and the measure of a set in the parameter space,such that for each point of the set the corresponding diffeomorphism possesses strange attractor.For some families of one-dimensional mapping satisfying certain transversality condition,we prove that there is a positive measure set in the parameter space, such that the system in the corresponding families of nearly singular diffeomorphism has strange attractor.Furthermore,we study the dynamics of this type of strange attractor.
文摘2015年11月26日,《加拿大岩土工程学报》（Canadian Geotechnical Journal）发表文章《针对流体注入诱发地震活动及激活断层的离散单元模型》（Discrete element modeling of fluid injection-induced seismicity and activation of nearby fault）,
基金The Second Tibetan Plateau Scientific Expedition and Research Program,No.2019QZKK0406National Natural Science Foundation of ChinaNo.42171204。
文摘This paper uses the fifth and sixth census data and 2018 demographic statistics to analyze the spatiotemporal evolution of the urbanization of county in China and the factors that influence the evolution.The paper reveals that the urbanization level of counties is a weak area in China’s overall urbanization.During the period from 2000 to 2010,the spatial patterns of the urbanization level of counties remained stable.Counties with high-level urbanization were concentrated in the coastal areas of the eastern region,while counties that experienced rapid urbanization were mainly located in the central and western regions.Regression analyses indicate that harsh natural endowments that constrain economic development are the most important factors that hinder the urbanization of county;these factors include marginalized locations far away from center cities,high altitudes,and a population with a low education level.This paper also compares two theoretical modes of new-type urbanization,nearby urbanization and remote urbanization,and argues that the new-type urbanization of county is the main form of nearby urbanization and provides an example of urbanization for developing countries worldwide.
基金National Natural Science Foundation of China,No.42121001,No.42171204,No.41822104。
文摘China has entered a new stage of high-quality urbanization.Therefore,it is critical to grasp the latest population distribution and dynamics.Using mean-variance grading,Moran’s index,and the Theil index,this study compared the differences in population changes between 2010–2020 and 2000–2010 at the prefecture-level city scale based on census data to analyze the new trends in population evolution.We found that:(1)New growth poles of the population are inland provincial capitals,forming rapid-growing zones together with coastal urban agglomerations.Population growth in over 60%of the cities in the northern coastal urban agglomeration has slowed.(2)The scope of population loss in inland areas is constantly expanding.In the northeastern part of China,92.7%of the cities have lost population,making this a typical population loss area.(3)Population shrinkage in the northeastern region and growth in the Pearl River Delta urban agglomeration show diffusion characteristics,while population patterns around the provincial capital are in a polarized stage.(4)The Theil index of population distribution increased,with 83.91%of differences coming from between groups,indicating that the gap between cities of different sizes has further expanded.This study provides scientific support for the coordinated promotion of nearby and remote urbanization.
基金supported by the National Natural Science Foundation of China under Grant No.61806138KeyR&DProgram of Shanxi Province(International Cooperation)under Grant No.201903D421048+1 种基金National Key Research and Development Program of China under Grant No.2018YFC1604000School Level Postgraduate Education Innovation Projects under Grant No.XCX212082.
文摘The video compression sensing method based onmulti hypothesis has attracted extensive attention in the research of video codec with limited resources.However,the formation of high-quality prediction blocks in the multi hypothesis prediction stage is a challenging task.To resolve this problem,this paper constructs a novel compressed sensing-based high-quality adaptive video reconstruction optimizationmethod.Itmainly includes the optimization of prediction blocks(OPBS),the selection of searchwindows and the use of neighborhood information.Specifically,the OPBS consists of two parts:the selection of blocks and the optimization of prediction blocks.We combine the high-quality optimization reconstruction of foreground block with the residual reconstruction of the background block to improve the overall reconstruction effect of the video sequence.In addition,most of the existing methods based on predictive residual reconstruction ignore the impact of search windows and reference frames on performance.Therefore,Block-level search window(BSW)is constructed to cover the position of the optimal hypothesis block as much as possible.To maximize the availability of reference frames,Nearby reference frame information(NRFI)is designed to reconstruct the current block.The proposed method effectively suppresses the influence of the fluctuation of the prediction block on reconstruction and improves the reconstruction performance.Experimental results showthat the proposed compressed sensing-based high-quality adaptive video reconstruction optimization method significantly improves the reconstruction performance in both objective and supervisor quality.
基金financially supported by the National Natural Science Foundation of China(Nos.21227802,21303216 and21473217)
文摘Sum frequency generation spectroscopy（SFG） has been widely used to study the interfacial chemistry of aqueous salt solutions of biological or environmental importance. Most of the SFG data analysis used the same bulk refractive index for different salt concentrations despite of the variations of the refractive indices. Here we systematically investigate the influence of the refractive index on the SFG intensities at various experimental conditions. It is discovered that the SFG intensities are the most sensitive to the refractive index at solid/liquid interfaces nearby the total internal reflection geometries. At air/liquid interfaces, the effect of the refractive indices is also nonegligible. Consequently some important SFG results, such as the response of water structures to the ionic strength at the SiO2/aqueous interfaces, are necessary to be reevaluated. These conclusions on the effect of the small variations of the refractive index are generally useful for the common practice of SFG data analysis.
文摘To ascertain whether the gene expression is altered byexposure of living organisms to strong magnetic field,4-7 days old males of fruit fly Drosophila melanogasterwere exposed to 10,000 G static magnetic field
基金Project supported by the National Natural Science Foundation of China (Grant No.11904042)the Natural Science Foundation of Chongqing,China (Grant No.cstc2019jcyj-msxmX0534)the Science and Technology Research Program of Chongqing Municipal Education Commission,China (Grant No.KJQN202000617)。
文摘The cavitation dynamics and mechanical stress in viscoelastic tissues, as the primary mechanisms of some ultrasound therapies, are extremely complex due to the interactions of cavitation bubble with adjacent bubbles and surrounding tissues.Therefore, the cavitation dynamics and resultant mechanical stress of two-interacting bubbles in the viscoelastic tissues are numerically investigated, especially focusing on the effects of the adjacent bubble. The results demonstrate that the mechanical stress is highly dependent on the bubble dynamics. The compressive stress and tensile stress are generated at the stage of bubble expansion and collapse stage, respectively. Furthermore, within the initial parameters examined in this paper, the effects of the adjacent bubble will distinctly suppress the radial expansion of the small bubble and consequently lead its associated stresses to decrease. Owing to the superimposition of two stress fields, the mechanical stresses surrounding the small bubble in the direction of the neighboring bubble are smaller than those in other directions. For two interacting cavitation bubbles, the suppression effects of the nearby bubble on both the cavitation dynamics and the stresses surrounding the small bubble increase as the ultrasound amplitude and the initial radius of the large bubble increase, whereas they decrease with the inter-bubble distance increasing. Moreover, increasing the tissue viscoelasticity will reduce the suppression effects of the nearby bubble, except in instances where the compressive stress and tensile stress first increase and then decrease with the tissue elasticity and viscosity increasing respectively. This study can provide a further understanding of the mechanisms of cavitation-associated mechanical damage to the adjacent tissues or cells.
文摘"Wesincerely hope that not only Mercedes Benz can realize an increase in car sales volume in China for35 months in line,but also Geely will get popular in Europe;not only can we go to Carrefour after work,but also these Europeans can shop in a Wangfujing Department Store nearby,"said Jiang Zengwei,Chairman of China Council for the Promotion of International Trade(CCPIT),at the symposium
文摘The 28-year-old had spent six years working at night whileshe attended university during the day.“I always wanted to be ateacher,”she says,“and I worked hard to earn my degree.When Ifinally graduated.I was very optimistic.”She had her eye on ateaching position at a nearby primary school.
文摘During the war, a fighter pilot was injured. Fortunately, he wassaved by a group-of nuns from a nearby convent. He had beenvery weak, and lost his sense When he came to, he was astonished t^find a woman beside him. It was Sister Mary, the nun in charge. She said to the pilot,'This convent is a teaching hospital. We have many young girls here,learning to be nurses. We will hide you here as long as possible,
文摘hand作为名词时,常与不同的介词搭配.表示不同的意义。常见的有atband、in hand,on band,by hand,to bud等.如果不弄清楚它们各自的意义、用法,在使用时就很容易出现错误。现将它们的用法比较如下: (1)at hand表示“在时间、空间上临近”或”在手头”.包含有“即可使用”之意,相当于nearby;near;coming:ready for use ①The summer vacation is at hand.暑假马上就到了。②It is easy to find him.He lives close at hand. 要找到他很容易,他就住在附近. ③I didn’t buy the coat because I had no money at hand. 因为手里没钱,我没有买那件外套.
