The Olympic Games and Ⅰ

On a hot summer night, Ⅰ went downstairs to cool off myself under the tree after Ⅰ played basketball with my friends. Ⅰ felt a little bored and sleepy. Then Ⅰ turned on the radio. The pro- gram was about the news of the Olympics Games in 2008. Ⅰ learnt that a lot of things would be done before the games were hold. The radio said that now we were improving the natural environment so that we would have a better place to hold the games, that we were bringing in and also self-researehing the high technology so as to help us hold the game more easily, and that we were enhancing our country＇s fame in history culture, economy achievement, politic function and so on. A picture began to form in my mind slowly.     

Load on Bicycle Frame During Cycling with Different Speeds and Gestures

Experiment and dynamic simulation were combined to obtain the loads on bicycle frame. A dynamic model of body-bicycle system was built in ADAMS. Then the body gestures under different riding conditions were captured by a motion analysis system. Dynamic simulation was carried out after the data of body motions were input into the simulation system in ADAMS and a series of loads that the body applied on head tube, seat pillar and bottom bracket were obtained. The results show that the loads on frame and their distribution are apparently different under various riding conditions. Finally, finite element analysis was done in ANSYS, which showed that the stress and its distribution on frame were apparently different when the frame was loaded according to the bicycle testing standard and simulation respectively. An efficient way to obtain load on bicycle frame accurately was proposed, which is significant for the safety of cycling and will also be the basis for the bicycle design of digitalization, lightening and customization.     

Performance of underground heat storage system in a double-film-covered greenhouse

An underground heat storage system in a double-film-covered greenhouse and an adjacent greenhouse without the heat storage system were designed on the basis of plant physiology to reduce the energy consumption in greenhouses. The results indicated that the floor temperature was respectively 5.2℃, 4.6℃ and 2.0 ℃ higher than that of the soil in the adjacent reference greenhouse after heat storage in a clear, cloudy and overcast sky in winter. Results showed that the temperature and humidity were feasible for plant growth in the heat saving greenhouse.     

Three-dimensional water-quality simulation for river based on VOF method

In the present study, considering the transport and transformation processes of variables, a threedimensional water quality model for the river system was established, which coupled the volume of fluid(VOF) method with the k-ε turbulence mathematical model. Then, the water hydrodynamic characteristics and transport processes for BOD_5, NH_(3~-)N and TP were analyzed. The results showed that the water surface of convex bank was a little lower than that of concave bank due to the centrifugal force near the bend, and most concentrations were inferior to the type Ⅴ standard indexes of surface water environmental quality. The model validation indicated that the errors between the simulated and monitored values were comparatively small, satisfying the application demands and providing scientific basis and decision support for the restoration and protection of water quality.     

Test and numerical analysis on performance of reinforced concrete segment in subway tunnel

To investigate the mechanical behavior of segmental lining,a three-dimensional numerical analysis and test using three actual segments were used to analyze the effects of axial force and reinforcement ratio on the failure mechanism and ultimate bearing capacity of segmental lining.Both numerical and test results confirmed that the cracking load,yield and ultimate load were strongly influenced by axial force,and it was also proved that the yield and ultimate load would increase with the increase of reinforcement ratio,but the cracking load was almost not affected.The cracking load,yield and ultimate load are about 28.7%,500% and 460% larger due to the effect of axial force respectively.The comparison between numerical calculation and test results showed that the finite element analysis results were in good agreement with the test results.     

On the application of calcium carbide slag as CO2 absorbent

Calcium carbide slag, generated in the hydrolysis process of calcium carbide, is an potential carbon capture reagent because its main ingredient is Ca(OH)2. Calcium carbide slag, a by-product of a resin factory was used as carbon capture reagent. The change of pH and electrical conductivity (EC) of the calcium carbide slag slurry with different solid-to-liquid ratios, as well as the capture efficiency and dynamics under different temperatures and flow rates of CO2 were studied. The properties of solid were characterized with XRD, TG-DTA, SEM and FT-IR before and after capturing carbon. The results show that the change of pH and EC were greater with low solid-to-liquid ratio than that with high solid-to-liquid ratio. The analysis of XRD and SEM show that the content of CaCO3 increased significantly, which improved that Ca(OH)2 and free CaO were reacted with CO2. The results of TG-DTA and FT-IR show that the physicochemical properties and microstructure of the slag changed after capturing CO2 because of the increase of CaCO3 content. All the results mentioned above improve the feasibility of utilizing calcium carbide slag to capture CO2 and offer a practical way for carbon emission reduction and disposal of wasted calcium carbide slag.     

Outlier detection by means of robust regression estimators for use in engineering science

This study compares the ability of different robust regression estimators to detect and classify outliers. Well-known estimators with high breakdown points were compared using simulated data. Mean success rates （MSR） were computed and used as comparison criteria. The results showed that the least median of squares （LMS） and least trimmed squares （LTS） were the most successful methods for data that included leverage points, masking and swamping effects or critical and concentrated outliers. We recommend using LMS and LTS as diagnostic tools to classify outliers, because they remain robust even when applied to models that are heavily contaminated or that have a complicated structure of outliers.     

Wind-induced internal pressure response for structure with single windward opening and background leakage

Theoretical analysis and wind tunnel tests were carried out to study wind-induced intemal pressure response for the structure with single windward opening and background leakage. Its goveming differential equation was derived by the Bemoulli equation in an unsteady-isentropic form. Numerical examples were provided to study the additive damping caused by background leakage in laminar and turbulent flow, and the influence of background leakage on fluctuating internal pressure response was quantized. A series of models for low-rise building with various opening ratios and background leakage were designed and wind tunnel tests were conducted. It is shown that the fluctuating intemal pressure reduces when the background leakage are considered and that the effect of background leakage can be predicted accurately by the governing differential equation deduced in this paper.     

Experiment and numerical simulation on axial compressive performance of autoclaved fly ash solid brick masonry columns

To study the influence of slenderness on the axial compressive performance of autoclaved fly ash solid brick masonry columns, compression experiments were conducted on 12 samples of autoclaved fly ash solid brick masonry column and 4 samples of fired clay brick masonry column. The damage patterns and compressive performance were compared and analyzed. The experimental results indicate that the compressive bearing capacity decreases as slenderness increases from 3 to 18, and the compressive bearing capacity of the autoclaved fly ash solid brick masonry columns is lower than that of the fired clay brick masonry columns. The formulae for the axial compressive bearing capacity of autoclaved fly ash solid brick masonry columns were derived based on the experiments. The nonlinear FEA program ANSYS was adopted to simulate the behaviors of masonry columns. By comparing the simulation results and experimental results, it is shown that the simulation results agree well with the experimental ones. The rationality and applicability of the simulation results were verified.     

Stable response of axisymmetric two-phase water-saturated soil

Biot's dynamic consolidation equations and Hankel transform were used to derive the integral solutions of stress and displacement for axisymmetric harmonic excitations in the two-phase saturated soil with subjacent rock-stratum. The influence of the coefficient of permeability and loading frequency on the soil displacement at the ground surface were studied. The results showed that higher loading frequency led to more dynamic characteristics; and that the effect of the soil permeability was more obvious at higher frequencies.     

ure filed in molding process and

es were discussed mostly.The factors that affected motorcycle tail cup warpage,such as mould temperature were analyzed,and the cause of warpage and the improving measures for the injection prod     

Flexural Capacity Formula of Diaphragm-Through Joints of Concrete-Filled Square Steel Tubular Columns

Finite element analysis and parametric studies were performed to investigate the flexural capacity of the panel zone of diaphragm-through joints between concretefilled square steel tubular columns and H-shaped steel beams.Through the comparisons of failure modes,load–displacement curves,and bearing capacity,it was found that the flexural capacity of the panel zone of diaphragmthrough joints was determined by the tensile action and influence of the web of H-shaped steel beams,and the axial load should be taken into account.The steel tube and the diaphragm were the major parts of the joint that resisted the bending moment.The contribution of in-filled concrete had little influence on the flexural capacity of the panel zone of the joint and could be neglected.According to the results of these numerical studies,a formula that considered the influence of the web of H-shaped steel beams and the axial load was developed based on the yield lines in the diaphragm and the steel tube.The results of the proposed formula were in good agreement with the numerical data of this investigation.     

C.S. 路易斯和他的《狮子、女巫和衣橱》

Onee there were four children whose names were Peter,Susan,Edmund and Lucy.This story is about something that happened tothem when they were sent away from London during the war becauseof the air-raids1.They were sent to the house of an old Professor wholived in the heart of the country,ten miles from the nearest railwaystation and two miles from the nearest post office.He had no wife and     

Molecular dynamics simulation and microscopic observation of compatibility and interphase of composited polymer modified asphalt with carbon nanotubes

Interfacing and compatibility are the most challenging issues that affect the performance of polymer modified asphalt. Mechanisms of interfacial enhancement among four base asphalt components(asphaltenes, resins, aromatics, and saturate), styrene-butadiene-styrene(SBS), and carbon nanotubes(CNTs) were investigated by molecular dynamics simulation, with the aim of understanding the key parameters that control the compatibility of CNTs and interphase behavior on the molecular scale. The compatibility of SBS-modified asphalt(SBSMA) was simulated based on self-assembly theory using indexes of binding energy, mean square displacement, diffusion coefficient, and relative concentration distribution. The interphase behavior and microstructure were observed by fluorescence microscopy and scanning electron microscopy. In addition, a rutting experiment was used to verify the molecular dynamics simulation based on macroscopic performance. The results showed that after adding CNTs, the binding energy of the SBS and aromatics increased from 301.8343 to 327.1102 kcal/mol. The diffusion coefficient of the SBS and asphaltenes decreased more than 3.2×10-11 m2/s, and the correlation coefficients between the diffusion coefficient and the molecular weight, surface area and volume were all lower than 0.3. Relative concentration distribution curves indicated that CNTs promote the ability of SBS to swell. Microscopic observations demonstrated that the swelling ability of SBS was increased by CNTs. Overall, the interphase of SBSMA was improved by the additional reinforcement, swelling, and diffusion provided by CNTs. Finally, the rutting experiment found that no matter what the temperature, the rutting factor of CNT/SBSMA is higher than that of SBSMA, which corroborates the findings from the molecular dynamics simulations.     

Experimental investigation on mixing enhancement mechanism of turbulent jet flow with tabbed nozzle

Flow visualization and hot-wire measurement techniques were combined to investigate the influence of the size and number of tabs on jet flow field and vortex structure generation mechanism. Streamwise vortices generated by the tabs of different sizes and numbers were ob- served from the flow visualization images. Combined with flow visualization, hot-wire measurement gave a quantitative insight of the effect of various tabbed jet flows. Instantaneous two-component velocity signals （longitudinal and transverse velocity components） at different cross sections along radius direction and streamwise direction with different tabbed jet nozzles were measured using hot-wire anemometer. Average flow field parameters of tabbed jet flow such as mean velocity, turbulence intensity, vorticity were analyzed and the effects of tabs with different sizes and numbers were compared with that of circular no-tab jet flow. It is revealed that the generation of a series of counter-rotating quasi-streamwise vortices, azimuthal vortices and double-row azi-muthal vortex are the reasons for mixing enhancement of tabbed turbulent jet flow.     

On Academic Conflict in Medical Research Articles

Objective:To investigate the distribution of academic conflicts, if any, in medical research articles. Methods:Twenty-seven and 25 medical research articles in the field of internal medicine were selected from English and Chinese respectable jour nals, respectively. Then, the speech acts that reflected a conflict between a scientist’s knowledge claim and another scientist’s knowledge claim were manually searched and recorded in each paper. Data were analyzed using non-parametric Chi-test. Results:There were 123 academic conflicts recorded in the English corpus and 49 Academic Conflicts in the Chinese corpus. Significant difference was observed in the overall frequency of academic conflicts between the English and Chinese medical discourse (p=0.001). Besides, as for the distribution within research articles, introduction and discussion sections were the sections where Academic Conflict speech acts were most likely to occur in both corpra. Conclusion:The Chinese scholars are less likely to criticize peers. Introduction and discussion sections were the sections where Academic Conflict speech acts were most likely to occur. Our results are in agreement with previous results and confirmed the claim that highly different cultures vary in their discourse preferences. Our findings are of pedagogical significance.     

Influence of learning techniques on information processing

The present study establishes the fact that effective information processing is dependent on the learning techniques one adopts. A sample of 100 students in the age group from 13 to 17 including boys and girls were chosen. They were divided into two groups of control and experimental. To the experimental group, certain specific learning techniques were taught for a period of six months. The same group was tested taking blood samples to study the neuro transmitter serotonin levelshenme before and after adopting learning techniques. Results of the study proved that there is significant relationship between learning techniques and the information processing ability of an individual.     

Microstructure and mechanical properties analysis of β-tricalcium phosphate/carbon nanotubes scaffold based on rapid prototyping

β-TCP ceramic scaffolds were fabricated with selective laser sintering(SLS)in this work. Carbon nanotubes(CNTs)were mixed with porous β-TCP matrix to enhance the mechanical performance of the bone tissue engineering scaffolds. Scaffold reconstruction and microstructure analysis were fulfilled based on micro-computed tomography(Micro-CT)scanning data.Results show that the strength of scaffold mixed with 0.2% CNTs reaches 0.819 MPa which has been improved by 85.7% compared with that without CNTs. Micro-CT analysis shows that the scaffold has a good interconnectivity, and pore size mainly distributes in the two regions of 60-340 μm and 500 620 μm.     

完形填空专练（2）

The Inspector of Schools arrived yesterday morning, and he spent the whole day examining the classes. The headmaster had told us a few days 1 that he was coming. I think the headmaster was very 2 about it, for every day, he came to all the classes, 3 the teacher over and over again what they must do and examined the boy himself to see 4 they were ready for the Inspector. He told us in our class that we were all fools and would be sure to 5 him lose face before the Inspector.     

Study of Cellular Experiment of Electric Pulse Imposed on Cancer Cell

The objective of the study is the cytocidal and inhibitory effect of energy-controllable pulse on ovarian cancer cell line SKOV3.Ovarian cancer cell suspension were treated by electric pulse with different parameters,.The inhibitory rate(IR) was assayed by modified colorimetric MTT methods,the growth curves of two test groups and one control group were also measured.and the ultrasturctureal changes were observed under electron microscopy(EM) and scan electron microscopy (SEM),It was found that the treated SKOV3 cell proliferated more slowly.IR was increased with the enhancement of pulse paramters,The ultrastructural study showed that morphological changes occured obviously.Swollen mitochondria,fracutured ridges,cytoplasmic vacuoles and membrane holes appeard in most of the processed cells,and a part of bilayer membrane was ruptured.It is indicated that irreversible electric breakdown occurred in some of the treated cells,and the electric pulse could kill cancer cell and inhibit its recovery and growth.