The effects of rapid solidification on the microstructure and melting behavior of the Sn-8Zn-3Bi alloy were studied. The evolution of the microstructuraI characteristics of the solder/Cu joint after an isothermal agin...The effects of rapid solidification on the microstructure and melting behavior of the Sn-8Zn-3Bi alloy were studied. The evolution of the microstructuraI characteristics of the solder/Cu joint after an isothermal aging at 150 ℃ was also analyzed to evaluate the interconnect reliability. Results showed that the Bi in Sn-8Zn-3Bi solder alloy completely dissolved in the Sn matrix with a dendritic structure after rapid solidification. Compared with as-solidified Sn-8Zn-3Bi solder alloy, the melting temperature of the rapid solidified alloy rose to close to that of the Sn-Zn eutectic alloy due to the extreme dissolution of Bi in Sn matrix. Meanwhile, the adverse effect on melting behavior due to Bi addition was decreased significantly. The interfacial intermetallic compound (IMC) layer of the solder/Cu joint was more compact and uniform. Rapid solidification process obviously depressed the formation and growth of the interfacial IMC during the high-temperature aging and improved the high-temperature stability of the Sn-8Zn-3Bi solder/Cu joint.展开更多
Based on an available parking space occupancy (APSO) survey conducted in Nanjing, China, an APSO forecasting model is proposed. The APSO survey results indicate that the time series of APSO with different time-secti...Based on an available parking space occupancy (APSO) survey conducted in Nanjing, China, an APSO forecasting model is proposed. The APSO survey results indicate that the time series of APSO with different time-sections are periodical and self-similar, and the fluctuation of the APSO increases with the decrease in time-sections. Taking the short-time change behavior into account, an APSO forecasting model combined wavelet analysis and a weighted Markov chain is presented. In this model, an original APSO time series is first decomposed by wavelet analysis, and the results include low frequency signals representing the basic trends of APSO and several high frequency signals representing disturbances of the APSO. Then different Markov models are used to forecast the changes of low and high frequency signals, respectively. Finally, integrating the predicted results induces the final forecasted APSO. A case study verifies the applicability of the proposed model. The comparisons between measured and forecasted results show that the model is a competent model and its accuracy relies on real-time update of the APSO database.展开更多
By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emis...By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emissions(AE),joint response characteristics of the velocity field and AE during rock fracture were analyzed.Moreover,the localization effect of damage during rock fracture was explored by applying wave velocity imagings.The experimental result showed that the wave velocity imagings enable three-dimensional(3-D)visualization of the extent and spatial position of damage to the rock.A damaged zone has a low wave velocity and a zone where the low wave velocity is concentrated tends to correspond to a severely damaged zone.AE parameters and wave velocity imagings depict the changes in activity of cracks during rock fracture from temporal and spatial perspectives,respectively:the activity of cracks is strengthened,and the rate of AE events increases during rock fracture;correspondingly,the low-velocity zones are gradually aggregated and their area gradually increases.From the wave velocity imagings,the damaged zones in rock were divided into an initially damaged zone,a progressively damaged zone,and a fractured zone.During rock fracture,the progressively damaged zone and the fractured zone both develop around the initially damaged zone,showing a typical localization effect of the damage.By capturing the spatial development trends of the progressively damaged zone and fractured zone in wave velocity imagings,the development of microfractures can be predicted,exerting practical significance for determining the position of the main fracture.展开更多
OBJECTIVE To investigate the role of chronochemotherapy in the treatment of nasopharyngeal carcinoma (NPC). METHODS Sixty NPC patients were randomly designated for induction chrono-chemotherapy plus radiotherapy (C...OBJECTIVE To investigate the role of chronochemotherapy in the treatment of nasopharyngeal carcinoma (NPC). METHODS Sixty NPC patients were randomly designated for induction chrono-chemotherapy plus radiotherapy (CC, 30 patients) or for induction routine-chemotherapy plus radiotherapy (RC, 30 patients). The differences in immediate response, side effects and changes in immunologic parameters between these two groups were analyzed. The chemotherapy regimen of the CC group consisted of cisplatin (DDP) 80 mg/m^2 d1 at 10:00-22:00 h, 5-flurouracil (5-FU) 750 mg/m^2/d1-3 at 22:00-10:00 on the next day and 5-CHO-FH4 (CF) 200 mg/m^2/d1-3 starting at 10:00 h, and repeated every 14 days. The regimen of the RC group was the same as the CC group, with the delivery of cisplatin at a conventional rate and the CF via a continuous 24 h venous injection. The radiotherapy regimen was same in the two groups. RESULTS The complete response rates for the CC and RC groups were 36.7% and 20.0%, respectively(P〈0.05)and the response rates (complete response+partial response ) were 96.7% and 73.3% respectively. The grade I and II myelosuppression was more serious in the RC group, with rates of 43.3% and 70% in the CC and RC groups (P〈0.05) respectively. The differences in CD3, CD4, CD3/CD8, T+B+NK and CD8 cell levels between before and after treatment of the CC group were significant (P〈 0.05), but differences in the RC group were not significant. CONCLUSION The immediate therapeutic response is better with concurrent chronochemotherapy plus radiotherapy and there are fewer side effect compared to concurrent routine-chemotherapy plus radiotherapy.展开更多
For the mixing-sensitive reactions, both chemical kinetics and mixing conditions of the reactants determine the distributions of products. The direct quadrature method of moments combining with the interaction by exch...For the mixing-sensitive reactions, both chemical kinetics and mixing conditions of the reactants determine the distributions of products. The direct quadrature method of moments combining with the interaction by exchange with the mean micro-mixing model(DQMOM-IEM) has been validated for the chemical reacting flows in microreactors. Quite encouraging simulation results offer great promise, but the applicability of this method is needed to be explored furthermore, such as in stirred reactors. In this work, the two-environment DQMOM-IEM model was created with C language and used to customize Fluent through the user-defined functions. The mixing effects on the course of parallel competing chemical reactions carried out in a semi-batch single-phase stirred reactor were predicted. The simulation results show that the rising feed velocity enlarges the volume of reaction zone and maximize the yield of the by-product, which also indicates that the feed stream is more difficultly dispersed into the main stream and the zone surrounding feedpipe exit with high turbulent kinetic dissipation rate cannot be efficiently used.展开更多
Three types of new high-efficiency phosphate fertilizers were made when pillared clays at certain proportions were added into ground phosphate rock. Chemical analyses showed that their soluble phosphorus content decre...Three types of new high-efficiency phosphate fertilizers were made when pillared clays at certain proportions were added into ground phosphate rock. Chemical analyses showed that their soluble phosphorus content decreased more than that of superphosphate. Pot experiment showed that, under equal weights, the new fertilizers increased their efficiency by a large margin over that of superphosphate. Researches on their structures by means of XRD, IR and EPR spectrum revealed that their crystal structures changed considerably, improving their activity and preventing the fixation of available phosphorus in the soil, and consequently, greatly improved the bioavailability and became the main cause of the increase of biomass.展开更多
AIM: To investigate the ultrastructural and morphological changes of non-specific duodenitis (NSD) in an attempt to grade them according to the extent of the lesions. METHODS: Biopsies were taken from the mucosa of du...AIM: To investigate the ultrastructural and morphological changes of non-specific duodenitis (NSD) in an attempt to grade them according to the extent of the lesions. METHODS: Biopsies were taken from the mucosa of duodenal bulb of 44 patients selected from the patients undergoing upper gastrointestinal endoscopy for epigastric discomforts. From each patient, two pinch biopsies on the same area were obtained from duodenal bulb. One was for scanning electron microscopy and the other was stained with hematoxylin-eosin, Warthin-Starry silver and both were then examined under light microscope. A total of 12 specimens (three from each degree of the normal and I-III of NSD diagnosed and graded by histology) selected from the 44 patients were dehydrated, critical point dried, coated with gold palladium and examined under a JEOL JSM-30 scanning electron microscope (SEM) at 20 kV. RESULTS: According to the ultrastructural morphologic changes, non-specific duodenitis was divided into normal (as control group), mild, moderate and severe degrees according to results of SEM. The normal villi of duodenal bulb were less than 0.2 mm. There were inflammation cells, occasionally red blood cells and macrophages on the mucosal epithelial surface. Erosion and desquamation of epithelium could be seen. Three cases (25%, 3/12) had gastric metaplasia and Helicobacter pylori(H pylori) infection could be found in 5 cases (41.67%, 5/12) in duodenal bulb mucosa. The most distinctive feature was the ulcer-like defect on the surface of epithelial cells. CONCLUSION: Non-specific duodenitis is a separate entity disease caused by different factors. SEM is of value as an aid in the diagnosis of mucosal diseases of duodenum.展开更多
Corrosion of steel structures is unavoidable and the structural performance decreases dramatically due to the corrosion. As a repairing method for corroded steel members, bonding carbon fiber sheets with resin had bee...Corrosion of steel structures is unavoidable and the structural performance decreases dramatically due to the corrosion. As a repairing method for corroded steel members, bonding carbon fiber sheets with resin had been developed. The purpose of this study is to propose the flexural strengthening method for steel members by using CFRP (carbon fiber reinforced polymer) strand sheets. In order to clarify the stiffening effect and the debonding characteristics of CFRP strand sheets, and to optimize the strengthening design specifications, the flexural tests using high tension steel beams strengthened with CFRP strand sheets are performed. Two cases of experiments are carried out. In Experiment 1, the result from previous research is reflected in the strengthening design. Moreover in Experiment 2, the debonding characteristics obtained from Experiment 1 are reflected. As a result, it was clarified that CFRP strand sheets have stiffening effect equivalent to the theoretical value and its debonding property is practically high enough when FRP (fiber reinforcement polymer) sheets have an appropriate bonding length.展开更多
Wide-size-range medium-solids are used in a modularized coal beneficiation demonstration system with a gas-solid fluidized bed. The characteristics of fluidization and dry-beneficiation of the medium solids were studi...Wide-size-range medium-solids are used in a modularized coal beneficiation demonstration system with a gas-solid fluidized bed. The characteristics of fluidization and dry-beneficiation of the medium solids were studied. The numerical simulation results show that 0.15–0.06 mm fine magnetite powder can decrease the disturbances caused by the bubbles. This is beneficial to the uniformity of the gas-solid interactions and thus to the uniformity and stability of the bed density and height. The experimental results show that, with an increase in the fine coal content in medium solids, both the fluidization quality and the beneficiation performance of the bed decreased gradually. When the fine coal content was no more than 13%, a relatively high superficial gas velocity increased the beneficiation efficiency. When the content was more than 13%, part of the fine coal was separated, leading to product layers. The separation efficiency was therefore gradually decreased. The models for predicting the bed density standard deviation and the probable error, E, value were both proposed. The E value can reach to 0.04–0.07 g/cm^3 under the optimized experimental parameters. This work provides a foundation for the adjustment of the bed density and the separation performance of the modularized 40–60 ton per hour dry coalbeneficiation industrial system.展开更多
Objective: To observe the therapeutic effect of moxibustion of some specific acupoints for treatment of functional dyspepsia (FD, qi-distension type). Methods:A total of 50 cases of FD patients were randomly divided i...Objective: To observe the therapeutic effect of moxibustion of some specific acupoints for treatment of functional dyspepsia (FD, qi-distension type). Methods:A total of 50 cases of FD patients were randomly divided into treatment group (n=26) and medication group (n=24). In treatment group, bird-pecking moxibustion was applied to Zhongwan (CV 12), Qihai (CV 6), Neiguan (PC 6) and Gongsun (SP 4) 5~6 times in every treatment till the local skin got flush. The treatment was given once daily, continuously for 10 days. In control group, the patients were ordered to take Motilium 10 mg/time, 3 times daily. Following 10 days’ treatment the therapeutic effect was assessed.Results:After treatment, of the 26 cases in treatment group, 11 (42.3%) were cured, 7 (26.92%) had remarkable improvement in their symptoms, 6 (23.07%) had improvement and 2 (7.69%) failed, with a total effective rate of 92.31%. Of the 24 cases in medication group, 9 (37.50%) were cured, 6 (25.00%) experienced remarkable improvement in their symptoms, 6 (25.00%) were improved and 3 (12.50%) failed, with a total effective rate of 87.50%. Comparison between two groups showed that the therapeutic effect of moxibustion was significantly superior to that of medication (P<0.05). In addition, the difference value of the therapeutic effect index (TEI) between post-and pre-treatment in treatment group was also significantly higher than that of medication group (P<0.05). Conclusion: Bird-pecking moxibustion of specific acupoints can effectively improve clinical symptoms of FD patients.展开更多
A computational method and a mechanical model for evaluating the vertical dynamic harmonic response characteristics of a single pile embedded in non-homogeneous soil layers and subjected to harmonic loadings were esta...A computational method and a mechanical model for evaluating the vertical dynamic harmonic response characteristics of a single pile embedded in non-homogeneous soil layers and subjected to harmonic loadings were established based on a certain assumption and the improved dynamic model of beam-on-Winkler foundation by using the principle of soil dynamics and structure dynamics. Both non-homogeneity of soil strata and softening effect of soil layer around the pile during vibration were simultaneously taken into account in the proposed computational model. It is shown through the comparative study on a numerical example that the numerical results of dynamic response of the single pile computed by the proposed method are relatively rational and can well agree with the numerical results computed from the well-known software of finite element method. Finally the parametric studies were conducted for a varied range of main parameters to discuss the effects of relevant factors on dynamic responses of the single pile embedded in non-homogeneous layered soils excited by harmonic loading with different frequencies.展开更多
The dietary protein requirement of juvenile turbot(initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with ...The dietary protein requirement of juvenile turbot(initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with fish meal as protein source, which contained different concentrations of protein(47.2%, 51.0%, 54.6%, 59.3% and 63.6% of dry diet). Three groups of fish with 18 individuals in each, were cultured in 300-L tanks and fed twice a day for 8 weeks. During culture, temperature was controlled between 15.0 and 18.0℃, salinity was controlled between 28.5 and 32.0, acidity was controlled between p H7.8 and p H8.5, and ammonia nitrogen was maintained below 0.03 mg L-1 and dissolved oxygen was maintained about 7 mg L-1. Results showed that the growth of fish was significantly affected by dietary protein content(P < 0.05). Specific growth rate(SGR) of turbot increased when dietary protein content varied between 47.2% and 51.0%(P < 0.05), and then kept stable when dietary protein content was higher than 51.0%. Fish which were fed the diet containing 63.6% protein showed the highest SGR while those fed the diet containing 59.3% protein showed the highest feed efficiency rate. No significant difference of feed intake and protein efficiency ratio was found among experimental diets(P > 0.05). Broken-line regression analysis of SGR showed that the optimal dietary protein requirement of turbot was about 57.0%.展开更多
During the hydration process, the Ultra-fine Cements present specific physical and chemical characteristics; they are, very short setting time and high heat release. For special applications, such as rapid hardening a...During the hydration process, the Ultra-fine Cements present specific physical and chemical characteristics; they are, very short setting time and high heat release. For special applications, such as rapid hardening and early high strength mortars or concretes, these characteristics can be considered advantageous. Some commercial products used for concrete reinforcement and repairs are the Rapid Hardening Mortars, these mortars must develop a time of setting up to 3 h and an initial compressive strength of about 3.5 MPa once the hardening of the paste is reached. The objective of the present research work is to use Ultra-fine Cement for the preparation of a series of different Rapid Hardening Mortars (with different percentages of Ultra-fine Cement), these mortars required the addition of a polycarboxylate-base specification F Superplasticizer. It was observed that the optimum water/cement (W/C) ratio for the hydration of the Ultra-fine Cements is W/C = 0.385. The Ultra-fine Cements were obtained by the High Energy Ball-milling technique at laboratory scale, 90% of the Particle Size Distribution is below 11 μm and the Blaine Specific Surface Area is over 9000 cm^2/g.展开更多
Cognitive radio(CR) is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access techniques.However,c...Cognitive radio(CR) is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access techniques.However,cognitive radio networks(CRNs)may also impose some challenges due to the ever increasing complexity of network architecture,the increasing complexity with configuration and management of large-scale networks,fluctuating nature of the available spectrum,diverse Quality-of-Service(QoS)requirements of various applications,and the intensifying difficulties of centralized control,etc.Spectrum management functions with self-organization features can be used to address these challenges and realize this new network paradigm.In this paper,fundamentals of CR,including spectrum sensing,spectrum management,spectrum mobility and spectrum sharing,have been surveyed,with their paradigms of self-organization being emphasized.Variant aspects of selforganization paradigms in CRNs,including critical functionalities of Media Access Control(MAC)- and network-layer operations,are surveyed and compared.Furthermore,new directions and open problems in CRNs are also identified in this survey.展开更多
Recently, a kind of hybrid solution MEA-methanol shows a better CO_2 capture performance over aqueous MEA solution. However, the vaporization of methanol is the biggest disadvantage that hinders its application, so it...Recently, a kind of hybrid solution MEA-methanol shows a better CO_2 capture performance over aqueous MEA solution. However, the vaporization of methanol is the biggest disadvantage that hinders its application, so it is necessary to minimize the vaporization of methanol during both the absorption and regeneration processes. In this work, two kinds of hybrid solutions were studied and compared with aqueous MEA solution and MEA-methanol solution, including MEA/TEA/methanol solution and MEA/glycerol/methanol solution. The absorption property of MEA/glycerol/methanol solution is better than aqueous MEA solution within a certain period of time and the absorption property of MEA/TEA/methanol solution is too poor to be used in CO_2 capture. By increasing the concentration of TEA and decreasing the concentration of MEA, the absorption rate, CO_2 capture efficiency and absorption capacity all decreased. Upon adding glycerol, the cyclic capacity decreased and the generation temperature increased, and moreover, the density and viscosity also increased considerably. So after adding TEA and glycerol, the CO_2 capture performance of MEAmethanol solvent cannot be improved.展开更多
Thirty-seven years since reform and opening up, China has sustained rapid economic growth and urbanization. However, there was inadequate protection of natural, historical, and cultural heritage, especially in the pas...Thirty-seven years since reform and opening up, China has sustained rapid economic growth and urbanization. However, there was inadequate protection of natural, historical, and cultural heritage, especially in the past 17 years, which led to the outcome that urban and rural construction lacked features. To rebuild our urban features during urbanization, and avoid destroying them,we should probe into the reason of lacking features and how to protect them. Therefore, taking Jinan City as an example, this paper explored the crisis and its causes of urban characteristics during the period of rapid urbanization based on discussing roles of spring features, including economic effects, social effects, ecological effects and so on. What is more, this paper listed and analyzed those protection measures taken by Jinan. The results showed that spring groups spewed again and kept for 8 years through those measures, which meant that urban characteristics restored. Thus, Jinan City provides successful and significant reference for other cities in restoring urban features during urbanization construction. Also, the author deemed that cities could recollect their urban features as long as they take reasonable measures.展开更多
An exploratory study was conducted in the coastal plantation (12-and 17-year-old Sonneratia apetala) of Char Alim and Char Piya and on their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya of Noak...An exploratory study was conducted in the coastal plantation (12-and 17-year-old Sonneratia apetala) of Char Alim and Char Piya and on their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya of Noakhali district, in Bangladesh to determine afforestation effects on soil properties. At soil depths of 0-10, 10-30 and 30-40 cm across three different land strips viz. inland, middle and sea side in 12-and 17-year-old keora (Sonneratia apetala) plantations, soil moisture, particle density, organic matter and C, total N, pH, available P, K, Na, Ca and Mg were significantly (p≤0.05, p≤0.01, p≤0.001) higher, and soil salinity significantly (p≤0.001) lower than that in their adjacent barren lands. Soil moisture, particle density, organic matter and C, total N, pH, soil salinity, available P, K, Na, Ca and Mg of surface soil in Char Alim plantation at inland were 31.09%, 2.24 g·cm-3, 2.41%, 4.14%, 0.58%, 7.07, 0.09 dS·cm-1, 28.06 mg·L-1, 0.50 mg·L-1 11.5 mg·L-1, 3.30 mg·L-1 and 2.7 mmol·kg-1, respectively. Their corresponding values for the same depth and land position at adjacent Char Rehania barren land were 16.69%, 1.25g·cm-3, 0.43%, 0.74%, 0.25%, 6.57, 0.13 dS·cm-1, 13.07mg·L-1, 0.30 mg·L-1, 1.4 mg·L-1, 0.30 mmol·kg-1 and 0.50 mg·L-1, respectively. Soil moisture, particle density, organic matter and C, total N, pH, available P, K and Ca decreased, and soil salinity, available Na and Mg increased from inland towards sea side in the plantations. Although soil texture did not differ in most soil depths between plantation and adjacent barren land, proportion of sand particle was significantly (p≤0.01) lower and silt particle significantly (p≤0.001) in the plantations higher than that in their adjacent barren lands. In the study, evaluation of all the parameters was also done for the other pair of lands.展开更多
基金Project(50675234)supported by the National Natural Science Foundation of China
文摘The effects of rapid solidification on the microstructure and melting behavior of the Sn-8Zn-3Bi alloy were studied. The evolution of the microstructuraI characteristics of the solder/Cu joint after an isothermal aging at 150 ℃ was also analyzed to evaluate the interconnect reliability. Results showed that the Bi in Sn-8Zn-3Bi solder alloy completely dissolved in the Sn matrix with a dendritic structure after rapid solidification. Compared with as-solidified Sn-8Zn-3Bi solder alloy, the melting temperature of the rapid solidified alloy rose to close to that of the Sn-Zn eutectic alloy due to the extreme dissolution of Bi in Sn matrix. Meanwhile, the adverse effect on melting behavior due to Bi addition was decreased significantly. The interfacial intermetallic compound (IMC) layer of the solder/Cu joint was more compact and uniform. Rapid solidification process obviously depressed the formation and growth of the interfacial IMC during the high-temperature aging and improved the high-temperature stability of the Sn-8Zn-3Bi solder/Cu joint.
基金The National Natural Science Foundation of China(No50738001)the National Basic Research Program of China (973Program) (No2006CB705501)
文摘Based on an available parking space occupancy (APSO) survey conducted in Nanjing, China, an APSO forecasting model is proposed. The APSO survey results indicate that the time series of APSO with different time-sections are periodical and self-similar, and the fluctuation of the APSO increases with the decrease in time-sections. Taking the short-time change behavior into account, an APSO forecasting model combined wavelet analysis and a weighted Markov chain is presented. In this model, an original APSO time series is first decomposed by wavelet analysis, and the results include low frequency signals representing the basic trends of APSO and several high frequency signals representing disturbances of the APSO. Then different Markov models are used to forecast the changes of low and high frequency signals, respectively. Finally, integrating the predicted results induces the final forecasted APSO. A case study verifies the applicability of the proposed model. The comparisons between measured and forecasted results show that the model is a competent model and its accuracy relies on real-time update of the APSO database.
基金Projects(51774138,51804122,51904105)supported by the National Natural Science Foundation of ChinaProjects(E2021209148,E2021209052)supported by the Natural Science Foundation of Hebei Province,China。
文摘By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emissions(AE),joint response characteristics of the velocity field and AE during rock fracture were analyzed.Moreover,the localization effect of damage during rock fracture was explored by applying wave velocity imagings.The experimental result showed that the wave velocity imagings enable three-dimensional(3-D)visualization of the extent and spatial position of damage to the rock.A damaged zone has a low wave velocity and a zone where the low wave velocity is concentrated tends to correspond to a severely damaged zone.AE parameters and wave velocity imagings depict the changes in activity of cracks during rock fracture from temporal and spatial perspectives,respectively:the activity of cracks is strengthened,and the rate of AE events increases during rock fracture;correspondingly,the low-velocity zones are gradually aggregated and their area gradually increases.From the wave velocity imagings,the damaged zones in rock were divided into an initially damaged zone,a progressively damaged zone,and a fractured zone.During rock fracture,the progressively damaged zone and the fractured zone both develop around the initially damaged zone,showing a typical localization effect of the damage.By capturing the spatial development trends of the progressively damaged zone and fractured zone in wave velocity imagings,the development of microfractures can be predicted,exerting practical significance for determining the position of the main fracture.
文摘OBJECTIVE To investigate the role of chronochemotherapy in the treatment of nasopharyngeal carcinoma (NPC). METHODS Sixty NPC patients were randomly designated for induction chrono-chemotherapy plus radiotherapy (CC, 30 patients) or for induction routine-chemotherapy plus radiotherapy (RC, 30 patients). The differences in immediate response, side effects and changes in immunologic parameters between these two groups were analyzed. The chemotherapy regimen of the CC group consisted of cisplatin (DDP) 80 mg/m^2 d1 at 10:00-22:00 h, 5-flurouracil (5-FU) 750 mg/m^2/d1-3 at 22:00-10:00 on the next day and 5-CHO-FH4 (CF) 200 mg/m^2/d1-3 starting at 10:00 h, and repeated every 14 days. The regimen of the RC group was the same as the CC group, with the delivery of cisplatin at a conventional rate and the CF via a continuous 24 h venous injection. The radiotherapy regimen was same in the two groups. RESULTS The complete response rates for the CC and RC groups were 36.7% and 20.0%, respectively(P〈0.05)and the response rates (complete response+partial response ) were 96.7% and 73.3% respectively. The grade I and II myelosuppression was more serious in the RC group, with rates of 43.3% and 70% in the CC and RC groups (P〈0.05) respectively. The differences in CD3, CD4, CD3/CD8, T+B+NK and CD8 cell levels between before and after treatment of the CC group were significant (P〈 0.05), but differences in the RC group were not significant. CONCLUSION The immediate therapeutic response is better with concurrent chronochemotherapy plus radiotherapy and there are fewer side effect compared to concurrent routine-chemotherapy plus radiotherapy.
基金Supported by the National Basic Research Program of China(2012CB224806)the National Natural Science Foundation of China(21306197,91434126)+1 种基金the Major National Scientific Instrument Development Project(21427814)Jiangsu National Synergetic Innovation Center for Advanced Materials
文摘For the mixing-sensitive reactions, both chemical kinetics and mixing conditions of the reactants determine the distributions of products. The direct quadrature method of moments combining with the interaction by exchange with the mean micro-mixing model(DQMOM-IEM) has been validated for the chemical reacting flows in microreactors. Quite encouraging simulation results offer great promise, but the applicability of this method is needed to be explored furthermore, such as in stirred reactors. In this work, the two-environment DQMOM-IEM model was created with C language and used to customize Fluent through the user-defined functions. The mixing effects on the course of parallel competing chemical reactions carried out in a semi-batch single-phase stirred reactor were predicted. The simulation results show that the rising feed velocity enlarges the volume of reaction zone and maximize the yield of the by-product, which also indicates that the feed stream is more difficultly dispersed into the main stream and the zone surrounding feedpipe exit with high turbulent kinetic dissipation rate cannot be efficiently used.
基金Project supported by the National Science Foundation of China (No.40202007) and the Provincial National Science Foundation ofGuangdong, China (Nos. 000623, 020938, 04020017)
文摘Three types of new high-efficiency phosphate fertilizers were made when pillared clays at certain proportions were added into ground phosphate rock. Chemical analyses showed that their soluble phosphorus content decreased more than that of superphosphate. Pot experiment showed that, under equal weights, the new fertilizers increased their efficiency by a large margin over that of superphosphate. Researches on their structures by means of XRD, IR and EPR spectrum revealed that their crystal structures changed considerably, improving their activity and preventing the fixation of available phosphorus in the soil, and consequently, greatly improved the bioavailability and became the main cause of the increase of biomass.
文摘AIM: To investigate the ultrastructural and morphological changes of non-specific duodenitis (NSD) in an attempt to grade them according to the extent of the lesions. METHODS: Biopsies were taken from the mucosa of duodenal bulb of 44 patients selected from the patients undergoing upper gastrointestinal endoscopy for epigastric discomforts. From each patient, two pinch biopsies on the same area were obtained from duodenal bulb. One was for scanning electron microscopy and the other was stained with hematoxylin-eosin, Warthin-Starry silver and both were then examined under light microscope. A total of 12 specimens (three from each degree of the normal and I-III of NSD diagnosed and graded by histology) selected from the 44 patients were dehydrated, critical point dried, coated with gold palladium and examined under a JEOL JSM-30 scanning electron microscope (SEM) at 20 kV. RESULTS: According to the ultrastructural morphologic changes, non-specific duodenitis was divided into normal (as control group), mild, moderate and severe degrees according to results of SEM. The normal villi of duodenal bulb were less than 0.2 mm. There were inflammation cells, occasionally red blood cells and macrophages on the mucosal epithelial surface. Erosion and desquamation of epithelium could be seen. Three cases (25%, 3/12) had gastric metaplasia and Helicobacter pylori(H pylori) infection could be found in 5 cases (41.67%, 5/12) in duodenal bulb mucosa. The most distinctive feature was the ulcer-like defect on the surface of epithelial cells. CONCLUSION: Non-specific duodenitis is a separate entity disease caused by different factors. SEM is of value as an aid in the diagnosis of mucosal diseases of duodenum.
文摘Corrosion of steel structures is unavoidable and the structural performance decreases dramatically due to the corrosion. As a repairing method for corroded steel members, bonding carbon fiber sheets with resin had been developed. The purpose of this study is to propose the flexural strengthening method for steel members by using CFRP (carbon fiber reinforced polymer) strand sheets. In order to clarify the stiffening effect and the debonding characteristics of CFRP strand sheets, and to optimize the strengthening design specifications, the flexural tests using high tension steel beams strengthened with CFRP strand sheets are performed. Two cases of experiments are carried out. In Experiment 1, the result from previous research is reflected in the strengthening design. Moreover in Experiment 2, the debonding characteristics obtained from Experiment 1 are reflected. As a result, it was clarified that CFRP strand sheets have stiffening effect equivalent to the theoretical value and its debonding property is practically high enough when FRP (fiber reinforcement polymer) sheets have an appropriate bonding length.
基金financially supported by the National Program on Key Basic Research Project of China (No.2012CB214904)the National Natural Science Foundation of China (Nos.51221462,51134022 and 51174203)
文摘Wide-size-range medium-solids are used in a modularized coal beneficiation demonstration system with a gas-solid fluidized bed. The characteristics of fluidization and dry-beneficiation of the medium solids were studied. The numerical simulation results show that 0.15–0.06 mm fine magnetite powder can decrease the disturbances caused by the bubbles. This is beneficial to the uniformity of the gas-solid interactions and thus to the uniformity and stability of the bed density and height. The experimental results show that, with an increase in the fine coal content in medium solids, both the fluidization quality and the beneficiation performance of the bed decreased gradually. When the fine coal content was no more than 13%, a relatively high superficial gas velocity increased the beneficiation efficiency. When the content was more than 13%, part of the fine coal was separated, leading to product layers. The separation efficiency was therefore gradually decreased. The models for predicting the bed density standard deviation and the probable error, E, value were both proposed. The E value can reach to 0.04–0.07 g/cm^3 under the optimized experimental parameters. This work provides a foundation for the adjustment of the bed density and the separation performance of the modularized 40–60 ton per hour dry coalbeneficiation industrial system.
文摘Objective: To observe the therapeutic effect of moxibustion of some specific acupoints for treatment of functional dyspepsia (FD, qi-distension type). Methods:A total of 50 cases of FD patients were randomly divided into treatment group (n=26) and medication group (n=24). In treatment group, bird-pecking moxibustion was applied to Zhongwan (CV 12), Qihai (CV 6), Neiguan (PC 6) and Gongsun (SP 4) 5~6 times in every treatment till the local skin got flush. The treatment was given once daily, continuously for 10 days. In control group, the patients were ordered to take Motilium 10 mg/time, 3 times daily. Following 10 days’ treatment the therapeutic effect was assessed.Results:After treatment, of the 26 cases in treatment group, 11 (42.3%) were cured, 7 (26.92%) had remarkable improvement in their symptoms, 6 (23.07%) had improvement and 2 (7.69%) failed, with a total effective rate of 92.31%. Of the 24 cases in medication group, 9 (37.50%) were cured, 6 (25.00%) experienced remarkable improvement in their symptoms, 6 (25.00%) were improved and 3 (12.50%) failed, with a total effective rate of 87.50%. Comparison between two groups showed that the therapeutic effect of moxibustion was significantly superior to that of medication (P<0.05). In addition, the difference value of the therapeutic effect index (TEI) between post-and pre-treatment in treatment group was also significantly higher than that of medication group (P<0.05). Conclusion: Bird-pecking moxibustion of specific acupoints can effectively improve clinical symptoms of FD patients.
基金the Post Doctor Science Foundation of China(Grant No.20060390806 &20060400241)the Taishan Scholar Foundation of Shandong ProvinceScience Development Foundation of Shandong University of Science and Technology(Grant No.05g002)
文摘A computational method and a mechanical model for evaluating the vertical dynamic harmonic response characteristics of a single pile embedded in non-homogeneous soil layers and subjected to harmonic loadings were established based on a certain assumption and the improved dynamic model of beam-on-Winkler foundation by using the principle of soil dynamics and structure dynamics. Both non-homogeneity of soil strata and softening effect of soil layer around the pile during vibration were simultaneously taken into account in the proposed computational model. It is shown through the comparative study on a numerical example that the numerical results of dynamic response of the single pile computed by the proposed method are relatively rational and can well agree with the numerical results computed from the well-known software of finite element method. Finally the parametric studies were conducted for a varied range of main parameters to discuss the effects of relevant factors on dynamic responses of the single pile embedded in non-homogeneous layered soils excited by harmonic loading with different frequencies.
基金supported by the earmarked fund for Modern Agro-Industry Technology Research System with Grant No. CARS 50-G-08
文摘The dietary protein requirement of juvenile turbot(initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with fish meal as protein source, which contained different concentrations of protein(47.2%, 51.0%, 54.6%, 59.3% and 63.6% of dry diet). Three groups of fish with 18 individuals in each, were cultured in 300-L tanks and fed twice a day for 8 weeks. During culture, temperature was controlled between 15.0 and 18.0℃, salinity was controlled between 28.5 and 32.0, acidity was controlled between p H7.8 and p H8.5, and ammonia nitrogen was maintained below 0.03 mg L-1 and dissolved oxygen was maintained about 7 mg L-1. Results showed that the growth of fish was significantly affected by dietary protein content(P < 0.05). Specific growth rate(SGR) of turbot increased when dietary protein content varied between 47.2% and 51.0%(P < 0.05), and then kept stable when dietary protein content was higher than 51.0%. Fish which were fed the diet containing 63.6% protein showed the highest SGR while those fed the diet containing 59.3% protein showed the highest feed efficiency rate. No significant difference of feed intake and protein efficiency ratio was found among experimental diets(P > 0.05). Broken-line regression analysis of SGR showed that the optimal dietary protein requirement of turbot was about 57.0%.
文摘During the hydration process, the Ultra-fine Cements present specific physical and chemical characteristics; they are, very short setting time and high heat release. For special applications, such as rapid hardening and early high strength mortars or concretes, these characteristics can be considered advantageous. Some commercial products used for concrete reinforcement and repairs are the Rapid Hardening Mortars, these mortars must develop a time of setting up to 3 h and an initial compressive strength of about 3.5 MPa once the hardening of the paste is reached. The objective of the present research work is to use Ultra-fine Cement for the preparation of a series of different Rapid Hardening Mortars (with different percentages of Ultra-fine Cement), these mortars required the addition of a polycarboxylate-base specification F Superplasticizer. It was observed that the optimum water/cement (W/C) ratio for the hydration of the Ultra-fine Cements is W/C = 0.385. The Ultra-fine Cements were obtained by the High Energy Ball-milling technique at laboratory scale, 90% of the Particle Size Distribution is below 11 μm and the Blaine Specific Surface Area is over 9000 cm^2/g.
基金ACKNOWLEDGEMENT This work was supported by National Natural Science Foundation of China (No. 61172050), Program for New Century Excellent Talents in University (NECT-12-0774), the open research fund of National Mobile Communications Research Laboratory, Southeast University (No.2013D12), the Foundation of Beijing Engineering and Technology Research Center for Convergence Networks and Ubiquitous Services. The corresponding author is Dr. Zhongshan Zhang.
文摘Cognitive radio(CR) is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access techniques.However,cognitive radio networks(CRNs)may also impose some challenges due to the ever increasing complexity of network architecture,the increasing complexity with configuration and management of large-scale networks,fluctuating nature of the available spectrum,diverse Quality-of-Service(QoS)requirements of various applications,and the intensifying difficulties of centralized control,etc.Spectrum management functions with self-organization features can be used to address these challenges and realize this new network paradigm.In this paper,fundamentals of CR,including spectrum sensing,spectrum management,spectrum mobility and spectrum sharing,have been surveyed,with their paradigms of self-organization being emphasized.Variant aspects of selforganization paradigms in CRNs,including critical functionalities of Media Access Control(MAC)- and network-layer operations,are surveyed and compared.Furthermore,new directions and open problems in CRNs are also identified in this survey.
基金supported by the Sinopec Ningbo Engineering Co., Ltd. (No. 14850000-14-ZC0609-0003, H8XY-0032)
文摘Recently, a kind of hybrid solution MEA-methanol shows a better CO_2 capture performance over aqueous MEA solution. However, the vaporization of methanol is the biggest disadvantage that hinders its application, so it is necessary to minimize the vaporization of methanol during both the absorption and regeneration processes. In this work, two kinds of hybrid solutions were studied and compared with aqueous MEA solution and MEA-methanol solution, including MEA/TEA/methanol solution and MEA/glycerol/methanol solution. The absorption property of MEA/glycerol/methanol solution is better than aqueous MEA solution within a certain period of time and the absorption property of MEA/TEA/methanol solution is too poor to be used in CO_2 capture. By increasing the concentration of TEA and decreasing the concentration of MEA, the absorption rate, CO_2 capture efficiency and absorption capacity all decreased. Upon adding glycerol, the cyclic capacity decreased and the generation temperature increased, and moreover, the density and viscosity also increased considerably. So after adding TEA and glycerol, the CO_2 capture performance of MEAmethanol solvent cannot be improved.
基金supported by National Natural Science Foundation[grant number 41371170]Technology Project of Shandong Province[grant number2012GSF12204]
文摘Thirty-seven years since reform and opening up, China has sustained rapid economic growth and urbanization. However, there was inadequate protection of natural, historical, and cultural heritage, especially in the past 17 years, which led to the outcome that urban and rural construction lacked features. To rebuild our urban features during urbanization, and avoid destroying them,we should probe into the reason of lacking features and how to protect them. Therefore, taking Jinan City as an example, this paper explored the crisis and its causes of urban characteristics during the period of rapid urbanization based on discussing roles of spring features, including economic effects, social effects, ecological effects and so on. What is more, this paper listed and analyzed those protection measures taken by Jinan. The results showed that spring groups spewed again and kept for 8 years through those measures, which meant that urban characteristics restored. Thus, Jinan City provides successful and significant reference for other cities in restoring urban features during urbanization construction. Also, the author deemed that cities could recollect their urban features as long as they take reasonable measures.
文摘An exploratory study was conducted in the coastal plantation (12-and 17-year-old Sonneratia apetala) of Char Alim and Char Piya and on their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya of Noakhali district, in Bangladesh to determine afforestation effects on soil properties. At soil depths of 0-10, 10-30 and 30-40 cm across three different land strips viz. inland, middle and sea side in 12-and 17-year-old keora (Sonneratia apetala) plantations, soil moisture, particle density, organic matter and C, total N, pH, available P, K, Na, Ca and Mg were significantly (p≤0.05, p≤0.01, p≤0.001) higher, and soil salinity significantly (p≤0.001) lower than that in their adjacent barren lands. Soil moisture, particle density, organic matter and C, total N, pH, soil salinity, available P, K, Na, Ca and Mg of surface soil in Char Alim plantation at inland were 31.09%, 2.24 g·cm-3, 2.41%, 4.14%, 0.58%, 7.07, 0.09 dS·cm-1, 28.06 mg·L-1, 0.50 mg·L-1 11.5 mg·L-1, 3.30 mg·L-1 and 2.7 mmol·kg-1, respectively. Their corresponding values for the same depth and land position at adjacent Char Rehania barren land were 16.69%, 1.25g·cm-3, 0.43%, 0.74%, 0.25%, 6.57, 0.13 dS·cm-1, 13.07mg·L-1, 0.30 mg·L-1, 1.4 mg·L-1, 0.30 mmol·kg-1 and 0.50 mg·L-1, respectively. Soil moisture, particle density, organic matter and C, total N, pH, available P, K and Ca decreased, and soil salinity, available Na and Mg increased from inland towards sea side in the plantations. Although soil texture did not differ in most soil depths between plantation and adjacent barren land, proportion of sand particle was significantly (p≤0.01) lower and silt particle significantly (p≤0.001) in the plantations higher than that in their adjacent barren lands. In the study, evaluation of all the parameters was also done for the other pair of lands.