An efficient cycle slip detection method is proposed for high precision positioning and navigation results with global positioning system （GPS）,which is based on the assumption of a high sampling interval, measureme...An efficient cycle slip detection method is proposed for high precision positioning and navigation results with global positioning system （GPS）,which is based on the assumption of a high sampling interval, measurement errors are so small that they can be ignored in the temporal single difference observables. And ambiguities are ordinarily equal to zero,but could be the number of cycles that have ＂slipped＂ if loss-of-lock has occurred.Therefore,cycle slips are estimated as parameters of time-relative positioning observation equations.Because the temporal single difference observables are taken at different epochs and different stations with a single GPS receiver,if time-relative positioning observation equations are linearized as that of conventional relative positioning,the design matrix will be rank defective.To obtain a stable linearization scheme,time-relative positioning observation equations are further analyzed,and the concept of virtual measurement is applied.A sample of data collected on a vehicle test shows that a cycle slip detection approach based on time-relative positioning theory can detect slips at the value of one cycle.The results also indicate if two satellites are so near to each other that they have the same equivalent to satellite-receiver geometry,cycle slip detection will be difficult and may get wrong results.Cycle slips of different satellites also affect detection by satellite-receiver geometry.展开更多
For efficient energy consumption and control of effluent quality, the cycle duration for a sequencing batch reactor (SBR) needs to be adjusted by real-time control according to the characteristics and loading of waste...For efficient energy consumption and control of effluent quality, the cycle duration for a sequencing batch reactor (SBR) needs to be adjusted by real-time control according to the characteristics and loading of waste-water. In this study, an on-line information system for phosphorus removal processes was established. Based on the analysis for four systems with different ecological community structures and two operation modes, anaerobic-aerobic process and anaerobic-anaerobic process, the characteristic patterns of oxidation-reduction potential (ORP) and pH were related to phosphorous dynamics in the anaerobic, anoxic and aerobic phases, for determination of the end of phosphorous removal. In the operation mode of anaerobic-aerobic process, the pH profile in the anaerobic phase was used to estimate the relative amount of phosphorous accumulating organisms (PAOs) and glycogen accumulat-ing organisms (GAOs), which is beneficial to early detection of ecology community shifts. The on-line sensor val-ues of pH and ORP may be used as the parameters to adjust the duration for phosphorous removal and community shifts to cope with influent variations and maintain appropriate operation conditions.展开更多
The grey forecasting model has been successfully applied to many fields. However, the precision of GM(1,1) model is not high. In order to remove the seasonal fluctuations in monitoring series before building GM(1,1) m...The grey forecasting model has been successfully applied to many fields. However, the precision of GM(1,1) model is not high. In order to remove the seasonal fluctuations in monitoring series before building GM(1,1) model, the forecasting series of GM(1,1) was built, and an inverse process was used to resume the seasonal fluctuations. Two deseasonalization methods were presented , i.e., seasonal index-based deseasonalization and standard normal distribution-based deseasonalization. They were combined with the GM(1,1) model to form hybrid grey models. A simple but practical method to further improve the forecasting results was also suggested. For comparison, a conventional periodic function model was investigated. The concept and algorithms were tested with four years monthly monitoring data. The results show that on the whole the seasonal index-GM(1,1) model outperform the conventional periodic function model and the conventional periodic function model outperform the SND-GM(1,1) model. The mean Absolute error and mean square error of seasonal index-GM(1,1) are 30.69% and 54.53% smaller than that of conventional periodic function model, respectively. The high accuracy, straightforward and easy implementation natures of the proposed hybrid seasonal index-grey model make it a powerful analysis technique for seasonal monitoring series.展开更多
AIM： To determine the factors affecting mortality in pa- tients who developed graft-versus-host disease （GvHD） after liver transplantation （LT）. METHODS： We performed a review of studies of GvHD following LT pub...AIM： To determine the factors affecting mortality in pa- tients who developed graft-versus-host disease （GvHD） after liver transplantation （LT）. METHODS： We performed a review of studies of GvHD following LT published in the English literature and ac- cessed the PubMed, Medline, EBSCO, EMBASE, and Google Scholar databases. Using relevant search phras- es, 88 articles were identified. Of these, 62 articles con- raining most of the study parameters were considered eligible for the study. Risk factors were first examined using a univariate Kaplan-Meier model, and variables with a significant association （P 〈 0.05） were then sub- jected to multivariate analyses using a Cox proportional- hazards model. RESULTS： The 61 articles reported 87 patients, 58 male and 29 female, mean age, 40.4 ± 15.5 years （range： 8 mo to 74 years）, who met the inclusion criteria for the present study. Deaths occurred in 59 （67.8%） patients, whereas 28 （32.2%） survived after a mean follow-up period of 280.8 ± 316.2 d （range： 27-2285 d）. Among the most frequent symptoms were rash （94.2%）, fever （66.6%）, diarrhea （54%）, and pancytopenia （54%）. The average time period between LT and first symptom on- set was 60.6 ± 190.1 d （range： 2-1865 d）. The Kaplan- Meier analysis revealed that pancytopenia （42.8% vs 59.3%, P = 0.03）, diarrhea （39.2% vs 61.0%, P = 0.04）, age difference between the recipient and the donor （14.6 ± 3.1 years vs 22.6 ± 2.7 years, P 〈 0.0001）, and time From first symptom occurrence to diagnosis or treatment （13.3 ± 2.6 mo vs 15.0 ± 2.3 mo, P 〈 0.0001） were significant factors affecting mortality, whereas age, sex, presence of rash and fever, use of immunosuppressive agents, acute rejection before GvHD, etiological causes, time of onset, and donor type were not associated with mortality risk. The Cox proportional-hazards model, de- termined that an age difference between the recipient and donor was an independent risk Factor （P = 0.03; hazard ratio, 7.395, 95% confidence interval, 1.2-46.7）. CONCLUSION： This study showed that an age differ- ence between the recipient and donor is an independent risk factor for mortality in patients who develop GvHD after LT.展开更多
Adsorbents are important components in adsorption refrigeration. The diameter of an adsorbent can affect the heat and mass transfer of an adsorber. The effect of particle diameter on effective thermal conductivity was...Adsorbents are important components in adsorption refrigeration. The diameter of an adsorbent can affect the heat and mass transfer of an adsorber. The effect of particle diameter on effective thermal conductivity was investigated. The heat transfer coefficient of the refrigerant and the void rate of the adsorbent layer can also affect the effective thermal conductivity of adsorbents. The performance of mass transfer in the adsorber is better when pressure drop decreases. Pressure drop decreases with increasing permeability. The permeability of the adsorbent layer can be improved with increasing adsorbent diameter. The effect of adsorbent diameter on refrigeration output power was experimentally studied. Output power initially increases and then decreases with increasing diameter under different cycle time conditions. Output power increases with decreasing cycle time under similar diameters.展开更多
AIM: To determine whether routine nasogastric (NG) decompression benefitted patients undergoing radical gastric surgery. METHODS: Between January 1998 and December 2008, 519 patients who underwent distal gastrectomy f...AIM: To determine whether routine nasogastric (NG) decompression benefitted patients undergoing radical gastric surgery. METHODS: Between January 1998 and December 2008, 519 patients who underwent distal gastrectomy for gastric cancer were retrospectively divided into 2 time-period cohorts; those treated with Billroth Ⅱ (BⅡ) reconstruction in the first 6 years and those with Roux-en-Y (RY) reconstruction in the last 5 years. In the latter group, the patients were further divided into 2 subgroups; with and without nasogastric decompression.RESULTS: Postoperatively, there were no significant differences in the number of anastomotic leaks between the 3 groups. In the tubeless RY group, time to semiliquid diet was significantly shorter than in the other 2 groups (4.4 d ± 1.4 d vs 7.2 d ± 1.3 d and 5.9 d ± 1.2 d, P = 0.005). The length of postoperative stay was significantly increased in patients with BⅡ reconstruction compared with patients with RY reconstruction with/without NG decompression (15.4 d ± 4.3 d in BⅡ group vs 12.6 d ± 3.1 d in decompressed RY and 11.4 d ± 3.4 d in the tubeless RY group, P = 0.035). The postoperative pneumonia rate was lowest in the tubeless group and highest in the BⅡ group (1.4% vs 4.6%, P = 0.01). Severe sore throat was noted in 59 (20.7%) members of the BⅡ group, 18 (17.4%) members of the decompressed RY group and 6 (4.2%) members of the tubeless RY group. Fewer patients in the tubeless group complained of severe sore throat (P = 0.001). CONCLUSION: This study provides support for abandoning routine NG decompression in patients undergoing subtotal gastrectomy with Roux-en-Y gastrojejunostomy.展开更多
How much more can be gained from a piece of World Literature when the reader is semiotically literate in the culture that produced the work？ What are the implications of introducing the element of cultural literacy i...How much more can be gained from a piece of World Literature when the reader is semiotically literate in the culture that produced the work？ What are the implications of introducing the element of cultural literacy into the teaching of world literature, and how might culturally contextualizing the narrative enhance the reading experience for those who may not be familiar with the national culture that produced the work？ This paper examines these questions using as a case study The Tale of Genji （n.d.）, a novel from llth century Japan and ＂La Troisi6me Jeunesse de Madame Prune＂ （1905）, a French text set in Japan at the turn of the 20th century. Using examples taken from each writer＇s text, the author will show how a knowledge of both the target culture and the time period in which the work was produced can serve as a critical tool for analyzing the text; the former text shall be used to argue for an integration of a cultural anthropology element into the teaching of world literature, while the latter example shall be used to argue for the importance of contextualizing a text within its historical creation period. In concluding, the author shall examine the ways in which including an element of cultural literacy can lead to a truly interdisciplinary, trans-national, and trans-linguistic understanding of a particular literary text.展开更多
According to a great deal of experimental findings and theoretical analysis, when the COD of inlet is 1 000-1 200 mg/L, NH3--N is 200~250 mg/L, the periodic time of operation is 24 h, the aeration time is 16 h and the...According to a great deal of experimental findings and theoretical analysis, when the COD of inlet is 1 000-1 200 mg/L, NH3--N is 200~250 mg/L, the periodic time of operation is 24 h, the aeration time is 16 h and the sludge density is 5 000-7 000 mg/L, COD of outlet is 150-200 mg/L, NH3--N is less than 25 mg/L, the volume load of COD and NH3--N remove 0.50 and 0.12 kg/（m3od） respectively. Meanwhile, studied the influence of various crafts parameter change on the treating effect and absorbing the yielding water of the SBR reactor with pulverized coal ash for improving the removing effect of COD and chromaticity further.展开更多
Objective The aim of this study was to test whether carcinoembryonic antigen （CEA） and cytokeratin 19 fragments （CYFRA21-1） can be used as a prognostic factor for non-small-cell lung cancer （NSCLC） after two cyc...Objective The aim of this study was to test whether carcinoembryonic antigen （CEA） and cytokeratin 19 fragments （CYFRA21-1） can be used as a prognostic factor for non-small-cell lung cancer （NSCLC） after two cycles of adjuvant chemotherapy in NSCLC patients. Methods A total of 169 patients underwent at least two cycles of adjuvant chemotherapy. The serum levels of CEA and CYFRA21-1 were recorded after the second cycle of chemotherapy, and the patient follow-up was conducted. Overall survival （OS） and disease- free survival （DFS） were used as the primary endpoint and the secondary endpoint, respectively. Results The high levels of CEA and CYFRA21-1 after two cycles of adjuvant chemotherapy were poor prognostic factors for OS, with risk ratios （RR） of 2.003 and 1.702, respectively. A high CEA level was a poor prognostic factor （RR 1.152） for DFS. The median survival time （MST） of the high CEA level group was 26 months, whereas that of the normal group was 61 months （P〈0.0001）. The median DFS time of the high CEA group and the normal group was 34 and 53 months, respectively （P〈0.0001）. The MST of the high CYFRA21-1 group and the normal group was 43 and 56 months, respectively （P〈0.0001）. Conclusions The high serum levels of CEA or CYFRA21-1 after two cycles of adjuvant chemotherapy are poor prognostic factors for NSCLC patients.展开更多
基金国家自然科学基金面上项目“环境中Pu的地球化学运移”(编号:40873086),“黔中大气核素(Pb-210,Be-7)与气溶胶关系”(编号:40773071),“Pb-210和Be-7大气沉降通量研究”(编号:40373038),“利用7Be和210Pb示踪研究高原大气微量气体成分的输送特征”(编号:40175032)中美国际合作项目“Tracing recent climate and environmental changes by measuring lowlevel radionuclides in the Yunnan-Guizhou plateau,China(2001-2005)”资助
文摘An efficient cycle slip detection method is proposed for high precision positioning and navigation results with global positioning system （GPS）,which is based on the assumption of a high sampling interval, measurement errors are so small that they can be ignored in the temporal single difference observables. And ambiguities are ordinarily equal to zero,but could be the number of cycles that have ＂slipped＂ if loss-of-lock has occurred.Therefore,cycle slips are estimated as parameters of time-relative positioning observation equations.Because the temporal single difference observables are taken at different epochs and different stations with a single GPS receiver,if time-relative positioning observation equations are linearized as that of conventional relative positioning,the design matrix will be rank defective.To obtain a stable linearization scheme,time-relative positioning observation equations are further analyzed,and the concept of virtual measurement is applied.A sample of data collected on a vehicle test shows that a cycle slip detection approach based on time-relative positioning theory can detect slips at the value of one cycle.The results also indicate if two satellites are so near to each other that they have the same equivalent to satellite-receiver geometry,cycle slip detection will be difficult and may get wrong results.Cycle slips of different satellites also affect detection by satellite-receiver geometry.
基金Supported by the Project of Scientific Research Base and Scientific Innovation Platform of Beijing Municipal Education Com-mission (PXM2008_014204_050843)the National Natural Science Foundation of China (50808004)the DoctoralStartup Research Program of Beijing University of Technology
文摘For efficient energy consumption and control of effluent quality, the cycle duration for a sequencing batch reactor (SBR) needs to be adjusted by real-time control according to the characteristics and loading of waste-water. In this study, an on-line information system for phosphorus removal processes was established. Based on the analysis for four systems with different ecological community structures and two operation modes, anaerobic-aerobic process and anaerobic-anaerobic process, the characteristic patterns of oxidation-reduction potential (ORP) and pH were related to phosphorous dynamics in the anaerobic, anoxic and aerobic phases, for determination of the end of phosphorous removal. In the operation mode of anaerobic-aerobic process, the pH profile in the anaerobic phase was used to estimate the relative amount of phosphorous accumulating organisms (PAOs) and glycogen accumulat-ing organisms (GAOs), which is beneficial to early detection of ecology community shifts. The on-line sensor val-ues of pH and ORP may be used as the parameters to adjust the duration for phosphorous removal and community shifts to cope with influent variations and maintain appropriate operation conditions.
文摘The grey forecasting model has been successfully applied to many fields. However, the precision of GM(1,1) model is not high. In order to remove the seasonal fluctuations in monitoring series before building GM(1,1) model, the forecasting series of GM(1,1) was built, and an inverse process was used to resume the seasonal fluctuations. Two deseasonalization methods were presented , i.e., seasonal index-based deseasonalization and standard normal distribution-based deseasonalization. They were combined with the GM(1,1) model to form hybrid grey models. A simple but practical method to further improve the forecasting results was also suggested. For comparison, a conventional periodic function model was investigated. The concept and algorithms were tested with four years monthly monitoring data. The results show that on the whole the seasonal index-GM(1,1) model outperform the conventional periodic function model and the conventional periodic function model outperform the SND-GM(1,1) model. The mean Absolute error and mean square error of seasonal index-GM(1,1) are 30.69% and 54.53% smaller than that of conventional periodic function model, respectively. The high accuracy, straightforward and easy implementation natures of the proposed hybrid seasonal index-grey model make it a powerful analysis technique for seasonal monitoring series.
文摘AIM： To determine the factors affecting mortality in pa- tients who developed graft-versus-host disease （GvHD） after liver transplantation （LT）. METHODS： We performed a review of studies of GvHD following LT published in the English literature and ac- cessed the PubMed, Medline, EBSCO, EMBASE, and Google Scholar databases. Using relevant search phras- es, 88 articles were identified. Of these, 62 articles con- raining most of the study parameters were considered eligible for the study. Risk factors were first examined using a univariate Kaplan-Meier model, and variables with a significant association （P 〈 0.05） were then sub- jected to multivariate analyses using a Cox proportional- hazards model. RESULTS： The 61 articles reported 87 patients, 58 male and 29 female, mean age, 40.4 ± 15.5 years （range： 8 mo to 74 years）, who met the inclusion criteria for the present study. Deaths occurred in 59 （67.8%） patients, whereas 28 （32.2%） survived after a mean follow-up period of 280.8 ± 316.2 d （range： 27-2285 d）. Among the most frequent symptoms were rash （94.2%）, fever （66.6%）, diarrhea （54%）, and pancytopenia （54%）. The average time period between LT and first symptom on- set was 60.6 ± 190.1 d （range： 2-1865 d）. The Kaplan- Meier analysis revealed that pancytopenia （42.8% vs 59.3%, P = 0.03）, diarrhea （39.2% vs 61.0%, P = 0.04）, age difference between the recipient and the donor （14.6 ± 3.1 years vs 22.6 ± 2.7 years, P 〈 0.0001）, and time From first symptom occurrence to diagnosis or treatment （13.3 ± 2.6 mo vs 15.0 ± 2.3 mo, P 〈 0.0001） were significant factors affecting mortality, whereas age, sex, presence of rash and fever, use of immunosuppressive agents, acute rejection before GvHD, etiological causes, time of onset, and donor type were not associated with mortality risk. The Cox proportional-hazards model, de- termined that an age difference between the recipient and donor was an independent risk Factor （P = 0.03; hazard ratio, 7.395, 95% confidence interval, 1.2-46.7）. CONCLUSION： This study showed that an age differ- ence between the recipient and donor is an independent risk factor for mortality in patients who develop GvHD after LT.
基金Supported by the Chinese Academy of Science Visiting Professorship for Senior International Scientists project(2009Z2-1973)
文摘Adsorbents are important components in adsorption refrigeration. The diameter of an adsorbent can affect the heat and mass transfer of an adsorber. The effect of particle diameter on effective thermal conductivity was investigated. The heat transfer coefficient of the refrigerant and the void rate of the adsorbent layer can also affect the effective thermal conductivity of adsorbents. The performance of mass transfer in the adsorber is better when pressure drop decreases. Pressure drop decreases with increasing permeability. The permeability of the adsorbent layer can be improved with increasing adsorbent diameter. The effect of adsorbent diameter on refrigeration output power was experimentally studied. Output power initially increases and then decreases with increasing diameter under different cycle time conditions. Output power increases with decreasing cycle time under similar diameters.
文摘AIM: To determine whether routine nasogastric (NG) decompression benefitted patients undergoing radical gastric surgery. METHODS: Between January 1998 and December 2008, 519 patients who underwent distal gastrectomy for gastric cancer were retrospectively divided into 2 time-period cohorts; those treated with Billroth Ⅱ (BⅡ) reconstruction in the first 6 years and those with Roux-en-Y (RY) reconstruction in the last 5 years. In the latter group, the patients were further divided into 2 subgroups; with and without nasogastric decompression.RESULTS: Postoperatively, there were no significant differences in the number of anastomotic leaks between the 3 groups. In the tubeless RY group, time to semiliquid diet was significantly shorter than in the other 2 groups (4.4 d ± 1.4 d vs 7.2 d ± 1.3 d and 5.9 d ± 1.2 d, P = 0.005). The length of postoperative stay was significantly increased in patients with BⅡ reconstruction compared with patients with RY reconstruction with/without NG decompression (15.4 d ± 4.3 d in BⅡ group vs 12.6 d ± 3.1 d in decompressed RY and 11.4 d ± 3.4 d in the tubeless RY group, P = 0.035). The postoperative pneumonia rate was lowest in the tubeless group and highest in the BⅡ group (1.4% vs 4.6%, P = 0.01). Severe sore throat was noted in 59 (20.7%) members of the BⅡ group, 18 (17.4%) members of the decompressed RY group and 6 (4.2%) members of the tubeless RY group. Fewer patients in the tubeless group complained of severe sore throat (P = 0.001). CONCLUSION: This study provides support for abandoning routine NG decompression in patients undergoing subtotal gastrectomy with Roux-en-Y gastrojejunostomy.
文摘How much more can be gained from a piece of World Literature when the reader is semiotically literate in the culture that produced the work？ What are the implications of introducing the element of cultural literacy into the teaching of world literature, and how might culturally contextualizing the narrative enhance the reading experience for those who may not be familiar with the national culture that produced the work？ This paper examines these questions using as a case study The Tale of Genji （n.d.）, a novel from llth century Japan and ＂La Troisi6me Jeunesse de Madame Prune＂ （1905）, a French text set in Japan at the turn of the 20th century. Using examples taken from each writer＇s text, the author will show how a knowledge of both the target culture and the time period in which the work was produced can serve as a critical tool for analyzing the text; the former text shall be used to argue for an integration of a cultural anthropology element into the teaching of world literature, while the latter example shall be used to argue for the importance of contextualizing a text within its historical creation period. In concluding, the author shall examine the ways in which including an element of cultural literacy can lead to a truly interdisciplinary, trans-national, and trans-linguistic understanding of a particular literary text.
文摘According to a great deal of experimental findings and theoretical analysis, when the COD of inlet is 1 000-1 200 mg/L, NH3--N is 200~250 mg/L, the periodic time of operation is 24 h, the aeration time is 16 h and the sludge density is 5 000-7 000 mg/L, COD of outlet is 150-200 mg/L, NH3--N is less than 25 mg/L, the volume load of COD and NH3--N remove 0.50 and 0.12 kg/（m3od） respectively. Meanwhile, studied the influence of various crafts parameter change on the treating effect and absorbing the yielding water of the SBR reactor with pulverized coal ash for improving the removing effect of COD and chromaticity further.
文摘Objective The aim of this study was to test whether carcinoembryonic antigen （CEA） and cytokeratin 19 fragments （CYFRA21-1） can be used as a prognostic factor for non-small-cell lung cancer （NSCLC） after two cycles of adjuvant chemotherapy in NSCLC patients. Methods A total of 169 patients underwent at least two cycles of adjuvant chemotherapy. The serum levels of CEA and CYFRA21-1 were recorded after the second cycle of chemotherapy, and the patient follow-up was conducted. Overall survival （OS） and disease- free survival （DFS） were used as the primary endpoint and the secondary endpoint, respectively. Results The high levels of CEA and CYFRA21-1 after two cycles of adjuvant chemotherapy were poor prognostic factors for OS, with risk ratios （RR） of 2.003 and 1.702, respectively. A high CEA level was a poor prognostic factor （RR 1.152） for DFS. The median survival time （MST） of the high CEA level group was 26 months, whereas that of the normal group was 61 months （P〈0.0001）. The median DFS time of the high CEA group and the normal group was 34 and 53 months, respectively （P〈0.0001）. The MST of the high CYFRA21-1 group and the normal group was 43 and 56 months, respectively （P〈0.0001）. Conclusions The high serum levels of CEA or CYFRA21-1 after two cycles of adjuvant chemotherapy are poor prognostic factors for NSCLC patients.
