The influences of two kinds of casting modules of metal casting （MC） and expandable pattern casting （EPC） on the corrosion behavior of Mg-11Gd-3Y alloy were studied by electrochemical measurements, scanning electr...The influences of two kinds of casting modules of metal casting （MC） and expandable pattern casting （EPC） on the corrosion behavior of Mg-11Gd-3Y alloy were studied by electrochemical measurements, scanning electron microscopy （SEM） observation, X-ray diffractometry （XRD） and X-ray photoelectron spectroscopy （XPS） analysis. It is found that the quantity of the Mg 24 （Gd, Y） 5 phase in MC is more than that in EPC due to the cooling rate. There is more alloying element dissolved in the matrix compared with MC. For EPC, the galvanic corrosion effect between the matrix and the Mg 24 （Gd, Y） 5 phase decreases and the corrosion resistance increases compared with the MC. The chief corrosion mode for Mg-11Gd-3Y alloy is pitting corrosion because most of the alloying elements are transformed into intermetallic phases. The average corrosion rate of the MC alloy in the immersion test is five times higher than that of EPC alloy and yttrium is present in the product film, which will provide increased protection for Mg-11Gd-3Y alloy. The electrochemical measurements and immersion test show that the EPC process increases the corrosion resistance compared with the MC Mg-11Gd-3Y alloy.展开更多
Acute upper gastrointestinal bleeding(UGIB) is a gastroenterological emergency with a mortality of 6%-13%.The vast majority of these bleeds are due to peptic ulcers.Nonsteroidal anti-inflammatory drugs and Helicobacte...Acute upper gastrointestinal bleeding(UGIB) is a gastroenterological emergency with a mortality of 6%-13%.The vast majority of these bleeds are due to peptic ulcers.Nonsteroidal anti-inflammatory drugs and Helicobacter pylori are the main risk factors for peptic ulcer disease.Endoscopy has become the mainstay for diagnosis and treatment of acute UGIB,and is recommended within 24 h of presentation.Proton pump inhibitor(PPI) administration before endoscopy can downstage the bleeding lesion and reduce the need for endoscopic therapy,but has no effect on rebleeding,mortality and need for surgery.Endoscopic therapy should be undertaken for ulcers with high-risk stigmata,to reduce the risk of rebleeding.This can be done with a variety of modalities.High-dose PPI administration after endoscopy can prevent rebleeding and reduce the need for further intervention and mortality,particularly in patients with high-risk stigmata.展开更多
AIM: To investigate the differences in biological features of gastric dysplasia (Dys), indefinite dysplasia (IDys) and reactive hyperplasia (RH) by studying the biomarker alterations in cell proliferation, cell differ...AIM: To investigate the differences in biological features of gastric dysplasia (Dys), indefinite dysplasia (IDys) and reactive hyperplasia (RH) by studying the biomarker alterations in cell proliferation, cell differentiation, cell cycle control and the expression of house-keeping genes, and further to search for markers which could be used in guiding the pathological diagnosis of three lesions. METHODS: Expressions of MUC5AC, MUC6, adenomatous polyposis coli (APC), p53, Ki-67, proliferation cell nuclear antigen (PCNA) and EGFR were studied by immunohistochemistry with a standard Envision technique in formalinfixed and paraffin-embedded specimens from 43 RH, 35 IDys, 35 Dys and 36 intestinal type gastric carcinomas (IGC). In addition, Bayes discriminant analysis was used to investigate the value of markers studied in differential diagnosis of RH, IDys, Dys and IGC. RESULTS: The MUC5AC and MUC6 antigen expressions in RH, IDys, Dys and IGC decreased gradually (MUC5AC:86.04%, 77.14%, 28.57%, 6.67%; MUC6: 65.15%, 54.29%, 20.00%, 25.00%, respectively). The expressions of the two markers had no significant difference between RH and IDys, but were all significantly higher than those ofthe other two lesions (MUC5AC: x2 = 27.607, 38.027 and 17.33, 26.092; MUC6: x2= 16.54, 12.665 and 9.282, 6.737, P＜0.01). There was no significant differencebetween RH and IDys, Dys and IGC in MUC6 expression. The APC gene expression in the four lesions had a similar decreasing tendency (RH 69.76%, IDys 68.57%, Dys39.39%, IGC 22.86%), and it was significantly higher in the first two lesions than in the last two (x2 = 7.011,16.995 and 14.737, 19.817, P＜0.05). The p53 expressionin RH, IDys, Dys and IGC was 6.98%, 20%, 57.14% and 50%, respectively. There was no significant differencebetween RH and IDys or Dys and IGC, but the p53 expression in RH and IDys was significantly lower than that in Dys and IGC (x2 = 7.011, 16.995 and 14.737, 19.817, P＜0.01).The Ki-67 label index was significantly different among four lesions (RH: 0.298±8.92%, IDys: 0.358±9.25%,Dys: 0.498±9.03%, IGC: 0.620±10.8%, P＜0.001). Positive immunostaining of PCNA was though observed in all specimens, significant differences were detected among four lesions (F= 95.318, P＜0.01). In addition, we used Bayes discriminant analysis to investigate molecular pathological classification of the lesions, and obtained the best result with the combination of MUC5AC, Ki-67 and PCNA. The overall rate of correct classification was67.4% (RH), 68.6% (IDys), 70.6% (Dys) and 84.8% (IGC), respectively.CONCLUSION: Dys has neoplastic biological characteristics, while RH and IDys display hyperplastic characteristics. MUC5AC and proliferation-related biomarkers (Ki-67, PCNA) are more specific in distinguishing Dys from RH and IDys.展开更多
AIM:To study the prevalence of functional dyspepsia(FD)(Rome Ⅲ criteria) across eating disorders(ED),obese patients,constitutional thinner and healthy volunteers.METHODS:Twenty patients affected by anorexia nervosa,6...AIM:To study the prevalence of functional dyspepsia(FD)(Rome Ⅲ criteria) across eating disorders(ED),obese patients,constitutional thinner and healthy volunteers.METHODS:Twenty patients affected by anorexia nervosa,6 affected by bulimia nervosa,10 affected by ED not otherwise specified according to diagnostic and statistical manual of mental disorders,4th edition,nine constitutional thinner subjects and,thirtytwo obese patients were recruited from an outpatients clinic devoted to eating behavior disorders.Twentytwo healthy volunteers matched for age and gender were enrolled as healthy controls.All participants underwent a careful clinical examination.Demographic and anthropometric characteristics were obtained from a structured questionnaires.The presence of FD and,its subgroups,epigastric pain syndrome and postprandial distress syndrome(PDS) were diagnosed according to Rome Ⅲ criteria.The intensity-frequency score of broader dyspeptic symptoms such as early satiety,epigastric fullness,epigastric pain,epigastric burning,epigastric pressure,belching,nausea and vomiting were studied by a standardized questionnaire(0-6).Analysis of variance and post-hoc Sheffè tests were used for comparisons.RESULTS:90% of patients affected by anorexia nervosa,83.3% of patients affected by bulimia nervosa,90% of patients affected by ED not otherwise specified,55.6% of constitutionally thin subjects and 18.2% healthy volunteers met the Postprandial Distress Syndrome Criteria(χ 2,P < 0.001).Only one bulimic patient met the epigastric pain syndrome diagnosis.Postprandial fullness intensity-frequency score was significantly higher in anorexia nervosa,bulimia nervosa and ED not otherwise specified groups compared to the score calculated in the constitutional thinner group(4.15 ± 2.08 vs 1.44 ± 2.35,P = 0.003;5.00 ± 2.45vs 1.44 ± 2.35,P = 0.003;4.10 ± 2.23vs 1.44 ± 2.35,P = 0.002,respectively),the obese group(4.15 ± 2.08vs 0.00 ± 0.00,P < 0.001;5.00 ± 2.45vs 0.00 ± 0.00,P < 0.001;4.10 ± 2.23 vs 0.00 ± 0.00,P < 0.001,respectively) and healthy volunteers(4.15 ± 2.08 vs 0.36 ± 0.79,P < 0.001;5.00 ± 2.45 vs 0.36 ± 0.79,P < 0.001;4.10 ± 2.23 vs 0.36 ± 0.79,P < 0.001,respectively).Early satiety intensity-frequency score was prominent in anorectic patients compared to bulimic patients(3.85 ± 2.23 vs 1.17 ± 1.83,P = 0.015),obese patients(3.85 ± 2.23 vs 0.00 ± 0.00,P < 0.001) and healthy volunteers(3.85 ± 2.23 vs 0.05 ± 0.21,P < 0.001).Nausea and epigastric pressure were increased in bulimic and ED not otherwise specified patients.Specifically,nausea intensity-frequencyscore was significantly higher in bulimia nervosa and ED not otherwise specified patients compared to anorectic patients(3.17 ± 2.56 vs 0.89 ± 1.66,P = 0.04;2.70 ± 2.91 vs 0.89 ± 1.66,P = 0.05,respectively),constitutional thinner subjects(3.17 ± 2.56 vs 0.00 ± 0.00,P = 0.004;2.70 ± 2.91 vs 0.00 ± 0.00,P = 0.005,respectively),obese patients(3.17 ± 2.56 vs 0.00 ± 0.00,P < 0.001;3.17 ± 2.56 vs 0.00 ± 0.00,P < 0.001 respectively) and,healthy volunteers(3.17 ± 2.56 vs 0.17 ± 0.71,P = 0.002;3.17 ± 2.56 vs 0.17 ± 0.71,P = 0.001,respectively).Epigastric pressure intensityfrequency score was significantly higher in bulimic and ED not otherwise specified patients compared to constitutional thin subjects(4.67 ± 2.42 vs 1.22 ± 1.72,P = 0.03;4.20 ± 2.21 vs 1.22 ± 1.72,P = 0.03,respectively),obese patients(4.67 ± 2.42 vs 0.75 ± 1.32,P = 0.001;4.20 ± 2.21vs 0.75 ± 1.32,P < 0.001,respectively) and,healthy volunteers(4.67 ± 2.42 vs 0.67 ± 1.46,P = 0.001;4.20 ± 2.21vs 0.67 ± 1.46,P = 0.001,respectively).Vomiting was referred in 100% of bulimia nervosa patients,in 20% of ED not otherwise specified patients,in 15% of anorexia nervosa patients,in 22% of constitutional thinner subjects,and,in 5.6% healthy volunteers(χ 2,P < 0.001).CONCLUSION:PDS is common in eating disorders.Is it mandatory in outpatient gastroenterological clinics to investigate eating disorders in patients with PDS?展开更多
Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rare...Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.展开更多
Linear dispersion codes (LDCs) were originally designed based on maximum likelihood detection. They do not have good performance when using ordered successive interference cancellation (OSIC) detection. In this paper,...Linear dispersion codes (LDCs) were originally designed based on maximum likelihood detection. They do not have good performance when using ordered successive interference cancellation (OSIC) detection. In this paper,we propose a new improved linear dispersion codes transmission scheme to combat performance loss of original LDCs when using OSIC detection. We introduce an interleaver to each data substream transmitted over different antennas after LDCs encoder. Furthermore,a new computer search criterion for a linear transformation matrix is also proposed. New search criterion is to minimize the symbol error rate based on OSIC detection. Computer simulations show that the performance of proposed LDCs transmission scheme is better than the original LDCs.展开更多
Most of the traditional taxi path planning studies assume that the aircraft is in uniform speed,and the optimization goal is the shortest taxi time.Although it is easy to solve,it does not consider the changes in the ...Most of the traditional taxi path planning studies assume that the aircraft is in uniform speed,and the optimization goal is the shortest taxi time.Although it is easy to solve,it does not consider the changes in the speed profile of the aircraft when turning,and the shortest taxi time does not necessarily bring the best taxi fuel consumption.In this paper,the number of turns is considered,and the improved A*algorithm is used to obtain the P static paths with the shortest sum of the straight-line distance and the turning distance of the aircraft as the feasible taxi paths.By balancing taxi time and fuel consumption,a set of Pareto optimal speed profiles are generated for each preselected path to predict the 4-D trajectory of the aircraft.Based on the 4-D trajectory prediction results,the conflict by the occupied time window in the taxiing area is detected.For the conflict aircraft,based on the priority comparison,the waiting or changing path is selected to solve the taxiing conflict.Finally,the conflict free aircraft taxiing path is generated and the area occupation time window on the path is updated.The experimental results show that the total taxi distance and turn time of the aircraft are reduced,and the fuel consumption is reduced.The proposed method has high practical application value and is expected to be applied in real-time air traffic control decision-making in the future.展开更多
基金Project(2007CB613705)supported by the National Basic Research Program of China
文摘The influences of two kinds of casting modules of metal casting （MC） and expandable pattern casting （EPC） on the corrosion behavior of Mg-11Gd-3Y alloy were studied by electrochemical measurements, scanning electron microscopy （SEM） observation, X-ray diffractometry （XRD） and X-ray photoelectron spectroscopy （XPS） analysis. It is found that the quantity of the Mg 24 （Gd, Y） 5 phase in MC is more than that in EPC due to the cooling rate. There is more alloying element dissolved in the matrix compared with MC. For EPC, the galvanic corrosion effect between the matrix and the Mg 24 （Gd, Y） 5 phase decreases and the corrosion resistance increases compared with the MC. The chief corrosion mode for Mg-11Gd-3Y alloy is pitting corrosion because most of the alloying elements are transformed into intermetallic phases. The average corrosion rate of the MC alloy in the immersion test is five times higher than that of EPC alloy and yttrium is present in the product film, which will provide increased protection for Mg-11Gd-3Y alloy. The electrochemical measurements and immersion test show that the EPC process increases the corrosion resistance compared with the MC Mg-11Gd-3Y alloy.
文摘Acute upper gastrointestinal bleeding(UGIB) is a gastroenterological emergency with a mortality of 6%-13%.The vast majority of these bleeds are due to peptic ulcers.Nonsteroidal anti-inflammatory drugs and Helicobacter pylori are the main risk factors for peptic ulcer disease.Endoscopy has become the mainstay for diagnosis and treatment of acute UGIB,and is recommended within 24 h of presentation.Proton pump inhibitor(PPI) administration before endoscopy can downstage the bleeding lesion and reduce the need for endoscopic therapy,but has no effect on rebleeding,mortality and need for surgery.Endoscopic therapy should be undertaken for ulcers with high-risk stigmata,to reduce the risk of rebleeding.This can be done with a variety of modalities.High-dose PPI administration after endoscopy can prevent rebleeding and reduce the need for further intervention and mortality,particularly in patients with high-risk stigmata.
基金Supported by the National Key Fundamental Research Project,No.G1998051203
文摘AIM: To investigate the differences in biological features of gastric dysplasia (Dys), indefinite dysplasia (IDys) and reactive hyperplasia (RH) by studying the biomarker alterations in cell proliferation, cell differentiation, cell cycle control and the expression of house-keeping genes, and further to search for markers which could be used in guiding the pathological diagnosis of three lesions. METHODS: Expressions of MUC5AC, MUC6, adenomatous polyposis coli (APC), p53, Ki-67, proliferation cell nuclear antigen (PCNA) and EGFR were studied by immunohistochemistry with a standard Envision technique in formalinfixed and paraffin-embedded specimens from 43 RH, 35 IDys, 35 Dys and 36 intestinal type gastric carcinomas (IGC). In addition, Bayes discriminant analysis was used to investigate the value of markers studied in differential diagnosis of RH, IDys, Dys and IGC. RESULTS: The MUC5AC and MUC6 antigen expressions in RH, IDys, Dys and IGC decreased gradually (MUC5AC:86.04%, 77.14%, 28.57%, 6.67%; MUC6: 65.15%, 54.29%, 20.00%, 25.00%, respectively). The expressions of the two markers had no significant difference between RH and IDys, but were all significantly higher than those ofthe other two lesions (MUC5AC: x2 = 27.607, 38.027 and 17.33, 26.092; MUC6: x2= 16.54, 12.665 and 9.282, 6.737, P＜0.01). There was no significant differencebetween RH and IDys, Dys and IGC in MUC6 expression. The APC gene expression in the four lesions had a similar decreasing tendency (RH 69.76%, IDys 68.57%, Dys39.39%, IGC 22.86%), and it was significantly higher in the first two lesions than in the last two (x2 = 7.011,16.995 and 14.737, 19.817, P＜0.05). The p53 expressionin RH, IDys, Dys and IGC was 6.98%, 20%, 57.14% and 50%, respectively. There was no significant differencebetween RH and IDys or Dys and IGC, but the p53 expression in RH and IDys was significantly lower than that in Dys and IGC (x2 = 7.011, 16.995 and 14.737, 19.817, P＜0.01).The Ki-67 label index was significantly different among four lesions (RH: 0.298±8.92%, IDys: 0.358±9.25%,Dys: 0.498±9.03%, IGC: 0.620±10.8%, P＜0.001). Positive immunostaining of PCNA was though observed in all specimens, significant differences were detected among four lesions (F= 95.318, P＜0.01). In addition, we used Bayes discriminant analysis to investigate molecular pathological classification of the lesions, and obtained the best result with the combination of MUC5AC, Ki-67 and PCNA. The overall rate of correct classification was67.4% (RH), 68.6% (IDys), 70.6% (Dys) and 84.8% (IGC), respectively.CONCLUSION: Dys has neoplastic biological characteristics, while RH and IDys display hyperplastic characteristics. MUC5AC and proliferation-related biomarkers (Ki-67, PCNA) are more specific in distinguishing Dys from RH and IDys.
文摘AIM:To study the prevalence of functional dyspepsia(FD)(Rome Ⅲ criteria) across eating disorders(ED),obese patients,constitutional thinner and healthy volunteers.METHODS:Twenty patients affected by anorexia nervosa,6 affected by bulimia nervosa,10 affected by ED not otherwise specified according to diagnostic and statistical manual of mental disorders,4th edition,nine constitutional thinner subjects and,thirtytwo obese patients were recruited from an outpatients clinic devoted to eating behavior disorders.Twentytwo healthy volunteers matched for age and gender were enrolled as healthy controls.All participants underwent a careful clinical examination.Demographic and anthropometric characteristics were obtained from a structured questionnaires.The presence of FD and,its subgroups,epigastric pain syndrome and postprandial distress syndrome(PDS) were diagnosed according to Rome Ⅲ criteria.The intensity-frequency score of broader dyspeptic symptoms such as early satiety,epigastric fullness,epigastric pain,epigastric burning,epigastric pressure,belching,nausea and vomiting were studied by a standardized questionnaire(0-6).Analysis of variance and post-hoc Sheffè tests were used for comparisons.RESULTS:90% of patients affected by anorexia nervosa,83.3% of patients affected by bulimia nervosa,90% of patients affected by ED not otherwise specified,55.6% of constitutionally thin subjects and 18.2% healthy volunteers met the Postprandial Distress Syndrome Criteria(χ 2,P < 0.001).Only one bulimic patient met the epigastric pain syndrome diagnosis.Postprandial fullness intensity-frequency score was significantly higher in anorexia nervosa,bulimia nervosa and ED not otherwise specified groups compared to the score calculated in the constitutional thinner group(4.15 ± 2.08 vs 1.44 ± 2.35,P = 0.003;5.00 ± 2.45vs 1.44 ± 2.35,P = 0.003;4.10 ± 2.23vs 1.44 ± 2.35,P = 0.002,respectively),the obese group(4.15 ± 2.08vs 0.00 ± 0.00,P < 0.001;5.00 ± 2.45vs 0.00 ± 0.00,P < 0.001;4.10 ± 2.23 vs 0.00 ± 0.00,P < 0.001,respectively) and healthy volunteers(4.15 ± 2.08 vs 0.36 ± 0.79,P < 0.001;5.00 ± 2.45 vs 0.36 ± 0.79,P < 0.001;4.10 ± 2.23 vs 0.36 ± 0.79,P < 0.001,respectively).Early satiety intensity-frequency score was prominent in anorectic patients compared to bulimic patients(3.85 ± 2.23 vs 1.17 ± 1.83,P = 0.015),obese patients(3.85 ± 2.23 vs 0.00 ± 0.00,P < 0.001) and healthy volunteers(3.85 ± 2.23 vs 0.05 ± 0.21,P < 0.001).Nausea and epigastric pressure were increased in bulimic and ED not otherwise specified patients.Specifically,nausea intensity-frequencyscore was significantly higher in bulimia nervosa and ED not otherwise specified patients compared to anorectic patients(3.17 ± 2.56 vs 0.89 ± 1.66,P = 0.04;2.70 ± 2.91 vs 0.89 ± 1.66,P = 0.05,respectively),constitutional thinner subjects(3.17 ± 2.56 vs 0.00 ± 0.00,P = 0.004;2.70 ± 2.91 vs 0.00 ± 0.00,P = 0.005,respectively),obese patients(3.17 ± 2.56 vs 0.00 ± 0.00,P < 0.001;3.17 ± 2.56 vs 0.00 ± 0.00,P < 0.001 respectively) and,healthy volunteers(3.17 ± 2.56 vs 0.17 ± 0.71,P = 0.002;3.17 ± 2.56 vs 0.17 ± 0.71,P = 0.001,respectively).Epigastric pressure intensityfrequency score was significantly higher in bulimic and ED not otherwise specified patients compared to constitutional thin subjects(4.67 ± 2.42 vs 1.22 ± 1.72,P = 0.03;4.20 ± 2.21 vs 1.22 ± 1.72,P = 0.03,respectively),obese patients(4.67 ± 2.42 vs 0.75 ± 1.32,P = 0.001;4.20 ± 2.21vs 0.75 ± 1.32,P < 0.001,respectively) and,healthy volunteers(4.67 ± 2.42 vs 0.67 ± 1.46,P = 0.001;4.20 ± 2.21vs 0.67 ± 1.46,P = 0.001,respectively).Vomiting was referred in 100% of bulimia nervosa patients,in 20% of ED not otherwise specified patients,in 15% of anorexia nervosa patients,in 22% of constitutional thinner subjects,and,in 5.6% healthy volunteers(χ 2,P < 0.001).CONCLUSION:PDS is common in eating disorders.Is it mandatory in outpatient gastroenterological clinics to investigate eating disorders in patients with PDS?
基金Supported by the Qingdao Postdoctoral Application Research Project(No.Y6KY01110N)the National Natural Science Foundation of China(Nos.31472312,41306152,31402283)+2 种基金the Qingdao Innovation Talents Program(No.13-CX-16)the National Key Technologies R&D Program of China(No.2014BAD08B09)the Earmarked Fund for Modem AgroIndustry Technology Research System(No.CARS-48)
文摘Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.
文摘Linear dispersion codes (LDCs) were originally designed based on maximum likelihood detection. They do not have good performance when using ordered successive interference cancellation (OSIC) detection. In this paper,we propose a new improved linear dispersion codes transmission scheme to combat performance loss of original LDCs when using OSIC detection. We introduce an interleaver to each data substream transmitted over different antennas after LDCs encoder. Furthermore,a new computer search criterion for a linear transformation matrix is also proposed. New search criterion is to minimize the symbol error rate based on OSIC detection. Computer simulations show that the performance of proposed LDCs transmission scheme is better than the original LDCs.
基金supported by the National Key R&D Project(No.2020YFB1600101)National Natural Science Foundations of China(Nos.U1833103,71801215)Civil Aviation Flight Wide Area Surveillance and Safety Control Technology Key Laboratory Open Fund(No.202008)。
文摘Most of the traditional taxi path planning studies assume that the aircraft is in uniform speed,and the optimization goal is the shortest taxi time.Although it is easy to solve,it does not consider the changes in the speed profile of the aircraft when turning,and the shortest taxi time does not necessarily bring the best taxi fuel consumption.In this paper,the number of turns is considered,and the improved A*algorithm is used to obtain the P static paths with the shortest sum of the straight-line distance and the turning distance of the aircraft as the feasible taxi paths.By balancing taxi time and fuel consumption,a set of Pareto optimal speed profiles are generated for each preselected path to predict the 4-D trajectory of the aircraft.Based on the 4-D trajectory prediction results,the conflict by the occupied time window in the taxiing area is detected.For the conflict aircraft,based on the priority comparison,the waiting or changing path is selected to solve the taxiing conflict.Finally,the conflict free aircraft taxiing path is generated and the area occupation time window on the path is updated.The experimental results show that the total taxi distance and turn time of the aircraft are reduced,and the fuel consumption is reduced.The proposed method has high practical application value and is expected to be applied in real-time air traffic control decision-making in the future.
