Research on practical and verifiable prediction methods for the service life of bearings plays a critical role in improving the reliability and safety of aircraft engines. The concept of grade-life （GL） is introduce...Research on practical and verifiable prediction methods for the service life of bearings plays a critical role in improving the reliability and safety of aircraft engines. The concept of grade-life （GL） is introduced to de- scribe the service life of bearings. A GL prognostic model for aircraft engine bearings is proposed based on sup- port vector machine （SVM） and fuzzy logic inference. Firstly, the mathematical model is discussed to predict the physics-based GL （PGL）. Then, the diagnostic estimation model based on SVM is presented in detail to predict the empirical GL （EPL）. Thirdly, a fuzzy logic inference is adopted to fuse two GL predicted results. Finally, the GL prognostic model is verified by the run-to-failure data acquired from an accelerated life test of an aircraft bearing. The results show that the model provides a more practical and reliable prediction for the service life of bearings.展开更多
In order to more effectively assess the health status of a project, the monitoring indices in a project＇s life cycle are divided into quality index, cost index, time index, satisfaction index, and sustainable develop...In order to more effectively assess the health status of a project, the monitoring indices in a project＇s life cycle are divided into quality index, cost index, time index, satisfaction index, and sustainable development index. Based on the feature of qualitative and quantitative indices combining, the PCA-PR （principal component analysis and pattern recognition） model is constructed. The model first analyzes the principal components of the life-cycle indices system constructed above, and picks up those principal component indices that can reflect the health status of a project at any time. Then the pattern recognition model is used to study these principal components, which means that the real time health status of the project can be divided into five lamps from a green lamp to a red one and the health status lamp of the project can be recognized by using the PR model and those principal components. Finally, the process is shown with a real example and a conclusion consistent with the actual situation is drawn. So the validity of the index system and the PCA-PR model can be confirmed.展开更多
According to different mechanisms of dormancy,seeds of Gagea nigra L.Z.Shue were treated with different methods so as to investigate the effects of different treatments on seed germination of G.nigra.The results showe...According to different mechanisms of dormancy,seeds of Gagea nigra L.Z.Shue were treated with different methods so as to investigate the effects of different treatments on seed germination of G.nigra.The results showed that at 4 ℃,the seeds of G.nigra began to germinate on day 32 with germination period of 80 d and germination rate of 72%;room temperature（25 ℃） and acid and alkali treatments were all unsuitable for the germination of G.nigra seeds;no significant differences were found in germination rate of G.nigra seeds among warm water（50℃）,ultrasound and 200 mg/L GA_3treatments（P 0.05）;seed coat-removing treatment effectively promoted the germination of G.nigra seeds（P =0.002 0.01） with germination rate of 88%;seed coat piercing ＋ 200 mg/L GA_3 and 500 mg/L GA_3＋15% H_2O_2 treatments effectively promoted the germination of G.nigra seeds with germination rates of 84% and 82%,respectively（P0.05）;the germination vigor of G.nigra seeds in the seed coat piercing ＋ 200 mg/L GA_3 treatment was highest,and it was significantly higher than those in the other treatments.展开更多
The world is entering into a new era of economic globalization. Realizing the benefits of globalization depends on a host of realistic conditions including technology and infrastructure, geopolitical pattern and the s...The world is entering into a new era of economic globalization. Realizing the benefits of globalization depends on a host of realistic conditions including technology and infrastructure, geopolitical pattern and the structure of market power, and international institutional arrangements, i.e., the global governance structure, among others. In this new era of economic globalization, international competition boils down to the ＂good governance＂ of countries rather than the use of force and hegemonism. Most importantly, a country must promote the vibrancy of innovation in order to stay competitive and creative. In this sense, China＇s position in the new era of economic globalization hinges upon its transition from being the ＂leader of world economic growth＂ to being a future ＂leader of good governance and vibrancy. ＂ Interests of various economies become interlocked, intertwined and overlap. Despite the inevitability of conflicts and frictions, more inclusive and balanced global development serves the interests of most nations. For great powers with extended boundaries of interests across the world, the maintenance of the new balance of power in economic globalization is consistent with their respective national interests. Hence, in the new era of economic globalization characterized by the inevitability of intricate interests and inevitable conflicts, the world is likely to be more peaceful, competitive and inclusive than any previous age of economic globalization.展开更多
Lift cycle assessment(LCA)methodology was applied to evaluating and comparing two waste acid disposal processes in zinc smelting.The results indicate that environmental impacts of gas−liquid vulcanization technologies...Lift cycle assessment(LCA)methodology was applied to evaluating and comparing two waste acid disposal processes in zinc smelting.The results indicate that environmental impacts of gas−liquid vulcanization technologies are human toxicity,abiotic depletion potential,and global warming risk,which are mainly caused in neutralizing−evaporating−crystallization unit and electrodialysis unit.As for traditional lime neutralization method,vulcanization unit is the main factor.In this regard,the total environmental impact of traditional lime neutralization method is much higher than that of gas−liquid vulcanization technologies.Furthermore,the sensitive analysis shows that electricity and sodium sulfide(60%)are sensitive factors in two waste acid disposal technologies.In addition,the total cost of disposing a functional unit waste acid in traditional lime neutralization process is nearly 27 times that of the gas−liquid vulcanization waste acid disposal technologies.展开更多
Objective： To evaluate the efficacy and safety of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules in treatment of irritable bowel syndrome, Methods： Eighty-fve patients [male 32, female 53; a...Objective： To evaluate the efficacy and safety of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules in treatment of irritable bowel syndrome, Methods： Eighty-fve patients [male 32, female 53; age （45.31±11,72） years] were given live combined Bifidobacterium, Lactobacillus and Enterococcus capsules 1260 mg/d t.i.d. ×4 weeks. Syndrome scales were used to evaluate the efficacy in gastrointestinal syndrome. Fecal flora was also measured before and after the treatment. Six bacteria were cultured and the colony forming units were counted in stool. SPSS was used for data analysis. Results： Seventy-four patients finished the follow-up. No side-effect was found. For treatment of irritable bowel syndrome, the effective rate of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules was 56.8% in the second week, 74.3% in the fourth week and 73.0% in the sixth week. Single symptom was improved, especially in abdominal pain and stool character. The probiotica containing live combined Bifidobacterium, Lactobacillus and Enterococcus could increase bifidobacterium count （P〈0.01） and lactobacillus count （P〈0.05）; decrease bacteroides count （P〈0.05） and enterococci count （P〈0.01）; No obvious changes were observed in clostridium diffcile colonitis and enterobacteriaceae （P〉0.05）. Conclusion： The result of the study indicated that the administration of live combined Bifidobacterium, Lactobacillus and Enterococcus improved the symptom of irritable bowel syndrome and that there was a gradual increase of this effect. Thereafter conditions remained stable for 2 weeks. That improvement may be associated with alterations in gastrointestinal flora.展开更多
We in terms of optical theorem estimate the lifetime of B<SUB>c</SUB> meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and...We in terms of optical theorem estimate the lifetime of B<SUB>c</SUB> meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and D mesons. In the estimation, we find that the bound-state effects are important, and take them into account carefully in the framework which attributes the effects to the effective masses of the decay heavy quarks in the inclusive processes. We also find that to B<SUB>c</SUB> lifetime the penguin contribution is enhanced due to possible interference between the penguin and the 'tree part' c<SUB>1</SUB>O<SUB>1</SUB> + c<SUB>2</SUB>O<SUB>2</SUB>.展开更多
Background End-of-life care is not usually a priority in cardiology departments. We sought to evaluate the changes in end-of-life care after the introduction of a do-not-resuscitate （DNR） order protocol. Methods ＆ ...Background End-of-life care is not usually a priority in cardiology departments. We sought to evaluate the changes in end-of-life care after the introduction of a do-not-resuscitate （DNR） order protocol. Methods ＆ Results Retrospective analysis of all deaths in a cardiology department in two periods, before and after the introduction of the protocol. Comparison of demographic characteristics, use of DNR orders, and end-of-life care issues between both periods, according to the presence in the second period of the new DNR sheet （Group A）, a conven- tional DNR order （Group B） or the absence of any DNR order （Group C）. The number of deaths was similar in both periods （n = 198 vs. n = 197）. The rate of patients dying with a DNR order increased significantly （57.1% vs. 68.5%; P = 0.02）. Only 4% of patients in both periods were aware of the decision taken about cardiopulmonary resuscitation. Patients in Group A received the DNR order one day earlier, and 24.5% received it within the first 24 h of admission （vs. 2.6% in the first period; P 〈 0.001）. All patients in Group A with an implantable cardioverter defibrillator （ICD） had shock therapies deactivated （vs. 25.0% in the first period; P = 0.02）. Conclusions The introduction of a DNR order protocol may improve end-of-life care in cardiac patients by increasing the use and shortening the time of registration of DNR orders. It may also contribute to increase ICD deactivation in patients with these orders in place. However, the introduction of the sheet in late stages of the disease failed to improve patient participation.展开更多
基金Supported by the China Postdoctoral Science Foundation(20100481500)~~
文摘Research on practical and verifiable prediction methods for the service life of bearings plays a critical role in improving the reliability and safety of aircraft engines. The concept of grade-life （GL） is introduced to de- scribe the service life of bearings. A GL prognostic model for aircraft engine bearings is proposed based on sup- port vector machine （SVM） and fuzzy logic inference. Firstly, the mathematical model is discussed to predict the physics-based GL （PGL）. Then, the diagnostic estimation model based on SVM is presented in detail to predict the empirical GL （EPL）. Thirdly, a fuzzy logic inference is adopted to fuse two GL predicted results. Finally, the GL prognostic model is verified by the run-to-failure data acquired from an accelerated life test of an aircraft bearing. The results show that the model provides a more practical and reliable prediction for the service life of bearings.
基金The Social Science Fund of Hebei Province (No.200607011)the Key Science and Technology Project of Hebei Province(No.07213529)
文摘In order to more effectively assess the health status of a project, the monitoring indices in a project＇s life cycle are divided into quality index, cost index, time index, satisfaction index, and sustainable development index. Based on the feature of qualitative and quantitative indices combining, the PCA-PR （principal component analysis and pattern recognition） model is constructed. The model first analyzes the principal components of the life-cycle indices system constructed above, and picks up those principal component indices that can reflect the health status of a project at any time. Then the pattern recognition model is used to study these principal components, which means that the real time health status of the project can be divided into five lamps from a green lamp to a red one and the health status lamp of the project can be recognized by using the PR model and those principal components. Finally, the process is shown with a real example and a conclusion consistent with the actual situation is drawn. So the validity of the index system and the PCA-PR model can be confirmed.
文摘According to different mechanisms of dormancy,seeds of Gagea nigra L.Z.Shue were treated with different methods so as to investigate the effects of different treatments on seed germination of G.nigra.The results showed that at 4 ℃,the seeds of G.nigra began to germinate on day 32 with germination period of 80 d and germination rate of 72%;room temperature（25 ℃） and acid and alkali treatments were all unsuitable for the germination of G.nigra seeds;no significant differences were found in germination rate of G.nigra seeds among warm water（50℃）,ultrasound and 200 mg/L GA_3treatments（P 0.05）;seed coat-removing treatment effectively promoted the germination of G.nigra seeds（P =0.002 0.01） with germination rate of 88%;seed coat piercing ＋ 200 mg/L GA_3 and 500 mg/L GA_3＋15% H_2O_2 treatments effectively promoted the germination of G.nigra seeds with germination rates of 84% and 82%,respectively（P0.05）;the germination vigor of G.nigra seeds in the seed coat piercing ＋ 200 mg/L GA_3 treatment was highest,and it was significantly higher than those in the other treatments.
文摘The world is entering into a new era of economic globalization. Realizing the benefits of globalization depends on a host of realistic conditions including technology and infrastructure, geopolitical pattern and the structure of market power, and international institutional arrangements, i.e., the global governance structure, among others. In this new era of economic globalization, international competition boils down to the ＂good governance＂ of countries rather than the use of force and hegemonism. Most importantly, a country must promote the vibrancy of innovation in order to stay competitive and creative. In this sense, China＇s position in the new era of economic globalization hinges upon its transition from being the ＂leader of world economic growth＂ to being a future ＂leader of good governance and vibrancy. ＂ Interests of various economies become interlocked, intertwined and overlap. Despite the inevitability of conflicts and frictions, more inclusive and balanced global development serves the interests of most nations. For great powers with extended boundaries of interests across the world, the maintenance of the new balance of power in economic globalization is consistent with their respective national interests. Hence, in the new era of economic globalization characterized by the inevitability of intricate interests and inevitable conflicts, the world is likely to be more peaceful, competitive and inclusive than any previous age of economic globalization.
基金the National Key R&D Program of China(Nos.2018YFC1903304,2019YFC1907405)National Natural Science Foundation of China(No.51904354).
文摘Lift cycle assessment(LCA)methodology was applied to evaluating and comparing two waste acid disposal processes in zinc smelting.The results indicate that environmental impacts of gas−liquid vulcanization technologies are human toxicity,abiotic depletion potential,and global warming risk,which are mainly caused in neutralizing−evaporating−crystallization unit and electrodialysis unit.As for traditional lime neutralization method,vulcanization unit is the main factor.In this regard,the total environmental impact of traditional lime neutralization method is much higher than that of gas−liquid vulcanization technologies.Furthermore,the sensitive analysis shows that electricity and sodium sulfide(60%)are sensitive factors in two waste acid disposal technologies.In addition,the total cost of disposing a functional unit waste acid in traditional lime neutralization process is nearly 27 times that of the gas−liquid vulcanization waste acid disposal technologies.
文摘Objective： To evaluate the efficacy and safety of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules in treatment of irritable bowel syndrome, Methods： Eighty-fve patients [male 32, female 53; age （45.31±11,72） years] were given live combined Bifidobacterium, Lactobacillus and Enterococcus capsules 1260 mg/d t.i.d. ×4 weeks. Syndrome scales were used to evaluate the efficacy in gastrointestinal syndrome. Fecal flora was also measured before and after the treatment. Six bacteria were cultured and the colony forming units were counted in stool. SPSS was used for data analysis. Results： Seventy-four patients finished the follow-up. No side-effect was found. For treatment of irritable bowel syndrome, the effective rate of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules was 56.8% in the second week, 74.3% in the fourth week and 73.0% in the sixth week. Single symptom was improved, especially in abdominal pain and stool character. The probiotica containing live combined Bifidobacterium, Lactobacillus and Enterococcus could increase bifidobacterium count （P〈0.01） and lactobacillus count （P〈0.05）; decrease bacteroides count （P〈0.05） and enterococci count （P〈0.01）; No obvious changes were observed in clostridium diffcile colonitis and enterobacteriaceae （P〉0.05）. Conclusion： The result of the study indicated that the administration of live combined Bifidobacterium, Lactobacillus and Enterococcus improved the symptom of irritable bowel syndrome and that there was a gradual increase of this effect. Thereafter conditions remained stable for 2 weeks. That improvement may be associated with alterations in gastrointestinal flora.
文摘We in terms of optical theorem estimate the lifetime of B<SUB>c</SUB> meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and D mesons. In the estimation, we find that the bound-state effects are important, and take them into account carefully in the framework which attributes the effects to the effective masses of the decay heavy quarks in the inclusive processes. We also find that to B<SUB>c</SUB> lifetime the penguin contribution is enhanced due to possible interference between the penguin and the 'tree part' c<SUB>1</SUB>O<SUB>1</SUB> + c<SUB>2</SUB>O<SUB>2</SUB>.
文摘Background End-of-life care is not usually a priority in cardiology departments. We sought to evaluate the changes in end-of-life care after the introduction of a do-not-resuscitate （DNR） order protocol. Methods ＆ Results Retrospective analysis of all deaths in a cardiology department in two periods, before and after the introduction of the protocol. Comparison of demographic characteristics, use of DNR orders, and end-of-life care issues between both periods, according to the presence in the second period of the new DNR sheet （Group A）, a conven- tional DNR order （Group B） or the absence of any DNR order （Group C）. The number of deaths was similar in both periods （n = 198 vs. n = 197）. The rate of patients dying with a DNR order increased significantly （57.1% vs. 68.5%; P = 0.02）. Only 4% of patients in both periods were aware of the decision taken about cardiopulmonary resuscitation. Patients in Group A received the DNR order one day earlier, and 24.5% received it within the first 24 h of admission （vs. 2.6% in the first period; P 〈 0.001）. All patients in Group A with an implantable cardioverter defibrillator （ICD） had shock therapies deactivated （vs. 25.0% in the first period; P = 0.02）. Conclusions The introduction of a DNR order protocol may improve end-of-life care in cardiac patients by increasing the use and shortening the time of registration of DNR orders. It may also contribute to increase ICD deactivation in patients with these orders in place. However, the introduction of the sheet in late stages of the disease failed to improve patient participation.
