Course based ideological and political education (CIPE) is an important way to improve the quality of ideological and political work and talent cultivation. This study explores for the first time the implementation of...Course based ideological and political education (CIPE) is an important way to improve the quality of ideological and political work and talent cultivation. This study explores for the first time the implementation of ideological and political education in the teaching of pathophysiology courses, and also analyzes the evaluation of student psychological status and the importance of mental health education in the implementation of IPE courses. A survey was conducted on 211 students at Yangtze University to understand their motivation and behavior towards learning ideological, political, and pathophysiological courses. In addition, a questionnaire survey was used to explore the relationship between pathophysiology and ideological and political courses, as well as the importance of their satisfaction with the implementation of ideological and political courses in pathophysiology and mental health education. The research results indicate that factors such as educational background and gender differences affect the learning of CIPE. Graduate students are more interested in ideological and political courses, while female students find it difficult to study pathophysiology;In addition, the results of one-way ANOVA indicate that the implementation effect of IPE in pathophysiology courses depends on the level of interest in IPE and pathophysiology courses, the level of consideration for the importance of professional courses, the professional gains after studying pathophysiology, and the level of understanding of the relationship between IPE and CIPE. 81.04% of students believe that in the CIPE process, telling stories by teachers themselves is the most popular way of communication and education. This reflects the importance of mental health education from the perspective of CIPE. In addition, this study also indicates that PBL and flipped classroom teaching models are popular teaching models in CIPE. This study is beneficial for promoting the improvement and implementation of CIPE and mental health education in higher education curricula, thus providing valuable insights for educational decision-makers.展开更多
We report on a long wavelength interband cascade photodetector with type Ⅱ InAs/GaSb superlattice absorber.The device is a three-stage interband cascade structure.At 77 K,the 50%cutoff wavelength of the detector is 8...We report on a long wavelength interband cascade photodetector with type Ⅱ InAs/GaSb superlattice absorber.The device is a three-stage interband cascade structure.At 77 K,the 50%cutoff wavelength of the detector is 8.48μm and the peak photoresponse wavelength is 7.78μm.The peak responsivity is 0.93 A/W and the detectivity D*is 1.12×10^(11)cm·Hz0.5/W for 7.78μm at-0.20 V.The detector can operate up to about 260 K.At 260 K,the 50%cutoff wavelength is 11.52μm,the peak responsivity is 0.78 A/W and the D*is 5.02×10^(8)cm·Hz0.5/W for the peak wavelength of 10.39μm at-2.75 V.The dark current of the device is dominated by the diffusion current under both a small bias voltage of-0.2 V and a large one of-2.75 V for the temperature range of 120 to 260 K.展开更多
Recently,electric vehicles(EVs)have been widely used under the call of green travel and environmental protection,and diverse requirements for charging are also increasing gradually.In order to ensure the authenticity ...Recently,electric vehicles(EVs)have been widely used under the call of green travel and environmental protection,and diverse requirements for charging are also increasing gradually.In order to ensure the authenticity and privacy of charging information interaction,blockchain technology is proposed and applied in charging station billing systems.However,there are some issues in blockchain itself,including lower computing efficiency of the nodes and higher energy consumption in the consensus process.To handle the above issues,in this paper,combining blockchain and mobile edge computing(MEC),we develop a reliable billing data transmission scheme to improve the computing capacity of nodes and reduce the energy consumption of the consensus process.By jointly optimizing the primary and replica nodes offloading decisions,block size and block interval,the transaction throughput of the blockchain system is maximized,as well as the latency and energy consumption of the system are minimized.Moreover,we formulate the joint optimization problem as a Markov decision process(MDP).To tackle the dynamic and continuity of the system state,the reinforcement learning(RL)is introduced to solve the MDP problem.Finally,simulation results demonstrate that the performance improvement of the proposed scheme through comparison with other existing schemes.展开更多
Objective:Local recurrence of hepatocellular carcinoma(HCC)after radiofrequency ablation(RFA)treatment remains a serious problem.Tumor-initiating cells(TICs)are thought to be responsible for tumor relapse.Here,we inve...Objective:Local recurrence of hepatocellular carcinoma(HCC)after radiofrequency ablation(RFA)treatment remains a serious problem.Tumor-initiating cells(TICs)are thought to be responsible for tumor relapse.Here,we investigated the effect of the TIC differentiation inducer,all-trans retinoic acid(ATRA),on RFA and explored the potential molecular mechanisms.Methods:The proportions of CD133+and epithelial cell adhesion molecule(Ep CAM);TICs in recurrent HCC after RFA and primary HCC were first determined in clinic.Then,the effect of heat intervention or insufficient RFA(IRFA)on the malignant potential of HCC cells,including cell migration,sphere formation ability,tumor growth,the proportion of CD133+and Ep CAM+TICs and expression of stem cell-related genes,was evaluated in vitro and in vivo.Finally,the effect of ATRA on the tumor growth and the proportion of TICs was evaluated.Results:In clinical data,a higher proportion of CD133+and Ep CAM+TICs was found in recurrent tumors than in primary tumors.In vitro heat intervention promoted the cell migration and sphere formation ability.Additionally,it increased the proportion of CD133+and Ep CAM+TICs and the expression of stem cell-related genes.In addition,after IRFA the residual tumors in xenografts grew faster and had more TICs than untreated tumors.ATRA remarkably inhibited residual tumor growth after IRFA by elimination of TICs though the PI3 K/AKT pathway.Combination treatment with ATRA resulted in longer survival outcomes in mouse xenografts than RFA alone.Conclusions:ATRA,as a TIC differentiation inducer,could help to improve the effect of RFA treatment,which was partially attributed to its effect against TICs.The data indicated its potential as an alternative drug in the development of better therapeutic strategies for use in combination with RFA.展开更多
Barrier coverage of wireless sensor networks is an important issue in the detection of intruders who are attempting to cross a region of interest.However,in certain applications,barrier coverage cannot be satisfied af...Barrier coverage of wireless sensor networks is an important issue in the detection of intruders who are attempting to cross a region of interest.However,in certain applications,barrier coverage cannot be satisfied after random deployment.In this paper,we study how mobile sensors can be efficiently relocated to achieve k-barrier coverage.In particular,two problems are studied:relocation of sensors with minimum number of mobile sensors and formation of k-barrier coverage with minimum energy cost.These two problems were formulated as 0–1 integer linear programming(ILP).The formulation is computationally intractable because of integrality and complicated constraints.Therefore,we relax the integrality and complicated constraints of the formulation and construct a special model known as RELAX-RSMN with a totally unimodular constraint coefficient matrix to solve the relaxed 0–1 ILP rapidly through linear programming.Theoretical analysis and simulation were performed to verify the effectiveness of our approach.展开更多
Species of the Ericaceae or heath family are widely distribute in continental ecosystems and their special ericoid mycorrhizas(ERM)are considered benefi cial to their survival and persistence in variable habitats.Curr...Species of the Ericaceae or heath family are widely distribute in continental ecosystems and their special ericoid mycorrhizas(ERM)are considered benefi cial to their survival and persistence in variable habitats.Currently,increasing anthropogenic disturbances and improper forest management are aff ecting subtropical forests of China where these native species located.These activities not only aff ect plant communities above-ground,but also impose pressures on microbial communities below-ground.In this study,rootassociated fungal communities of Rhododendron simsii in four forest types under diff erent anthropogenic disturbances were identifi ed using an Illumina Miseq platform,i.e.,old growth forests,secondary forests with one cutting(SECⅠ),secondary forests with two cuttings(SECⅡ),and Chinesefi r plantations(PLF).Intra-and inter-annual variations were analyzed by comparing samples taken in diff erent seasons and years.The results show that:(1)over 1000 OTUs were found in hair roots with most from the division Ascomycota and Basidiomycota belonging to diff erent functional groups;(2)while there were a few indicator OTUs specifi c to diff erent forest types,seasons and years,the proportion of shared taxa was quite large,accounting for 44.9–79.4%of the total OTUs;(3)signifi cantly positive correlations were found between disturbance sensitivity and temporal variations in common fungal orders,and both in major fungal orders were signifi cantly diff erent among fungal functional groups in which putative and possible ERM fungi were highly resistant to disturbances and low temporal variations.The high disturbance resistance and temporal persistence of putative ERM fungi may be essential for the successful adaptation of R.simsii in disturbed subtropical forests of China.展开更多
The morphology and properties of corn starch and cassava starch were compared by SEM, DSC and TGA. Theeffects of amylose and amylopectin content on starch properties were studied by FT-IR, XRD and XPS. The plywood wa...The morphology and properties of corn starch and cassava starch were compared by SEM, DSC and TGA. Theeffects of amylose and amylopectin content on starch properties were studied by FT-IR, XRD and XPS. The plywood was pressed with the prepared adhesive and the bonding strength of the plywood was tested to analyze thedifference among the adhesives from different plant sources and the difference after blending PAPI prepolymer.FT-IR results showed that the hydroxyl peak of cassava starch was stronger and wider. TGA showed that the residue of cassava starch was lower, but the thermal stability of cassava starch was almost the same. XPS data showedthat the oxygen content of cassava starch was slightly higher, but the carbon content was slightly lower. SEM analysis showed that corn starch granules were more irregular and sharper than cassava starch, and cassava starchgranules were more uniform, regular and round.展开更多
Objective: To explore the importance of CBL in pathophysiology teaching. Methods: 218 undergraduate clinical medicine students in 2015 grade were divided into CBL group and control group, and each group had 109 studen...Objective: To explore the importance of CBL in pathophysiology teaching. Methods: 218 undergraduate clinical medicine students in 2015 grade were divided into CBL group and control group, and each group had 109 students. The CBL group was taught by CBL, while the control group was taught by routine teaching mode. The teaching effects was evaluated by questionnaire survey and stage test. Results: The CBL group was superior to the control group in learning interest, logical thinking, knowledge system construction, comprehensive use of knowledge to solve problems. Conclusion: CBL teaching enhanced students’ understanding of knowledge significantly, and also enhanced their clinical thinking and problem analysis ability.展开更多
Strong asymmetrical vortices appear on the leeward of slender body at high angles of attack, which has very unfavorable effect on the stability and control of the aircraft. A method is developed to control the side fo...Strong asymmetrical vortices appear on the leeward of slender body at high angles of attack, which has very unfavorable effect on the stability and control of the aircraft. A method is developed to control the side force of slender body at high angles of attack, and is verified in wind tunnel. A thin-film triangular self-excited oscillation flag is fixed at the tip of the slender body model whose semi-apex angle is 10°. Side force is approximately linearly proportional to roll-setting angle of self-excited oscillation flag at high angles of attack, and the slop of fitting straight line obtained by the least square method is -0.158. The linear relationship between side force and roU-setting angle provides convenience for developing side force control law of slender body at high angles of attack. Experimental data shows that the side force coefficients vary linearly with roll-setting angles when a specific plastic self-excited oscillation flag is used as the control flag. The range of side force coefficient and roll-setting angle are, respectively, -3.2 to 3.0 and -20° to 20°. The device is simple, effective, and is of great potential in engineering application.展开更多
Poplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spa...Poplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.展开更多
On the basis of the fluid theory and the drift-diffusion approximation, a numerical model for dual-frequency atmospheric pressure helium discharge is established, in order to investigate the effects of the high freque...On the basis of the fluid theory and the drift-diffusion approximation, a numerical model for dual-frequency atmospheric pressure helium discharge is established, in order to investigate the effects of the high frequency source (HF) on the characteristics of dual-frequency atmospheric pressure helium discharge. The numerical results showed that the electron heating rate increases with enhancing HF frequency, as well as the particles densities, electron dissipation rate, current density, net electron generation and bulk plasma region. Moreover, it is also observed that the efficient electron heating region moves when the HF frequency has been changed. The plasma parameters are not linear change with the HF frequency linearly increasing.展开更多
With the continuous increase of user requirement, the Information and Communication Technology (ICT) has developed rapidly. As a result, both capacity and coverage performances have been improved, and at the same time...With the continuous increase of user requirement, the Information and Communication Technology (ICT) has developed rapidly. As a result, both capacity and coverage performances have been improved, and at the same time, the communication networks have been more energy-intensive. In order to improve the energy efficiency of cellular networks, the green communication must be realized in the future networks. In this article, we present a short survey on energy-efficient technology of cellular networks. Moreover, we classify them into three categories based on theirapplication scenarios: energy-efficient architectures, energy-efficient resource management and energy-efficient radio technologies. For the first scenario, the applications of relay, Coordinated Multiple Points (CoMP) and heterogeneous network are discussed in detail. For the second scenario, the switching off scheme will be introduced as an emphasis of this part. And for the third scenario, the Multiple-Input Multiple-Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) will be introduced as the representatives of the Energy-Efficient Radio Technologies. Finally, based on the technologies introduced above, a prospect forecast of the energy-efficient wireless cellular network is presented.展开更多
This study was to investigate the epidemiology of lung cancer in Jianghan Plain, providing scientific basis for prevention and treatment of lung cancer. Pathology and clinical data of 1290 patients diagnosed lung canc...This study was to investigate the epidemiology of lung cancer in Jianghan Plain, providing scientific basis for prevention and treatment of lung cancer. Pathology and clinical data of 1290 patients diagnosed lung cancer from the largest hospital in Jianghan Plain were collected and analyzed. Results found that the lung cancer incidence increased gradually from the age of 40 and at the peak during 61 to 70 years old;the male to female ratio was 2.45:1;Smoking patients were 841 cases, accounting for 65.2% of all cases. Smoke index > 400 was 771 cases accounting for 91.7 percent of smokers and smoking index < 400 was 70 cases accounting for 8.3% of smoking patients. 93.6% of the patients were to start smoking at a young age. The rate of patient pathological cytology diagnosed by fiberoptic bronchoscopy was 31.8%, which showed that it was an important diagnostic method for lung cancer. The main reason for smoking is to break up the monotony and although many patients know nicotine, carbon monoxide is the main smoking harmful substances and smoking may cause lung cancer;not many people can take the initiative to quit smoking. It also showed that squamous cell carcinoma was the main type in smoking patients, while adeno-carcinoma in non-smoking patients. The comprehensive epidemiological analysis suggested that smoking is an important factor in causing lung cancer, smoking cessation education and regular medical examinations to strengthen the prevention of lung cancer have a positive meaning to their family members.展开更多
文摘Course based ideological and political education (CIPE) is an important way to improve the quality of ideological and political work and talent cultivation. This study explores for the first time the implementation of ideological and political education in the teaching of pathophysiology courses, and also analyzes the evaluation of student psychological status and the importance of mental health education in the implementation of IPE courses. A survey was conducted on 211 students at Yangtze University to understand their motivation and behavior towards learning ideological, political, and pathophysiological courses. In addition, a questionnaire survey was used to explore the relationship between pathophysiology and ideological and political courses, as well as the importance of their satisfaction with the implementation of ideological and political courses in pathophysiology and mental health education. The research results indicate that factors such as educational background and gender differences affect the learning of CIPE. Graduate students are more interested in ideological and political courses, while female students find it difficult to study pathophysiology;In addition, the results of one-way ANOVA indicate that the implementation effect of IPE in pathophysiology courses depends on the level of interest in IPE and pathophysiology courses, the level of consideration for the importance of professional courses, the professional gains after studying pathophysiology, and the level of understanding of the relationship between IPE and CIPE. 81.04% of students believe that in the CIPE process, telling stories by teachers themselves is the most popular way of communication and education. This reflects the importance of mental health education from the perspective of CIPE. In addition, this study also indicates that PBL and flipped classroom teaching models are popular teaching models in CIPE. This study is beneficial for promoting the improvement and implementation of CIPE and mental health education in higher education curricula, thus providing valuable insights for educational decision-makers.
基金supported in part by China’s NSF Program 61874103
文摘We report on a long wavelength interband cascade photodetector with type Ⅱ InAs/GaSb superlattice absorber.The device is a three-stage interband cascade structure.At 77 K,the 50%cutoff wavelength of the detector is 8.48μm and the peak photoresponse wavelength is 7.78μm.The peak responsivity is 0.93 A/W and the detectivity D*is 1.12×10^(11)cm·Hz0.5/W for 7.78μm at-0.20 V.The detector can operate up to about 260 K.At 260 K,the 50%cutoff wavelength is 11.52μm,the peak responsivity is 0.78 A/W and the D*is 5.02×10^(8)cm·Hz0.5/W for the peak wavelength of 10.39μm at-2.75 V.The dark current of the device is dominated by the diffusion current under both a small bias voltage of-0.2 V and a large one of-2.75 V for the temperature range of 120 to 260 K.
基金in part by the National Natural Science Foundation of China under Grant 61901011in part by the Foundation of Beijing Municipal Commission of Education under Grant KM202110005021 and KM202010005017.
文摘Recently,electric vehicles(EVs)have been widely used under the call of green travel and environmental protection,and diverse requirements for charging are also increasing gradually.In order to ensure the authenticity and privacy of charging information interaction,blockchain technology is proposed and applied in charging station billing systems.However,there are some issues in blockchain itself,including lower computing efficiency of the nodes and higher energy consumption in the consensus process.To handle the above issues,in this paper,combining blockchain and mobile edge computing(MEC),we develop a reliable billing data transmission scheme to improve the computing capacity of nodes and reduce the energy consumption of the consensus process.By jointly optimizing the primary and replica nodes offloading decisions,block size and block interval,the transaction throughput of the blockchain system is maximized,as well as the latency and energy consumption of the system are minimized.Moreover,we formulate the joint optimization problem as a Markov decision process(MDP).To tackle the dynamic and continuity of the system state,the reinforcement learning(RL)is introduced to solve the MDP problem.Finally,simulation results demonstrate that the performance improvement of the proposed scheme through comparison with other existing schemes.
基金supported by National Natural Science Foundation of China(No.81773286,81971718,and 81772632)Beijing Baiqianwan Talents Project(No.2020A47)Science Foundation of Peiking University Cancer Hospital(No.2020-9)。
文摘Objective:Local recurrence of hepatocellular carcinoma(HCC)after radiofrequency ablation(RFA)treatment remains a serious problem.Tumor-initiating cells(TICs)are thought to be responsible for tumor relapse.Here,we investigated the effect of the TIC differentiation inducer,all-trans retinoic acid(ATRA),on RFA and explored the potential molecular mechanisms.Methods:The proportions of CD133+and epithelial cell adhesion molecule(Ep CAM);TICs in recurrent HCC after RFA and primary HCC were first determined in clinic.Then,the effect of heat intervention or insufficient RFA(IRFA)on the malignant potential of HCC cells,including cell migration,sphere formation ability,tumor growth,the proportion of CD133+and Ep CAM+TICs and expression of stem cell-related genes,was evaluated in vitro and in vivo.Finally,the effect of ATRA on the tumor growth and the proportion of TICs was evaluated.Results:In clinical data,a higher proportion of CD133+and Ep CAM+TICs was found in recurrent tumors than in primary tumors.In vitro heat intervention promoted the cell migration and sphere formation ability.Additionally,it increased the proportion of CD133+and Ep CAM+TICs and the expression of stem cell-related genes.In addition,after IRFA the residual tumors in xenografts grew faster and had more TICs than untreated tumors.ATRA remarkably inhibited residual tumor growth after IRFA by elimination of TICs though the PI3 K/AKT pathway.Combination treatment with ATRA resulted in longer survival outcomes in mouse xenografts than RFA alone.Conclusions:ATRA,as a TIC differentiation inducer,could help to improve the effect of RFA treatment,which was partially attributed to its effect against TICs.The data indicated its potential as an alternative drug in the development of better therapeutic strategies for use in combination with RFA.
基金supported by the NSFC(U1536206,61232016,U1405254,61373133,61502242,71401176)BK20150925the PAPD fund
文摘Barrier coverage of wireless sensor networks is an important issue in the detection of intruders who are attempting to cross a region of interest.However,in certain applications,barrier coverage cannot be satisfied after random deployment.In this paper,we study how mobile sensors can be efficiently relocated to achieve k-barrier coverage.In particular,two problems are studied:relocation of sensors with minimum number of mobile sensors and formation of k-barrier coverage with minimum energy cost.These two problems were formulated as 0–1 integer linear programming(ILP).The formulation is computationally intractable because of integrality and complicated constraints.Therefore,we relax the integrality and complicated constraints of the formulation and construct a special model known as RELAX-RSMN with a totally unimodular constraint coefficient matrix to solve the relaxed 0–1 ILP rapidly through linear programming.Theoretical analysis and simulation were performed to verify the effectiveness of our approach.
基金supported by the National Natural Science Foundation of China(31170469 and 31700476)Zhejiang Natural Science Foundation(LY19C030002)the Technology Division of Shaoxing(2017B70061)
文摘Species of the Ericaceae or heath family are widely distribute in continental ecosystems and their special ericoid mycorrhizas(ERM)are considered benefi cial to their survival and persistence in variable habitats.Currently,increasing anthropogenic disturbances and improper forest management are aff ecting subtropical forests of China where these native species located.These activities not only aff ect plant communities above-ground,but also impose pressures on microbial communities below-ground.In this study,rootassociated fungal communities of Rhododendron simsii in four forest types under diff erent anthropogenic disturbances were identifi ed using an Illumina Miseq platform,i.e.,old growth forests,secondary forests with one cutting(SECⅠ),secondary forests with two cuttings(SECⅡ),and Chinesefi r plantations(PLF).Intra-and inter-annual variations were analyzed by comparing samples taken in diff erent seasons and years.The results show that:(1)over 1000 OTUs were found in hair roots with most from the division Ascomycota and Basidiomycota belonging to diff erent functional groups;(2)while there were a few indicator OTUs specifi c to diff erent forest types,seasons and years,the proportion of shared taxa was quite large,accounting for 44.9–79.4%of the total OTUs;(3)signifi cantly positive correlations were found between disturbance sensitivity and temporal variations in common fungal orders,and both in major fungal orders were signifi cantly diff erent among fungal functional groups in which putative and possible ERM fungi were highly resistant to disturbances and low temporal variations.The high disturbance resistance and temporal persistence of putative ERM fungi may be essential for the successful adaptation of R.simsii in disturbed subtropical forests of China.
基金This work was supported by the National Natural Science Foundation of China(No.31670569)the Fundamental Research Funds for the Central Universities(No.2572019CG05)Special thanks to the support of the Chinese University Students,Innovation and Entrepreneurship Project(202010225071).
文摘The morphology and properties of corn starch and cassava starch were compared by SEM, DSC and TGA. Theeffects of amylose and amylopectin content on starch properties were studied by FT-IR, XRD and XPS. The plywood was pressed with the prepared adhesive and the bonding strength of the plywood was tested to analyze thedifference among the adhesives from different plant sources and the difference after blending PAPI prepolymer.FT-IR results showed that the hydroxyl peak of cassava starch was stronger and wider. TGA showed that the residue of cassava starch was lower, but the thermal stability of cassava starch was almost the same. XPS data showedthat the oxygen content of cassava starch was slightly higher, but the carbon content was slightly lower. SEM analysis showed that corn starch granules were more irregular and sharper than cassava starch, and cassava starchgranules were more uniform, regular and round.
文摘Objective: To explore the importance of CBL in pathophysiology teaching. Methods: 218 undergraduate clinical medicine students in 2015 grade were divided into CBL group and control group, and each group had 109 students. The CBL group was taught by CBL, while the control group was taught by routine teaching mode. The teaching effects was evaluated by questionnaire survey and stage test. Results: The CBL group was superior to the control group in learning interest, logical thinking, knowledge system construction, comprehensive use of knowledge to solve problems. Conclusion: CBL teaching enhanced students’ understanding of knowledge significantly, and also enhanced their clinical thinking and problem analysis ability.
基金supported by the ‘‘National Natural Science Foundation-Outstanding Youth Foundation’’
文摘Strong asymmetrical vortices appear on the leeward of slender body at high angles of attack, which has very unfavorable effect on the stability and control of the aircraft. A method is developed to control the side force of slender body at high angles of attack, and is verified in wind tunnel. A thin-film triangular self-excited oscillation flag is fixed at the tip of the slender body model whose semi-apex angle is 10°. Side force is approximately linearly proportional to roll-setting angle of self-excited oscillation flag at high angles of attack, and the slop of fitting straight line obtained by the least square method is -0.158. The linear relationship between side force and roU-setting angle provides convenience for developing side force control law of slender body at high angles of attack. Experimental data shows that the side force coefficients vary linearly with roll-setting angles when a specific plastic self-excited oscillation flag is used as the control flag. The range of side force coefficient and roll-setting angle are, respectively, -3.2 to 3.0 and -20° to 20°. The device is simple, effective, and is of great potential in engineering application.
基金The work was supported by the National Key Research and Development Program of China(Grant Number 2016YFD0600402).
文摘Poplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.
基金financially supported by National Natural Science Foundation of China (Grant No. 11505089)the Doctoral Scientific Research Foundation of Liaoning Province (Grant No. 20170520381)
文摘On the basis of the fluid theory and the drift-diffusion approximation, a numerical model for dual-frequency atmospheric pressure helium discharge is established, in order to investigate the effects of the high frequency source (HF) on the characteristics of dual-frequency atmospheric pressure helium discharge. The numerical results showed that the electron heating rate increases with enhancing HF frequency, as well as the particles densities, electron dissipation rate, current density, net electron generation and bulk plasma region. Moreover, it is also observed that the efficient electron heating region moves when the HF frequency has been changed. The plasma parameters are not linear change with the HF frequency linearly increasing.
文摘With the continuous increase of user requirement, the Information and Communication Technology (ICT) has developed rapidly. As a result, both capacity and coverage performances have been improved, and at the same time, the communication networks have been more energy-intensive. In order to improve the energy efficiency of cellular networks, the green communication must be realized in the future networks. In this article, we present a short survey on energy-efficient technology of cellular networks. Moreover, we classify them into three categories based on theirapplication scenarios: energy-efficient architectures, energy-efficient resource management and energy-efficient radio technologies. For the first scenario, the applications of relay, Coordinated Multiple Points (CoMP) and heterogeneous network are discussed in detail. For the second scenario, the switching off scheme will be introduced as an emphasis of this part. And for the third scenario, the Multiple-Input Multiple-Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) will be introduced as the representatives of the Energy-Efficient Radio Technologies. Finally, based on the technologies introduced above, a prospect forecast of the energy-efficient wireless cellular network is presented.
文摘This study was to investigate the epidemiology of lung cancer in Jianghan Plain, providing scientific basis for prevention and treatment of lung cancer. Pathology and clinical data of 1290 patients diagnosed lung cancer from the largest hospital in Jianghan Plain were collected and analyzed. Results found that the lung cancer incidence increased gradually from the age of 40 and at the peak during 61 to 70 years old;the male to female ratio was 2.45:1;Smoking patients were 841 cases, accounting for 65.2% of all cases. Smoke index > 400 was 771 cases accounting for 91.7 percent of smokers and smoking index < 400 was 70 cases accounting for 8.3% of smoking patients. 93.6% of the patients were to start smoking at a young age. The rate of patient pathological cytology diagnosed by fiberoptic bronchoscopy was 31.8%, which showed that it was an important diagnostic method for lung cancer. The main reason for smoking is to break up the monotony and although many patients know nicotine, carbon monoxide is the main smoking harmful substances and smoking may cause lung cancer;not many people can take the initiative to quit smoking. It also showed that squamous cell carcinoma was the main type in smoking patients, while adeno-carcinoma in non-smoking patients. The comprehensive epidemiological analysis suggested that smoking is an important factor in causing lung cancer, smoking cessation education and regular medical examinations to strengthen the prevention of lung cancer have a positive meaning to their family members.