在线编程评测系统(Online Judge,OJ)是一种被广泛应用于计算机编程教学与竞赛的代码测评系统。用户在规模庞大的题库中寻找适合当前学习阶段的题目时,往往会感到迷茫。如何为用户推荐合适的题目和规划学习路径,是在线编程测评系统研发...在线编程评测系统(Online Judge,OJ)是一种被广泛应用于计算机编程教学与竞赛的代码测评系统。用户在规模庞大的题库中寻找适合当前学习阶段的题目时,往往会感到迷茫。如何为用户推荐合适的题目和规划学习路径,是在线编程测评系统研发中的一个重要研究课题。传统推荐算法存在可解释性和准确性难以兼顾的问题。文中提出了基于知识图谱与协同过滤混合策略的在线评测系统推荐模型(A Hybrid Programming Task Recommendation Model Based on Knowledge Graph and Collaborative Filtering,HKGCF)。该模型通过推荐与用户当前知识和技能掌握程度相匹配的题目,来帮助用户提升学习效果。文中设计和实现了该模型,并将其集成到了北京航空航天大学在线编程测评系统中,以适应OJ平台特有的交互形式。线上测试和离线测试实验的结果表明,提出的HKGCF模型在准确率和可解释性方面均优于典型传统算法。展开更多
Soil contamination by heavy metals is a serious environmental problem worldwide, and reduction of heavy metal accumulation in vegetables grown on contaminated land is a matter of urgency. A pot experiment was conducte...Soil contamination by heavy metals is a serious environmental problem worldwide, and reduction of heavy metal accumulation in vegetables grown on contaminated land is a matter of urgency. A pot experiment was conducted to study the effects of intercropping with the Cd hyperaccumulators Solanum nigrum and Solanum photeinocarpum from two ecoclimatic regions, Ya＇an and Chengdu, Sichuan Province, China, on the growth and cadmium （Cd） uptake of eggplant （Solanum melongena L.）. The biomass, photosynthetic pigment contents, and activities of antioxidant enzymes of eggplant were enhanced by intercropping. The biomass of eggplant was the highest after intercropping with S. photeinocarpum from Ya＇an, but did not differ significantly from that after intercropping with S. nigrum from Chengdu. The shoot Cd content of eggplant was significantly reduced by intercropping with the hyperaccumulators, which ranked as follows： S. nigrum from Chengdu 〉 S. nigrum from Ya＇an 〉 S. photeinocarpum from Chengdu 〉 S. photeinocarpum from Ya＇an, with the decreases being 19.60%, 14.36%, 9.66%, and 6.42%, respectively, as compared with the control. The lowest shoot Cd content and translocation factor of eggplant were attained after intercropping with S. nigvum from Chengdu. Therefore, it was feasible to intercrop eggplant with S. nigrum and S. photeinocarpurn on Cd-contaminated soil.展开更多
Objective This review focuses on current knowledge of traditional Chinese herbs on prevention and treatment of viral respiratory infections,especially caused by Severe Acute Respiratory Syndromes （SARS） virus,respir...Objective This review focuses on current knowledge of traditional Chinese herbs on prevention and treatment of viral respiratory infections,especially caused by Severe Acute Respiratory Syndromes （SARS） virus,respiratory syncytial virus （RSV） and influenza viruses.Data sources The data used in this review were obtained from PubMed and CNKI up to May 2013.Terms of Chinese herbs and infections of respiratory tract were used in the search.Study selection Articles related that Chinese herbs preventing and treating infections in respiratory tract were retrieved and reviewed.The risk of bias of included studies was assessed by the method in the ＂Cochrane Handbook of Systematic Reveiws of Interventionsand studies＂ with high risk of bias were excluded.Four criteria for selections were set as following：randomized controlled trial,particular effective compound or derivative,reproducible result and animal test.Results Infectious respiratory tract diseases cause most mortality among infectious illnesses around the world.As traditional medicines,Chinese herbs have been widely used to deal with diseases for centuries and have been proved effective in practice.The administration of some Chinese herbs stimulates,suppresses or regulates the activity of immune system,thus protecting the respiratory tract or relieving infections of pathogens.Many herbs have remarkable antiviral effects,therefore they are used as substitutes of antimicrobial drugs.Based on the theory of traditional Chinese medicine,mix-using herbs provide a synergistic benefit on preventing and healing respiratory tract infections.Many commercial herbal medicines containing one or more compounds have been successfully applied to prevent and treat viral infections of respiratory tract clinically.Conclusions Traditional Chinese herbs could directly inhibit pathogens infecting respiratory tract,or coordinate the activity of immune system to avoid or relieve infections.With the emergence of antidrug pathogens or new variants,Chinese herbs.give strong evidence to protect human health.展开更多
文摘在线编程评测系统(Online Judge,OJ)是一种被广泛应用于计算机编程教学与竞赛的代码测评系统。用户在规模庞大的题库中寻找适合当前学习阶段的题目时,往往会感到迷茫。如何为用户推荐合适的题目和规划学习路径,是在线编程测评系统研发中的一个重要研究课题。传统推荐算法存在可解释性和准确性难以兼顾的问题。文中提出了基于知识图谱与协同过滤混合策略的在线评测系统推荐模型(A Hybrid Programming Task Recommendation Model Based on Knowledge Graph and Collaborative Filtering,HKGCF)。该模型通过推荐与用户当前知识和技能掌握程度相匹配的题目,来帮助用户提升学习效果。文中设计和实现了该模型,并将其集成到了北京航空航天大学在线编程测评系统中,以适应OJ平台特有的交互形式。线上测试和离线测试实验的结果表明,提出的HKGCF模型在准确率和可解释性方面均优于典型传统算法。
基金supported by the Scientific Research Fund of Sichuan Provincial Education Department, China (No. 15ZA0011)the Scientific Research Fund of Sichuan Tobacco Monopoly Administration, China (No. SCYC201504)the Program for Creative Group Construction in "211 Project" of Sichuan Agricultural University, China
文摘Soil contamination by heavy metals is a serious environmental problem worldwide, and reduction of heavy metal accumulation in vegetables grown on contaminated land is a matter of urgency. A pot experiment was conducted to study the effects of intercropping with the Cd hyperaccumulators Solanum nigrum and Solanum photeinocarpum from two ecoclimatic regions, Ya＇an and Chengdu, Sichuan Province, China, on the growth and cadmium （Cd） uptake of eggplant （Solanum melongena L.）. The biomass, photosynthetic pigment contents, and activities of antioxidant enzymes of eggplant were enhanced by intercropping. The biomass of eggplant was the highest after intercropping with S. photeinocarpum from Ya＇an, but did not differ significantly from that after intercropping with S. nigrum from Chengdu. The shoot Cd content of eggplant was significantly reduced by intercropping with the hyperaccumulators, which ranked as follows： S. nigrum from Chengdu 〉 S. nigrum from Ya＇an 〉 S. photeinocarpum from Chengdu 〉 S. photeinocarpum from Ya＇an, with the decreases being 19.60%, 14.36%, 9.66%, and 6.42%, respectively, as compared with the control. The lowest shoot Cd content and translocation factor of eggplant were attained after intercropping with S. nigvum from Chengdu. Therefore, it was feasible to intercrop eggplant with S. nigrum and S. photeinocarpurn on Cd-contaminated soil.
文摘Objective This review focuses on current knowledge of traditional Chinese herbs on prevention and treatment of viral respiratory infections,especially caused by Severe Acute Respiratory Syndromes （SARS） virus,respiratory syncytial virus （RSV） and influenza viruses.Data sources The data used in this review were obtained from PubMed and CNKI up to May 2013.Terms of Chinese herbs and infections of respiratory tract were used in the search.Study selection Articles related that Chinese herbs preventing and treating infections in respiratory tract were retrieved and reviewed.The risk of bias of included studies was assessed by the method in the ＂Cochrane Handbook of Systematic Reveiws of Interventionsand studies＂ with high risk of bias were excluded.Four criteria for selections were set as following：randomized controlled trial,particular effective compound or derivative,reproducible result and animal test.Results Infectious respiratory tract diseases cause most mortality among infectious illnesses around the world.As traditional medicines,Chinese herbs have been widely used to deal with diseases for centuries and have been proved effective in practice.The administration of some Chinese herbs stimulates,suppresses or regulates the activity of immune system,thus protecting the respiratory tract or relieving infections of pathogens.Many herbs have remarkable antiviral effects,therefore they are used as substitutes of antimicrobial drugs.Based on the theory of traditional Chinese medicine,mix-using herbs provide a synergistic benefit on preventing and healing respiratory tract infections.Many commercial herbal medicines containing one or more compounds have been successfully applied to prevent and treat viral infections of respiratory tract clinically.Conclusions Traditional Chinese herbs could directly inhibit pathogens infecting respiratory tract,or coordinate the activity of immune system to avoid or relieve infections.With the emergence of antidrug pathogens or new variants,Chinese herbs.give strong evidence to protect human health.
