在渔业标准文本中,定量指标识别对标准内容服务具有重要的意义,针对目前常用的命名实体识别方法对渔业标准定量指标识别准确率不高的问题,该研究提出了融合注意力机制与BERT+BiLSTM+CRF(Bidirectional Encoder Representations from Tra...在渔业标准文本中,定量指标识别对标准内容服务具有重要的意义,针对目前常用的命名实体识别方法对渔业标准定量指标识别准确率不高的问题,该研究提出了融合注意力机制与BERT+BiLSTM+CRF(Bidirectional Encoder Representations from Transformers+Bi-directional Long Short-Term Memory+Conditional Random Field,来自转换器的双向编码器表征量+双向长短时记忆网络+条件随机场)模型的渔业标准定量指标识别方法,该方法将渔业标准中定量指标拆分为指标名、指标值、单位、限制词4类实体,通过分析渔业标准语料的特点发现位置信息对指标名等实体识别效果具有重要影响,首先利用BERT模型中位置向量信息提高指标名等实体的识别效果,其次采用BiLSTM(Bi-directional Long Short-Term Memory,双向长短时记忆网络)模型学习渔业标准文本定量指标中长序列语义特征,然后再将注意力机制与BERT+BiLSTM模型进行融合以解决长序列语义稀释问题,最后利用CRF(Conditional Random Field,条件随机场)层得到预测序列标签。试验结果表明,融合注意力机制与BERT+BiLSTM+CRF模型的渔业标准定量指标识别准确率为94.51%、召回率为96.37%、F1值为95.43%,研究表明,该方法解决了渔业标准定量指标识别准确率不高的问题,可以比较准确地识别由指标名、指标值、单位、限制词组成的渔业标准定量指标,是一种有效的渔业标准定量指标识别方法,可为农业、医学、生物等其他领域定量指标命名实体识别提供新思路。展开更多
The effect of cooling rate during quenching on the microstructure and creep property of nickel-based superalloy FGH96 was investigated. Three groups of samples were quenched continuously with three fixed cooling rates...The effect of cooling rate during quenching on the microstructure and creep property of nickel-based superalloy FGH96 was investigated. Three groups of samples were quenched continuously with three fixed cooling rates, respectively, then subjected to a creep test under a constant load of 690 MPa at 700℃. Clear differences in size of secondary γ′ precipitates, creep properties and substructure of creep-tested samples were observed. The quantitative relationship among cooling rate, the size of secondary γ′ precipitates, and steady creep rate was constructed. It was found that with increasing cooling rate, the size of secondary γ′ precipitates decreases gradually, showing that the relationship between the size of secondary γ′ precipitates and the cooling rate obeys a power law, with an exponent of about –0.6, and the creep rate of steady state follows a good parabola relationship with cooling γ′ precipitate size. For 235℃/min, FGH96 alloy exhibited very small steady creep rate. The density of dislocation was low, and the isolated stacking fault was the dominant deformation mechanism. With decreasing cooling rates, the density of dislocation increased remarkably, and deformation microtwinning was the dominant deformation process. Detailed mechanisms for different cooling rate were discussed.展开更多
Land use issue is an important constraining force to limit economic sustainable development of China. Urban and rural rapid expansion depletes valued land resources under the background of rapid urbanization. An exten...Land use issue is an important constraining force to limit economic sustainable development of China. Urban and rural rapid expansion depletes valued land resources under the background of rapid urbanization. An extensive use pattern might cause a serious waste of land resources. The study on influencing mechanism of land intensive use （LIU） in China at the county level is a key tool for effective LIU practice and policy-making. This paper uses OLS model, Spatial Panel Lagged model and Spatial Panel Error model to quantitatively analyze the influencing mechanisms of five class factors and 17 variables supported by GIS （Geographic Information System） and MATLAB. And a comprehensive data set was devel- oped including physical geography and socio-economic information of 2286 counties. Meanwhile, the spatiotemporal pattern of LIU has discussed by means of GIS. The results show that Spatial Panel Data models are slightly superior to OLS model in terms of signifi- cance and confidence level. Regression results of these models indicate that industrialization, urbanization, economic development level, location, transportation and policy have significant impact on LIU of counties. The variables of physical geography are less significant than socio-economic variables. An ignored variable of historical factor, however, became the best significant factor. In the future, the LIU at the county level should take advantage of the new situation by enhancing favorable factors and reducing disadvantageous ones, which can be acquired by improving the entire level and quality of industrialization and urbanization. We argued that an efficient and complete land market and operating system should be built to reflect market-oriented activities at the first place, then, differential LIU regulation policies and measurements should be optimized according to regional differences. In the meantime, we should pay close attention to the carrying capacity of local resources and environments when conducting LIU practices.展开更多
文摘在渔业标准文本中,定量指标识别对标准内容服务具有重要的意义,针对目前常用的命名实体识别方法对渔业标准定量指标识别准确率不高的问题,该研究提出了融合注意力机制与BERT+BiLSTM+CRF(Bidirectional Encoder Representations from Transformers+Bi-directional Long Short-Term Memory+Conditional Random Field,来自转换器的双向编码器表征量+双向长短时记忆网络+条件随机场)模型的渔业标准定量指标识别方法,该方法将渔业标准中定量指标拆分为指标名、指标值、单位、限制词4类实体,通过分析渔业标准语料的特点发现位置信息对指标名等实体识别效果具有重要影响,首先利用BERT模型中位置向量信息提高指标名等实体的识别效果,其次采用BiLSTM(Bi-directional Long Short-Term Memory,双向长短时记忆网络)模型学习渔业标准文本定量指标中长序列语义特征,然后再将注意力机制与BERT+BiLSTM模型进行融合以解决长序列语义稀释问题,最后利用CRF(Conditional Random Field,条件随机场)层得到预测序列标签。试验结果表明,融合注意力机制与BERT+BiLSTM+CRF模型的渔业标准定量指标识别准确率为94.51%、召回率为96.37%、F1值为95.43%,研究表明,该方法解决了渔业标准定量指标识别准确率不高的问题,可以比较准确地识别由指标名、指标值、单位、限制词组成的渔业标准定量指标,是一种有效的渔业标准定量指标识别方法,可为农业、医学、生物等其他领域定量指标命名实体识别提供新思路。
基金financially supported by the National Material Special Program of China (No. JPPT-F2008-5-1)
文摘The effect of cooling rate during quenching on the microstructure and creep property of nickel-based superalloy FGH96 was investigated. Three groups of samples were quenched continuously with three fixed cooling rates, respectively, then subjected to a creep test under a constant load of 690 MPa at 700℃. Clear differences in size of secondary γ′ precipitates, creep properties and substructure of creep-tested samples were observed. The quantitative relationship among cooling rate, the size of secondary γ′ precipitates, and steady creep rate was constructed. It was found that with increasing cooling rate, the size of secondary γ′ precipitates decreases gradually, showing that the relationship between the size of secondary γ′ precipitates and the cooling rate obeys a power law, with an exponent of about –0.6, and the creep rate of steady state follows a good parabola relationship with cooling γ′ precipitate size. For 235℃/min, FGH96 alloy exhibited very small steady creep rate. The density of dislocation was low, and the isolated stacking fault was the dominant deformation mechanism. With decreasing cooling rates, the density of dislocation increased remarkably, and deformation microtwinning was the dominant deformation process. Detailed mechanisms for different cooling rate were discussed.
基金The National Science and Technology Support Planning,No.2012BAJ22B03
文摘Land use issue is an important constraining force to limit economic sustainable development of China. Urban and rural rapid expansion depletes valued land resources under the background of rapid urbanization. An extensive use pattern might cause a serious waste of land resources. The study on influencing mechanism of land intensive use （LIU） in China at the county level is a key tool for effective LIU practice and policy-making. This paper uses OLS model, Spatial Panel Lagged model and Spatial Panel Error model to quantitatively analyze the influencing mechanisms of five class factors and 17 variables supported by GIS （Geographic Information System） and MATLAB. And a comprehensive data set was devel- oped including physical geography and socio-economic information of 2286 counties. Meanwhile, the spatiotemporal pattern of LIU has discussed by means of GIS. The results show that Spatial Panel Data models are slightly superior to OLS model in terms of signifi- cance and confidence level. Regression results of these models indicate that industrialization, urbanization, economic development level, location, transportation and policy have significant impact on LIU of counties. The variables of physical geography are less significant than socio-economic variables. An ignored variable of historical factor, however, became the best significant factor. In the future, the LIU at the county level should take advantage of the new situation by enhancing favorable factors and reducing disadvantageous ones, which can be acquired by improving the entire level and quality of industrialization and urbanization. We argued that an efficient and complete land market and operating system should be built to reflect market-oriented activities at the first place, then, differential LIU regulation policies and measurements should be optimized according to regional differences. In the meantime, we should pay close attention to the carrying capacity of local resources and environments when conducting LIU practices.
