确定矿山开采沉陷边界有助于评估矿区生产活动对周围环境和基础设施的潜在影响,为制定有效的灾害防控措施提供技术手段。充分考虑到概率积分法等传统方法在划定矿山开采沉陷边界时的不足,采用在获取矿区大范围高精度地表沉降数据方面具...确定矿山开采沉陷边界有助于评估矿区生产活动对周围环境和基础设施的潜在影响,为制定有效的灾害防控措施提供技术手段。充分考虑到概率积分法等传统方法在划定矿山开采沉陷边界时的不足,采用在获取矿区大范围高精度地表沉降数据方面具有优势的SBAS-InSAR技术,并结合淘金算法(Gold Rush Optimizer,GRO)优化双向长短期记忆(Bidirectional Long Short Term Memory,BiLSTM)模型的预测方法,实现矿区开采沉陷边界划定。以红会煤矿为研究对象,依据SBAS-InSAR技术提取矿区沉降边缘高相干点在2018-11-29—2020-02-04时间段内共37期沉降数据,以下沉10 mm等值线划定沉陷边界,利用GRO-BiLSTM优化模型预测高相干点的地表沉降值,并将预测结果与LSTM和BiLSTM模型预测结果进行了对比分析。结果表明:GRO-BiLSTM模型在整体测试集中均方根误差为3.204mm,比LSTM和BiLSTM模型分别降低了22.16%和8.21%;平均绝对误差为2.062 mm,比LSTM和BiLSTM模型分别降低了23.96%和5.43%,表明该方法可以有效监测和预测矿区边界地区的沉陷状况。展开更多
GRO(Global Navigation satellite system Radio Occultation)和LRO(Low Earth Orbit Radio Occultation)联合组网探测地球大气是无线电掩星探测技术的主要发展方向.本文根据掩星事件的数学判据,仿真分析了LEO卫星主要轨道参数对CRO和LR...GRO(Global Navigation satellite system Radio Occultation)和LRO(Low Earth Orbit Radio Occultation)联合组网探测地球大气是无线电掩星探测技术的主要发展方向.本文根据掩星事件的数学判据,仿真分析了LEO卫星主要轨道参数对CRO和LRO掩星事件数量和全球分布情况的影响.研究表明:卫星轨道越低GRO掩星事件越多:轨道倾角在30°和75°之间时,GRO掩星事件较多.全球覆盖率也较大;利用极轨卫星进行LRO掩星探测时.LRO掩星事件较均匀地分布在各纬度带.研究成果对GRO和LRO联合星座设计具有参考价值.展开更多
AIM:To determine the association between serum levels of growth-related gene product β(GROβ) and clinical parameters in esophageal squamous cell carcinoma(ESCC).METHODS:Using enzyme-linked immunosorbent assay,serum ...AIM:To determine the association between serum levels of growth-related gene product β(GROβ) and clinical parameters in esophageal squamous cell carcinoma(ESCC).METHODS:Using enzyme-linked immunosorbent assay,serum GROβ levels were measured in ESCC patients(n = 72) and healthy volunteers(n = 83).The association between serum levels of GROβ and clinical parameters of ESCC was analyzed statistically.RESULTS:The serum GROβ levels were much higher in ESCC patients than in healthy controls(median:645 ng/L vs 269 ng/L,P < 0.05).Serum GROβ levels were correlated positively with tumor size,lymph node metastasis,and tumor-node-metastasis(TNM) staging,but not with gender or the histological grade of tumors in ESCC patients.The sensitivity and specificity of the assay for serum GROβ were 73.61% and 56.63%,respectively.CONCLUSION:GROβ may function as an oncogene product and contribute to tumorigenesis and metastasis of ESCC.展开更多
文摘确定矿山开采沉陷边界有助于评估矿区生产活动对周围环境和基础设施的潜在影响,为制定有效的灾害防控措施提供技术手段。充分考虑到概率积分法等传统方法在划定矿山开采沉陷边界时的不足,采用在获取矿区大范围高精度地表沉降数据方面具有优势的SBAS-InSAR技术,并结合淘金算法(Gold Rush Optimizer,GRO)优化双向长短期记忆(Bidirectional Long Short Term Memory,BiLSTM)模型的预测方法,实现矿区开采沉陷边界划定。以红会煤矿为研究对象,依据SBAS-InSAR技术提取矿区沉降边缘高相干点在2018-11-29—2020-02-04时间段内共37期沉降数据,以下沉10 mm等值线划定沉陷边界,利用GRO-BiLSTM优化模型预测高相干点的地表沉降值,并将预测结果与LSTM和BiLSTM模型预测结果进行了对比分析。结果表明:GRO-BiLSTM模型在整体测试集中均方根误差为3.204mm,比LSTM和BiLSTM模型分别降低了22.16%和8.21%;平均绝对误差为2.062 mm,比LSTM和BiLSTM模型分别降低了23.96%和5.43%,表明该方法可以有效监测和预测矿区边界地区的沉陷状况。
文摘GRO(Global Navigation satellite system Radio Occultation)和LRO(Low Earth Orbit Radio Occultation)联合组网探测地球大气是无线电掩星探测技术的主要发展方向.本文根据掩星事件的数学判据,仿真分析了LEO卫星主要轨道参数对CRO和LRO掩星事件数量和全球分布情况的影响.研究表明:卫星轨道越低GRO掩星事件越多:轨道倾角在30°和75°之间时,GRO掩星事件较多.全球覆盖率也较大;利用极轨卫星进行LRO掩星探测时.LRO掩星事件较均匀地分布在各纬度带.研究成果对GRO和LRO联合星座设计具有参考价值.
基金Supported by The Grants from International Science & Technology Cooperation and Exchange Programs, No. 2008DFA31130Joint China/South Africa Science and Technology Agreement+1 种基金National Natural Science Foundation of China, No. 81021061, No. 0772507 and No. 30700992State Key Projects for Basic Research of China, No. 2011CB910703
文摘AIM:To determine the association between serum levels of growth-related gene product β(GROβ) and clinical parameters in esophageal squamous cell carcinoma(ESCC).METHODS:Using enzyme-linked immunosorbent assay,serum GROβ levels were measured in ESCC patients(n = 72) and healthy volunteers(n = 83).The association between serum levels of GROβ and clinical parameters of ESCC was analyzed statistically.RESULTS:The serum GROβ levels were much higher in ESCC patients than in healthy controls(median:645 ng/L vs 269 ng/L,P < 0.05).Serum GROβ levels were correlated positively with tumor size,lymph node metastasis,and tumor-node-metastasis(TNM) staging,but not with gender or the histological grade of tumors in ESCC patients.The sensitivity and specificity of the assay for serum GROβ were 73.61% and 56.63%,respectively.CONCLUSION:GROβ may function as an oncogene product and contribute to tumorigenesis and metastasis of ESCC.
