Pendulum-type ( μ wave) wave is a new type of elastic wave propagated with low frequency and low velocity in deep block rock masses. The μ wave is sharply different from the traditional longitudinal and transverse w...Pendulum-type ( μ wave) wave is a new type of elastic wave propagated with low frequency and low velocity in deep block rock masses. The μ wave is sharply different from the traditional longitudinal and transverse waves propagated in continuum media and is also a phenomenon of the sign-variable reaction of deep block rock masses to dynamic actions, besides the Anomalous Low Friction (ALF) phenomenon. In order to confirm the existence of the μ wave and study the rule of variation of this μ wave experimentally and theoretically, we first carried out one-dimensional low-speed impact experiments on granite and cement mortar blocks and continuum block models with different characteristic dimensions, based on the multipurpose testing system developed by us independently. The effects of model material and dimensions of models on the propagation properties of 1D stress wave in blocks medium are discussed. Based on a comparison and analysis of the propagation properties (acceleration amplitudes and Fourier spectra) of stress wave in these models, we conclude that the fractures in rock mass have considerable effect on the attenuation of the stress wave and retardarce of high frequency waves. We compared our model test data with the data of in-situ measurements from deep mines in Russia and their conclusions. The low-frequency waves occurring in blocks models were validated as Pendulum-type wave. The frequencies corresponding to local maxima of spectral density curves of three-directional acceleration satisfied several canonical sequences with the multiple of 2～(1/2), most of those frequencies satisfied the quantitative expression (2～(1/2))i V p/2△ .展开更多
Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based ...Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based on in-situ investigations and theoretical studies,we have summarized typical forms of destruction and identified high stress and unrestricted support at both sides of junction arch as its main causes.In this study,we also presented double-directional control bolt support technology for a large Y-type span intersection,applied to deep intersection engineering in the Jiahe Coal Mine,which has proved effective.展开更多
目的探讨腹腔镜下子宫深静脉入路C型宫颈癌根治术治疗宫颈癌的疗效。方法2021年1月~2022年12月我院采用腹腔镜下子宫深静脉入路C型宫颈癌根治术+盆腔淋巴结清扫术±腹主动脉旁淋巴结切除术治疗58例宫颈癌。建立通道后,在阔韧带后叶...目的探讨腹腔镜下子宫深静脉入路C型宫颈癌根治术治疗宫颈癌的疗效。方法2021年1月~2022年12月我院采用腹腔镜下子宫深静脉入路C型宫颈癌根治术+盆腔淋巴结清扫术±腹主动脉旁淋巴结切除术治疗58例宫颈癌。建立通道后,在阔韧带后叶定位输尿管,分离输尿管后暴露子宫动脉,沿子宫动静脉背侧分离结缔组织,逐渐暴露子宫深静脉。将包绕子宫深静脉周围的宫旁淋巴结切除,单独送病理检查。继续向膀胱方向追踪子宫深静脉,游离其属支,血管夹双重夹闭。结果手术时间(307.2±54.1)min,出血量中位数50(20,100)ml,淋巴结清扫(26.3±6.9)枚,留置导尿管时间(20.6±4.7)d,拔除腹腔引流管时间(9.4±4.1)d,肛门排气时间(36.7±4.1)h,抗生素使用时间(9.2±4.2)d,住院时间(13.4±2.6)d。术后并发症发生率3.4%(2/58)。术后病理分期升级率为22.4%(13/58)。术后欧洲癌症研究治疗组织(European Organization of Research and Treatment of Cancer,EORTC)生活质量核心30问卷(Quality of Life Questionnaire-Core 30,QLQ-C30)评分较术前显著升高[(78.6±10.7)分vs.(47.1±7.6)分,t=17.177,P=0.000]。58例随访4~25个月,(13.5±6.2)月,无复发。结论腹腔镜下子宫深静脉入路C型宫颈癌根治术疗效确切、安全可靠。展开更多
基金Projects 50525825 and 90815010 supported by the National Natural Science Foundation of China2009CB724608 by the National Basic Research Program of ChinaBK2008002 by the Natural Science Foundation of Jiangsu Province
文摘Pendulum-type ( μ wave) wave is a new type of elastic wave propagated with low frequency and low velocity in deep block rock masses. The μ wave is sharply different from the traditional longitudinal and transverse waves propagated in continuum media and is also a phenomenon of the sign-variable reaction of deep block rock masses to dynamic actions, besides the Anomalous Low Friction (ALF) phenomenon. In order to confirm the existence of the μ wave and study the rule of variation of this μ wave experimentally and theoretically, we first carried out one-dimensional low-speed impact experiments on granite and cement mortar blocks and continuum block models with different characteristic dimensions, based on the multipurpose testing system developed by us independently. The effects of model material and dimensions of models on the propagation properties of 1D stress wave in blocks medium are discussed. Based on a comparison and analysis of the propagation properties (acceleration amplitudes and Fourier spectra) of stress wave in these models, we conclude that the fractures in rock mass have considerable effect on the attenuation of the stress wave and retardarce of high frequency waves. We compared our model test data with the data of in-situ measurements from deep mines in Russia and their conclusions. The low-frequency waves occurring in blocks models were validated as Pendulum-type wave. The frequencies corresponding to local maxima of spectral density curves of three-directional acceleration satisfied several canonical sequences with the multiple of 2～(1/2), most of those frequencies satisfied the quantitative expression (2～(1/2))i V p/2△ .
基金supported by the National Basic Research Program of China (No.2006CB202200)the Major Program of the National Natural Science Foundation of China (No.50490270)the Innovative Team Development Project of the Ministry of Education of China (No.IRT0656)
文摘Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based on in-situ investigations and theoretical studies,we have summarized typical forms of destruction and identified high stress and unrestricted support at both sides of junction arch as its main causes.In this study,we also presented double-directional control bolt support technology for a large Y-type span intersection,applied to deep intersection engineering in the Jiahe Coal Mine,which has proved effective.
文摘目的探讨腹腔镜下子宫深静脉入路C型宫颈癌根治术治疗宫颈癌的疗效。方法2021年1月~2022年12月我院采用腹腔镜下子宫深静脉入路C型宫颈癌根治术+盆腔淋巴结清扫术±腹主动脉旁淋巴结切除术治疗58例宫颈癌。建立通道后,在阔韧带后叶定位输尿管,分离输尿管后暴露子宫动脉,沿子宫动静脉背侧分离结缔组织,逐渐暴露子宫深静脉。将包绕子宫深静脉周围的宫旁淋巴结切除,单独送病理检查。继续向膀胱方向追踪子宫深静脉,游离其属支,血管夹双重夹闭。结果手术时间(307.2±54.1)min,出血量中位数50(20,100)ml,淋巴结清扫(26.3±6.9)枚,留置导尿管时间(20.6±4.7)d,拔除腹腔引流管时间(9.4±4.1)d,肛门排气时间(36.7±4.1)h,抗生素使用时间(9.2±4.2)d,住院时间(13.4±2.6)d。术后并发症发生率3.4%(2/58)。术后病理分期升级率为22.4%(13/58)。术后欧洲癌症研究治疗组织(European Organization of Research and Treatment of Cancer,EORTC)生活质量核心30问卷(Quality of Life Questionnaire-Core 30,QLQ-C30)评分较术前显著升高[(78.6±10.7)分vs.(47.1±7.6)分,t=17.177,P=0.000]。58例随访4~25个月,(13.5±6.2)月,无复发。结论腹腔镜下子宫深静脉入路C型宫颈癌根治术疗效确切、安全可靠。
