基于“三轴图”分析法的我国海洋产业结构演进及优化分析

海洋产业结构的优化调整对海洋经济的发展至关重要。运用"三轴图"分析法和GRA分析法分别分析我国海洋产业结构的演进过程以及我国海洋产业中的主导产业。结果表明:我国海洋产业结构已经实现了三二一的产业结构模式,但渔业等传统产业仍旧占据着主导地位,而高新技术产业的比重十分低。最后针对分析结果,给出相应的对策建议。

水云之间的三轴构建——读《天一言》中引用的唐诗《终南别业》

程抱一在他的小说《天一言》中,全文引用了唐朝王维的山水诗名篇《终南别业》。这种引用并非对唐诗的单纯借用,而是完成着一个精彩的再创作过程,充分体现了他对中国诗歌语言的'三轴构建'理论的建树与实践。

运用“三轴图”法进行白城市产业结构分析

运用三轴图方法分析白城市产业结构现状及发展趋势,得出相应结论和建议,有利于实现白城市区域经济的可持续发展。

“三点一轴三带”:辽宁区域协调发展的战略思考

党的十八届五中全会创造性地提出了"创新、协调、绿色、开放、共享"五大发展理念,这是"十三五"乃至未来更长时期我国发展思路、方向和着力点的集中体现。其中,协调发展理念就是要破解我国长期存在的发展不协调问题,形成平衡结构,增强发展整体性。当前,我国在深入实施"一带一路"、长江经济带和京津冀协同发展三大区域战略,意在使我国经济发展由东向西梯度推进,打造新的经济支撑带和具有全球影响力的开放合作新平台,进而实现全国区域整体协调发展。

Prediction and critical transition mechanism for granite fracture:Insights from critical slowing down theory

Rock fracture warning is one of the significant challenges in rock mechanics.Many true triaxial and synchronous acoustic emission(AE)tests were conducted on granite samples.The investigation focused on the characteristics of AE signals preceding granite fracture,based on the critical slowing down(CSD)theory.The granite undergoes a transition from the stable phase to the fracture phase and exhibits a clear CSD phenomenon,characterized by a pronounced increase in variance and autocorrelation coefficient.The variance mutation points were found to be more identifiable and suitable as the primary criterion for predicting precursor information related to granite fracture,compared to the autocorrelation coefficient.It is noteworthy to emphasize that the CSD factor holds greater potential in elucidating the underlying mechanisms responsible for the critical transition of granite fracture,in comparison to the AE timing parameters.Furthermore,a novel multi-parameter collaborative prediction method for rock fracture was developed by comprehensively analyzing predictive information,including abnormal variation modes and the CSD factor of AE characteristic parameters.This method enhances the understanding and prediction of rock fracture-related geohazards.

Effect of fractures on mechanical behavior of sand powder 3D printing rock analogue under triaxial compression

In practical engineering applications,rock mass are often found to be subjected to a triaxial stress state.Concurrently,defects like joints and fractures have a notable impact on the mechanical behavior of rock mass.Such defects are identified as crucial contributors to the failure and instability of the surrounding rock,subsequently impacting the engineering stability.The study aimed to investigate the impact of fracture geometry and confining pressure on the deformation,failure characteristics,and strength of specimens using sand powder 3D printing technology and conventional triaxial compression tests.The results indicate that the number of fractures present considerably influences the peak strength,axial peak strain and elastic modulus of the specimens.Confining pressure is an important factor affecting the failure pattern of the specimen,under which the specimen is more prone to shear failure,but the initiation,expansion and penetration processes of secondary cracks in different fracture specimens are different.This study confirmed the feasibility of using sand powder 3D printing specimens as soft rock analogs for triaxial compression research.The insights from this research are deemed essential for a deeper understanding of the mechanical behavior of fractured surrounding rocks when under triaxial stress state.

Temperature effects on the failure of deep circular tunnel under true-triaxial compression

The failure characteristics of thermal treated surrounding rocks should be studied to evaluate the stability and safety of deep ground engineering under high-ground-temperature and high-ground-stress conditions.The failure process of the inner walls of fine-grained granite specimens at different temperatures(25–600℃)was analyzed using a true-triaxial test system.The failure process,peak intensity,overall morphology(characteristics after failure),rock fragment characteristics,and acoustic emission(AE)characteristics were analyzed.The results showed that for the aforementioned type of granite specimens,the trend of the failure stress conditions changed with respect to the critical temperature(200℃).When the temperature was less than 200℃,the initial failure stress increased,final failure stress increased,and failure severity decreased.When the temperature exceeded 200℃,the initial failure stress decreased,final failure stress decreased,and failure severity increased.When the temperature was 600℃,the initial and final failure stresses of the specimens decreased by 60.93%and 19.77%compared with those at 200℃,respectively.The numerical results obtained with the software RFPA3D-Thermal were used to analyze the effect of temperature on the specimen and reveal the mechanism of the failure process in the deep tunnel surrounding rock.

A coupled strain softening and hardening model for completely weathered granite in a fault zone

his study focused on exploring the specificity of mechanical behavior for completely weathered granite,as a special soil,by consolidated drained triaxial tests.The influences of dry density(1.60,1.70,1.80 and 1.90 g/cm^(3)),confining pressure(100,200,400 and 600 kPa),and moisture content(13.0%,that is,natural moisture content)were investigated in the present work.A newly developed Duncan-Chang model was established based on the experimental data and Duncan-Chang model.The influence of each parameter on the type of the proposed model curve was also evaluated.The experimental results revealed that with varying dry density and confining pressure,the deviatoric stress–strain curves have diversified characteristics including strain-softening,strain-stabilization and strain-hardening.Under high confining pressure condition,specimens with different densities all showed strain-hardening characteristic.Whereas at the low confining pressure levels,specimens with higher densities gradually transform into softening characteristics.Except for individual compression shear failure,the deformation modes of the specimens all showed swelling deformation,and all the damaged specimens maintained good integrity.Through comparing the experiment results,the strain-softening or strain-hardening behavior of CWG specimens could be predicted following the proposed model with high accuracy.Additionally,the proposed model can accurately characterize the key mechanical indicators,such as tangent modulus,peak value and residual strength,which is simple to implement and depends on fewer parameters.

长龙山抽蓄电站两种机型转子现场组装工艺对比分析

转子作为机组运行的核心部件,极大程度上影响着机组运行的安全性和稳定性,因此把控转子组装质量,是提高机组安全稳定运行的必要措施。本文以长龙山抽水蓄能电站布置的两种不同高额定转速抽蓄机组为例,在机组结构对比分析的基础上,重点阐述两种不同高额定转速抽蓄机组转子组装工艺的控制重点及施工工艺,最后总结转子组装过程中的注意事项,为同类型机组的安装提供有益的借鉴和参考。

粤港澳大湾区铁路客运量预测研究

粤港澳大湾区是国家战略区域,为支撑粤港澳大湾区建设国际一流湾区,必须尽快开展粤港澳大湾区铁路网规划,加快构建功能完善、层次清晰、便捷衔接、安全高效、低碳绿色的现代铁路运输网络。其中,铁路客运量预测是开展路网规划、支撑路网方案的必要环节和重要组成部分。笔者结合铁路运量预测和区域运量预测的研究成果,结合大湾区铁路在综合交通运输体系中的定位,综合运用多种方法开展运量预测。参照大湾区发展格局,铁路客运分为对外客流、内部客流和跨境通过客流。

Failure properties of rocks in true triaxial unloading compressive test

Slabbing failure often occurs in the surround rock near a deep underground excavation. The mechanism of slabbing failure is still unclear. In order to reveal the influence of the intermediate principal stress （σ2） on slabbing failure, true triaxial unloading compressive test was carried out based on the stress path of the underground engineering excavation, i.e., unloading the minimum principal stress （σ3）, keeping σ2, increasing the maximum principal stress （σ1）. The initiation and the propagation of slabbing fracture in rock specimens were identified by examining the acoustic emission （AE） and the infrared radiation characterization. The test results show that the failure modes of the granite and red sandstone specimens are changed from shear to slabbing with the increase of σ2. The AE characteristic of rock specimen under low σ2 is swarm type which is the main shock type under high σ2. The infrared radiation properties of rock specimen under different σ2 are also different. The temperature change area is just along the shear fracture such as the uniaxial compression. With the increase of σ2, the temperature change area is planar of rock specimen which proofs that the failure mode of rock specimen turns into slabbing.

辽宁沿海经济带产业结构分析

辽宁沿海经济带开发开放上升为国家战略之后不仅使其成为全省经济总量扩张承载的重要区域,而且还肩负着辽宁转变经济发展方式、加大产业结构调整的重要使命。在应用"三轴图"法研究辽宁沿海经济带产业结构的变化及其轨迹的基础上,利用SSM模型及其计算公式对辽宁沿海经济带产业结构进行比较分析,认为营口、丹东、锦州等城市的第一产业竞争力较强,其第二产业的发展水平都较高,尤以大连、营口两市为突出,锦州、营口两市的第三产业发展速度较快。依据分析结果并结合辽宁"十二五"经济社会发展战略,提出辽宁沿海经济带加快转变经济发展方式、加大产业结构调整的对策建议。

Relationship between repeated triaxial test and Hamburg wheel tracking test on asphalt mixtures

Both the repeated triaxial test （RTT） and the Hamburg wheel tracking test （HWTT） are adopted to evaluate the high temperature performance of the stone mastic asphalt （SMA） and the mastic asphalt （MA）. The correlation of the permanent deformations of the MA and the correlation of the deformation developments of the SMA between the two tests are analyzed, respectively. Results show that both the two tests can effectively identify the high temperature performance of mixtures, and the correlation between the final results of the two tests as well as that between the deformation developments of the two tests are excellent with R20.9. In order to further prove the correlation, viscoelastic parameters estimated from the RTT results is used to simulate the rutting development in the HWTT slabs by the finite element method （FEM）. Results indicate that the correlation between the two tests is significant with errors less than 10%. It is suitable to predict the rutting development with the viscoelastic parameters obtained from the RTT.

我国海洋产业结构演化的过程研究

海洋产业结构的优化升级是海洋经济健康持续发展的重要保障,并直接影响着人类未来的发展。在有关学者对海洋产业结构演化的研究基础之上,运用三轴图分析法,构建了海洋产业结构演进模式图,可直观清晰地看出我国海洋三次产业结构的动态演变过程,显示我国海洋产业结构已实现第三产业占据主导地位的三、二、一产业结构模式,并在此基础上对海洋产业结构的演化阶段进行分析。从加强国家宏观调控、优化产业布局、加强科技创新、建立人才队伍等方面提出优化海洋产业结构的对策。

“一带一路”背景下辽宁沿海产业结构转型的思考

《辽宁沿海经济带发展规划》上升为国家战略以来,借助"一带一路"的政策指引,辽宁沿海6市的区域经济发展对于推动全省经济增量发展和优化经济增长方式,起到了关键的作用。本文在运用"三轴图"法研究辽宁沿海经济带产业结构逐年演进的基础上,运用SSM模型对辽宁沿海6市的产业结构布局进行比较分析,并依据分析结论提出推进"十三五"时期辽宁沿海经济带产业结构转型和区域经济协调发展的合理化对策和建议。

A fatigue life prediction method of rolling bearing under elliptical contact elastohydrodynamic lubrication

In order to more accurately predict the contact fatigue life of rolling bearing, a prediction method of fatigue life of rolling bearing is proposed based on elastohydrodynamic lubrication （EHL）, the 3-paameter Weibull distribution ad fatigue strength. First,the contact stress considering elliptical EHL is obtained by mapping film pressure onto the Hertz zone. Then,the basic strength model of rolling bearing based on the 3-parameter Weibull distribution is deduced by the series connection reliability theory. Considering the effect of the type of stress, variation of shape and fuctuation of load, the mathematical models of the 尸 -tS-TV curve of the minimum life and the characteristic life for rolling bearing are established, respectively, and thus the prediction model of fatigue life of rolling bearing based on the 3-paameter Weibull distribution and fatigue strength is further deduced. Finally, the contact fatigue life obtained by the proposed method ad the latest international standard （IS0281： 2007） about the fatigue life prediction of rolling bearing are compared with those obtained by the statistical method. Results show that the proposed prediction method is effective and its relative error is smaier than that of the latest international standard （IS0281： 2007） with reliability R 〉 0. 93.

Acoustic emission precursors of static and dynamic instability for coarse-grained hard rock

To investigate the acoustic emission(AE)precursors of coarse-grained hard rock instability,an experimental study on the rockburst and slabbing process of granite was carried out using a true triaxial test system.The evolution of the AE signals was monitored and analyzed in terms of the AE hit rate,fractal dimension of the AE hit number,AE count rate,b-value,dominant frequency and microcrack type.The test results show that after rock slabbing occurs,the AE precursors that can be used to predict the final dynamic instability(rockburst)are as follows:indicators such as the AE hit rate and AE count rate suddenly increase and then suddenly decrease;the AE hit rate exhibits a“quiet period”;during the“quiet period”,a small number of high-amplitude and low-frequency hits occur,and the signals corresponding to shear fracture continue to increase.The AE precursors for the final static instability(spalling)are as follows:both the AE hit rate and the b-value continuously decrease,and intermittent sudden increases appear in the high-frequency hits or the AE count rate.

Strainburst process of marble in tunnel-excavation-induced stress path considering intermediate principal stress

Strainburst is one type of rockburst that generally occurs in deep tunnel.In this study,the strainburst behaviors of marble specimens were investigated under tunnel-excavation-induced stress condition,and two stress paths were designed,a commonly used stress path in true triaxial unloading rockburst tests and a new test path in which the intermediate principal stress was varied.During the tests,a high-speed camera was used to record the strainburst process,and an acoustic emission(AE)monitoring system was used to monitor the AE characteristics of failure.In these two stress paths,all the marble specimens exhibited strainbursts;however,when the intermediate principal stress was varied,the rockburst became more violent.The obtained results indicate that the intermediate principal stress has a significant effect on rockburst behavior of marble.Under a higher intermediate principal stress before the unloading,more elastic strain energy was accumulated in the specimen,and the cumulative AE energy was higher in the rockburst-induced failure,i.e.,more elastic strain energy was released during the failure.Therefore,more violent failure was observed:more rock fragments with a higher mass and larger size were ejected outward.

Experimental simulation investigation of influence of depth on spalling characteristics in circular hard rock tunnel

A series of true-triaxial compression tests were performed on red sandstone cubic specimens with a circular hole to investigate the influence of depth on induced spalling in tunnels.The failure process of the hole sidewalls was monitored and recorded in real-time by a micro-video monitoring equipment.The general failure evolution processes of the hole sidewall at different initial depths(500 m,1000 m and 1500 m)during the adjustment of vertical stress were obtained.The results show that the hole sidewall all formed spalling before resulting in strain rockburst,and ultimately forming a V-shaped notch.The far-field principal stress for the initial failure of the tunnel shows a good positive linear correlation with the depth.As the depth increases,the stress required for the initial failure of the tunnels clearly increased,the spalling became more intense;the size and mass of the rock fragments and depth and width of the V-shaped notches increased,and the range of the failure zone extends along the hole sidewall from the local area to the entire area.Therefore,as the depth increases,the support area around the tunnel should be increased accordingly to prevent spalling.

Damage mechanism of soil-rock mixture after freeze-thaw cycles

As a widely distributed geological and engineering material,the soil-rock mixture always undergoes frequentative and short-term freeze-thaw cycles in some regions.Its internal structure is destroyed seriously,but the damage mechanism is not clear.Based on the damage factor,the damage research of properties of soil-rock mixture after different times of freeze-thaw cycles is investigated.Firstly,the size-distributed subgrade gravelly soil samples are prepared and undergo different times of freeze-thaw cycles periodically(0,3,6,10),and indoor large-scale triaxial tests are completed.Secondly,the degradation degree of elastic modulus is considered as a damage factor,and applied to macro damage analysis of soil-rock mixture.Finally,the mesoscopic simulation of the experiments is achieved by PFC3D,and the influence on strength between soil-rock particles caused by freeze-thaw cycles is analyzed.The results show that freeze-thaw cycles cause internal damage of samples by weakening the strength between mesoscopic soil-rock particles,and ultimately affect the macro properties.After freeze-thaw cycles,on the macro-scale,elastic modulus and shear strength of soil-rock mixture both decrease,and the decreasing degree is related to the times of cycles with the mathmatical quadratic form;on the meso-scale,freeze-thaw cycles mainly cause the degradation of the strength between soil-rock particles whose properties are different significantly.