回弹和钻芯检测砼强度方法在灾后建筑物鉴定检测中的应用

一般在实际应用中,回弹法及钻芯法用得较多。这两种方法,从优缺点上来说,大致成一个互相补充的情况：回弹法从原理上来说能检测到混凝土受火面层的强度情况,并以此来判断混凝土损伤状况,缺点是不能够确定受火混凝土本身的强度状况,本文简要的介绍了回弹和钻芯检测砼强度方法在灾后建筑物鉴定检测中的应用。     

回弹法与钻芯法现场检测混凝土强度的技术与应用

现场检测混凝土的质量,已成为工程质量管理的重要手段。文章从回弹法和钻芯法在现场检测混凝土强度的技术与应用以及回弹法和钻芯在检测中如何提高准确性和科学性进行了分析。     

混凝土强度检测方法的合理应用

本文对回弹法、超声法、超声回弹综合法、钻芯法的优缺点和适用范围进行深入分析,通过工程实例讨论了混凝土强度检测方法的适用性,对正确选用检测方法具有指导意义.     

回弹法在混凝土质量管理中的应用

回弹值换算成混凝土强度可通过对比试验建立实测的测强曲线来进行换算.本文对专用测强曲线的建立方法进行了探讨,得到了某桥梁工程混凝土强度推定值计算公式.     

芯样混凝土抗压强度异常数据处理对检测结果的影响

本文列举了不同芯样混凝土抗压强度异常数据的处理方法,利用实例对比不同的处理方法对钻芯修正回弹法检测结果的影响,验证异常数据处理方法在实际使用时的实用性。     

包头地区超声回弹综合法测强曲线的建立

文章利用超声回弹综合法对混凝土构件的强度进行了检测试验,建立了包头地区的超声回弹综合法测强曲线方程,并且和全国的基准曲线方程相比较,验证由试验得到曲线方程在包头地区有很好的实用性和适用性。     

采用回弹及超声波检测混凝土构件强度方法

工程施工中混凝土强度检测一般通过两种方式检测,一种是取芯试压,此种方式可直接反应混凝凝土的真实强度。但对混凝土结构会造成一定程度破坏,或因构件含筋率较高,不易取出完整的素混凝土芯样,操作起来有一定的难度;另一种方式是采用现场回弹,此种方法常因仪器或操作人员操作方式不当影响混凝土回弹数值的准确性,只能作为混凝土强度值参考指标。本文通过介绍南广高铁混凝土现浇梁采用回弹超声波检测综合法的检测方式,能真实检测混凝土实体的强度值。     

浅析超声回弹综合法检测混凝土强度

本文对回弹法、超声法、超声回弹综合法的优缺点和适用范围进行深入分析通过,并对回弹法、超声法和超声回弹综合法及抽芯实压法对混凝土检测的数据进行数理分析对比,认为超声回弹综合法比单一的回弹法得出的结论要准确得多,是目前无破损检测混凝土构件强度最有效的方法之一。     

回弹检测及抗压试验下混凝土强度试验研究

利用回弹仪对两年龄期C30混凝土试件进行回弹测试及抗压强度测试,对试件的两种抗压强度进行分析。结果表明,混凝土真实抗压强度略高于回弹强度,回弹抗压能较好地表征其真实抗压强度,且具备一定安全储备。     

芯样端面补平方式对抗压强度影响的分析

本文介绍了钻芯法检测混凝土强度的特最和方法,采用钻芯法检测混凝土抗压强度的过程中,对芯样端面的加工通常有磨平法和补平法两种方式。本文就磨平法、水泥净浆补平法和硫磺胶泥补平法加工处理后的芯样进行了分析,将三组抗压强度检测值的结果比较,说明了三者之间存在一定的差异,指出了磨平法的优越性和减小补平法测试误差的途径。     

Excel软件在回弹法检测及推定混凝土强度中的应用

本文对如何利用Excel电子表格实现回弹法检测及推定混凝土强度的数据处理进行了分析,能极大地提高利用回弹法检测混凝土强度的效率。     

Data-driven-based adaptive fuzzy neural network control for the antimony flotation plant

Due to the unknown system structure of the froth flotation process and frequent fluctuations in production conditions, design of control strategy is a challenging problem. As a result, manual operation is still widely applied in practice by observing froth image features. However, since the manual observation is subjective and the production conditions are time-varying, the manual operation cannot make decisions quickly and accurately. In this paper, a data-driven-based adaptive fuzzy neural network control strategy is developed to implement the automatic control of the antimony flotation process. The strategy is composed of fuzzy neural network (FNN) controllers, a data-driven model, and an on-line adaptive algorithm. The FNN is constructed to derive the control laws of the reagent dosages. The parameters of the FNN controllers are tuned by gradient descent algorithm. To obtain the real-time error feedback information, the data-driven model is established, which integrates the long short term memory (LSTM) network and radial basis function neural network (RBFNN). The LSTM network is utilized as a primary model, and the RBFNN is used as an error compensation model. To handle the challenges of the frequent fluctuations in the production conditions, the on-line adaptive algorithm is proposed to tune the parameters of the FNN controllers. Simulations and experiments are carried out in a real-world antimony flotation plant in China. The results demonstrate that the proposed adaptive fuzzy neural network control strategy produces better control performance than the other two existing methods.     

WSVR-based fuzzy neural network with annealing robust algorithm for system identification

This paper proposes a fuzzy neural network (FNN) based on wavelet support vector regression (WSVR) approach for system identification, in which an annealing robust learning algorithm (ARLA) is adopted to adjust the parameters of the WSVR-based FNN (WSVR-FNN). In the WSVR-FNN, first, the WSVR method with a wavelet kernel function is used to determine the number of fuzzy rules and the initial parameters of FNN. After initialization, the adjustment for the parameters of FNNs is performed by the ARLA. Combining the self-learning ability of neural networks, the compact support of wavelet functions, the adaptive ability of fuzzy logic, and the robust learning capability of ARLA, the proposed FNN has the superiority among the several existed FNNs. To demonstrate the performance of the WSVR-FNN, two nonlinear dynamic plants and a chaotic system taken from the extant literature are considered to illustrate the system identification. From the simulation results, it shows that the proposed WSVR-FNN has the superiority over several presented FNNs even the number of training parameters is considerably small.     

Type-2 fuzzy consensus control of nonlinear multi-agent systems: An LMI approach

This paper considers a class of nonlinear fractional-order multi-agent systems (FOMASs) with time-varying delay and unknown dynamics, and a new robust adaptive control technique is proposed for cooperative control. The unknown nonlinearities of the systems are online approximated by the introduced recurrent general type-2 fuzzy neural network (RGT2FNN). The unknown nonlinear functions are estimated, simultaneously with the control process. In other words, at each sample time the parameters of the proposed RGT2FNNs are updated and then the control signals are generated. In addition to the unknown dynamics, the orders of the fractional systems are also supposed to be unknown. The biogeography-based optimization algorithm (BBO) is extended to estimate the unknown parameters of RGT2FNN and fractional-orders. A LMI based compensator is introduced to guarantee the robustness of the proposed control system. The excellent performance and effectiveness of the suggested method is verified by several simulation examples and it is compared with the other methods. It is confirmed that the introduced cooperative controller results in a desirable performance in the presence of time-varying delay, unknown dynamics, and unknown fractional-orders.     

再生混凝土抗压强度的实验研究

定量研究了天然和再生骨料强度、实际水灰比和计算水灰比对混凝土抗压强度的影响。试验结果表明,混凝土抗压强度不仅与水灰比密切相关,而且与骨料压碎指标有关。通过进一步的分析,揭示了混凝土抗压强度与灰水比和骨料压碎指标之间良好线性相关性,并建立起天然与再生骨料混凝土的Bolomey统一公式。     

粉煤灰混凝土抗压性能的试验研究

以C30混凝土为基准,将两种粉煤灰分别按照五种设计掺量等质量替代水泥,研究粉煤灰对混凝土抗压强度的影响,试验结果表明,掺入的粉煤灰品质及质量不同,对混凝土强度的影响程度不同,粉煤灰混凝土的前期强度增长较弱而后期较强;粉煤灰等质量最佳替代水泥量为30％。     

Disparate delays-induced bifurcations in a fractional-order neural network

The problem of bifurcation for delayed fractional neural networks(FNNs) with single delay has been considerably researched. It is more realistic to portray the dynamical properties of FNNs with multiple delays, but this has been not investigated before. This paper attempts to conduct a research on the stability and bifurcation for a FNN with double delays. The criteria of heterogeneous delays-induced bifurcations are decidedly procured. Then, the influence of solitary delay on the bifurcation point is ulteriorly displayed by delicate computation. It is demonstrated that the stability performance of the proposed FNN can be undermined or enhanced by varying properly time delay. Finally, illustrative examples are addressed to validate the availability of the proposed results.     

努力提升学校科技综合实力创建高水平研究型大学

通过对中国科学技术大学“九五”期间科研工作的全面分析和总结,阐述了努力提升学校科技综合实力,创建高水平研究型大学的具体作法及产生的效果。