Analysis on the Structural Type of Large-span Steel Truss Bridge Specially Designed for Cables

When the installation of cables and pipelines needs to go across rivers, bridges are usually adopted to support the cables and pipelines for crossing the rivers. The measure can make full use of the space resources and have no effect on the flow pattern of rivers. For this reason, analysis on the structural-type design of a large-span steel truss bridge specially used for cables has been performed. The numerical results indicate that the stayed-cable bridge with steel truss beam and concrete main tower has better performance and improved structural type caparisoned with that of the beam and arch bridges, and the construction of the major beam can be without the temporary support

The splicing of backscattered scanning electron microscopy method used on evaluation of microscopic pore characteristics in shale sample and compared with results from other methods

The splicing of backscattered scanning electron microscopy (SB-SEM) method was applied to evaluate the microscopic pore characteristics of the Lower Silurian Longmaxi Shale samples from Py1 well in Southeast Chongqing, China. The results from SB-SEM, including frequencies, volumes and specific surface areas of organic and inorganic pores with different sizes, were compared with those of low temperature nitrogen adsorption/desorption (LTNA) and mercury intrusion porosimetry (MIP). The results show that the changes in organic and inorganic surface porosity with increasing image area estimated from the SB-SEM method become almost stable when the SB-SEM image areas are larger than 0.4 mm, which indicates that the heterogeneities of organic and inorganic pore volumes in shale samples can be largely overcome. This method is suitable for evaluating the microscopic pore characteristics of shale samples. Although the SB-SEM underestimates the frequencies, volumes and specific surface areas of pores smaller than its resolution, it can obtain these characteristics of pores larger than 100 nm in width, which are not effectively evaluated by the LTNA method and are underestimated by the MIP method

Evaluating the Performance of Large Language Models on GAOKAO Benchmark

Large language models have demonstrated remarkable performance across various natural language processing tasks; however, their efficacy in more challenging and domain-specific tasks remains less explored. This paper introduces the GAOKAO-Benchmark (GAOKAO-Bench), an intuitive benchmark that employs questions from the Chinese Gaokao examination as test samples for evaluating large language models.In order to align the evaluation results with humans as much as possible, we designed a method based on zero-shot prompts to analyze the accuracy and scoring rate of the model by dividing the questions into subjective and objective types. We evaluated the ChatGPT model on GAOKAO-Benchmark performance.Our findings reveal that the ChatGPT model excels in tackling objective questions, while also shedding light on its shortcomings and areas for improvement. To further scrutinize the model's responses, we incorporate human evaluations.In conclusion, this research contributes a robust evaluation benchmark for future large-scale language models and offers valuable insights into the limitations of such models

Evaluating Hallucinations in Chinese Large Language Models

In this paper, we establish a benchmark named HalluQA (Chinese Hallucination Question-Answering) to measure the hallucination phenomenon in Chinese large language models. HalluQA contains 450 meticulously designed adversarial questions, spanning multiple domains, and takes into account Chinese historical culture, customs, and social phenomena. During the construction of HalluQA, we consider two types of hallucinations: imitative falsehoods and factual errors, and we construct adversarial samples based on GLM-130B and ChatGPT. For evaluation, we design an automated evaluation method using GPT-4 to judge whether a model output is hallucinated. We conduct extensive experiments on 24 large language models, including ERNIE-Bot, Baichuan2, ChatGLM, Qwen, SparkDesk and etc. Out of the 24 models, 18 achieved non-hallucination rates lower than 50%. This indicates that HalluQA is highly challenging. We analyze the primary types of hallucinations in different types of models and their causes. Additionally, we discuss which types of hallucinations should be prioritized for different types of models.Comment: Work in progres

Typical difference analysis and benefit-oriented development countermeasures of normal and high pressure shale gas in southeastern Chongqing

Southeastern Chongqing is located in the transition zone of the southeastern margin of Sichuan Basin. Shale gas reservoirs of normal and high pressure are developed in this area. In order to promote normal pressure shale gas development benefits, starting from the typical difference analysis of normal and high pressure shale gas, through the research of drilling, core observation, experimental analysis, accumulation conditions, and production dynamics, combined with shale gas exploration and development practices in southeastern Chongqing, it is clarified that the normal pressure shale gas has the typical geological characteristics of small thickness of high-quality shale, low porosity, poor preservation conditions, and medium gas content. The accumulation of normal pressure shale gas is controlled by sedimentary facies, preservation conditions, and in-situ stress field. Affected by multi-stage structural transformation and differential uplift, the mechanism of normal pressure shale gas generation is complex, which has the characteristics of low initial production, short stable production period, slow decline, and high flowback rate. There are obvious differences between normal and high pressure shale gas in geological characteristics, enrichment regularities, generation mechanism, and production law. Considering the poor grade of normal pressure shale gas resources in southeastern Chongqing, four key countermeasures for the benefit-based development of normal pressure shale gas are put forward: (1) The basic geological research is furthered and the enrichment regularities and sweet spots are clarified. (2) The development technology of variable well spacing, long horizontal section, small inclined angle, strong transformation, low height difference and controlled pressure difference is established to increase the production of single well. (3) The innovation of engineering technology such as low-cost drilling and efficient fracturing is increased to achieve speed acceleration, efficiency improvement, and cost reduction. (4) The institutional mechanism is innovated and an efficient organization and operation mode is created. The four key countermeasures effectively promote the transformation of normal pressure shale gas from resources to reserves and from reserves to benefits, facilitating the efficient development of normal pressure shale gas in southeastern Chongqing

Non-Contact Monitoring of Human Vital Signs Using FMCW Millimeter Wave Radar in the 120 GHz Band

A non-contact heartbeat/respiratory rate monitoring system was designed using narrow beam millimeter wave radar. Equipped with a special low sidelobe and small-sized antenna lens at the front end of the receiving and transmitting antennas in the 120 GHz band of frequency-modulated continuous-wave (FMCW) system, this sensor system realizes the narrow beam control of radar, reduces the interference caused by the reflection of other objects in the measurement background, improves the signal-to-clutter ratio (SCR) of the intermediate frequency signal (IF), and reduces the complexity of the subsequent signal processing. In order to solve the problem that the accuracy of heart rate is easy to be interfered with by respiratory harmonics, an adaptive notch filter was applied to filter respiratory harmonics. Meanwhile, the heart rate obtained by fast Fourier transform (FFT) was modified by using the ratio of adjacent elements, which helped to improve the accuracy of heart rate detection. The experimental results show that when the monitoring system is 1 m away from the human body, the probability of respiratory rate detection error within ±2 times for eight volunteers can reach 90.48%, and the detection accuracy of the heart rate can reach 90.54%. Finally, short-term heart rate measurement was realized by means of improved empirical mode decomposition and fast independent component analysis algorithm

Multitask Pre-training of Modular Prompt for Chinese Few-Shot Learning

Prompt tuning is a parameter-efficient approach to adapting pre-trained language models to downstream tasks. Although prompt tuning has been shown to match the performance of full model tuning when training data is sufficient, it tends to struggle in few-shot learning settings. In this paper, we present Multi-task Pre-trained Modular Prompt (MP2) to boost prompt tuning for few-shot learning. MP2 is a set of combinable prompts pre-trained on 38 Chinese tasks. On downstream tasks, the pre-trained prompts are selectively activated and combined, leading to strong compositional generalization to unseen tasks. To bridge the gap between pre-training and fine-tuning, we formulate upstream and downstream tasks into a unified machine reading comprehension task. Extensive experiments under two learning paradigms, i.e., gradient descent and black-box tuning, show that MP2 significantly outperforms prompt tuning, full model tuning, and prior prompt pre-training methods in few-shot settings. In addition, we demonstrate that MP2 can achieve surprisingly fast and strong adaptation to downstream tasks by merely learning 8 parameters to combine the pre-trained modular prompts.Comment: Accepted to ACL 2023 (main conference). Code and data are publicly available at https://github.com/Hzfinfdu/MPM

Exploration and development practice of normal pressure shale gas in Dongsheng structural belt, Nanchuan area, southeast Chongqing

The Dongsheng structural belt in Nanchuan area, southeast Chongqing, is located in the transitional zone of the southeastern margin of Sichuan Basin. It has experienced multi-period tectonic reformation and has typical geological characteristics of complex structure, complex preservation conditions and complex in-situ stress field, which leads to a significant difference in single well production. In order to increase the single well production of normal pressure shale gas wells in Dongsheng complex structural belt and realize profitable development, through target processing of seismic data, analysis of structural characteristics, study of accumulation regularity and analysis of production dynamics, as well as the strengthening of basic research and exploration and development practice, four key technical countermeasures for realizing profitable development of normal pressure shale gas in Dongsheng complex structural belt are defined: (1) improve the accuracy of shallow velocity model and structure interpretation; (2) optimize well pattern deployment, increase well-controlled reserves; (3) integrate geology and engineering, and coordinate drilling, orientation and steering to improve the drilling rate of sweet spots; (4) establish a zonal differentiated fracturing scheme to improve fracture complexity. These four countermea-sures provide technical support for the profitable development of normal pressure shale gas in complex structural zones, and provide reference for the exploration and development of other similar areas along the basin margin