sEMG Sensor Using Polypyrrole-Coated Nonwoven Fabric Sheet for Practical Control of Prosthetic Hand

One of the greatest challenges of using a myoelectric prosthetic hand in daily life is to conveniently measure stable myoelectric signals. This study proposes a novel surface electromyography (sEMG) sensor using polypyrrole-coated nonwoven fabric sheet as electrodes (PPy electrodes) to allow people with disabilities to control prosthetic limbs. The PPy electrodes are sewn on an elastic band to guarantee close contact with the skin and thus reduce the contact electrical impedance between the electrodes and the skin. The sensor is highly customizable to fit the size and the shape of the stump so that people with disabilities can attach the sensor by themselves. The performance of the proposed sensor was investigated experimentally by comparing measurements of Ag/AgCl electrodes with electrolytic gel and the sEMG from the same muscle fibers. The high correlation coefficient (0.87) between the two types of sensors suggests the effectiveness of the proposed sensor. Another experiment of sEMG pattern recognition to control myoelectric prosthetic hands showed that the PPy electrodes are as effective as Ag/AgCl electrodes for measuring sEMG signals for practical myoelectric control. We also investigated the relation between the myoelectric signals\u27 signal-to-noise ratio and the source impedances by simultaneously measuring the source impedances and the myoelectric signals with a switching circuit. The results showed that differences in both the norm and the phase of the source impedance greatly affect the common mode noise in the signal

Second-Line Combination Chemotherapy with Docetaxel and Nedaplatin for Cisplatin-Pretreated Refractory Metastatic/Recurrent Esophageal Squamous Cell Carcinoma

Background:There is an urgent need for an effective second-line chemotherapy regimen after failure of the standard cisplatin and 5-fluorouracil therapy.Patients and Methods:This study investigated the efficacy and toxicity of the combination of docetaxel (30 mg/m2) during a 1-hour infusion, followed by nedaplatin (50 mg/m2) during a 2-hour infusion (both drugs were administered on day 1 as an outpatient regimen and repeated every 2 weeks) as second-line chemotherapy for patients with cisplatin-pretreated refractory metastatic/recurrent esophageal squamous cell carcinoma after surgery.Results:Forty-six of the 48 patients (95.8%) were assessable for response. Partial response was confirmed in 13 of 48 cases yielding a response rate of 27.1% (95% confidence interval [CI], 14.5–39.7%). The median overall time to progression and overall survival was 3.1 months (95% CI, 2.3–3.9 months) and 5.9 months (95% CI, 3.9–7.8 months), respectively. The estimate of overall survival at 12 months was 16.7% (95% CI, 6.1–27.2%). Grade 3 anemia leucopenia, grade 4 anemia leucopenia and neutropenia were detected in only 4 (8.7%), 8 (17.4%), and 9 patients (19.6%), respectively.Conclusions:The combination chemotherapy of docetaxel and nedaplatin in the outpatient setting is well tolerated and useful as second-line chemotherapy for cisplatin-pretreated refractory metastatic/recurrent esophageal squamous cell carcinoma

Distributed Aperture Coherence-synthetic Radar Technology

The distributed aperture coherence-synthetic radar could accomplish long-range and high-precision detection performance according to include multi-unit radars and energy synthesize in space. It provides an effective measurement to resolve the contradiction between platform restriction and detection performance. As the new radar has many advantages, such as strong survival ability, high cost-effectiveness ratio, high angular accuracy, strong expandability, and easy realization, it significantly orients the development of radars. In this paper, the operating principle, technical advantage, development of domestic and foreign, and the key technology of the distributed aperture coherence-synthetic radar are illustrated; in particular, the principle verification experiments are also described. Lastly, the future perspective for the development and typical application of this new radar is also discussed

Failure law of floor during strip mining backfill with paste-tailings over confined aquifer: A case study in China mine

To tackle the challenge of extracting residual coal resources in Zhangzhao Coal Mine while preventing floor water inrush, a strip filling mining method has been proposed. A two-step mining approach was designed to ensure roof stability and avoid floor water inrush. The first step involves mining and filling at 15 m intervals, leaving a 20 m strip coal pillar. In the second step, a 20 m strip coal pillar is mined and filled at intervals. To meet the filling mining requirements, tailings and industrial slag are used to create the filling body, designed using a paste ratio test. The optimal ratio for silt has been determined to be 1:5, with a mass concentration of 70 %. Simulation tests were conducted to determine the dynamic failure development of the floor under different advancing footage. The self-designed pressurized water sac was used in the simulation experiment, and the results showed that maximum floor damage occurred at 130 m. Additionally, monitoring stations were installed during mining to track the failure depth of the floor. The research revealed that filling mining significantly reduces the failure depth of the floor and prevents water bursting passages, demonstrating the potential of this method for use under similar conditions. This study provides useful references and recommendations for future mining efforts

Application of the grey theory to dynamic analyses of the Baiquan Spring flow rate in Xinxiang

The Baiquan Spring in Xinxiang has many functions, such as water supply, agricultural irrigation, humanities, tourism and ecology. It is of great significance to study the dynamics of the spring flow rate and establish a dynamic prediction model for the spring water resources evaluation and protection. In order to further study the dynamic characteristics of the Baiquan Spring flow rate in Xinxiang and evaluate karst water resources in the spring area, based on the data of annually measured spring flow rate and annual average precipitation in the spring area from 1964 to 1978, the main influencing factors of the spring flow rate are determined by using the stepwise regression analysis, and a stepwise regression model is established, with remarkable regression effect. On the basis of the stepwise regression analysis, this paper establishes the GM(1, 2) model, NSGM(1, 2) model and GM(0, 2) model for the dynamic prediction of the spring flow rate. The results show that (1) from 1964 to 1978, the Baiquan spring flow rate was mainly controlled by the precipitation in the spring area, and the spring flow rate lagged behind the precipitation for one year, reflecting the dynamic characteristics of the spring water in the natural state. (2) The accuracy levels of the three grey models are the highest (excellent). (3) From 1964 to 1978, the measured discharge of the Baiquan spring ranged from 2.347 to 6.448 m3/s, with an average of 3.904 m3/s. The predicted values of the stepwise regression model range from 1.882 to 6.383 m3/s, with an average of 3.904 m3/s. The predicted value of the GM(1, 2) model varies between 2.327 and 6.448 m3/s, with an average of 3.939 m3/s. The predicted values of the NSGM(1, 2) model range from 2.133 to 6.448 m3/s, with an average of 3.927 m3/s. The predicted values of the GM(0, 2) model range from 1.787 to 6.448 m3/s, with an average of 3.907 m3/s. (4) The average relative errors of the stepwise regression model and the three grey models mentioned above are 7.794%, 7.292%, 7.122% and 7.797% respectively, all of which are less than 10%, indicating that they can be used for dynamic prediction of the spring water. Among them, the NSGM(1, 2) model has a higher accuracy and better fitting to the inflection point of the curve. (5) According to the spring flow rate from 1964 to 2030 predicted by the four models, the exploitation resources of the karst water in the Baiquan spring area should not exceed 1.69 m3/s from the angle of spring protection. The research results can not only provide scientific basis for spring flow dynamic prediction and spring area water resources evaluation, but also provide reference for the study of groundwater dynamics in similar areas

Distribution of the Mesozoic in the continental margin basins of the South China Sea and its petroliferous significance

Based on 40 wells encountering the Mesozoic sedimentary rocks, 52 thousands kilometers of seismic profiles covering most parts of the South China Sea (SCS) and the latest collection of gravity and magnetic data, the distribution of the Mesozoic in the continental margin of South China Sea and the oil and gas exploration prospect are studied. The Mesozoic is distributed in three main areas in the SCS: (1) the area of eastern Pearl River Mouth Basin and Southwest Taiwan Basin, where the Mesozoic buried at 1–3 km deep and 2–8 km thick, is thickest in the Chaoshan Depression and east Dongsha Uplift, and there is a long axis gentle fold in the east of the Pearl River Mouth Basin; (2) Liyue-Palawan Basin area, where the Mesozoic, 2–4 km deep and 2–5 km thick, is thickest in the south depression of the Liyue Basin; (3) Zhongjiannan-Wan'an-western Nanwei Basin area, where the Mesozoic is 3–5 km deep and 2–3 km thick. According to the spatial location relationship between the Mesozoic distribution and deep faults, it is inferred that the Mesozoic distribution is controlled by the eastern Yangjiang-Yitong Shoal fault, Balabac fault and YueDong-Wan'an fault, and affected by the uneven base uplifting and block faulting caused by the Mesozoic Pacific plate subduction to the East Asian continent. The study on the distribution of residual Mesozoic strata, structural traps and source rocks concludes that there are two favorable areas for the Mesozoic hydrocarbon exploration, namely, Chaoshan Depression and Dongsha Uplift in the east of Pearl River Mouth Basin, and south depression in the Liyue Basin. However, the exploration prospect of the Zhongjiannan-Wan'an-western Nanwei Basin area needs further investigation. Key words: South China Sea, continental margin, Mesozoic, fold, source rock, petroleum prospec

A New Logging-While-Drilling Method for Resistivity Measurement in Oil-Based Mud

Resistivity logging is an important technique for identifying and estimating reservoirs. Oil-based mud (OBM) can improve drilling efficiency and decrease operation risks, and has been widely used in the well logging field. However, the non-conductive OBM makes the traditional logging-while-drilling (LWD) method with low frequency ineffective. In this work, a new oil-based LWD method is proposed by combining the capacitively coupled contactless conductivity detection (C4D) technique and the inductive coupling principle. The C4D technique is to overcome the electrical insulation problem of the OBM and construct an effective alternating current (AC) measurement path. Based on the inductive coupling principle, an induced voltage can be formed to be the indirect excitation voltage of the AC measurement path. Based on the proposed method, a corresponding logging instrument is developed. Numerical simulation was carried out and results show that the logging instrument has good measurement accuracy, deep detection depth and high vertical resolution. Practical experiments were also carried out, including the resistance box experiment and the well logging experiment. The results of the resistance box experiment show that the logging instrument has good resistance measurement accuracy. Lastly, the results of the well logging experiment indicate that the logging instrument can accurately reflect the positions of different patterns on the wellbore of the experimental well. Both numerical simulation and practical experiments verify the feasibility and effectiveness of the new method

Stability evaluation of mined-out area and Borehole Grouting Treatment-a case study in China

In consideration of the practical demand for the reuse of mined-out areas as construction land, the assessment of foundation stability over mined-out areas has become a critical issue. Using a goaf in China as an example, this study investigates the overburden structure, void distribution law, and goaf treatment process through theoretical analysis, similar material simulation, and field measurements. The results show that the mining-induced voids in the compression zone are small and stable in distribution, whereas the voids in the tensile zone are subject to mutation, especially under external factors. Therefore, the tensile zone is the key processing position when dealing with long-wall goaf. To ensure accurate evaluation for the different positions of the goaf under the building, various methods are proposed. The compression zone in the middle of the goaf is evaluated using the additional stress method, which is modified under the grouting condition through theoretical analysis. The boundary tensile area is evaluated based on the inclination angle of the first key block of the masonry beam, ensuring evaluation accuracy. Furthermore, a void distribution model of longwall goaf is established. Under the guidance of the theoretical model, the goaf is reinforced by grouting and the optimal design of grouting materials is carried out. The final grouting test results show that the average strength of the gob after grouting treatment is high, which can ensure the stability of the gob, and the grouting treatment effect is good. This study provides a theoretical foundation and practical experience for similar goaf grouting treatments