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Correlation between Low Tube Voltage in Dual Source CT Coronary Artery Imaging with Image Quality and Radiation Dose 被引量:6
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作者 雷子乔 韩萍 +2 位作者 徐海波 余建明 刘红利 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2014年第4期616-620,共5页
The influence of low tube voltage in dual source CT(DSCT) coronary artery imaging on image quality and radiation dose and its application value in clinical practice were investigated. Totally, 300 cases of chest pai... The influence of low tube voltage in dual source CT(DSCT) coronary artery imaging on image quality and radiation dose and its application value in clinical practice were investigated. Totally, 300 cases of chest pain with low body mass index(BMI 〈18.5 kg/m2) subjected to DSCT coronary artery imaging were prospectively enrolled. The heart rate in all patients were greater than 65/min. The retrospective ECG gated scanning mode and simple random sampling method were used to assign the patients into groups A, B and C(n=100 each). The patients in groups A, B and C experienced 120-, 100-, and 80-kV tube voltage imaging respectively, and the image quality was evaluated. The CT volume dose index(CTDIvol) and dose length product(DLP) were recorded, and the effective dose(ED) was calculated in each group. The image quality scores and radiation doses in groups were compared, and the influence of tube voltage on image quality and radiation dose was analyzed. The results showed that the excellent rate of image quality in groups A, B and C was 95.69%, 94.72% and 96.33% respectively with the difference being not statistically significant among the three groups(P〉0.05). The CTDIvol values in groups A, B and C were 51.35±12.21, 21.28±7.13 and 6.34±3.34 mGy, respectively, with the difference being statistically significant(P〈0.05). The ED values in groups A, B and C were 9.27±1.63, 4.56±2.29 and 2.29±1.69 mSv, respectively, with the difference being statistically significant(P〈0.05). It was suggested that for the patients with low BMI, the application of DSCT coronary artery imaging with low tube voltage can obtain satisfactory image quality, and simultaneously, significantly reduce the radiation dose. 展开更多
关键词 dual source CT coronary angiography TOMOGRAPHY radiation dose low body mass index
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Heat source analyses of dual laser-beam bilateral synchronous welding for T-joint 被引量:4
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作者 占小红 陈洁 +2 位作者 魏艳红 董志波 陈彦宾 《China Welding》 EI CAS 2011年第1期28-33,共6页
The DLBSW( dual laser-beam bilateral synchronous welding) technology of T-type joint has been widely used for the connection of skins and stringers in airplane industry. To understand the thermodynamic and mechanica... The DLBSW( dual laser-beam bilateral synchronous welding) technology of T-type joint has been widely used for the connection of skins and stringers in airplane industry. To understand the thermodynamic and mechanical behavior of this process, it is necessary to establish a reasonable heat source model. Two different surface-body combination heat source models are adopted in this paper. Both models use the Gaussian surface heat source model and one is combined with the cone body heat source model and the other is combined with Gaussian rotator body heat source model. The simulation results of these two different models are investigated. And the temperature field results of DLBSW process for T-joint with two different heat sources are discussed. It is indicated that the combination heat source model is effective to simulate the DLBSW process and the current study is useful for more profound research in this field. 展开更多
关键词 dual laser-beam bilateral synchronous welding heat source model simulation
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Non-enhanced Low-tube-voltage High-pitch Dual-source Computed Tomography with Sinogram Affirmed Iterative Reconstruction Algorithm of the Abdomen and Pelvis 被引量:3
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作者 Hao Sun Hua-dan Xue +5 位作者 Zheng-yu Jin Xuan Wang Yu Chen Yong-lan He Da-ming Zhang Liang Zhu 《Chinese Medical Sciences Journal》 CAS CSCD 2014年第4期214-220,共7页
Objective To investigate the image quality, radiation dose and diagnostic value of the low-tube-voltage high-pitch dual-source computed tomography(DSCT) with sinogram affirmed iterative reconstruction(SAFIRE) for non-... Objective To investigate the image quality, radiation dose and diagnostic value of the low-tube-voltage high-pitch dual-source computed tomography(DSCT) with sinogram affirmed iterative reconstruction(SAFIRE) for non-enhanced abdominal and pelvic scans. Methods This institutional review board-approved prospective study included 64 patients who gave written informed consent for additional abdominal and pelvic scan with DSCT in the period from November to December 2012. The patients underwent standard non-enhanced CT scans(protocol 1) [tube voltage of 120 k Vp/pitch of 0.9/filtered back-projection(FBP) reconstruction] followed by high-pitch non-enhanced CT scans(protocol 2)(100 k Vp/3.0/SAFIRE). The total scan time, mean CT number, signal-to-noise ratio(SNR), image quality, lesion detectability and radiation dose were compared between the two protocols. Results The total scan time of protocol 2 was significantly shorter than that of protocol 1(1.4±0.1 seconds vs. 7.6±0.6 seconds, P<0.001). There was no significant difference between protocol 1 and protocol 2 in mean CT number of all organs(liver, 55.4±6.3 HU vs. 56.1±6.8 HU, P=0.214; pancreas, 43.6±5.9 HU vs. 43.7±5.8 HU, P=0.785; spleen, 47.9±3.9 HU vs. 49.4±4.3 HU, P=0.128; kidney, 32.2±2.3 HU vs. 33.1±2.3 HU, P=0.367; abdominal aorta, 44.8±5.6 HU vs. 45.0±5.5 HU, P=0.499; psoas muscle, 50.7±4.1 HU vs. 50.3±4.5 HU, P=0.279). SNR on images of protocol 2 was higher than that of protocol 1(liver, 5.0±1.2 vs. 4.5±1.1, P<0.001; pancreas, 4.0±1.0 vs. 3.6±0.8, P<0.001; spleen, 4.7±1.0 vs. 4.1±0.9, P<0.001; kidney, 3.1±0.6 vs. 2.8±0.6, P<0.001; abdominal aorta, 4.1±1.0 vs. 3.8±1.0, P<0.001; psoas muscle, 4.5±1.1 vs. 4.3±1.2, P=0.012). The overall image noise of protocol 2 was lower than that of protocol1(9.8±3.1 HU vs. 11.1±3.0 HU, P<0.001). Image quality of protocol 2 was good but lower than that of protocol 1(4.1±0.7 vs. 4.6±0.5, P<0.001). Protocol 2 perceived 229 of 234 lesions(97.9%) that were detected in protocol 1 in the abdomen and pelvis. Radiation dose of protocol 2 was lower than that of protocol 1(4.4±0.4 m Sv vs. 7.3±2.4 m Sv, P<0.001) and the mean dose reduction was 41.4%. Conclusion The high-pitch DSCT with SAFIRE can shorten scan time and reduce radiation dose while preserving image quality in non-enhanced abdominal and pelvic scans. 展开更多
关键词 high PITCH dual-source COMPUTED tomography iterative reconstruction imagequality radiation DOSE
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Three Phase Dual Input Direct Matrix Converter for Integration of Two AC Sources from Wind Turbines
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作者 M. Saravanan T. S. Sivakumaran 《Circuits and Systems》 2016年第11期3807-3817,共11页
This project proposes a novel dual-input matrix converter (DIMC) which is used to integrate the output of the wind energy to a power grid. The proposed matrix converter is developed based on the traditional indirect m... This project proposes a novel dual-input matrix converter (DIMC) which is used to integrate the output of the wind energy to a power grid. The proposed matrix converter is developed based on the traditional indirect matrix converter under reverse power flow operation mode, but with its six-switch voltage source converter replaced by a nine-switch configuration followed by the current source inverter (CSI). Matrix electric power conversion topologies and their switch functions are flexible and are used for specific applications. With the additional three switches, the proposed DIMC can provide six input terminals, which make it possible to integrate two independent AC sources from two independent wind turbines into a single grid tied power electronics interface. Commanded currents can be extracted from the two input sources to the grid. The proposed PI control and modulation schemes guaranteed sinusoidal input and output waveforms as well as reduced THD. The simulation results are provided to validate the effectiveness of the proposed control and modulation schemes for the proposed converter. 展开更多
关键词 dual Input Matrix Converter (DIMC) Matrix Converter (MC) Current source Inverter (CSI) Voltage source Converter (VSI)
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Exploration the Method of Low Dose Coronary Artery Imaging with Dual-Source CT
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作者 Zhiwei Huang Bo Xiao Lisha Zhong 《Journal of Biosciences and Medicines》 2013年第1期6-10,共5页
Objective: On the premise that the image quality meets the requirements of clinical diagnosis, we explored the methods to reduce the radiation dose of coronary artery imaging with Dual-Source CT (DSCT). Methods: We ra... Objective: On the premise that the image quality meets the requirements of clinical diagnosis, we explored the methods to reduce the radiation dose of coronary artery imaging with Dual-Source CT (DSCT). Methods: We randomly selected 200 patients with coronary heat disease (BIM 0.05). The average image noise in group A is (41.76 ± 7.98) HU, in group B the average image noise is (43.97 ± 3.88) HU, the dif- ference between the two groups was not statistically significant (P>0.05). The average CTDIvol of group A and B were (20.63 ± 2.24) mGy, (38.11 ± 10.69) mGy, respectively, then P <0.01. The average DLP of group A and B are (235.75 ± 28.64) mGycm and (492.59 ± 125.49) mGycm respectively, then P <0.01, the dif- ference of radiation dose had statistical significance (P<0.05). Conclusions: For coronary artery imaging with DSCT the heart electric pulse (AUTO) regulation technology can meet the diagnostic requirements and effectively reduce the radiation dose. 展开更多
关键词 dual-source CT(DSCT) CORONARY CT ANGIOGRAPHY Low DOSE Noise
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Application of an Advanced Image-Based Virtual Monoenergetic Reconstruction of Dual Source Dual-Energy CT Data at Low keV Increases Image Quality for Esophageal Cancer Patients Imaging
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作者 Shuiqing Zhuo Xiaoling Chen +2 位作者 Jingping Yu Jian Zhou Chuanmiao Xie 《Open Journal of Medical Imaging》 2018年第3期81-88,共8页
Purpose: To explore the significance of dual-source computed tomography (DECT) virtual monoenergetic reconstructions technology in improving the imaging quality of esophageal cancer patients. Materials and methods: 68... Purpose: To explore the significance of dual-source computed tomography (DECT) virtual monoenergetic reconstructions technology in improving the imaging quality of esophageal cancer patients. Materials and methods: 68 patients with clinically suspected esophageal cancer (all confirmed by pathology) were collected. Routine plain scan was performed with SIEMENS Force dual-energy CT and then dual-phase scans were performed. The venous phase images were respectively subjected to traditional virtual monoenergetic reconstructions (Mono_E) and new generation virtual monoenergetic reconstructions (Mono+). Mono_E 55 keV and Mono+ 55 keV virtual single-energy images were obtained respectively. The signal-to-noise ratio (SNR) of normal esophageal tissue and esophageal cancer lesions, noise and contrast noise ratio (CNR tumor) of normal esophageal tissue and esophageal cancer lesions were compared among 100 kV images, Mono_E images and Mono+ images. At the same time, two imaging physicians read the films and scored the images of each group by using a 5-point scoring method. Results: Mono+ 55 keV images, SNR, SNRtumor, noise and CNRtumor were statistically different from those of 100 kV images and Mono_E images (P < 0.05). And Mono+ 55 keV images also had the highest subjective score, with statistical significance (P 55 keV images had the best quality. Conclusion: The new generation of virtual monoenergetic reconstructions post-processing (Mono+) could reduce image noise and improve the contrast between esophageal cancer lesions and normal esophageal tissues, which was of great significance to improve the imaging quality of esophageal cancer patients and improve the early detection rate of esophageal cancer. 展开更多
关键词 dual-source dual-ENERGY VIRTUAL Monoenergetic RECONSTRUCTIONS COMPUTED Tomography ESOPHAGEAL Cancer
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Dose Efficiency in Dual Source High-Pitch Computed Tomography of the Chest
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作者 Boris Bodelle Thomas Lehnert +2 位作者 Martin Beeres Thomas Josef Vogl Boris Schulz 《Advances in Computed Tomography》 2014年第4期51-58,共8页
Objectives: Evaluation of radiation efficiency of dual source high-pitch (DSHP) chest CT in comparison to single source technique with special regards to individual patient anatomy. Methods: 150 consecutive patients w... Objectives: Evaluation of radiation efficiency of dual source high-pitch (DSHP) chest CT in comparison to single source technique with special regards to individual patient anatomy. Methods: 150 consecutive patients who underwent chest CT with automated tube current modulation were evaluated retrospectively and divided into three study groups, each with an equal quantity of 50 patients (DSHP vs. single source 128 slices vs. single source 16 slices). By using a dedicated workstation, volumetric analyses of each of the scanned anatomic area were performed and correlated to the individual dose length product (DLP). The calculated result was defined as dose efficiency. Results: DLP was 203 mGycm (DSHP), vs. 269 mGycm (single source) vs. 273 mGycm (16 slice CT). The total patient volume was lowest in the dual source group with 18956.3 cm3 (vs. 22481.2 cm3 vs. 22133.8 cm3). With regards to the DLP, the calculated dose efficiency of dual source CT was better than the 128 slice CT (p = 0.045) and the 16 slice CT (p < 0.01). Conclusions: DSHP CT has considerably better dose efficiency compared to 16 slice CT. Compared to 128 slice single source technique, the high-pitch mode does not cause any dose penalty when performing chest CT. 展开更多
关键词 COMPUTED Tomography LUNG Radiation Exposure Imaging dual-source
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Significance of an Advanced Image-Based Virtual Monoenergetic Reconstruction of Dual Source Dual-Energy CT Data at Low keV Increases Image Quality for Portal Vein System of Pancreatic Cancer Patients
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作者 Shuiqing Zhuo Sihui Zeng +1 位作者 Jingping Yu Lizhi Liu 《Journal of Cancer Therapy》 2018年第10期827-837,共11页
Purpose: To explore the significance of dual-source computed tomography (DECT) virtual monoenergetic reconstructions technology in improving image quality for portal vein system of pancreatic cancer patients. Material... Purpose: To explore the significance of dual-source computed tomography (DECT) virtual monoenergetic reconstructions technology in improving image quality for portal vein system of pancreatic cancer patients. Materials and methods: 47 patients with clinically suspected pancreatic cancer (all confirmed by pathology) were collected. Routine plain scan was performed with Siemens Force dual-source dual-energy CT followed by 3 scans respectively carried out in arterial phase, portal phase and delayed phase. Traditional virtual monoenergetic reconstructions (Mono_E) and new generation of virtual monoenergetic reconstructions (Mono+) were respectively performed on portal vein images to obtain virtual single energy images including Mono_ E70 keV, Mono_E 55 keV and Mono+ 70 keV and Mono+ 55 keV. The signal-to-noise ratio (SNR) and noise of portal vein, normal pancreatic tissues and pancreatic lesions of 100 kV, Mono_E and Mono+ images were compared. In addition, the contrast noise ratio of portal vein and lesions as well as pancreatic tissues and lesions (CNR PV, CNRtumor) were also compared. At the same time, two imaging physicians with rich clinical experiences read the films and scored the images of each group by using the 5-point scoring method. Results: Mono+ 55 keV images including SNRpv, SNRpanc, SNRtumor, Noise, CNRpv, CNRtumor were statistically different from 100 KV images and Mono_E images (P < 0.05). As for the subjective score, Mono+ 55 keV image score also had the highest score, which had statistical significance (P < 0.05). The results showed that Mono+ 55 keV images had the best quality. Conclusion: The new generation of virtual Mono+ post-treatment can reduce image noise. Low energy Mono+ images can improve the contrast between pancreatic cancer lesions and portal of pancreatic cancer patients. 展开更多
关键词 dual-source VIRTUAL Monoenergetic RECONSTRUCTIONS Computed Tomography PANCREATIC Tumors Portal VEIN SYSTEM CT Angiography Image Quality
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Application of Dual-Source CT TurboFlash Coarse Pitch Scanning in Coronary Artery Imaging
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作者 Shuiqing Zhuo Xiaoling Chen +3 位作者 Jingping Yu Haoqiang He Guixiao Xu Chuanmiao Xie 《Open Journal of Medical Imaging》 2018年第3期64-72,共9页
Objective: To compare and analyze the image quality and radiation dose of three scanning modes of dual-source CT coronary artery retrospectively, and to discuss the application value of TurboFlash coarse pitch scannin... Objective: To compare and analyze the image quality and radiation dose of three scanning modes of dual-source CT coronary artery retrospectively, and to discuss the application value of TurboFlash coarse pitch scanning mode. Methods: The imaging data of 100 patients who underwent CT coronary angiography (CCTA) using Siemens force CT retrospective gated triggering spiral scan (RES-SPIRAL), adaptive prospective gated triggering sequence scan (SEQ) and prospective coarse pitch scan (TurboFlash) retrospectively was collected. The image quality was evaluated by objective and subjective methods. The effective radiation dose of patients was compared and analyzed, and the indications of the three scanning modes were analyzed. The application value of dual-source CT TurboFlash coarse pitch scanning in coronary artery imaging was evaluated. Results: The results showed that the left main coronary artery, the right coronary artery and their tertiary branches could be clearly displayed in the three groups of images: the left anterior descending branch, the left circumflex branch, and their three-level branches. There was no statistical difference in subjective image quality among the three groups of pictures (P > 0.05). There was no statistical difference in objective evaluation indexes, such as CT value, SNR, CNR and Noise among the three groups (P > 0.05). The patient radiation dose results showed that the effective radiation dose ED of RES-SPIRA scan was (9.22 ± 1.33) mSv. The dose of SEQ was (2.88 ± 2.47) mSv, and the dose of TurboFlash was (0.51 ± 0.16) mSv. There was significant difference in comparison of the three groups (P 0.05). RES-spiral scanning had the highest radiation dose and TurboFlash coarse pitch scanning (TurboFlash) had the lowest radiation dose. Conclusion: TurboFlash coarse pitch scanning is low in dosage, fast in speed and wide in adaptability. It is especially suitable for the elderly, children, coma and other patients who cannot cooperate with breath-holding examination, as well as for the screening and examination of coronary artery diseases in asymptomatic population. Undoubtedly, it is a worthy method of heart coronary artery examination. 展开更多
关键词 dual-source CT CORONARY COMPUTED Tomographic ANGIOGRAPHY Coarse PITCH SPIRAL SCANNING Image Quality Radiation Dose
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Application of Dual-Energy CT Non-Linear Fusion Technology in Improving CTA Image Quality of Renal Cancer 被引量:1
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作者 Shuiqing Zhuo Xiaoling Chen +2 位作者 Jingping Yu Sihui Zeng Lizhi Liu 《Open Journal of Medical Imaging》 2018年第3期73-80,共8页
Objective: To explore the significance of dual-energy CT non-linear fusion technique in improving the quality of CTA image of renal cancer. Methods: The CTA images of 100 patients who had been confirmed by pathology a... Objective: To explore the significance of dual-energy CT non-linear fusion technique in improving the quality of CTA image of renal cancer. Methods: The CTA images of 100 patients who had been confirmed by pathology as renal cancer were collected and were randomly divided into experimental group and control group with 50 cases respectively. The two groups of patients were treated with iodine concentration of 300 mg/ml and 350 mg/ml non-ionic contrast agent, with a dosage of 1.5 ml/kg and an injection rate of 4 ml/s. The contrast agent intelligently tracking method was adopted bolus. The control group used the conventional CTA scanning, with a reference tube voltage/tube current of 100 kv/ref150 mas. The experimental group adopted the double energy scanning, with ball tube A and ball tube B. The reference tube voltage/tube current was 100 kv/ref250 mas and sn150 kv/ref125 mas respectively. The images of the experimental group were non-linear fused to obtain the Mono+ 55 kev single-energy images. The CT value, SNR contrast ratio of the abdominal aorta, renal artery and tumor tissue of the experimental group images and the 100 KV images and the Mono+ 55 kev images of the control group were compared. The objective evaluation and subjective evaluation of the image quality of the three groups of images was performed. Results: The results showed that the 100 kV images of the experimental group were statistically different from those of the control group (P05) in CT value, SNR and CNR (P 0.05). And there was no statistically significant difference between the non-linear fusion single-energy Mono+ 55 kev images and the control group images in CT value, SNR and CNR (P > 0.05). The subjective evaluation of image quality showed that there was no significant difference between Mono+ 55 kev images and control group images, and the quality of Mono+ 55 kev images was higher than that of experimental group 100 kV images. Conclusion: The dual-energy CT non-linear fusion technique can improve the quality of CTA image in patients with renal cancer, and it is possible to obtain high quality CTA images with low iodine concentration contrast agent. 展开更多
关键词 dual-source CT NON-LINEAR FUSION Technology RENAL Cancer COMPUTED Tomographic ANGIOGRAPHY Image Quality
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Dual Power Allocation Optimization Based on Stackelberg Game in Heterogeneous Network with Hybrid Energy Supplies
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作者 Shiyu Ji Liangrui Tang +1 位作者 Mengxi Zhang Shimo Du 《China Communications》 SCIE CSCD 2017年第10期84-94,共11页
In heterogeneous network with hybrid energy supplies including green energy and on-grid energy, it is imperative to increase the utilization of green energy as well as to improve the utilities of users and networks. A... In heterogeneous network with hybrid energy supplies including green energy and on-grid energy, it is imperative to increase the utilization of green energy as well as to improve the utilities of users and networks. As the difference of hybrid energy source in stability and economy, thus, this paper focuses on the network with hybrid energy source, and design the utility of each user in the hybrid energy source system from the perspective of stability, economy and environment pollution. A dual power allocation algorithm based on Stackelberg game to maximize the utilities of users and networks is proposed. In addition, an iteration method is proposed which enables all players to reach the Stackelberg equilibrium(SE). Simulation results validate that players can reach the SE and the utilities of users and networks can be maximization, and the green energy can be efficiently used. 展开更多
关键词 dual power allocation Stackelberg game heterogeneous network hybrid energy source
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安徽省燃气炮人工增雨作业效果综合评估 被引量:1
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作者 杨慧玲 孙跃 +5 位作者 肖辉 曹亚楠 冯亮 冯强 舒未希 朱明佳 《应用气象学报》 CSCD 北大核心 2024年第1期103-117,共15页
选取2021—2023年安徽省81次燃气炮作业的双偏振天气雷达、雨量计等多源观测数据,综合评估燃气炮作业增雨效果并分析可能机理。结果显示:在降水开始前作业个例增雨效果较好,并伴有水平反射率因子Z_(H)、差分反射率Z_(DR)的增加和共极化... 选取2021—2023年安徽省81次燃气炮作业的双偏振天气雷达、雨量计等多源观测数据,综合评估燃气炮作业增雨效果并分析可能机理。结果显示:在降水开始前作业个例增雨效果较好,并伴有水平反射率因子Z_(H)、差分反射率Z_(DR)的增加和共极化相关系数ρ_(hv)的减少;降水开始后作业增雨效果欠佳。使用携带暖云催化剂的燃气炮作业后云体变化主要在零度层以下,且维持时间较短;使用携带冷云催化剂的燃气炮作业后暖云区和冷云区均有明显变化,且作业影响持续时间更长。燃气炮作业过程中雷达速度谱宽增大,可能是作业引起气流涡旋的增加所导致。统计结果显示:增雨的显著性与作业时长呈负相关,作业时长与Z_(DR)增量呈负相关,过量播撒会导致减雨;增雨的显著性与作业前影响区雨量呈负相关;增雨量与Z_(H)、中低层风速、风切变呈正相关,与高层风速呈负相关。 展开更多
关键词 燃气炮 人工增雨 双偏振天气雷达 多源观测
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Head dual energy-computed tomography angiography versus neuro-digital subtraction angiography
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作者 Dan Han Liang Wen Yan Xu 《Neural Regeneration Research》 SCIE CAS CSCD 2010年第24期1910-1914,共5页
Dual-energy X-ray absorptiometry provides two modes of head computed tomography (CT) angiography scanning: neuro-digital subtraction angiography and dual-energy CT angiography (DE-CTA). Previous studies have comp... Dual-energy X-ray absorptiometry provides two modes of head computed tomography (CT) angiography scanning: neuro-digital subtraction angiography and dual-energy CT angiography (DE-CTA). Previous studies have compared image quality, radiation exposure, and bone removal between neuro-digital subtraction angiography and DE-CTA. However, the number of cases was relatively small. The present study examined 300 suspected cases of cerebrovascular disease and observed the methods and duration of post-processing, examination time, and data volume. Results demonstrated similar image quality between the two methods, but lower radiation doses and shorter examination time in DE-CTA. DE-CTA allowed for faster and more stable scanning performance and post-processing methods, facilitating accurate and direct diagnosis of cerebrovascular disease. 展开更多
关键词 tomography X-ray computer dual-source computec/tomography dual-ENERGY neuro- digital subtraction angiography cerebral angiography neural regeneration
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光伏光热联合双源热泵系统运行模式研究(1):最佳切换模式验证 被引量:2
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作者 曲明璐 刘锡荣 +1 位作者 王海洋 张斌 《暖通空调》 2024年第8期67-72,80,共7页
讨论了光伏光热联合双源热泵系统制热运行的最佳切换模式。利用TRNSYS软件建立了仿真模型,对双源(水源、空气源)热泵系统性能系数(COP_(s))进行了计算,提出以某时刻空气源热泵模式或水源热泵模式运行COP_(s)较大者优先运行作为COP_(s)... 讨论了光伏光热联合双源热泵系统制热运行的最佳切换模式。利用TRNSYS软件建立了仿真模型,对双源(水源、空气源)热泵系统性能系数(COP_(s))进行了计算,提出以某时刻空气源热泵模式或水源热泵模式运行COP_(s)较大者优先运行作为COP_(s)切换模式。通过前期实验结果验证了模拟结果的正确性,并与常规的集热水箱温度切换模式进行了对比实验,验证了COP_(s)切换模式的有效性。结果表明,该实验系统以COP_(s)最佳切换模式运行时发电量和发电效率较集热水箱温度切换模式分别提高了5.35%和1.73%,耗电量降低了17.03%,COP_(s)提高了4.91%。 展开更多
关键词 光伏光热 双源热泵 空气源热泵 水源热泵 运行模式 切换模式 系统性能系数(COP_(s))
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Research on Grid Planning of Dual Power Distribution Network Based on Parallel Ant Colony Optimization Algorithm
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作者 Shuaixiang Wang 《Journal of Electronic Research and Application》 2023年第1期32-41,共10页
A distribution network plays an extremely important role in the safe and efficient operation of a power grid.As the core part of a power grid’s operation,a distribution network will have a significant impact on the s... A distribution network plays an extremely important role in the safe and efficient operation of a power grid.As the core part of a power grid’s operation,a distribution network will have a significant impact on the safety and reliability of residential electricity consumption.it is necessary to actively plan and modify the distribution network’s structure in the power grid,improve the quality of the distribution network,and optimize the planning of the distribution network,so that the network can be fully utilized to meet the needs of electricity consumption.In this paper,a distribution network grid planning algorithm based on the reliability of electricity consumption was completed using ant colony algorithm.For the distribution network structure planning of dual power sources,the parallel ant colony algorithm was used to prove that the premise of parallelism is the interactive process of ant colonies,and the dual power distribution network structure model is established based on the principle of the lowest cost.The artificial ants in the algorithm were compared with real ants in nature,and the basic steps and working principle of the ant colony optimization algorithm was studied with the help of the travelling salesman problem(TSP).Then,the limitations of the ant colony algorithm were analyzed,and an improvement strategy was proposed by using python for digital simulation.The results demonstrated the reliability of model-building and algorithm improvement. 展开更多
关键词 Parallel ant colony optimization algorithm dual power sources Distribution network Grid planning
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双源CT电子密度/有效原子序数(Rho/Z)在孤立性肺结节中的诊断价值 被引量:1
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作者 黄梅萍 兰长青 王洁 《现代医用影像学》 2024年第1期43-47,共5页
目的:探讨双源CT(DSCT)双能量技术电子密度/有效原子序数(Rho/Z)在孤立性肺结节中良恶性的诊断价值。方法:回顾性收集130例双能量平扫及增强的孤立性肺结节患者,其中恶性组68例,良性组62例,利用Rho/Z应用程序对平扫及增强静脉期图像进... 目的:探讨双源CT(DSCT)双能量技术电子密度/有效原子序数(Rho/Z)在孤立性肺结节中良恶性的诊断价值。方法:回顾性收集130例双能量平扫及增强的孤立性肺结节患者,其中恶性组68例,良性组62例,利用Rho/Z应用程序对平扫及增强静脉期图像进行评估,记录参数Rho、Z和双能量指数(DEI)值,比较两组间的差异,对于有统计学差异的参数,将绘制受试者工作特性(ROC)曲线,以评估其诊断效能。结果:平扫时,恶性组Rho (31.1±22.33)HU明显高于良性组(24.69±20.91)HU,两组之间存在显著统计学差异(P=0.003<0.05),Z与DEI在两组间差异无统计学意义(P>0.05);增强静脉期,恶性组Rho (35.3±20.85)HU明显高于良性组(24.73±17.93)HU,两组之间可见显著统计学差异(P=0.001<0.05),Z与DEI在两组间差异均无统计学意义(P>0.05)。在两组的鉴别诊断中,平扫及增强静脉期Rho的ROC曲线下面积分别为0.652、0.696。结论:DSCT双能量技术Rho/Z有一定特征,有助于孤立性肺结节的诊断。 展开更多
关键词 双源CT 电子密度 有效原子系数 双能量指数 肺结节
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西门子Force双源CT故障维修案例分析与探讨 被引量:1
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作者 孙小磊 肖吴进 +1 位作者 汪缨 张晖 《中国医疗设备》 2024年第8期177-180,共4页
西门子Force双源CT属于高端CT,设备整体配置高、性能佳、应用范围广、稳定性好,在医院运行中发挥了巨大作用。由于设备使用量大,故障时有发生,且设备集成程度较高、整体维修难度大。本文详细分析了使用过程中发生的水冷系统、患者检查... 西门子Force双源CT属于高端CT,设备整体配置高、性能佳、应用范围广、稳定性好,在医院运行中发挥了巨大作用。由于设备使用量大,故障时有发生,且设备集成程度较高、整体维修难度大。本文详细分析了使用过程中发生的水冷系统、患者检查床、探测器电源3例故障的故障排除过程,并通过更换三通阀、维护升降电机轴承、焊接X10接头解决故障,节省了维修费用,并为同行维修此类故障提供参考。 展开更多
关键词 双源CT 水冷系统 检查床 探测器电源
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光伏光热联合双源热泵系统运行模式研究(2):供暖季系统仿真研究 被引量:1
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作者 曲明璐 白宇森 +1 位作者 闫楠楠 张斌 《暖通空调》 2024年第9期87-92,共6页
使用TRNSYS软件建立了光伏光热-双源热泵(PV/T-DSHP)系统的仿真模型。选取夏热冬冷地区某一近零能耗居住建筑作为研究对象,模拟研究了供暖季PV/T-DSHP系统在COP_(s)切换模式下的运行特性和能耗。结果表明:平均光电效率为15.08%,平均光... 使用TRNSYS软件建立了光伏光热-双源热泵(PV/T-DSHP)系统的仿真模型。选取夏热冬冷地区某一近零能耗居住建筑作为研究对象,模拟研究了供暖季PV/T-DSHP系统在COP_(s)切换模式下的运行特性和能耗。结果表明:平均光电效率为15.08%,平均光热效率为33.05%;水源热泵运行模式下供暖季平均COP为4.55,空气源热泵运行模式下供暖季平均COP为3.19,PV/T-DSHP系统的平均COP_(s)为2.98;供暖季系统自满足率为61%。 展开更多
关键词 光伏光热 双源热泵 水源热泵 空气源热泵 运行模式 近零能耗建筑 性能系数(COP)
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双源CT双能量虚拟平扫对直肠癌壁外血管侵犯的诊断价值
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作者 杨振兴 张宇琦 +5 位作者 刘挨师 吴慧 赵磊 高伟 施琳 郝粉娥 《CT理论与应用研究(中英文)》 2024年第1期42-48,共7页
目的:探讨双源CT双能量虚拟平扫(VNC)对直肠癌壁外血管侵犯(EMVI)的术前诊断价值。方法:选取2019年11月至2021年12月间拟手术治疗的150例直肠癌患者术前行双源CT双能量虚拟平扫,女性64例(42.7%)、男性86例(57.3%),平均年龄为(62.3±... 目的:探讨双源CT双能量虚拟平扫(VNC)对直肠癌壁外血管侵犯(EMVI)的术前诊断价值。方法:选取2019年11月至2021年12月间拟手术治疗的150例直肠癌患者术前行双源CT双能量虚拟平扫,女性64例(42.7%)、男性86例(57.3%),平均年龄为(62.3±11.8)岁。两名高年资影像科医师独立分析术前影像资料(包括ctEMVI情况及有无局部淋巴结浸润和远处转移),判断是否存在术前EMVI。以手术病理结果为金标准,分别评价VNC诊断EMVI的敏感性、特异性、准确性、阳性预测值和阴性预测值并采用受试者操作特征(ROC)曲线下面积评价其诊断效能。结果:150例直肠癌患者中,术后病理证实56例(37.3%)为EMVI阳性,94例(62.7%)为EMVI阴性。医师1对EMVI评价准确性、敏感性、特异性、阳性预测值、阴性预测值分别为86%、80.36%、89.36%、81.82%、88.42%,AUC为0.831(95%CI 0.756~0.905);医师2的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为88.67%、80.36%、93.62%、88.24%、88.89%,AUC为0.870(95%CI 0.802~0.938),医师1与医师2的评估结果一致性较高(k=0.943)。结论:双源CT双能量虚拟平扫对直肠癌EMVI术前评估具有一定的诊断价值。 展开更多
关键词 双源CT 双能量虚拟平扫 直肠癌 壁外血管侵犯
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双源CT在胃肠道穿孔定位诊断的应用
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作者 兰国宾 戴士林 +4 位作者 路凯 郝泽普 郭福庆 王庆海 冯娜娜 《中国CT和MRI杂志》 2024年第10期124-126,共3页
目的 探讨双源CT在胃肠道穿孔定位诊断中的价值。方法选择我院2020年1月至2023年10月临床以胃肠道穿孔收治入院患者共124例,期间都先后进行了腹部X线平片和腹部双源CT检查,针对两种方法诊断的敏感性及定位诊断准确率进行对比研究。结果... 目的 探讨双源CT在胃肠道穿孔定位诊断中的价值。方法选择我院2020年1月至2023年10月临床以胃肠道穿孔收治入院患者共124例,期间都先后进行了腹部X线平片和腹部双源CT检查,针对两种方法诊断的敏感性及定位诊断准确率进行对比研究。结果经手术证实确诊。124例中82例(66.13%)诊断为胃肠道穿孔,其中胃穿孔36例(43.90%),小肠穿孔30例(24.19%),阑尾炎并穿孔6例(4.84%),结肠穿孔10例(8.06%)。双源CT对胃肠道穿孔诊断敏感度为98.78%、准确率为98.39%,均明显高于腹部X线诊断68.29%的敏感度、72.58%的准确率,之间差异明显(P<0.05)。双源CT对胃穿孔、小肠穿孔、阑尾炎并穿孔、结肠穿孔检出率高于腹部X线,双源CT对腹腔游离气体检出率92.68%明显高于腹部X线的54.88%,差异明显(P<0.05)。结论双源CT对胃肠道穿孔有较高的诊断价值,定位准确,值得临床应用。 展开更多
关键词 双源CT 腹部X线平片 胃肠道穿孔
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