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玉米增密度提单产栽培技术探讨
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作者 冯敏 郝晓艳 《中文科技期刊数据库(全文版)农业科学》 2024年第10期0155-0158,共4页
玉米是我国粮食的主要产物之一,它的产量对国家的粮食安全和农业的发展十分重要。玉米增密度提单产栽培技术是指通过提升玉米的种植密度提高玉米产量的种植方法,本文主要通过研究陕西省靖边县的气候和土壤特征,探讨当地玉米高密度种植... 玉米是我国粮食的主要产物之一,它的产量对国家的粮食安全和农业的发展十分重要。玉米增密度提单产栽培技术是指通过提升玉米的种植密度提高玉米产量的种植方法,本文主要通过研究陕西省靖边县的气候和土壤特征,探讨当地玉米高密度种植的方法,讲解技术的实施步骤,对增密度种植技术在我国玉米种植的应用进行了探讨,并提出了一些策略,希望能以此推动玉米种竹的产量提升。 展开更多
关键词 玉米 密度单产 技术
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几种提高居住密度方法的量化评价 被引量:8
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作者 陈昌勇 《城市规划》 CSSCI 北大核心 2010年第5期66-71,共6页
通过数学模型对几种提高居住密度(容积率)方法的效能进行比较、排序,根据结果分析了各种方法的适用范围;通过实际调研进行检验,指出提高居住密度的注意点,研究了提高居住密度的综合方法。
关键词 密度 数学模型 适用范围 量化评价
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Underwater Image Enhancement Based on Multi-scale Adversarial Network
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作者 ZENG Jun-yang SI Zhan-jun 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第5期70-77,共8页
In this study,an underwater image enhancement method based on multi-scale adversarial network was proposed to solve the problem of detail blur and color distortion in underwater images.Firstly,the local features of ea... In this study,an underwater image enhancement method based on multi-scale adversarial network was proposed to solve the problem of detail blur and color distortion in underwater images.Firstly,the local features of each layer were enhanced into the global features by the proposed residual dense block,which ensured that the generated images retain more details.Secondly,a multi-scale structure was adopted to extract multi-scale semantic features of the original images.Finally,the features obtained from the dual channels were fused by an adaptive fusion module to further optimize the features.The discriminant network adopted the structure of the Markov discriminator.In addition,by constructing mean square error,structural similarity,and perceived color loss function,the generated image is consistent with the reference image in structure,color,and content.The experimental results showed that the enhanced underwater image deblurring effect of the proposed algorithm was good and the problem of underwater image color bias was effectively improved.In both subjective and objective evaluation indexes,the experimental results of the proposed algorithm are better than those of the comparison algorithm. 展开更多
关键词 Underwater image enhancement Generative adversarial network Multi-scale feature extraction Residual dense block
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催化裂化装置沉降器藏量失灵原因分析及改进 被引量:5
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作者 于福东 卢亮 李福临 《石油化工设计》 CAS 2011年第1期42-43,47,共3页
针对青岛石油化工有限公司1.4Mt/a催化裂化装置沉降器藏量失灵以及汽提段上部密度大幅度波动的现象,对待生催化剂塞阀以及沉降器藏量的测量进行了考察分析。通过采用改变沉降器藏量正压室引压点位置的措施解决了待生催化剂塞阀误动作以... 针对青岛石油化工有限公司1.4Mt/a催化裂化装置沉降器藏量失灵以及汽提段上部密度大幅度波动的现象,对待生催化剂塞阀以及沉降器藏量的测量进行了考察分析。通过采用改变沉降器藏量正压室引压点位置的措施解决了待生催化剂塞阀误动作以及汽提段上部密度大幅度波动的问题,达到了平稳操作的目的。 展开更多
关键词 催化裂化 密度 沉降器藏量 塞阀
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大港南部油区刚性楔入承压堵漏技术
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作者 何鹏 侯士立 +3 位作者 黄达全 杨俊良 舒儒宏 陈庭贵 《内蒙古石油化工》 CAS 2017年第9期77-79,共3页
枣21断块、官87外围断块馆陶组砾岩、沙河街组生物灰岩玄武岩、孔店组玄武岩、中生界安山岩目的层容易发生漏失,同时井深结构简化表层套管下深浅,导致套管脚处破裂压力小,井口憋堵压力受到限制,达不到地层所需当量密度。为了满足后续固... 枣21断块、官87外围断块馆陶组砾岩、沙河街组生物灰岩玄武岩、孔店组玄武岩、中生界安山岩目的层容易发生漏失,同时井深结构简化表层套管下深浅,导致套管脚处破裂压力小,井口憋堵压力受到限制,达不到地层所需当量密度。为了满足后续固井施工要求,优化了刚性楔入承压堵漏技术配方和施工工艺,并且现场通过提高堵漏泥浆的密度,来降低井口憋堵压力,既能满足地层所需的当量密度,又能防止套管鞋处被压漏。在现场3口井的应用中,均一次承压堵漏成功,节约了堵漏时间,减少堵漏浆消耗量,增强了地层承压能力,满足了后续固井施工的要求。 展开更多
关键词 井漏 堵漏 承压 刚性 提密度 大港南部油区
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Study on Chironomid Larvae Recognition Based on DWT and Improved KNN
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作者 赵晶莹 郭海 孙兴滨 《Agricultural Science & Technology》 CAS 2009年第4期146-149,共4页
A chironomid larvae images recognition method based on wavelet energy feature and improved KNN is developed. Wavelet decomposition and color information entropy are selected to construct vectors for KNN that is used t... A chironomid larvae images recognition method based on wavelet energy feature and improved KNN is developed. Wavelet decomposition and color information entropy are selected to construct vectors for KNN that is used to classify of the images. The distance function is modified according to the weight determined by the correlation degree between feature and class, which effectively improves classification accuracy. The result shows the mean accuracy of classification rate is up to 95.41% for freshwater plankton images, such as chironomid larvae, cyclops and harpacticoida. 展开更多
关键词 Freshwater plankton Chironomid larvae Wavelet decomposition Color features K-Nearest Neighbor (KNN)
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Energy distribution and effective components analysis of 2^(n) sequence pseudo-random signal 被引量:6
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作者 Yang YANG Ji-shan HE Di-quan LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第7期2102-2115,共14页
In order to extract usable harmonics from real 2^(n) sequence pseudo-random data,a technical method is proposed.An equation for predicting the average amplitude of the main frequencies is proposed to guide the choice ... In order to extract usable harmonics from real 2^(n) sequence pseudo-random data,a technical method is proposed.An equation for predicting the average amplitude of the main frequencies is proposed to guide the choice of signal type for different exploration tasks.By the threshold of the amplitude of the transmitted signal,a set of candidate frequencies are first selected.Then,by operating a spectrum envelope method at these candidate frequencies on received data,effective components in data are extracted.A frequency density calculation method is proposed based on a logical number summation method,to reasonably characterize the frequency density in different frequency bands.By applying this method to real data in Sichuan,China,with signal Type 13,75 effective components are extracted,including both main frequencies and harmonics.The result suggests that the number of effective frequencies in the 2^(n) sequence pseudo-random signal can be increased by extracting usable harmonics,without any additional fieldwork. 展开更多
关键词 electromagnetic prospecting 2^(n) pseudo-random signal energy conservation harmonic extraction frequency density
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Hydrodynamics and Lateral Gas Dispersion in a High-Density Circulating Fluidized Bed Reactor with Bluff Internals 被引量:3
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作者 杨艳辉 贾新莉 +1 位作者 魏飞 金涌 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2001年第3期291-296,共6页
Effect of bluff internals on the hydrodynamics and lateral gas mixing was studied in a 0.186m ID high-density riser. With the bluff internals, the extremely non-uniform radial profiles of solid fraction and particle v... Effect of bluff internals on the hydrodynamics and lateral gas mixing was studied in a 0.186m ID high-density riser. With the bluff internals, the extremely non-uniform radial profiles of solid fraction and particle velocity become flat and the dense downflow layer near the wall disappears, indicating the significant enhancement of solid turbulence introduced by the internals. The fluctuation velocity and solid fraction transient signal analysis indicates a significant increase in fluctuation intensity near the wall region. The length influenced by the internals on the flow structure is about 1 meter. The lateral gas dispersion coefficient increases significantly as the bluff internals exist in the riser. 展开更多
关键词 high-density riser bluff internal solid fraction particle velocity transient analysis gas mixing gas dispersion model
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CQSP-3钻井液技术在宁定区块水平井中的应用
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作者 王岗 陈敏杰 《石化技术》 CAS 2017年第9期202-202,共1页
本文从钻井液的润滑性、携岩能力、降滤失效果等方面出发,试验、总结形成了CQSP-3钻井液体系,同时制定出合理的钻井液维护处理方案。
关键词 宁定区块 密度 防塌抑制
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Effects of purified herbal extract of Salvia miltiorrhiza on lipid profile in hyperlipidemic patients 被引量:2
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作者 Zuchang Li Ling Zhu Bin Huang 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2009年第2期99-101,共3页
Background and Objective Hyperlipidemia is one of the most potent and best substantiated risk factors for coronary heart disease (CHD). Purified Salvia miltiorrhiza extract (PSME) had been shown to have hypolipide... Background and Objective Hyperlipidemia is one of the most potent and best substantiated risk factors for coronary heart disease (CHD). Purified Salvia miltiorrhiza extract (PSME) had been shown to have hypolipidemic effect in animal experiments. This study aimed to evaluate its lipids modulating effects in hyperlipidemic patients. Methods In this single-blind, placebo cantrolled study, lipid profiles of 80 hyperlipidemic patients were checked at same conditions. They were divided into two equal groups randomly (each composing of 40 patients). They were given PSME tablet (800 mg) three times per day, or placebo tablet. All patients were put on NCEP type II diet and six weeks later, lipid profiles were checked. Results In PSME group, total cholesterol decreased by 27.32 mg/dl (12.3% reduction), LDL-cholesterol decreased by 23.13 mg/dl (16.8% reduction) and HDL-cholesterol increased by 9.06 mg/dl (11.1%), all were statistically significant. Although triglyceride dropped by 12.12 mg/dl (5.1%) but this was not significant statistically (P=0.34). There were no significant changes oflipids levels in the placebo group. Conclusions PSME has significant favorable effect on total cholesterol, LDL-cholesterol, and HDL-cholesterol and may be a potential agent for the treatment ofatherogenic dyslipidemia. 展开更多
关键词 Hypcrlipidemia Salvia miltiorrhiza randomized trial
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Bone Marrow Mononuclear Cell Extraction. Does the Operator Performance Affect Processing Efficacy?
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作者 Jakobsons Eriks Cakstina Inese +9 位作者 Erglis Kristaps Erglis Martins Pirtniece Liene Elina Krumina NarbuteInga Briede Ieva Jegere Sanda Smolova Rita Muiznieks Indrikis Erglis Andrejs 《Journal of Pharmacy and Pharmacology》 2016年第5期192-198,共7页
Different cell populations from bone marrow are used in various clinical trials for cardiac diseases during last decade. Four clinical studies are on going in our institution and enrol patients with cardiac diseases, ... Different cell populations from bone marrow are used in various clinical trials for cardiac diseases during last decade. Four clinical studies are on going in our institution and enrol patients with cardiac diseases, coronary disease and type 2 diabetes, patients with osteoarthritis. Density gradient is used to separate bone marrow mononuclear cells. Cell processing looses are significant. To find out critical control points we analysed processing process and differences in cell yields between operators performing cell extraction. Bone marrow mononuclear cells were isolated using Ficoll density gradient centrifugation. Cells were counted using flow cytometry for mononuclear cell total counts, CD34+ population count and viability analysis. The patients who underwent bone marrow aspiration followed by cell isolation received cell suspension for transplantation. Two cells processing for separate patients were performed at once. Same standard operation procedures were applied. Processing looses between operators performing cell extraction were analysed. Bone marrow samples from eight patients were processed. Mononuclear cells were extracted. Operator performances were compared. Operator A average bone marrow mononuclear cell yield in starting material was 9,97 ± 9,98 %, CD34+ population yield 75,46±79,67%. Operator B average bone marrow mononuclear cell yield in starting material was 24,68 ± 14,8 %, CD34+ population yield 70,42 ±44.84%. Operator A average cell viability in starting material was 45,24 ± 9,55%, after cell processing 42,96 ± 23,66 %. Operator B average cell viability in starting material was 49,85 ± 5,48%, after cell processing 69,52 ± 6,65 %. 展开更多
关键词 Bone marrow mononuclear cells cell yield cell extraction cell count
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