期刊文献+
共找到498篇文章
< 1 2 25 >
每页显示 20 50 100
Assessment of flexural properties of different grade dimension lumber by ultrasonic technique 被引量:2
1
作者 江京辉 吕建雄 +2 位作者 任海青 龙超 骆秀琴 《Journal of Forestry Research》 SCIE CAS CSCD 2007年第4期305-308,共4页
The dimension lumber (45mm×90mm×3700mm) of plantation Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) was graded to four different classes as SS, No. 1, No.2 and No.3, according to national lumber ... The dimension lumber (45mm×90mm×3700mm) of plantation Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) was graded to four different classes as SS, No. 1, No.2 and No.3, according to national lumber grades authority (NLGA) for structure light framing and structure joists and planks. The properties of apparent density was determined at 15% moisture content, bending strength and stiffness were tested according to American Society for Testing and Materials (ASTM) D198-99, and dynamic modulus of elasticity (Eusw) was measured by ultrasonic technique, for predicting the flexural properties of different grade lumbers. The results showed that Eosw was larger than the static MOE. The relationship between Eusw and static MOE was significant at 0.01 level, and the determination coefficients (R2) of the four grade lumbers followed the sequence as R^2No.2 (0.616)〉 R^2ss (0.567)〉 R^2No1 (0.366)〉 R^2No.3 (0.137). The R^2 of Fusw and MOR were lower than that of the Etru and MOR for each grade. The Eusw of all the grade lumbers, except No.3-grade, had significant correlation with the static MOE and MOR, thus the bending strengthof those grade lumbers can be estimated by the E The Etru valuesof four grade lumbers followed a sequence as No.2-grade (10.701 GPa) 〉 SS-grade (10.359 GPa) 〉 No.l-grade (9.840 GPa) 〉 No.3-grade (9.554 GPa). For the same grade dimension lumber, its Eusw value was larger than static MOE. Mean values of MOR for four grade lumbers follow a sequence as No.2-grade (48.67 MPa) 〉 SS-grade (48.16 MPa) 〉 No.3-grade (46.55 MPa) 〉 No. 1-grade (43.39MPa). 展开更多
关键词 dimension lumber Lumber grade Ultrasonic technique Dynamic modulus of elasticity Static modulus of elasticity Modulus of rupture
下载PDF
On the Techniques of Communicative Dimensional Transformation Between Hypotaxis and Parataxis in Tourist Publicity C-E Translation
2
作者 肖付良 《大学英语教学与研究》 2016年第1期49-50,共2页
Communicative dimension,as one of the three key dimensions of eco-translatology,plays a very important role in translating tourist publicity materials.With the communicative dimensional transformation techniques of pa... Communicative dimension,as one of the three key dimensions of eco-translatology,plays a very important role in translating tourist publicity materials.With the communicative dimensional transformation techniques of parataxis and hypotaxis,translators should exert their subjectivity and creativity to achieve in maximizing the degree of holistic adaptation and selection for achieving successful translations. 展开更多
关键词 大学 英语 课外阅读 阅读材料
下载PDF
Multiple Dimensions Convey Design and Application in CIS based on CG Technique
3
作者 Weijun Yu 《International Journal of Technology Management》 2015年第1期97-99,共3页
In the art design field, CG technique has been applied in many aspects like third dimension graphical display, human-computer interaction, virtual reality, three-dimensional cartoon and so on. In the meanwhile, the ap... In the art design field, CG technique has been applied in many aspects like third dimension graphical display, human-computer interaction, virtual reality, three-dimensional cartoon and so on. In the meanwhile, the applications reflected in art design was appeared in computer assisted convey design, bothway or multi-ways interactive convey design and multimedia convey design. Computer assisted convey design included the application of the most CG technique in visual. Interactive convey design reflected interaction, which was the most obvious character of CG. However, multimedia convey design was used not only in CG technique, but also in digital media techniaue. 展开更多
关键词 CG technique Human-computer interaction Multiple dimensions Convey design CIS
下载PDF
On the Transformation Techniques of Hypotaxis and Parataxis in Tourist Publicity C-E Translation from the Perspective of Linguistic Dimension
4
作者 肖付良 《海外英语》 2016年第3期150-151,共2页
This paper, with its basis on linguistic dimension of eco- translatology, aims to present transformation techniques of parataxis and hypotaxis in translating tourist publicity between Chinese and English. It is hoped ... This paper, with its basis on linguistic dimension of eco- translatology, aims to present transformation techniques of parataxis and hypotaxis in translating tourist publicity between Chinese and English. It is hoped that translators can exert their subjectivity and creativity to achieve the linguistic dimensional transformations of parataxis and hypotaxis to maximize the degree of holistic adaptation and selection for achieving successful translations. 展开更多
关键词 TOURIST PUBLICITY TRANSLATION PARATAXIS HYPOTAXIS linguistic dimension TRANSFORMATION technique
下载PDF
Cultural Dimensional Transformation Techniques of Hypotaxis and Parataxis in Tourist Publicity C-E Translation
5
作者 肖付良 《海外英语》 2015年第23期183-184,共2页
In order to make foreign tourists familiar with China's scenic spots, it is necessary that tourist publicity materials are properly translated. Cultural dimension, as one of the three key dimensions of eco-transla... In order to make foreign tourists familiar with China's scenic spots, it is necessary that tourist publicity materials are properly translated. Cultural dimension, as one of the three key dimensions of eco-translatology, plays a very important role in translating. With its basis on cultural dimension of eco- translatology, this paper aims to present transformation techniques of parataxis and hypotaxis between Chinese and English. It is suggested that, with the cultural dimensional transformation techniques of parataxis and hypotaxis, translators should exert their subjectivity and creativity to achieve in maximizing the degree of holistic adaptation and selection for achieving successful translations. 展开更多
关键词 TOURIST PUBLICITY materials TRANSLATION PARATAXIS HYPOTAXIS cultural dimension TRANSFORMATION techni
下载PDF
Experiences with Rice Grown on Permanent Raised Beds: Effect of Crop Establishment Techniques on Water Use, Productivity, Profitability and Soil Physical Properties 被引量:1
6
作者 R.K.NARESH S.S.TOMAR +5 位作者 Dipender KUMAR Samsher Purushottam S.P.SINGH Ashish DWIVEDI Vineet KUMAR 《Rice science》 SCIE 2014年第3期170-180,共11页
In recent years, conventional rice production technologies have been leading to deterioration of soil health and declining farm profitability due to high inputs of water and labor. Conservation agriculture (CA) base... In recent years, conventional rice production technologies have been leading to deterioration of soil health and declining farm profitability due to high inputs of water and labor. Conservation agriculture (CA) based resource-conserving technologies i.e. zero-tillage (ZT), raised-bed planting and direct-seeded rice (DSR) have shown promise as alternatives to conventional production technologies to overcome these problems. Present study was undertaken during 2009-2012 to establish an understanding of how permanent raised bed cropping system could be practiced to save water at the field application level to improve water productivity and also have the capability to enhance productivity, profitability and soil physical quality. The results showed that among different crop establishment techniques, conventional-tilled puddle transplanted rice (CT-TPR) required 14%-25% more water than other techniques. Compared with the CT-TPR system, zero till direct-seeded rice (ZT-DSR) consumed 6%-10%less water with almost equal system productivity and demonstrated higher water productivity. Wide raised beds saved about 15%-24% water and grain yield decrease of about 8%. Direct-seeded rice after ZT or reduced tillage or on unpuddled soil provided more net income than CT-TPR. The CT-TPR system had higher bulk density and penetration resistance due to compaction caused by the repeated wet tillage in rice. The steady-state infiltration rate and soil aggregation (〉 0.25 mm) were higher under permanent beds and ZT and lower in the CT-TPR system. Under CT-TPR, soil aggregation was static across seasons, whereas it improved under no-till and permanent beds. Similarly, mean weight diameter of aggregates was higher under ZT and permanent beds and increased over time. The study reveals that to sustain the rice productivity, CA-based planting techniques can be more viable options. However, the long-term effects of these alternative technologies need to be studied under varying agro-ecologies in western Uttar Pradesh, India. 展开更多
关键词 permanent raised bed water productivity PROFITABILITY YIELD water saving crop establishment technique
下载PDF
Recognition of the major scattering sources on complex targets based on the high frequency radar cross section integrated calculation technique 被引量:5
7
作者 黄敏杰 吕明云 +1 位作者 黄俊 武哲 《Journal of Shanghai University(English Edition)》 CAS 2009年第4期316-321,共6页
Based on the high frequency (HF) integrated radar cross section (RCS) calculation approach, a technique of detecting major scattering source is developed by using an appropriate arithmetic for scattering distribut... Based on the high frequency (HF) integrated radar cross section (RCS) calculation approach, a technique of detecting major scattering source is developed by using an appropriate arithmetic for scattering distribution and scattering source detection. For the perfect adaptability to targets and the HF of the HF integrated RCS calculation platform, this technique is suitable to solve large complex targets and has lower requirement to the target modeling. A comparison with the result of 2-D radar imaging confirms the accuracy and reliability of this technique in recognition of the major scattering source on complex targets. This technique provides the foundation for rapid integrated evaluation of the scattering performance and 3-D scattering model reconstruction of large complex targets. 展开更多
关键词 stealth technique radar cross section (RCS) scattering center scattering distribution map 2-dimension radar imaging
下载PDF
Review of Dimension Reduction Methods
8
作者 Salifu Nanga Ahmed Tijani Bawah +5 位作者 Benjamin Ansah Acquaye Mac-Issaka Billa Francis Delali Baeta Nii Afotey Odai Samuel Kwaku Obeng Ampem Darko Nsiah 《Journal of Data Analysis and Information Processing》 2021年第3期189-231,共43页
<strong>Purpose:</strong><span style="font-family:;" "=""><span style="font-family:Verdana;"> This study sought to review the characteristics, strengths, weak... <strong>Purpose:</strong><span style="font-family:;" "=""><span style="font-family:Verdana;"> This study sought to review the characteristics, strengths, weaknesses variants, applications areas and data types applied on the various </span><span><span style="font-family:Verdana;">Dimension Reduction techniques. </span><b><span style="font-family:Verdana;">Methodology: </span></b><span style="font-family:Verdana;">The most commonly used databases employed to search for the papers were ScienceDirect, Scopus, Google Scholar, IEEE Xplore and Mendeley. An integrative review was used for the study where </span></span></span><span style="font-family:Verdana;">341</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> papers were reviewed. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The linear techniques considered were Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Singular Value Decomposition (SVD), Latent Semantic Analysis (LSA), Locality Preserving Projections (LPP), Independent Component Analysis (ICA) and Project Pursuit (PP). The non-linear techniques which were developed to work with applications that ha</span></span><span style="font-family:Verdana;">ve</span><span style="font-family:Verdana;"> complex non-linear structures considered were Kernel Principal Component Analysis (KPC</span><span style="font-family:Verdana;">A), Multi</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">dimensional Scaling (MDS), Isomap, Locally Linear Embedding (LLE), Self-Organizing Map (SOM), Latent Vector Quantization (LVQ), t-Stochastic </span><span style="font-family:Verdana;">neighbor embedding (t-SNE) and Uniform Manifold Approximation and Projection (UMAP). DR techniques can further be categorized into supervised, unsupervised and more recently semi-supervised learning methods. The supervised versions are the LDA and LVQ. All the other techniques are unsupervised. Supervised variants of PCA, LPP, KPCA and MDS have </span><span style="font-family:Verdana;">been developed. Supervised and semi-supervised variants of PP and t-SNE have also been developed and a semi supervised version of the LDA has been developed. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> The various application areas, strengths, weaknesses and variants of the DR techniques were explored. The different data types that have been applied on the various DR techniques were also explored.</span></span> 展开更多
关键词 dimension Reduction Machine Learning Linear dimension Reduction techniques Non-Linear Reduction techniques
下载PDF
轴压下掺铁尾矿砂和水泥的生土材料细观损伤演化研究
9
作者 张坤 杨文豪 +3 位作者 吕雪瑞 付智勇 芦白茹 杨战社 《新疆大学学报(自然科学版中英文)》 CAS 2024年第4期488-496,共9页
为研究铁尾矿砂改性生土基材料在轴压下的损伤演化性能,采用CT技术,对不同应力状态下材料内部二值化图像进行分析.通过阈值分割,从细观上数值化各应力状态断面图像.研究材料分形维数、孔隙率和应力-应变(ε-σ)曲线演化规律,并阐明材料... 为研究铁尾矿砂改性生土基材料在轴压下的损伤演化性能,采用CT技术,对不同应力状态下材料内部二值化图像进行分析.通过阈值分割,从细观上数值化各应力状态断面图像.研究材料分形维数、孔隙率和应力-应变(ε-σ)曲线演化规律,并阐明材料从受荷直至破坏的细观机理.结果表明:分形维数随受荷增大显著增加,σ=2.38 MPa时,分形维数最大.分形维数的变化趋势可间接表征试件受压时各扫描断面的不规则程度、粗糙度、裂缝与孔隙的发展情况.材料孔隙率随应力增大明显增加.以孔隙率为指标的材料损伤因子变化趋势与孔隙率变化规律相同,可有效反映材料在轴压下的破坏发展规律,也可作为研究改性生土试件损伤演化的定量参数. 展开更多
关键词 计算机断层扫描(CT)技术 改性生土材料 分形维数 孔隙率 损伤因子
下载PDF
云南永胜古滑坡堰塞湖沉积物粒度多重分形特征及其指标适用研究
10
作者 张宇 徐宗恒 +1 位作者 查玲珑 陈云英 《地理科学》 CSSCI CSCD 北大核心 2024年第9期1666-1675,共10页
本文以云南永胜县下院滑坡堰塞湖沉积物为研究对象,依据粒度测试结果采用传统粒度指标与分形理论相结合的方式对其沉积环境进行系统化研究,探讨各传统指标在堰塞湖沉积解析中的适用性,探索多重分形理论在沉积学中的应用价值。研究结果表... 本文以云南永胜县下院滑坡堰塞湖沉积物为研究对象,依据粒度测试结果采用传统粒度指标与分形理论相结合的方式对其沉积环境进行系统化研究,探讨各传统指标在堰塞湖沉积解析中的适用性,探索多重分形理论在沉积学中的应用价值。研究结果表明:①堰塞湖沉积物粒度统计参数明显不同于其他环境下的沉积物,具有河湖相沉积独特的分布曲线形式、分选状态和分形特征。优势粒级在分形计算中起主导地位,全局分形维数与分选系数有着良好的对应关系。不同的分形维数对应着不同的堰塞湖沉积条件,分形维数在堰塞湖粒度解析中有着很好的运用前景;②多重分形结果显示2种不同时期的堰塞湖沉积物均以高聚集度组分为主体,表明粒径分布集中,反映出堰塞湖沉积过程中水动力的稳定性,沉积来源的唯一性,进一步证明了该堰塞湖曾长期存在。细粒组沉积粒径分布范围较窄,分布相对集中,优势粒组多但单个含量低,尾端含量低,内部分异较大;粗粒组分布呈局部集中整体分散的趋势,高聚集度粒组数量少但含量高,低聚集度粒组数量多但单个含量低,呈现中间高,四周低的特点。③多重分形分析表明Δα、Δf在沉积物粒度分析中能够解析粒组内部分布特征,具有传统指标不可替代的作用,D_(0)和D_(1)两者结合可作为沉积环境解析的替代指标,与其他q阶多重分形联合可进一步作为堰塞湖解析指标,而D_(1)/D_(0)和D2则存在一定局限。 展开更多
关键词 堰塞湖沉积 粒度特征 图解法 分形维数 多重分形谱维数
下载PDF
基于点云技术的汽车外廓尺寸测量方法研究 被引量:1
11
作者 叶振洲 骆蕾 +2 位作者 王孖豪 周天龙 李健 《自动化仪表》 CAS 2024年第1期106-110,共5页
针对《机动车安全技术检验项目和方法》(GB 38900—2020)中对于汽车外廓尺寸测量的新要求,采用整车点云数据技术,对牵引车与各类挂车连接后外形上的共性和外廓分割的关键位置进行了研究。通过改进三维点云分割算法,提出一种一并式测量... 针对《机动车安全技术检验项目和方法》(GB 38900—2020)中对于汽车外廓尺寸测量的新要求,采用整车点云数据技术,对牵引车与各类挂车连接后外形上的共性和外廓分割的关键位置进行了研究。通过改进三维点云分割算法,提出一种一并式测量汽车列车和挂车外廓尺寸的测量新方法。该方法可在不改变硬件的前提下,仅通过软件和算法升级,实现一次测量即可测得汽车列车(牵引车、半挂车组合)外廓尺寸参数。以多种结构挂车为试验案例验证了所提方法的可行性,并通过适应性试验分析了所提方法的有效性。研究结果表明,该方法完全能够满足GB 38900—2020中的新增要求,具有广泛的适用性与较高的测量精确度。该方法可将传统方法测量耗时从“小时级”提升为“秒级”,显著提高相关机构的工作效率。 展开更多
关键词 GB 38900—2020 车辆外廓尺寸 点云技术 半挂车 算法分割
下载PDF
基于“三维五法”治疗顽固性面瘫的临床研究 被引量:1
12
作者 杨禾财 赵佳彤 +2 位作者 金永琦 马琳 刘征 《针灸临床杂志》 2024年第7期17-22,共6页
目的:观察“三维五法”治疗周围性顽固性面瘫的临床疗效。方法:40例周围性顽固性面瘫的患者随机分为治疗组20例与对照组20例。治疗组给予“三维五法”操作,对照组采用安慰剂和常规治疗,两组均治疗4周。比较两组治疗后的临床疗效,观察两... 目的:观察“三维五法”治疗周围性顽固性面瘫的临床疗效。方法:40例周围性顽固性面瘫的患者随机分为治疗组20例与对照组20例。治疗组给予“三维五法”操作,对照组采用安慰剂和常规治疗,两组均治疗4周。比较两组治疗后的临床疗效,观察两组House-Brackmann面神经瘫痪分级、面部残疾指数[包括躯体功能(FDIP)和社会生活功能(FDIS)]、患者闭眼时上下眼睑距离、患者健侧与患侧口角距前正中垂线距离差值的变化。结果:治疗组总有效率为90.00%(18/20),明显高于对照组的60.00%(12/20),差异有统计学意义(P<0.05);治疗后,两组H-B评分、FDIS、上下眼睑距离、健侧与患侧口角距前正中垂线距离差值均减小(P<0.05),且治疗组明显优于对照组,差异有统计学意义(P<0.05);治疗后,两组FDIP评分明显增加,差异有统计学意义(P<0.05),且治疗组显著高于对照组,差异有统计学意义(P<0.05)。结论:“三维五法”能有效改善顽固性周围性面瘫患者临床症状,提高面神经传导功能,促进面肌功能恢复,疗效显著。 展开更多
关键词 顽固性面瘫 三维五法 针灸疗法 扎跳法 滞针提拉法 经颅重复针刺刺激疗法
下载PDF
蒸汽发生器传热管的凹痕尺寸测量
13
作者 罗炜 邓道勇 +2 位作者 张立殷 代勤龙 程怒涛 《无损检测》 CAS 2024年第1期51-56,共6页
压水堆核岛主设备蒸汽发生器传热管在制造安装过程中易产生凹痕,要对凹痕进行残余应力分析、壁厚损失计算和运行寿命评估等工作,须获得凹痕的深度、长度和宽度等关键尺寸信息。针对已安装的传热管系密集和蒸汽发生器壳体限制导致凹痕尺... 压水堆核岛主设备蒸汽发生器传热管在制造安装过程中易产生凹痕,要对凹痕进行残余应力分析、壁厚损失计算和运行寿命评估等工作,须获得凹痕的深度、长度和宽度等关键尺寸信息。针对已安装的传热管系密集和蒸汽发生器壳体限制导致凹痕尺寸无法直接测量的问题,提出了一种利用视频内窥镜测量凹痕深度、同轴线圈内穿涡流测量凹痕长度及阵列内穿涡流测量凹痕宽度的方法。该方法为传热管凹痕的定量分析提供了依据,为后续核岛主设备热交换器传热管凹痕质量问题的处理累积了宝贵经验。 展开更多
关键词 传热管 凹痕 尺寸 测量技术
下载PDF
辽西地区大果沙棘繁殖及丰产栽培管理技术
14
作者 车晓芳 《林业勘查设计》 2024年第5期71-74,共4页
为更好地推动辽西地区大果沙棘产业的发展,从播种育苗、嫁接育苗、扦插(硬枝和嫩枝)育苗几个方面总结大果沙棘的繁殖技术要点,从建园选址、科学整地、栽植、土水肥管理、整形修剪以及病虫害防治等方面介绍大果沙棘丰产栽培技术。
关键词 大果沙棘 繁殖 丰产栽培技术 育苗 辽西地区
下载PDF
证候规范化研究的思路和方法探讨 被引量:46
15
作者 郭蕾 张启明 +2 位作者 王永炎 张俊龙 张志斌 《中国中西医结合杂志》 CAS CSCD 北大核心 2006年第3期258-261,共4页
采取“降维降阶”、“升阶升维”的研究思路,既排除非关键因素的干扰,又能真实反映证候的复杂程度,是证候规范化研究的可行途径。借助古代大型医案数据库,对部分证候及其相关因素进行统计分析,采用国际通用的SAS6.12统计软件中的非条件L... 采取“降维降阶”、“升阶升维”的研究思路,既排除非关键因素的干扰,又能真实反映证候的复杂程度,是证候规范化研究的可行途径。借助古代大型医案数据库,对部分证候及其相关因素进行统计分析,采用国际通用的SAS6.12统计软件中的非条件Logistic多元逐步回归方法筛选变量,最终获得回归方程数学模型,表达为logit(p)=α+β1X1+β2X2+…+βmXm。通过该模型的运用和统计数据结果的分析,对具有诊断意义的证候内容进行规范化研究,为证候诊断的规范化提供参考。 展开更多
关键词 证候规范化 降维降阶 升阶升维
下载PDF
1QL-70型固定垄起垄机设计与试验 被引量:30
16
作者 何进 李洪文 +2 位作者 张学敏 李问盈 张喜瑞 《农业机械学报》 EI CAS CSCD 北大核心 2009年第7期55-60,共6页
针对国内西北一年一熟绿洲农业区固定垄保护性耕作起垄机具缺乏的问题,设计了1QL-70型固定垄起垄机。分析和确定了起垄犁、垄面成形装置等关键部件的结构参数。采用熟地型起垄犁,具有较强的翻土和碎土能力;组合式垄面成形装置通过与圆... 针对国内西北一年一熟绿洲农业区固定垄保护性耕作起垄机具缺乏的问题,设计了1QL-70型固定垄起垄机。分析和确定了起垄犁、垄面成形装置等关键部件的结构参数。采用熟地型起垄犁,具有较强的翻土和碎土能力;组合式垄面成形装置通过与圆柱形镇压滚筒配合,在起垄时不仅具有较好的垄面成形能力,而且能对垄床起到很好的镇压作用。田间试验表明:1QL-70型固定垄起垄机的起垄和修垄效果良好,起、修垄作业后垄形尺寸和垄面平整度能较好地满足河西走廊地区的农艺要求。 展开更多
关键词 起垄机 固定垄保护性耕作 修垄 垄形尺寸 设计 试验
下载PDF
贵州省烤烟漂浮育苗技术研究及应用 被引量:9
17
作者 罗勇 李智勇 +2 位作者 李继新 冯勇刚 姜超英 《贵州农业科学》 CAS 北大核心 2011年第12期106-108,共3页
漂浮育苗技术在全省烤烟育苗生产上已全面普及,为了进一步对烟叶生产提供参考,笔者对1997-2011年贵州省烤烟漂浮育苗技术的应用效果、取得的成就、获得的专利、建立的技术体系和管理模式、形成的技术标准和管理标准进行了总结,并针对贵... 漂浮育苗技术在全省烤烟育苗生产上已全面普及,为了进一步对烟叶生产提供参考,笔者对1997-2011年贵州省烤烟漂浮育苗技术的应用效果、取得的成就、获得的专利、建立的技术体系和管理模式、形成的技术标准和管理标准进行了总结,并针对贵州省烤烟漂浮育苗技术应用存在的问题,提出了进一步提升漂浮育苗技术应用的相应对策。 展开更多
关键词 烤烟 育苗技术 漂浮育苗 应用效果 贵州
下载PDF
论“数字城市”及其三维再现关键技术 被引量:89
18
作者 顾朝林 段学军 +2 位作者 于涛方 孙毅中 陈启宁 《地理研究》 CSCD 北大核心 2002年第1期14-24,共11页
“数字城市”是以计算机技术、多媒体技术和大规模存储技术为基础 ,以宽带网络为纽带 ,运用 3S技术、遥测、仿真—虚拟技术等对城市进行多分辨率、多尺度、多时空和多种类的三维描述。通过“数字城市”技术可以将现代城市的信息收集、... “数字城市”是以计算机技术、多媒体技术和大规模存储技术为基础 ,以宽带网络为纽带 ,运用 3S技术、遥测、仿真—虚拟技术等对城市进行多分辨率、多尺度、多时空和多种类的三维描述。通过“数字城市”技术可以将现代城市的信息收集、整理、归纳起来 ,并按照地理坐标建立完整的空间数据模型 ,经过网络联结使每个人都能快速、完整、形象地了解城市的过去、现状和未来。目前国内外“数字城市”研究基本上是停留在软硬环境建设方面 ,至多处于研究的初期阶段 ,并没有在“数字城市”研究方面取得实质性的进展。本文主要探讨我国实现“数字城市”的关键技术 ,诸如 :数字城市空间基础设施、多种GIS系统集成模型研究、 3D GIS、三维城市规划、城市仿真与虚拟现实技术、数字城市支持下的数字社区等等。 展开更多
关键词 “数字城市” 关键技术 三维城市规划 虚拟现实
下载PDF
蚁蛉生物学研究进展 被引量:7
19
作者 黄伯有 苏志坚 +4 位作者 王方海 李广宏 张宣达 周汉辉 庞义 《昆虫知识》 CSCD 北大核心 2008年第5期703-707,共5页
蚁蛉科Myrmeleontidae昆虫的幼虫俗称蚁狮,我国古人很早就将其入药,是一种具有良好开发利用前景的药用昆虫。文章对蚁蛉分类学、生物学、人工饲养、药用价值和杀虫活性物质分离等方面的研究进行综述,以期较全面了解蚁蛉的研究进展,为进... 蚁蛉科Myrmeleontidae昆虫的幼虫俗称蚁狮,我国古人很早就将其入药,是一种具有良好开发利用前景的药用昆虫。文章对蚁蛉分类学、生物学、人工饲养、药用价值和杀虫活性物质分离等方面的研究进行综述,以期较全面了解蚁蛉的研究进展,为进一步研究、开发和利用蚁蛉提供参考。 展开更多
关键词 蚁狮 蚁蛉科 生物学 人工饲养 药用功能
下载PDF
三维电极在水处理中的应用 被引量:11
20
作者 冯国栋 赵卫星 +2 位作者 姜娈 王艳 张来新 《应用化工》 CAS CSCD 2010年第9期1390-1393,1396,共5页
综合近年来国内外有关三维电极水处理技术研究现状和特点,对三维电极在处理染料废水、有机废水、重金属离子废水等方面的应用进行了论述,同时对三维电极与其他技术的联合使用进行了总结,并提出三维电极目前研究存在的问题及今后的研究... 综合近年来国内外有关三维电极水处理技术研究现状和特点,对三维电极在处理染料废水、有机废水、重金属离子废水等方面的应用进行了论述,同时对三维电极与其他技术的联合使用进行了总结,并提出三维电极目前研究存在的问题及今后的研究方向。 展开更多
关键词 三维电极 电化学技术 废水处理
下载PDF
上一页 1 2 25 下一页 到第
使用帮助 返回顶部