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合成孔径雷达导引头技术 被引量:21
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作者 高烽 《制导与引信》 2004年第1期1-4,共4页
国外关于合成孔径雷达导引头(SARS),作为精确打击武器末段制导关键装置的报导屡见不鲜;国内雷达导引头设计师们对SARS技术也给予了充分的重视,并开展了相应的研究工作。在综述国外关于SARS报导的基础上,讨论了SARS的技术要点,指出了SAR... 国外关于合成孔径雷达导引头(SARS),作为精确打击武器末段制导关键装置的报导屡见不鲜;国内雷达导引头设计师们对SARS技术也给予了充分的重视,并开展了相应的研究工作。在综述国外关于SARS报导的基础上,讨论了SARS的技术要点,指出了SARS的主要用途。 展开更多
关键词 合成孔径雷达导引 精确打击武器 方位分辨力 搜索雷达导引 作战模式
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Seasonal variation in species composition and abundance of tintinnids in Shantou coastal water,China 被引量:2
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作者 刘华雪 黄良民 +2 位作者 谭烨辉 宋星宇 黄建荣 《Marine Science Bulletin》 CAS 2011年第1期80-86,共7页
Two cruises were conducted to study the composition and seasonal variation of tintinnids (Protozoa: Ciliata) in Shantou coast water dudng spring and fall. Remarkable seasonal variations in environmental parameters,... Two cruises were conducted to study the composition and seasonal variation of tintinnids (Protozoa: Ciliata) in Shantou coast water dudng spring and fall. Remarkable seasonal variations in environmental parameters, and tintinnids composition were observed. Tintinnids samples were enumerated and identified from 5 stations. 14 species belonging to 7 genuses of tintinnids were identified, and the dominate species was Leprotintinnus simple in these season. High tintinnids diversity and low abundance occurred in the fall, and on the contrary, low tintinnids diversity and high abundance occurred in the spring. No significant correlation occurred between tintinnids abundance and nutrients. Tintinnids abundance showed negative relationship with salinity (r2=0.63, P 〈 0.05), maybe this was due to the cold raised water carried sum nutrients rise to the surface water in the fall, rich nutrients and high phytoplankton biomass decrease the importance of tintinnids in the energy flow of aquatic food web. 展开更多
关键词 tinUnnids COMPOSITION DISTRIBUTION Shantou coast
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基于QoS的PQ_SIP协议栈设计
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作者 姜锐 余翔 《计算机工程》 CAS CSCD 北大核心 2009年第2期121-122,132,共3页
针对某些网络对业务和用户划分优先级的问题,该文基于现有会话初始化协议(SIP)栈设计一种支持服务质量(QoS)的PQ_SIP协议栈,并将其应用于某部人民防空应急通信指挥系统中。实践证明,改进后的协议栈能有效提高终端资源的利用率,体现用户... 针对某些网络对业务和用户划分优先级的问题,该文基于现有会话初始化协议(SIP)栈设计一种支持服务质量(QoS)的PQ_SIP协议栈,并将其应用于某部人民防空应急通信指挥系统中。实践证明,改进后的协议栈能有效提高终端资源的利用率,体现用户和数据业务的不同优先级,实现对呼叫和会话有差别的控制。 展开更多
关键词 下一代网络 会话初始化协议 优先级 请求消息 头域
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Ab initio Study on Spectral Properties of Charge-Compensated Ce^3+ in NaF
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作者 马乃玉 杨峰 +2 位作者 沈先春 黄玉成 宁利新 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第5期512-518,I0003,共8页
We report an ab initio〉/I〉 study of spectral properties of Ce^3+ doped at Na+ site of the NaF crys-tal, with the charge imbalance compensated by two oxygen substitutions for fluoride (OF') in the first coordina... We report an ab initio〉/I〉 study of spectral properties of Ce^3+ doped at Na+ site of the NaF crys-tal, with the charge imbalance compensated by two oxygen substitutions for fluoride (OF') in the first coordination shell or two sodium vacancies (VNa') in the second coordination sphere. Density functional theory calculations within the supercell model are first performed to op-timize the local structures of the charge-compensated Ce^3+, based on which Ce-centered embedded clusters are constructed and wave function-based CASSCF/CASPT2/RASSI-SO calculations are carried out to obtain the energies of 4f1 and 5d1 levels. By comparing the calculated 4f→5d transition energies with experimental excitation spectra at low temper-atures, the lowest 4f→5d transition band peaked at 390 nm is assigned to the Ce^3+ with charge compensation by two coordinating OF' substitutions, rather than to the Ce^3+ with compensation by two VNa0 vacancies, as proposed earlier. The electronic reason for the large redshift (by -8000 cm-1) of the lowest 4f→5d transition as induced by the two nearby OF' substitutions is analyzed in terms of the changes in the centroid shift and crystal-field splitting. 展开更多
关键词 Ab initio calculation NaF:Ce3+ Local structure Transition
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Survey of cyanomyovirus abundance in Shantou coastal waters by g20 被引量:1
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作者 李传标 丁俊 +4 位作者 周立镇 张昭 李升康 刘文华 温小波 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第3期604-615,共12页
To understand the genetic diversity and population changes in cyanophages in the coastal waters of Shantou, northeast South China Sea, we used the capsid assembly protein gene g20 as a marker of the abundance and phyl... To understand the genetic diversity and population changes in cyanophages in the coastal waters of Shantou, northeast South China Sea, we used the capsid assembly protein gene g20 as a marker of the abundance and phylogeny of natural cyanomyovirus communities. The abundance of total viruses, heterotrophic bacteria, and picophytoplankton in the coastal waters was monitored with flow cytometry. Hydrological parameters (NO3^-, NO2^-, NH3, soluble reactive phosphorus, total dissolved nitrogen, total dissolved phosphorus, dissolved oxygen, chemical oxygen demand, temperature, salinity, and chlorophyll a concentration) and microbial abundance (total viruses, total bacteria, Prochlorococcus, Synechococcus, and eukaryotes) were measured in the upper and lower layers at four sampling sites in the research area. In the direct viral counts, cyanomyoviruses accounted for 1.92% to 〉10% of the total viral community. A phylogenetic analysis showed that the g20 sequences in the Shantou coastal waters were very diverse, distributed in eight distinct operational taxonomic units, including the newly formed Cluster W. The g20 gene copies inferred from real time PCR assay indicated that cyanomyovimses were correlated significantly with the heterotrophic bacteria numbers and the nitrate and chlorophyll a concentrations. These results suggest that cyanomyoviruses are ubiquitous and are an abundant component of the virioplankton in Shantou coastal waters. 展开更多
关键词 cyanomyovims G20 Shantou coastal water
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Association between Helicobacterpylori, Epstein-Barr virus, human papillomavirus and gastric adenocarcinomas 被引量:6
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作者 Carolina Rosal Teixeira de Souza Marcelli Carolini Alves Almeida +4 位作者 Andre Salim Khayat Emerson Lucena da Silva Paulo Cardoso Soares Luiz Claudio Chaves Rommel Mario Rodriguez Burbano 《World Journal of Gastroenterology》 SCIE CAS 2018年第43期4928-4938,共11页
AIM TO correlate Helicobacter pylori (H. pylorli), EpsteinBarr virus (EBV) and human papillomavirus (HPV) with gastric cancer (GC) cases in Para State, Brazil.METHODS Tissue samples were obtained from 302 gast... AIM TO correlate Helicobacter pylori (H. pylorli), EpsteinBarr virus (EBV) and human papillomavirus (HPV) with gastric cancer (GC) cases in Para State, Brazil.METHODS Tissue samples were obtained from 302 gastric adenocarcinomas. A rapid urease test was used to detect the presence of H. pylori, and the presence of the cagA gene in the HP-positive samples was confirmed by PCR. An RNA in situ hybridization test designed to complement Eberl RNA was used to detect the presence of EBV in the samples, and the L1 region of HPV was detected using nested PCR. Positive HPV samples were genotyped and analyzed for E6 and E7 viral gene expression. Infections were also correlated with the clinical and pathological characteristics of the patients.RESULTS The majority of the 302 samples analyzed were obtained from men (65%) aged 55 years or older (67%) and were classified as the intestinal subtype (55%). All three pathogens were found in the samples analyzed in the present study (H. pylori: 87%, EBV: 20%, HPV: 3%). Overall, 78% of the H. pylori-positive (H. pylorl+) samples were cagA+ (H. pylori-cagA+), and there was an association between the cytotoxic product of this gene and EBV. Coinfections of H. pylori-cagA+ and EBV were correlated with the most advanced tumor stages. Although only 20% of the tumors were positive for EBV, infection with this virus was associated with distant metastasis. Only the HPV 16 and 18 strains were found in the samples, although no expression of the E6 and E7 oncoproteins was detected. The fundus of the stomach was the region least affected by the pathogens.CONCLUSION HPV was not involved in gastric tumorigenesis. Prophy- lactic and therapeutic measures against H. pylori and EBV may prevent the development of GC, especially the more aggressive forms. 展开更多
关键词 Gastric cancer Gastric adenocarcinomas MICROORGANISMS Helicobacter pylori CAGA Epstein-Barr virus Human papillomavirus
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Geomorphic Characteristics of Hillslope and Channelized Debris Flows: A Case Study in the Shitou Area of Central Taiwan 被引量:3
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作者 Jinn-Chyi CHEN Ching-Weei LIN Lung-Chang WANG 《Journal of Mountain Science》 SCIE CSCD 2009年第3期266-273,共8页
The data on the hillslope and channelized debris flows in the Shitou area of central Taiwan occurred during Typhoons Toraji and Nali in 2001 were applied in this paper. The geomorphic parameters, including the flow le... The data on the hillslope and channelized debris flows in the Shitou area of central Taiwan occurred during Typhoons Toraji and Nali in 2001 were applied in this paper. The geomorphic parameters, including the flow length, gully gradient, drainage area and form factor of the debris flows were determined by spatial analysis using a Geographic Information System (GIS) based on the data derived from field investigation, aerial photographs, and topographical maps. According to such determined geomorphic parameters, the threshold conditions and empirical equations, such as the relationship between the gully gradient and drainage area and that between gully length and drainage area and topographic parameter, are presented and used to distinguish the geomorphic characteristics between the channelized and hillslope debris flows. 展开更多
关键词 Hillslope debris flow Channelized debris flow Empirical equation Topographic parameter Central Taiwan China
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China's Service Economy in the Coming Five Years (2011-2015)
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作者 夏杰长 刘奕 李勇坚 《China Economist》 2011年第3期50-55,共6页
This paper suggests that a new approach should be taken for the development of China's service sector. Priorities for this include: appropriate objectives for service sector development, enhanced functionality, inte... This paper suggests that a new approach should be taken for the development of China's service sector. Priorities for this include: appropriate objectives for service sector development, enhanced functionality, integrated development between manufacturing and services, improved regional layout of the service sector, and the emergence of reputable brands and leading enterprises. Well-designed and effective industrial policies, as well as calls for major breakthroughs in institutional mechanisms, must support the development of the service sector. Additionally, excessive burdens and difficult financing channels need to be addressed. More attention should be paid to the construction of the credit system, service standardization, and service statistical accounting as element tasks. 展开更多
关键词 development of the service sector era of service economy servic'e sector policy
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Polydopamine-Assisted Fabrication of Fiber-Optic Localized Surface Plasmon Resonance Sensor Based on Gold Nanoparticles 被引量:1
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作者 苏荣欣 裴哲远 +4 位作者 黄仁亮 齐崴 王梦凡 王利兵 何志敏 《Transactions of Tianjin University》 EI CAS 2015年第5期412-419,共8页
A fast and facile method of fabricating fiber-optic localized surface plasmon resonance sensors baseff on spherical gold nanoparticles was introduced in this study. The gold nanoparticles with an average diameter of 5... A fast and facile method of fabricating fiber-optic localized surface plasmon resonance sensors baseff on spherical gold nanoparticles was introduced in this study. The gold nanoparticles with an average diameter of 55 nm were synthesized via the Turkevich method and were then immobilized onto the surface of an uncladded sensor probe using a polydopamine layer. To obtain a sensor probe with high sensitivity to changes in the refractive index, a set of key optimization parameters, including the sensing length, coating time of the potydopamine layer, and coating time of the gold nanoparticles, were investigated. The sensitivity of the optimized sensor probe was 522.80 nm per refractive index unit, and the probe showed distinctive wavelength shifts when the refractive index was changed from 1.328 6 to 1.398 7. When stored in deionized water at 4 ℃, the sensor probe proved to be stable over a period of two weeks. The sensor also exhibited advantages, such as low cost, fast fabrication, and simple optical setup, which indicated its potential application in remote sensing and real-time detection. 展开更多
关键词 localized surface plasmon resonance SENSOR gold nanoparticles POLYDOPAMINE optimization
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The Importance of Hair Goats in Turkey
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作者 Funda E. Atac Hakan Burcu 《Journal of Agricultural Science and Technology(A)》 2014年第4期364-369,共6页
Of the goat population in Turkey, 98% of the goat population consists of hair goats. They are the prime breeds of goats and they can be bred in the Mediterranean, Aegean and Southeast regions of Turkey. Hair goats are... Of the goat population in Turkey, 98% of the goat population consists of hair goats. They are the prime breeds of goats and they can be bred in the Mediterranean, Aegean and Southeast regions of Turkey. Hair goats are the main income for their breeders. The goats are typically raised in scarce conditions, thus giving rise to greater yield of meat. In spite of the fact that the studies are limited to hair goats bred by the public, in 2005, Republic of Turkey Ministry of Food, Agriculture and Livestock (TAGEM) initiated a countywide reclamation project aiming to identify the regional differences and characteristics of the hair goats. This paper focuses on the yearly quantity of hair goats' produce, particularly observing the proportions of goat milk, meat and other animal produce, and to highlight the importance of the hair goats. Recommendations are made from these findings. 展开更多
关键词 Hair goat population MILK MEAT suggestions.
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Identifying Key Environmental Factors Influencing Spatial Variation of Water Quality in Upper Shitoukoumen Reservoir Basin in Jilin Province,China
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作者 TANG Yanling ZHANG Guangxin +1 位作者 YANG Yuesuo GAO Yingzhi 《Chinese Geographical Science》 SCIE CSCD 2009年第4期365-374,共10页
Based on the observed data in monitored drainage areas and GIS spatial analysis tools,watershed basic database of Shitoukoumen Reservoir Basin was built.The multivariate analysis and redundancy analysis(RDA) were used... Based on the observed data in monitored drainage areas and GIS spatial analysis tools,watershed basic database of Shitoukoumen Reservoir Basin was built.The multivariate analysis and redundancy analysis(RDA) were used to analyze the spatial and temporal variations of water quality,identify the key environmental factors and their patterns influencing the spatial variation of water quality,and determine the main types and forms of the non-point source(NPS) pollutant export controlled by the key environmental factors.The results show that different patterns of environmental factors lead to great changes in water quality at spatial and seasonal scales.All selected environmental factors explain 64.5% and 68.2% of the spatial variation of water quality over dry season and rainy season,respectively,which shows clear seasonal difference.Over dry season,residential land is the most important environmental factor,which possesses 35.4% of the spatial variation,and drainage area is the second key environmental factor,which possesses 17.0% of spatial variation in the total variance.Over rainy season,slope length and drainage area are the key environmental factors,which possess 29.3% of the spatial variation together.Residential land influences nitrogen export by changing NH4+-N and particulate organic nitrogen(PON) discharge over dry season,and drainage area controls phosphorus export by regulating dissolved phosphorus(DP) drainage over dry season and phosphorus associated particulate(PAP) loss over rainy season,respectively.Although slope length is an important environmental factor,it does not influence NPS pollutant export.It is interesting that soil organic matter,as a minor environmental factor,highly determines phosphorus and nitrogen export by enhancing the DP,PAP and PON loss. 展开更多
关键词 non-point source pollution key environmental factor redundancy analysis Shitoukoumen Reservoir
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A Study on Average Velocity Ratios(V_P/V_S) in the Hohhot-Baotou Area
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作者 Han Xiaoming Zhang Fan 《Earthquake Research in China》 2012年第1期118-127,共10页
The geological structure is complex in the Hohhot-Baotou area.Several earthquakes with MS≥6.0 have occurred in the area in history.This article selected the Hohhot-Baotou area as the study region and divided it into ... The geological structure is complex in the Hohhot-Baotou area.Several earthquakes with MS≥6.0 have occurred in the area in history.This article selected the Hohhot-Baotou area as the study region and divided it into 2 sub-regions,each with a spatial scope of 3°×2°,according to the spatial distribution of ML≥1.0 earthquakes occurring between January 2001 and April 2010,and the layout of the seismic network in the study region.Average velocity ratios of respective sub-regions were calculated,and comparative analysis was made on their temporal and spatial variations.Results show that there are slight differences between sub-regions in the variation amplitude of average velocity ratio curves over time,which mostly remains between 2.5% to 2.584%.In the Hohhot area,the average velocity ratio is 1.722,significantly lower than the average velocity ratio of 1.733 in the Baotou area.We preliminarily concluded that this was related to the distribution of fault structures and properties of underground media in the Hohhot area. 展开更多
关键词 Hohhot-Baotou area Average velocity ratio (Vp/Vs) Spatio-temporalanalysis
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基于HTTP协议的隐蔽信道研究 被引量:10
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作者 吴其祥 李祖猛 马华 《信息安全与通信保密》 2009年第1期73-74,77,共3页
HTTP协议是目前Internet上使用最广泛的协议。HTTP协议语法定义较为宽松,并且在HTTP协议定义的许多头域中存在着大量具有随机特性的部分,这就为隐蔽信道的构造提供了条件。论文提出了一种利用Date头域时间值的随机性构造隐蔽信道的思想... HTTP协议是目前Internet上使用最广泛的协议。HTTP协议语法定义较为宽松,并且在HTTP协议定义的许多头域中存在着大量具有随机特性的部分,这就为隐蔽信道的构造提供了条件。论文提出了一种利用Date头域时间值的随机性构造隐蔽信道的思想,实现了一种在大流量载体信息下,利用低带宽隐蔽信道传输任意量隐蔽信息的方法,并分析了该隐蔽信道的性能。 展开更多
关键词 隐蔽信道 HTTP协议 网络安全 Date头域
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Local Structure and Dynamics Procedure of Impurities Fe,Al and Mn in Melt Beryllium
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作者 Zhang Jiqiang Jin Lei +2 位作者 Luo Jiangshan Luo Bingchi Wu Weidong 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2024年第11期3046-3052,共7页
The local structure and dynamics of impurities Fe,Al and Mn in beryllium were investigated on an atomic scale using ab initio molecular dynamics and statistical physics methods.The analysis of the radial distribution ... The local structure and dynamics of impurities Fe,Al and Mn in beryllium were investigated on an atomic scale using ab initio molecular dynamics and statistical physics methods.The analysis of the radial distribution function centered on impurity atoms shows that the density of beryllium atoms around Fe and Mn is 8.4%and 8.6%higher than that around Al,respectively.The statistics of the measure square displacement of impurity atoms show that the diffusion coefficients of Al atoms are 114%and 133%larger than that of Fe and Mn atoms in the melt beryllium,respectively.Statistical analysis of velocity autocorrelation function of impurity atom shows that Fe and Mn atoms collide strongly with beryllium atoms in the first coordination layer,indicating that they are tightly surrounded and bound by the surrounding beryllium atoms in the central position,while the beryllium atoms around Al are loosely arranged and have weak binding forces with Al.The analysis of the activity coefficients of the impurities shows that when Fe or Mn enters the melt beryllium,it reduces the free energy of the system,whereas when Al enters,it increases the system energy.In summary,the interatomic force of BeAl is weak,so they do not form intermetallic compounds,and Al diffuses quickly in beryllium.While BeFe and BeMn have strong interatomic forces,and tend to form more BeFe and BeMn bonds to reduce the free energy of the system,so Fe and Mn diffuse slowly in beryllium.Ab initio molecular dynamics can be used to forecast the best experimental temperature for the vacuum distillation of beryllium. 展开更多
关键词 BERYLLIUM PURIFICATION ab initio molecular dynamics local structure activity coefficients
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IMS网络的消息路由
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作者 曾舒 《广西通信技术》 2012年第4期6-9,22,共5页
IMS作为下一代网络核心方案,已经在运营商层面开始大范围部署。相较于之前的固网软交换和移动软交换而言,新的网络架构中网元的种类和数量都发生了巨大的变化。由于在IMS网络中主要应用到SIP消息,网元之间SIP消息的路由就成了我们关心... IMS作为下一代网络核心方案,已经在运营商层面开始大范围部署。相较于之前的固网软交换和移动软交换而言,新的网络架构中网元的种类和数量都发生了巨大的变化。由于在IMS网络中主要应用到SIP消息,网元之间SIP消息的路由就成了我们关心的一个关键问题。详细介绍了IMS网络中的SIP路由。 展开更多
关键词 IP多媒体子系统 会话发起协议 呼叫会话控制功能 路由 头域
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Effect of Individualized Needling on Gross Motor Function in Cerebral Palsy Infants 被引量:3
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作者 Wang Jun Sun Ke-xing +1 位作者 Wu Xu-bo Han Chou-ping 《Journal of Acupuncture and Tuina Science》 2013年第1期13-18,共6页
Objective: To observe the effect of individualized needling protocol (on the basis of functional brain mapping and standardized syndrome differentiation in Chinese medicine) on gross motor functions of infants with ce... Objective: To observe the effect of individualized needling protocol (on the basis of functional brain mapping and standardized syndrome differentiation in Chinese medicine) on gross motor functions of infants with cerebral palsy (CP) and thus study the innovative means of combining acupuncture with rehabilitation management technique. Methods: A total of 74 CP infants were randomized into a treatment group and a control group, 37 in each group. Combined individualized needling and rehabilitation training were used in the treatment group, versus combined Jin's needling (16 brain-benefiting points) and rehabilitation training in the control group. For both groups, acupuncture treatment was conducted once every other day and rehabilitation training every day. The dynamic changes of gross motor functions before treatment and after every 1-month treatment were measured and assessed using the Gross Motor Function Measure (GMFM)-66. Results: After treatment, the GMFM scores were significantly increased in both groups (P<0.01); there were no between-group statistical differences in increase range of the GMFM scores (P>0.05); the treatment protocol was not interacted with the treatment time; and the GMFM scores for spastic CP infants were better in the treatment group than that in the control group (P<0.05). Conclusion: Combined scalp acupuncture and rehabilitation training can produce positive effects on gross motor functions of CP infants. Individualized needling can obtain better effects than 16 brain-benefiting points in improving the gross motor functions of spastic CP infants. 展开更多
关键词 Scalp Acupuncture Scalp Stimulation Areas Cerebral Palsy SyndromeDifferentiation Treatment Standardization of Syndrome Differentiation Child Preschool
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