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Search Results: 1 - 10 of 44189 matches for " 郑舰艇? "
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bacillaene酮还原酶结构域的异源表达及底物特异性分析
孙潇慧?,车程川?,季俊杰?,舰艇,杨革?
生物工程学报 , 2015, DOI: 10.13345/j.cjb.140580
Abstract: bacillaene生物合成过程中,聚酮合酶第一个延伸模块的酮还原酶结构域(backr1)既催化α酮基的还原,也催化β酮基的还原,具有天然的底物宽泛性。为进一步研究该结构域的底物特异性,在大肠杆菌中对其进行了异源表达。体外酶学分析表明backr1可以催化聚酮类底物(±)-2-甲基-3-氧代戊酸-乙酰半胱胺硫酯外消旋体的立体选择性还原,仅生成4种非对映异构体中的一种,此外backr1还可以催化环己酮和对氯苯乙酮等非聚酮类底物的还原,暗示了聚酮合酶中酮还原酶结构域作为生物催化剂的潜力。
钢筋混凝土长桩双机四点吊吊装方案的研究
甘凤林,孔伟,舰艇
工程力学 , 2003,
Abstract: 主要根据钢筋混凝土长桩吊装的实际工程需要,分析了钢筋混凝土长桩吊装的各种工况,给出了最优吊点的定义.对于桩的水平吊装和旋转吊装,进行了双机四点吊吊点位置的优化,建立了双机四点吊吊装方案的数学模型,编制了微机软件,解决了双机四点吊中的难题.总结了《建筑工程手册》中给出的双机四点吊吊装方案存在的问题,最后文中给出了桩的水平吊装和旋转吊装的通用最优吊点位置.
红外辐射测量系统内外标定技术
王建军,黄晨,高昕,舰艇
红外与激光工程 , 2014,
Abstract: 为确保辐射测量精度,需要对红外辐射测量系统进行标定。在分析红外辐射测量系统工作原理的基础上,提出了内、外标定相结合的标定方法,区别于传统的标定方法,不再把测量系统当作“黑盒子”,而是对其内部分解进行分步标定,通过理论推导给出了内外标定方法计算公式。实验验证表明,该方法的标定精度与传统的全孔径黑体标定方法基本一致,两者之间的相对误差在1%以内,但该方法对外置大孔径面源黑体温度范围要求比较低,降低了黑体的研制难度和成本。
红外星表在地基红外辐射测量系统中的应用
黄晨,王建军,高昕,舰艇
红外与激光工程 , 2013,
Abstract: 国内已知的红外星库数量有限,辐射照度、覆盖波段范围小,分布密集度低,无法满足现有地基红外辐射测量系统天文标定的需要。根据系统的探测波段考察并选取IRAS、2MASS、WISE、AKARI4个全空域巡天计划及其生成的红外星表。综合考虑大气弥散、大气衰减的影响,分析计算系统在短波红外1~3μm、中波红外3~5μm、长波红外8~10μm的极限探测能力及在对应点源星表中的最低可探测的星等。搜索选取可供系统观测的恒星,结果显示在短波选取4599个恒星目标,中波选取125个恒星目标,长波选取1个恒星目标,为我国现有地基红外辐射测量系统天文标定及红外星表进一步应用提供理论依据。
青海三江源玛可河保护分区发现棕腹啄木鸟
陈振宁,鲍敏,舰艇,曾阳,张营,段培
动物学杂志 , 2015, DOI: DOI:10.13859/j.cjz.201501025
Abstract: 2013年4月24日、6月9日和6月27日,在青海省三江源玛可河保护区观察到7只?形目鸟类,经鉴定为棕腹啄木鸟Dendrocoposhyperythrus。该种为青海省鸟类分布新纪录。
“玉米田养鹅”农田生态系统下的土壤温度影响机制
Influence mechanism of the farmland ecosystem of “Raising geese in corn field” on soil temperature

仝淑萍,关法春,舰艇,张宇阳,边步云,程犇
- , 2017,
Abstract: 为了解农牧一体化下"玉米田养鹅"生产模式的土壤温度影响机制,通过对比试验方法进行田间试验,结果表明:玉米田养鹅处理杂草群落平均密度为171.33株/m2,是对照密度(11.11株/m2)的15.42倍,处理间差异极显著(P<0.01;n=9),该处理下杂草Shannon-Wiener多样性指数为1.76,Simpson多样性指数为0.77,均高于对照;玉米田养鹅处理的地上生物量为386.30 g/m2,是对照(5.67 g/m2)的68.13倍,处理间差异极显著(P<0.01;n=9),同时玉米田养鹅处理的盖度为90.56%,是对照(7.22%)的12.54倍,处理间差异极显著(P<0.01;n=9)。在白天土壤温度的变化过程中,玉米田养鹅处理较高的地上生物量和丰富的地表植被使得田间地下生物生理代谢活动旺盛,土壤呼吸作用增强,土壤CO2呼吸通量增加,高达308.64 mg/(m2·h),显著高于对照的234.90 mg/(m2·h)(P<0.05;n=9)。因此,在试验期间白天光照不足,地表接受光照辐射有限的情况下,生物代谢活动产生的热量是影响土壤温度的主导因素,白天的土壤温度高于对照。在夜间土壤温度的变化中,玉米田养鹅处理5~15 cm的土壤含水量为16.14%,显著高于对照1.27%(P<0.05;n=9),水的良好导热能力促进了土壤的散热,使得玉米田养鹅处理表层土壤夜间散热较快,以致夜间该处理下的土壤温度低于对照。因此,在"玉米田养鹅"模式生产过程的前期,生物代谢活动和土壤含水量是影响土壤温度变化的主要因素。
The principle of soil temperature change of agro-pastoral integration was studied in order to clarify factors and mechanism of soil temperature under "Raising geese in corn field" mode.Field experiments were conducted by using comparative method.The results showed that the mean density of weed communities in maize field was 171.33 plants/m2,which was 15.42 times of the control density (11.11 plants/m2),and the difference between treatments was extremely significant (P<0.01;n=9).Shannon-Wiener diversity index was 1.76 and Simpson diversity index was 0.77,which were all higher than those in the control.The above ground biomass of maize field was 386.30 g/m2,which was 68.13 times of control (5.67 g/m2),and the difference between treatments was extremely significant (P<0.01;n=9).The coverage of maize field geese was 90.56%,which was 12.54 times of that of control treatment (7.22%),and the difference between treatments was extremely significant (P<0.01;n=9).The physiologic metabolic activities of underground biota and soil respiration were also enhanced during the daytime soil temperature change due to high above ground biomass and abundant surface vegetation.In addition,soil CO2 flux increased to 308.64 mg/(m2·h),which was 1.31 times higher than that in control (234.90 mg/(m2·h)),and the difference was significant (P<0.05;n=9).During the test period,illumination was poor and surface radiation exposure was limited in the daytime.The light intensity of maize field goose was 5 488.89 Lx,the control treatment was 8 666.67 Lx.Soil temperature was mainly due to the heat generated by bio-metabolic activities,so the soil temperature during the day was higher than that in the control treatment;During night time,the soil water content in the 5-15 cm soil layer was 16.14%,which was significantly higher than that in control 1.27% (P<0.05;n=9).Good thermal conductivity of
玉米田养鹅对土壤理化性状、杂草多样性及玉米生长的影响
Effects of raising geese in cornfield on soil physical and chemical properties,weed diversity and maize growth

舰艇,关法春,仝淑萍,沙志鹏,边步云,程犇
- , 2018,
Abstract: 为探究"玉米田养鹅"对农田生态系统杂草多样性、土壤理化性质及玉米生长状况的影响,以林芝市八一镇章麦村试验田为研究对象,运用对比方法,研究玉米田养鹅 (Raising geese in cornfield,RGC)和对照(Control,CK)土壤理化性质、杂草多样性及玉米生长的异同,旨在通过田间状态的描述和中间状态的研究,为以后优化玉米田调控措施提供依据。结果表明:1)RGC处理有19种杂草,其中以菊科植物最多,对照组仅有9种。不同功能群杂草密度相差很大,双子叶一年生或越年生被子植物功能群杂草密度远远高于其他5种功能群;RGC处理提高了杂草群落Shannon-Wiener和Simpson多样性指数,但降低了Pielou均匀度指数和Margalef物种丰富度指数;2)RGC处理土壤含水率较对照高1.27%,与对照相比差异不显著(P>0.05);3)随着土层加深,RGC和对照土壤紧实度均呈逐渐增加趋势,且RGC对紧实度影响显著;4)对照土壤碱解氮含量为86.48 mg/kg,略高于RGC处理2.67 mg/kg(P>0.05),速效钾含量为161.07 mg/kg,略高于RGC处理28.66 mg/kg(P<0.05),而RGC的土壤中速效磷含量为120.98 mg/kg,是对照(106.25 mg/kg)的1.14倍(P>0.05)。结论:RGC处理增加了农田系统杂草数量、种类和生物量,提高了生物多样性,使土壤紧实度明显减小、土壤含水率增加及土壤养分含量出现差异,且玉米各项农艺性状低于对照。
In order to explore the effects of raising geese in cornfield on weed diversity,soil physical and chemical properties and maize growth status in farmland ecosystem.An experimental plot,which was located in Zhangmai Village,Bayi Town,Linzhi County,was taking as study object to investigate the similarities and differences between raising geese in cornfield (RGC) and control on the biodiversity of weeds in farmland ecosystem,physical and chemical properties of soil and growth of maize.The results showed that:1) RGC had 19 species of weeds,which were mainly composite,while CK had only 9 species.The total weed density of API was 15.42 times as much as that in CK,showing a significant difference (P>0.05).In RGC,the distribution of the dominant weed was considerably large.The number of dicotyledonous angiosperm and annual/biennial was much higher than other five functional groups.2) The soil moisture content of RGC was 1.27% higher than that of the control,which was not significantly different from that of the control (P>0.05);3) With the deepening of soil,the compactness of RGC and CK soil gradually increased,and RGC had a significant effect on soil compactness;4) The content of available nitrogen and K of CK were 86.48 and 161.07 mg/kg,2.67,28.66 mg/kg higher than RGC (P>0.05),but the content of available K in RGC was 120.98 mg/kg,1.14 times as much as CK which was 106.25 mg/kg (P<0.05),the content of available phosphorus in RGC was 120.98 mg/kg,which was 1.14 times of the control (P>0.05).In conclusion,the RGC treatment increased the number,species and biomass of weeds in farmland system,improved biodiversity,reduced soil compaction,increased soil water content and soil nutrient content,and however affected maize plant growth.
异质网络产品的价格变动机理研究综述
The Review on the Price Variation Mechanism of Heterogeneity-Network Products
 [PDF]

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Smart Grid (SG) , 2011, DOI: 10.12677/sg.2011.11008
Abstract: 对于异质市场网络产品价格生成与变动机理的研究是对传统价格理论的完善,同时提供了新的解释价格变动可能影响因素的思路,对于消费者福利的改进、市场环境的完善和政策条件的设计有实践应用价值。
The research on the price and price variation mechanism of heterogeneity-network products is the implement of traditional price theory. It also gives a new explanation on possible impact elements of price variation. It has the practical value on improvement of the consumers’ welfare, the perfection of the market environment and the planning of the political conditions.
基于web服务技术组件库的构建和实现

武汉理工大学学报 , 2004,
Abstract: ?以有效管理已开发的软件组件为目的,在对软件组件进行分类的基础上,构建了一个组件库管理系统,应用web服务技术将该组件库所提供的功能以服务的形式发布到uddi注册中心
一种基于企业级云的云模式构架
A Cloud Computer Architecture Based on Enterprises Cloud
 [PDF]


Computer Science and Application (CSA) , 2012, DOI: 10.12677/CSA.2012.24033
Abstract: 本文提出了一种基于企业级云的云模式构架,目的是为了提出一个适合企业需求的云平台方案。通过对企业级云模式概念的描述、对其难点与关键技术的分析及流程图构建与系统功能分析,给出了该模式的应用框架。
This paper presents a cloud computer architecture based on enterprises cloud. The architecture is suitable for the requirements of the enterprises. Its application framework of is elaborated by description of enterprises cloud notation, analysis of the difficulties and critical technologies, construction of flow chart, and system functional analysis.
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