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Search Results: 1 - 10 of 75626 matches for " 高维常 "
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种养平衡——农业污染减排模式探讨
,周慧平,
农业环境科学学报 , 2013, DOI: 10.11654/jaes.2013.11.003
Abstract: 种植业与养殖业缺乏协调规划导致“种养分离”日趋明显,由此影响了种养系统间物质循环利用过程,导致畜禽粪便过量对生态环境造成极大危害。为此,从种养系统间物质循环与农业污染之间的内在联系出发,提出“种养平衡”发展模式,分别从以种定养、以养促种的角度探讨了种植业与养殖业平衡发展模式的实现途径:“以种定养”是从种养系统物质循环的角度合理规划养殖规模,防止畜禽粪便过量产出增加环境压力;“以养促种”是通过畜禽粪便无害化处理和科学合理地还田利用等手段,降低畜禽粪便资源化的环境风险。通过建立“以种定养”、“以养促种”的农业生产模式,实现废弃物高效循环利用,降低环境污染风险,从而缓解农业污染减排压力。
Optimal threshold algorithm of EnviSat waveform retracking over coastal sea
近岸海域EnviSat卫星测高波形重定的Threshold 化法算法

郭金运,永刚,晓涛,黄金
地球物理学报 , 2010,
Abstract: Waveform retracking is an effective method to improve the accuracy of sea surface height measurement with the satellite altimetric technique. The improved threshold retracking algorithm is optimized in the paper. Several waveform retracking algorithms are analyzed. Then a waveform retracking system is programmed. Several retracking methods are used to retrack the EnviSat waveform over the Mediterranean Sea. The improved threshold retracking algorithm is the most robust retracking method and more suitable for the EnviSat waveform retracking over the coastal Mediterranean.
伶仃洋三角山以北抛泥区泥沙(推移质)运动及其对航道回淤影响的研究
尹毅,,乃环,陈爱萍,
华东政法大学学报 , 1995,
Abstract: 伴随着国民经济的发展,航运船只的吨位越来越大,航运船只的数量越来越多,珠江口目前所用的伶仃航道与航运业的发展已不相适应,为使大型船只能够直驶黄埔港,促进珠江三角洲经济的发展,国家决定在伶仃洋开辟一条大型航道,并将珠江口航道整治列为国家“八五”重点科技攻关项目.
近岸海域EnviSat卫星测高波形重定的Threshold优化算法
郭金运,永刚,晓涛,黄金
地球物理学报 , 2010, DOI: 10.3969/j.issn.0001-5733.2010.04.005
Abstract: 波形重定是改善近岸海域卫星测高数据精度的一种有效方法.分析了EnviSat雷达测高波形重定算法,并对Threshold算法进行了优化,开发了波形重定程序;以地中海为实验区,利用几种波形重定方法,对近岸海域的EnviSat测高波形进行重定,认为优化的Threshold算法是几种波形重定算法中最稳健的重定算法,适合于地中海近岸海域EnviSat测高波形的重定,对其他近岸海域的应用也有一定的参考意义.
云南沉积型磷矿成矿特征与资源潜力预测
,建国,李云灿,李定平,
地质通报 , 2012,
Abstract: 在典型矿床与区域成矿特征研究的基础上,系统总结云南沉积型磷矿的成矿地质、地球化学和岩相古地理特征,深入分析沉积型磷矿的成矿控制因素,建立了区域成矿模式。在此基础上,运用基于GIS的矿床模型综合地质信息预测方法对云南沉积型磷矿进行综合定位和定量预测,共圈定130个最小预测区,估算未查明的磷矿预测资源量121.98×108t。该成果对云南沉积型磷矿进一步的找矿工作具有重要的指导意义。
半膜覆盖栽培对烤烟生长发育的影响 Effect of semi-film mulching cultivation mode on growth and development of flue-cured tobacco
,胡伟,林叶春,陈伟,潘文杰,王劲,叶浩
- , 2015,
Abstract: 为降低烤烟生产的劳动强度,提高塑料地膜利用效率,通过田间小区试验,研究半膜覆盖栽培模式对烤烟生长发育的影响。结果表明,半膜覆盖栽培能提高植株叶片光能利用效率,半膜全生育期地膜覆盖(T1)与对照(CK)气孔导度(Gs)、胞间CO2浓度(Ci)差异达到显著水平(P<0.05);半膜覆盖栽培能促进植株根系直径增粗、根层下移和植株地上部生长势,移栽后90 d,半膜覆盖栽培平均根系直径比对照增加0.22 mm,与对照呈显著差异(P<0.05),根系下扎深度增加0.05 m,干物质积累量增加46.57 g·plant-1。同时,减少50.00%地膜使用量,降低50.00%的地膜成本,促进作物增产246.01 kg·hm-2,综合实现节本增效4 481.94元·hm-2。半膜覆盖栽培作为新的种植模式,在实现优质烟叶丰产同时,可提高生产效益,减轻地膜对环境污染,促进环境可持续发展,推广应用前景广阔。
井窖风场特征的CFD模拟与验证
CFD simulation and verification of wind field characteristic in transplanting hole

林叶春,,陈懿,陈伟,丁福章,潘文杰
- , 2018,
Abstract: 为明确井窖内部空气受外界气流的影响及井窖维持适宜水热条件的机制,通过建立未移栽作物条件下井窖的三维数值模拟模型,利用CFD计算流体力学软件分析在1.50、2.70和3.90 m/s近地表风速条件下,对井窖内部空气流速和流向进行数值模拟计算,并进行试验验证。模拟试验结果表明:近地表风速设为1.50、2.70和3.90 m/s时,模拟的井窖纵切面平均空气流速分别为0.25、0.48和0.72 m/s,井窖内的平均空气流速较近地表下降81.54%~83.34%;近地表风向由右向左时,井窖内纵切面的空气呈逆时针流动。验证试验结果表明:井窖内空气流速与地表风速成线性相关,模拟方程为y=0.220 9 x-0.176(R2=0.925 3);近地表风速为2.70 m/s时,井窖内实测空气流速为0.42 m/s,模拟值为0.48 m/s。井窖内部空气受外界大气扰动较弱,减少热量和水分向外散失,有利于保持烟苗生长适宜的水热条件。
In order to clarify the mechanism of suitable water and heat conditions in transplanting hole,this study analyzed the effects of the wind speed near the soil surface on air velocity in the transplanting hole.Based on the three-dimensional numerical simulation model of transplanting hole under the condition of no crops planted,CFD software was used to simulate the internal airflow in the transplanting hole at 1.50,2.70 and 3.90 m/s,respectively.The flow velocity was verified by experimental test.The simulation results showed that the average air speed of the longitudinal section was 0.25,0.48 and 0.72 m/s,respectively,when the wind speeds near the soil surface were 1.50,2.70 and 3.90 m/s.In general,the average air velocity in the transplanting hole was reduced by 81.54% to 83.34%.When the wind direction near the soil surface was from right to left,the air in the vertical section of the transplanting hole was counterclockwise.The verification results showed that there was a positive linear correlation between the air velocity in the transplanting hole and the wind speed near the soil surface,and this linear fitting equation was y=0.220 9x-0.176 (R2=0.925 3).When the wind speed near the soil surface was 2.70 m/s,the air flow rate was 0.42 m/s by measurement and was 0.48 m/s by simulation in the transplanting hole of well-cellar style transplanting,respectively.The dispersed heat and moisture from the transplanting hole were decreased due to small atmospheric disturbances from the soil surface,which contributed to the maintenance of the suitable water and heat conditions for the growth of tobacco seedlings.
高邮鸭prl基因内含子1的snp检测及其与产蛋性状的相关分析
张汤杰,李慧芳,陈宽,赵永,,薛敏开,张晶鑫
牲畜兽医学报 , 2007,
Abstract: ?利用pcr-rflp技术对高邮鸭催乳素(prolactin,prl)基因内含子1进行了snp检测和测序分析,并对该基因与高邮鸭产蛋性状的相关性进行了研究。结果表明:prl基因内含子1存在两个drai酶切位点,其中1个位点具有drai多态性。该位点由于在1326位点发生了t→c的碱基突变,产生了aa、ab和bb3种基因型。基因型bb和等位基因b的频率最高;bb基因型个体30周龄蛋重极显著高于ab基因型个体(p<0.01);ab基因型个体的双黄率显著高于bb基因型个体(p<0.05);3种基因型间产蛋数、最长连产天数和开产体重无显著差异。
创业板上市公司股权激励与公司绩效相关性 —研究综述与评价
Relationship between Equity Incentive of Listed Companies on Growth Enterprise Market and the Performance of Company—Review and Evaluation
 [PDF]

启诚,
Management Science and Engineering (MSE) , 2015, DOI: 10.12677/MSE.2015.43008
Abstract: 现代企业制度的两权分离使得企业的所有者与企业的经营者之间对自身利益的不同诉求成了潜在矛盾。股权激励制度的运用将二者的利益绑定,所有者通过授予经营者一定的股权,使得经营者以股东身份参与企业的管理决策、利益分配、承担经营风险。深交所创业板市场自2009年10月30开板以来,一直作为我国资本市场的有效补充,自2010年起,创业板上市公司不断进行着股权激励的尝试。本文对创业板上市公司股权激励与公司绩效相关性研究的相关文献进行了综述,并对现有研究成果进行评价。
Separation of two rights which operates in the modern enterprise system makes their own different profit pursuit between enterprise owners and operators become potential conflicts. The utilization of equity incentive bound interests of the both together. Through using this method, enterprise owners grant certain stock rights to operators and thus make the operators participate in management decisions and interests distribution and undertake operational risks. Since its estab-lishment on October thirtieth 2009, the Shenzhen Stock Exchange GEM market has been used as an effective complement to capital market of China. GEM listed companies has constantly tried to adopt equity incentive system since 2010. This paper reviews relevant literatures at home and abroad, and then gives an evaluation.
井窖式移栽对烟苗生长和光合特性的影响
Effects of well-cellar style transplanting on growth and photosynthetic characteristics of flue-cured tobacco seedlings

林叶春,陈伟,陈懿,,丁福章,李洪勋,梁贵林,潘文杰
- , 2015,
Abstract: 为探讨井窖式移栽烟苗生长发育过程中的光合生理变化,结合田间和盆栽试验,对比研究了常规膜上和井窖式2种移栽模式下烟苗生长环境的太阳光合有效辐射(PAR)水平和生长发育水平,进一步分析了烟苗叶片光合作用和光系统Ⅱ(PSⅡ)最大光化学效率(Fv/Fm)特征。结果表明:与常规膜上移栽比较,井窖内太阳光合有效辐射水平降低,其中,井窖内距井窖口4和8 cm处PAR分别为常规移栽的72.60%和52.85%;井窖式移栽提高了烟苗株高、增大了烟叶最大叶长和叶宽,但降低了叶片叶绿素含量;井窖式移栽降低了叶片最大净光合速率(Pmax)和光饱和点(LSP),但表观量子效率(AQY)提高了4.44%,光补偿点(LCP)和暗呼吸速率(Rd)分别减小了20.43%和17.78%,增强了烟苗对井窖内弱光的适应能力;井窖式和常规膜上移栽均降低了PSⅡ的最大光化学效率(Fv/Fm),但井窖式移栽烟苗Fv/Fm显著(P<0.05)高于常规膜上移栽,增幅5%~9%。采用井窖式移栽,烟苗对井窖内弱光环境的自我适应和光能利用能力增强,生长发育加快。
The well-cellar style transplanting (WCST) in China was an original transplanting method of flue-cured tobacco, and had obvious comparative advantages when compared to the conventional transplanting (CT).WCST accelerated the growth of tobacco seedlings, so it is necessary to study the characteristics of photosynthetic physiology of tobacco seedlings in WCST.Combined with the field and pot experiments, the study was conducted on photosynthetic active radiation (PAR) level, plant height, leaf length, leaf width and chlorophyll content.The leaf photosynthesis and maximal photochemical efficiency (Fv/Fm) of photosynthetic system Ⅱ (PSⅡ) were analyzed in WCST, compared with CT.The results showed that the photosynthetic active radiation (PAR) levels in WCST were decreased, e.g., the photosynthetic active radiation levels (PAR) were 72.60% and 52.85% at 4 cm and 8 cm in well-cellar respectively, compared with the conventional transplanting (CT).The plant height, leaf length and leaf width of tobacco seedlings were increased, but the leaf chlorophyll contents were reduced in WCST.In WCST, the maximum net photosynthetic rates (Pmax) and the light saturation points (LSP) were decreased;the light compensation points (LCP) and dark respiration rates (Rd) were reduced by 20.43% and 17.78% respectively;nonetheless, the apparent quantum yield (AQY) was improved by 4.44%, compared to CT.There was a possibility that the tobacco seedlings were fitted for weak light within well-cellar.PSⅡ maximal photochemical efficiency (Fv/Fm) of tobacco seedlings was reduced when transplanted in WCST or CT, but the Fv/Fm of transplanting seedlings was significantly (P<0.05) higher by 5% to 9% in WCST than in CT.The growth of tobacco seedlings transplanted by well-cellar style transplanting was accelerated in the well-cellar.The self-adaptation and the enhanced light use efficiency in weak light environment are the physiological basis to promote tobacco growth.
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