Effects of Cultivation Methods on Yield Formation and Photosynthetic Characteristics of Zhuliangyou 4024 and H You 159 as Doublecropping Rice

To explore the high-yield cultivation methods of Zhuliangyou 4024 and H You 159 when planted as double-cropping rice, the effects of two cultivation meth- ods, i.e., seedling broadcasting and transplanting, were studied on SPAD value, photosynthetic rate, grain yield and yield components. The results showed that the seedling broadcasting cultivation was conducive to Zhuliangyou 4024 and H You 159 to obtain higher yield. The higher chlorophyll content and photosynthetic rate and their slower decrease of flag leaf after full heading of the seedling broadcasting cultivation were thought to be the physiological basis of high yield.

Dynamic Characteristics of Growth and Development of Xiangsha Taro in Jingjiang

The growth and development of Jingjiang Taro [Colocasia esculenta（L.） Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting （7-8 leaves）; the first taro began to expand, from 125 d after sprouting （12 leaves） when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting （15-16 leaves）. The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.

The Impact of Electrode Configuration on Characteristics of Vacuum Discharge Plasma

Generation characteristics of vacuum discharge plasma are very important for the applied research of metal plasma. The vacuum discharge electrode configuration and the cathode material affect the generation characteristics of the metal plasma which consists of metal ions coming from cathode and generated by vacuum discharge. In this research, the generation characteristics of the metal plasma generated by vacuum discharge are discussed for four patterns of electrode configurations, i.e. cone-mesh electrode setup, cone-cross line electrode setup, cone-line electrode setup and cone-ring electrode setup. Characteristics of the metal plasma, such as elec- tron density, electron temperature, space potential, ion energy, are measured by the probe method for discussing the impacts of different electrode configurations on the density of generated metal plasma. Moreover, the diffusion velocities of the metal plasma are measured for cathode materials of Pb, Al, and Cu, respectively. The experimental results indicate that the plasma generated by the discharge of cone-ring electrode configuration possesses the maximum density and the metal plasma generated by the Al cathode possesses the fastest diffusion velocity and the highest kinetic energy.

Characteristic Analysis of AC Plasma Arc in Water

An experimental system of AC arc discharge in water was designed with pole-pole electrodes and a peak voltage of 1500 V and a test circuit was set up using virtual instrument technology. The mechanism of an AC plasma arc generated in water was analyzed. The voltage- current characteristic of the AC plasma are was obtained from the waveform. The temperature characteristic was tested with a spectrum diagnosis system, and the effect of different electrode materials on the striking voltage and peak current was analyzed. The results show that when a power supply of 6 kW is applied on electrodes with a gap of 2 mm in water, the striking voltage is from 900 V to 1300 V, the arc voltage is from 40 V to 100 V, the arc current is from 2 A to 7 A, and the zero rest period is from 1 ms to 2 ms. In addition, the arc voltage and current are different for electrodes in aluminum, copper and stainless steel. The arc voltage is lower and the current is higher for an aluminum electrode than those for copper and stainless steel ones. The highest temperature of the arc is 7643 K.

光逆境对叶绿体叶绿素蛋白质复合物的影响

研究了强光照射对菠菜叶绿体的叶绿素蛋白质复合物及一些光会特性的影响。实验结果表明，随着强光照射时间的延长，首先，属光系统Ⅱ核心的叶绿素蛋白质复合物的ＣＰａ带明显减少了；进而属ＬＨＣＩＩ的寡聚体和二聚体的带有了不同程度的降低；最后，包括光系统Ｉ在内的叶绿素蛋白质复合物带大部分被分解了。结果还表明，当光逆境还未使叶绿素蛋白质复会物发生明显变化时，代表光系统Ⅱ活性的Ｆ＿ｖ／Ｆｏ值及ＤＣＩＰ光还原活性就已显著地降低了。

Analysis on Characters and Growth Factors of academicians of Agriculture Faculty of Chinese Academy of Engineering

The research analyzed birthplace, work site and Work unit, discipline, agri- cultural product variety, current age, and selected age, as well as internal and exter- nal factors for growth, which providers references for exploring development of high- level agricultural S＆T talents and formulation of relevant policies.

石楠和女贞不同叶龄光合生理生态特征研究

以石楠(Photinia serrulata)、女贞(Ligustrum lucidum)这二种常绿园林植物为研究对象,利用LI-6400便携式光合作用测定系统测定了净光合速率,拟合了光响应曲线,计算或测定了光补偿点(LCP)、光饱和点(LSP)、最大净光合速率(Pn max)、表观量子效率(AQY)、叶绿素含量、叶绿素a/b和比叶重(LMA)等。

MECHANICAL BEHAVIORS OF SATURATED SAND UNDER COMPLICATED LOADING

The different physical states of saturated sand, including shear elasticity, positive dilatancy, and negative dilatancy (preliminary negative dilatancy, secondary negative dilatancy and reversal negative dilatancy) are revealed based on the pore water pressure response of saturated sand in undrained dynamic torsional tests of thin cylinder samples and also checked by the drained cyclic triaxial tests under a given mean effective normal stress. According to the effective stress path of different physical states under the undrained cyclic torsional tests the physical state transformation surface, stress history boundary and yield surface are determined, and the state boundary surface is also determined by the range of effective frictional stress state movement. Based on the moving yield surface without rotation, and the expanding stress history boundary surface relevant to the stress path variations under different physical states in 3D stress space, a physical state model is proposed to provide a new approach to calculating the transient pore water pressure under the undrained condition, and the volume strain of dilatation under drained condition in this paper.

不同光强处理对南瓜幼苗生长及田间性状的影响

以"百蜜5号"南瓜种子为试材,在一定红蓝光配比下(R∶B=9∶1),设置6种不同光照强度(80、120、160、200、240、280 W·m^(-2)),以普通日光灯为对照(CK),研究不同光照强度下LED红蓝光对南瓜幼苗生长及田间性状的影响,以期为培育南瓜壮苗寻找最适光源和培养高品质南瓜幼苗提供参考依据。结果表明:在光照强度为280 W·m^(-2)时,南瓜幼苗的可溶性糖、可溶性蛋白质、净光合速率(Pn)、茎长达到最大值;在光照强度为160 W·m^(-2)时,根系活力、茎粗、地上和地下鲜质量以及地上干质量为最大值;在光照强度为120 W·m^(-2)时,气孔导度(Gs)、根长、壮苗指数为最大值;在光照强度为200 W·m^(-2)时,丙二醛(MDA)含量达到最低值,在光照强度为240 W·m^(-2)时,真叶数、地下干质量、根冠比达到最大值。综上可知,在南瓜幼苗的生根阶段选用120~160 W·m^(-2)的光照强度适合根系和幼苗的生长;选用200~280 W·m^(-2)有利于南瓜幼苗的其它阶段的生长发育。

春季温室内两种竹类植物叶片解剖结构与光合特性研究

利用石蜡包埋法制作金丝葫芦竹(Bambusa ventricosa kimmei)与佛肚竹(Bambusa ventricosa McClure)的石蜡切片并解剖观察其显微结构,并利用CIRAS-3光合测量仪测量2种竹类植物叶片的光合特性指标及光响应参数。结果表明,金丝葫芦竹与佛肚竹的解剖结构和光合特性存在差异。佛肚竹叶片的上下表皮、栅栏组织和海绵组织的厚度均大于金丝葫芦竹;佛肚竹的净光合速率、气孔导度以及水分利用效率均强于金丝葫芦竹,但前者的蒸腾速率却不及后者。从二者光响应曲线对比发现,金丝葫芦竹对弱光的利用能力不如佛肚竹,且在高光环境下光合作用更容易受到抑制。

不同栽植模式对桐花幼苗光合特性影响研究

桐花树(Aegiceras corniculatum)为红树林重要树种之一,由于其较耐低温、适应性较强,已经成为三亚市最主要的红树造林树种。研究了不同栽植模式对桐花幼苗光合特性的影响并对相关性进行分析。结果表明,不同栽植模式对桐花幼苗光合特性的影响不同,表现最好的是桐花+木榄、秋茄。

青藏高原东缘川滇高山栎和西南花楸叶片性状对海拔的响应

叶片作为响应环境变化最为敏感的植物器官,是反映植物生存策略的重要指示者。为明晰高山植物响应海拔变化的生态适应策略,本研究于青藏高原东缘选取不同海拔(2600、2800、3000、3200和3400 m)下常绿阔叶树种川滇高山栎和落叶阔叶树种西南花楸为对象,测量叶片形态、解剖性状、气体交换参数、叶绿素荧光参数等指标,研究二者响应海拔变化的异同及生态适应策略。结果表明:随着海拔的升高,川滇高山栎的叶片干物质含量显著降低,西南花楸显著增加,两者叶片均逐渐变小;川滇高山栎的栅栏系数呈下降趋势,西南花楸的栅栏系数呈上升趋势,二者的叶片、栅栏组织、海绵组织、上表皮和下表皮的厚度均显著增加,与海拔2600 m相比,海拔3400 m处分别增加22.4%、4.9%、45.1%、23.3%、19.6%和28.2%、46.9%、8.9%、25.9%、20.8%。西南花楸叶片气体交换参数和叶绿素荧光参数随着海拔升高显著增大,而川滇高山栎与之相反。两者叶片解剖性状、气体交换和叶绿素荧光参数均具有较强的可塑性,绝大多数叶片性状间以及叶片性状与海拔之间存在显著相关关系。川滇高山栎应对海拔变化的生存策略较为保守,西南花楸的生存策略则较为积极,两者均通过调节自身性状以适应不同海拔。

短期深旋松对黄淮海沙姜黑土耕层结构及小麦生长的影响

针对黄淮海平原由于连年旋耕所导致的犁底层加厚上移、耕层变浅的问题,引入一种全新的耕作技术——深旋松耕,以改良耕层障碍因素,提高冬小麦产量.设置深松20 cm(SS20)、深旋松30 cm(DVR30)两个处理,以深松20 cm为对照,研究深旋松耕作对土壤物理特性及小麦开花期光合特性的影响.结果表明:DVR30处理能够充分破除犁底层,DVR30处理10~20和20~30 cm土层容重分别较SS20处理降低了9.5%和11.2%,DVR30处理20~30 cm穿透阻力较SS20处理降低了42.3%.DVR30能够增强水分入渗能力,提高土壤深层贮水量.随着深度的增加,DVR30处理土壤含水量显著增加,30~40和40~50 cm土层含水量分别较SS20处理提高16.9%和10.6%,且差异达到显著水平,0~50 cm土壤贮水量提高3.3%.DVR30处理创造了良好的耕层环境,促进了小麦开花期光合能力的提高,与SS20处理相比,DVR30处理小麦开花期叶片相对叶绿素含量(SPAD)及净光合速率分别提高1.3%和15.5%,小麦地上部、地下部干物质累积量亦有显著增加,同时DVR30处理通过提高小麦有效穗数,提高了产量,实际增产12.4%.综上,短期深旋松耕作能够充分破除犁底层、深松活土,为构建合理耕层结构、充分挖掘耕层潜力提供了一种新的技术手段.

元宝枫幼苗生长和光合特性对硬化地表的响应

以北京典型绿化树种元宝枫(Acer truncatum)幼苗为试验对象,设置透水硬化地表、不透水硬化地表和对照(自然地表)3种地表类型,分析了元宝枫幼苗主要生理生态指标和生长指标对硬化地表的响应特征。结果表明:相比于对照,2种硬化地表引起地表温度显著升高,元宝枫幼苗叶片净光合速率(Pn)、气孔导度(gs)、蒸腾速率(Tr)、光合色素含量、光系统II光化学有效量子产量(Fv'/Fm')、PSII实际光量子效率(ФPSII)、光合电子传递速率(ETR)、光化学猝灭系数(qp)及最大净光合速率(Pmax)、表观量子效率(AQY)和光饱和点(LSP)均下降,叶片丙二醛(MDA)含量增加,株高和基径降低。硬化地表引起地表温度升高,对元宝枫幼苗生长造成了热胁迫,严重伤害了植物光系统II,光合电子传递被限制,减少了植物叶片的光合作用,抑制了植物生长。与不透水地表相比,透水地表粗糙度和孔隙度较高,增加了透水地表的热储存和热传导能力,地表温度显著升高形成的热胁迫对植物的生理伤害和生长影响更大。因此,在城市建设中,应考虑降低硬化地表的温度,以缓解城市绿化树种可能受到的热胁迫。

冷浸田水旱轮作对作物生产及土壤特性的影响

通过连续2年4茬的田间试验,研究了冷浸田由单季稻改制为水旱轮作对作物生产及土壤特性的影响.结果表明：油菜-水稻（R-R）、春玉米-水稻（C-R）、紫云英-水稻（M-R）、蚕豆-水稻（B-R）4种轮作模式两年的水稻平均产量较水稻-冬闲模式（CK）提高5.3%~26.7%,其中C-R和R-R模式与CK差异显著.除M-R模式外,各轮作模式的年均经济效益较CK增加79.0%~392.4%,总产投比增加0.06~0.72个单位,均以C-R模式最高.水旱轮作模式均提高了水稻分蘖盛期叶片的叶绿素、类胡萝卜素含量和净光合速率.轮作下水稻收获期的土壤锈纹锈斑丰度明显,尤其是R-R、C-R、B-R模式;各轮作模式下的耕层土壤水稳性大团聚体（〉2 mm）数量均较CK有不同程度降低,而中团聚体（0.25~2 mm）数量（除M-R模式外）和微团聚体（〈0.25 mm）数量则相反;各轮作模式的土壤活性还原性物质含量逐渐下降,而速效养分含量呈上升趋势.与CK相比,C-R和B-R模式的土壤细菌数分别提高285.7%~403.0%,B-R的真菌数提高221.7%,R-R、C-R、B-R的纤维素菌提高64.6%~92.2%,B-R的固氮菌提高162.2%,差异均显著.冷浸田由冬闲-单季稻改制为C-R、R-R、B-R轮作模式,对提高作物总产量和经济效益有较好的效果,土壤理化生化性状得到改善,表现出脱潜特征.

不同秧龄及剪根程度对杂交水稻生长特性和产量的影响

以超级杂交稻F优498为材料,采用两因素裂区试验设计,在25 d和40 d秧龄下,设剪根1/3和2/3以及全部剪根3种剪根处理,以未剪根处理为对照,研究不同秧龄和剪根处理对杂交稻生长特性及产量的影响。结果表明,秧龄处理对有效穗数、总颖花量和千粒重的影响明显大于剪根处理,而剪根处理对主要生育时期干物质积累量、抽穗后根干重及结实率的影响更显著。2种秧龄下剪根1/3处理均能提高根干重,促进分蘖发生,提高干物质积累量以及齐穗后Pn,最终促进增产,其中以25 d秧龄下剪根1/3处理产量最高。而2种秧龄下,剪除全部根系的处理会导致各生长指标及总颖花量、结实率不同程度低于对照,进而导致产量显著降低。不同秧龄和剪根处理下,水稻各生育时期根干重、拔节前和抽穗至成熟期的干物质积累量以及齐穗后Pn与产量均呈显著或极显著正相关。剪根程度与产量呈极显著开口向下的二次曲线关系,25 d和40 d秧龄下,移栽的伤根程度分别在39.28%和32.63%时能达到最佳的增产效果。