大气环流模式与春玉米生长模拟模式联接的影响评估模拟试验

根据春玉米田间试验资料和历史气候资料,对春玉米生长模拟模式进行了验证与灵敏性分析,在此基础上,运用逐步订正法将当前气候前景和大气环流模式输出资料结合历史气候资料生成的未来气候情景订正到１ｏ×１ｏ网格点上,与春玉米生长模拟模式相联接,就未来气候变化对我国东北地区春玉米生长、发育和最终产量的可能影响进行了网格化定量模拟,并对一些适应性对策的效果进行了定性或定量的分析。结果表明,在ＤＫＲＺＯＰＹＣ模拟的未来情景下,若保持当前作物品种和生产技术措施不变,研究区域除北部将平均增产７０％外,其余地区都将有不同程度的减产,幅度在－１０％～－５０％之间,而在ＮＣＡＲ模拟的情景下,中西部地区将增产,其它地区可维持当前产量水平。适应性对策将对开发利用未来可能的气候资源,减缓未来气候变化的负效应,充分发挥其正效应起到积极作用,进而绝大部分区域将受益于未来水热条件的改变。     

锦州地区春玉米物候变化趋势及其与水热条件的关系

利用1980—1984年和2004—2020年锦州市农业气象观测站春玉米物候观测资料和气象观测资料,采用趋势系数、倾向率、相关分析和通径分析等方法,分析了锦州市春玉米生育期长度和水热条件的变化趋势,并探讨了锦州市春玉米生育期长度与水热条件的关系。结果表明：1980—1984年和2004—2020年锦州地区春玉米各生育期长度变化趋势不同,除抽雄期、成熟期和生殖生长期外,其他生育期长度均呈缩短的趋势。营养生长期长度极显著缩短,生殖生长期长度极显著延长,因此全生育期呈弱的延长趋势,变化不明显。春玉米各生育期水热条件变化趋势不同,热量条件变化显著,而水分条件变化不显著,多数生育期≥10℃活动积温(DT10)和生长度日(GDD)呈增加的趋势,其中抽雄期、成熟期和生殖生长期、全生育期热量条件呈极显著增加趋势,表明热量条件对春玉米生长发育影响最大。相关分析和通径分析表明,DT10和GDD对春玉米生育期长度影响最大,水分条件对春玉米生育期长度影响较小,其中出苗期、成熟期和全生育期长度与水分条件相关显著。可见,锦州地区水热因子之间相互制约、相互影响,共同影响春玉米的整个生育期。     

Effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone concentration in Juvenile Chinese shrimp, Fenneropenaeus chinensis

This experiment was conducted to examine the effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone (20-HE) concentration for juvenile Fenneropenaeus chinensis with an initial wet body weight of 1.115 g±0.012 g. The salinity of the control treatment (represented by D0) was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The range of salinity fluctuation was 4. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8 d, respectively; each original salinity was decreased abruptly to salinity 24, which first lasted for another 2 d and was then raised to its initial value 28. This constituted a salinity fluctuation cycle and afterwards the cycle repeated. It was found that: 1) The weight gain of shrimp in treatment D4 was 202.9% and significantly higher than that in treatment D0 (P<0.05). The molting rate in treatment D2 was the lowest, while that in treatment D6 was the highest and significantly higher than those in treatments D0 and D2 (P<0.05). 2) The hemolymph 20-HE concentration of shrimps in all treatments was at low levels and increased first gradually during the inter-molt period and then increased sharply. It reached a peak value during the pre-molt stage, and then decreased abruptly during the post-molt stage when the lowest level occurred. 3) During the post-molt stage, the hemolymph 20-HE concentration in treatment D2 was 7.47 pg μL⁻¹ and significantly higher than that in treatment D0 (P<0.05). There were, however, no significant differences in hemolymph 20-HE concentration among all five treatments during the inter-molt stage (P>0.05). During the pre-molt stage, the hemolymph 20-HE concentration in treatment D6 was significantly higher than that in treatment D0 (P<0.05), whereas the hemolymph 20-HE concentration in treatment D2 was significantly lower than that in other treatments (P<0.05). Adequate salinity fluctuation promoted the molting rate through increasing hemolymph 20-HE concentration at the pre-molt stage.     

松辽盆地南部白垩纪-古近纪挤压构造的发现与盆地性质探讨

松辽盆地位于欧亚板块东部,毗邻太平洋板块,是叠置于华北板块和西伯利亚板块之间的晚古生代碰撞造山带之上规模最大的中-新生代陆相含油气盆地,具有断、坳双重结构。自白垩纪以来,松辽盆地南部主要经历两期挤压作用:NW-SE向挤压作用发生在下白垩统营城组碎屑岩段-上白垩统泉头组沉积时期,挤压作用持续了18Myr;近E-W向挤压作用发生在四方台组-古近系沉积时期,挤压作用至少持续了39.1Myr。两期挤压作用都表现出东强西弱的特点,第二期挤压作用的变形强度远大于第一期,并且在明水组沉积晚期变形强度最大,这期挤压作用奠定了松辽盆地现今的构造格局。下白垩统营城组上部碎屑岩段-上白垩统泉头组和四方台组-古近系的沉积作用分别记录了第一期、第二期挤压作用形成的反转构造和断层相关褶皱的变形过程。上述构造在不同时期隆升速率与沉积速率之间的关系,控制了盆地的沉积范围、沉积地层的厚度和接触关系在空间上的变化。松辽盆地在上述两个构造演化阶段都处于活动大陆边缘的陆内区域,盆地性质都应属于陆内挤压坳陷盆地。     

Retardation of Fin Regeneration in Freshwater Fish Oreochromis mossambicusby Zinc

Regeneration of partially amputated caudal fin was studied in freshwater fish Oreochromis mossambicus exposed to sublethal concentrations of zinc (5.0 mg L^—1 and 10.0 mg L^—1) under ambient laboratory conditions over a period of 20 days. Caudal fin regeneration was measured on 5th, 10th, 15th and 20th day of exposure and after amputation. Significant ( p < 0.05) retardation in fin regeneration was observed on day 5th and 10th in fish exposed to the nominal concentration of 5.0 mg L^—1 Zn, while retardation was found highly significant ( p < 0.01) at all the observations in 10.0 mg L^—1. The maximum inhibition in caudal fin regeneration (20.8 % and 24.3 %) was found during the initial observation at both of the concentrations (5.0 mg L^—1 and 10.0 mg L^—1) of zinc exposure. Later on the regeneration rate was almost as good as in the control group. Thus in this study fin regeneration was significantly inhibited at all time points following Zn exposure as a detrimental effect of Zn to fish. This study demonstrates that fish caudal fin regeneration is a simple assay, sensitive and easy to perform, and can serve as a model to determine the toxicity of pollutants in aquatic environment.     

Cenozoic detachment folding in the southern Tianshan foreland,NW China: Shortening distances and rates

Intracontinental foreland basins with fold-and-thrust belts on the southern periphery of the Tianshan orogenic belt in China resulted from still-active contractional deformation ultimately cased by the India–Asia collision. To quantify the amounts of shortening distance and the rates of deformation, and to decipher the architectural framework, we mapped the stratigraphy and structure of four anticlines in the Kuqa and Baicheng foreland thrust belts in the central southern Tianshan. In the Baicheng foreland thrust belts, Lower Cretaceous Baxigai and Bashijiqike Formations located in the core of the Kumugeliemu anticline are overlain by the Paleocene to Eocene Kumugeliemu Formation, above which are conformable Oligocene through Pleistocene sediments. A disharmonic transition from parallel to unconformable bedding at the boundary of the Miocene Kangcun and Pliocene Kuqa Formations suggests a change from pre-detachment folded strata to beds deposited on top of a growing anticline. Most of the anticlines have steep limbs (70–90°) and are box to isoclinal folds, suggestive of detachment folding or faulted detachment folding (faults that transect a fold core or limb). Shortening estimates calculated from the cross-sections by the Excess area method indicate that the total shortening for the Kelasu, Kuchetawu, Kezile and Yaken sections are 6.3 km, 6.4 km, 5.8 km and 0.6 km, respectively, and the respective depths of the detachment zones are (2.3 km and 6.9 km), 2.3 km, 2.5 km and 3.4 km. Time estimates derived from a paleomagnetic study indicate that the transition to syn-folding strata occurred at ∼6.5 Ma at the Kuchetawu section along the Kuqa river. In addition, according to our field observations and previous sedimentary rate studies, the initial time of folding of the Yaken anticline was at 0.15–0.21 Ma. Therefore, the average shortening rate that began at ∼6 Ma was ∼2 mm/a for the Kelasu, Kuchetawu and Kezile sections. At 0.15–0.21 Ma, the average shortening rate increased to 3–4 mm/a in the Yaken section. Combined with the recent GPS data, the shortening rate in the central southern Tianshan area increased to 4.7 ± 1.5 mm/a at present. We suggest that there was a linear increase in shortening rate in the southern Tianshan foreland basin, which also indicates that the far field stress increased considerably from the late Miocene to Present in response to the India–Asia collision.     

遥感和生长模型相结合的小麦长势监测研究现状与展望

 遥感影像的信息波段及其组合可以反映农作物生长的空间信息，可对小麦进行长势监测和产量估算，具有及时性和广域性。生长模型是集气候、土壤、品种和栽培措施等因素为一体的，对作物的物候发育、光合生产、器官建成、同化物积累与分配以及产量与品质形成等生理过程及其与环境和技术因子关系综合量化的动态数学模型，具有机理性和预测性。将二者结合用于长势监测不但具有理论研究价值，还具有广泛的应用前景。本文在简要概述小麦生长模型和长势遥感监测研究进展的基础上，总结了生长模型和遥感相结合的小麦长势监测应用的研究进展，并提出一些今后研究设想。     

Wood productivity of Prosopis flexuosa D.C. woodlands in the central Monte: Influence of population structure and tree-growth habit

A balance between forest production and protection is hard to achieve in arid zones due to their low potential for wood production. Prosopis flexuosa woodlands are the major woody formations in the Monte desert and are currently in a degraded state due to intense use. The main degradation factors in the study area are overgrazing and firewood extraction. We developed allometric models to estimate the aerial biomass of P. flexuosa, compared annual growth rates of one- and multi-stemmed individuals through dendrochronological methods, and estimated the productivity of four structurally different woodlands in the central Monte. Total dry weight was best estimated by power equations. Annual increments in basal area and dry weight were initially larger for multi- than one-stemmed individuals. However, whereas multi-stemmed individuals rapidly decreased their growth rates after 60 years of age, one-stemmed trees maintained steady growth rates during the first 100 years. Depending on woodland density and tree size, total woodland biomass varied between 4000 and 15 000 kg ha⁻¹. Wood productivity was similar in all four woodlands studied (121.6-173.7 kg ha⁻¹ year⁻¹). Our results reveal the importance of tree growth habit to productivity, and suggest that regulated extraction of firewood and poles from old multi-stemmed individuals could optimize wood productivity and contribute to the sustainable use and conservation of these woodlands.     

北部湾长尾大眼鲷生长和死亡参数估计

根据20世纪60年代及90年代的生物学资料，本文运用体长频率分析法估算长尾大眼鲷的生长和死亡参数。Von Bertalanffy生长方程的主要参数L∞=29．4cm，K=0．65．τo=-0．42；体重的生长拐点为1．27龄；瞬时总死亡率(Z)、瞬时自然死亡率(M)和瞬时捕捞死亡率(F)分别为3．72，1．19和2．53。当前开发率为0．68。资源处于过度利用状态。     

影响三角褐指藻生长的生态因子间关系及其调节效应

运用 3× 3× 2析因试验 ,研究NO3 N质量浓度、光照强度和温度间的相互关系及其对三角褐指藻 (Phaeodactylumtricornutum)生长的调节效应。结果表明 :NO3 N以抛物线方式控制藻的生长 ,光照强度主要影响藻的指数生长期 ,对稳定态细胞密度影响减弱 ,温度升高有助于生长。当温度为 2 0℃ ,NO3 N质量浓度分别为 14 .7和 14 .6mg/L ,光照强度分别为5 36 4 .0和 4 0 35 .4lx时 ,藻相对生长率和细胞密度达到最大值 ,分别为 0 .6 5 15d-1和10 10 .7× 10 4/mL。光肥效应、温肥效应和光温效应存在于藻类生长过程 ,并且起协调作用。增产效应随NO3 N含量增加而减少 ,随光照强度和温度的升高而增加