纳米氧化锌晶体的分区生长

以ZnO粉和石墨粉为原料,用碳热还原法获得了分区生长的多种形貌ZnO晶体。采用XRD、FESEM、HRTEM、EDS和PL谱等测试手段分别对产物进行了分析表征。结果表明:所得产物均为六方纤锌矿ZnO晶体,但具有不同的晶体形态特征。浅黄色产物主要为四足和两足状ZnO晶须,白色产物为单一片状ZnO晶体。同时初步分析和讨论了产物分区生长的原因和生长机理。

黄土高原刺槐人工林立地指数变化及评价

【目的】在黄土高原研究刺槐人工林优势木平均高及立地指数(基准林龄15年时优势木平均高)对气候和立地因子的响应,建立模型评价立地质量。【方法】对样地调查及文献搜集数据,用外包线法确定优势木平均高的单因子响应规律和适宜函数形式,然后建立多因子耦合模型并用实测数据率定,籍此评价立地指数空间差异。【结果】地形部位对优势木平均高的影响差异较大,相对得分表现为沟底1.000>塬面0.906>梁坡下部0.837>梁坡中部0.438>沟坡0.210>梁坡上部0.176>梁峁顶0.000。当年均降水量小于550 mm时,优势木平均高随年均降水量升高快速增加,之后渐趋平缓;优势木平均高随年均气温升高呈先增后减,最适范围是7.5~11.0℃。建立了耦合气候和立地因子影响的优势木平均高模型,拟合度较好(R^(2)=0.72)。依据对优势木平均高的影响,将年均气温和降水量都分为4级(<6.0℃,太冷,不能生长;6.0~7.5℃,冷,不宜或较宜生长;7.5~11.0℃,温,最宜生长;>11.0℃,暖,较宜或不宜生长。<400 mm,太旱,不能生长;400~450 mm,旱,不宜生长;450~550 mm,润,较宜生长;>550 mm,湿,最宜生长),据此确定了黄土高原不能刺槐造林的区域,提出了可刺槐造林区域的气候分区,其中温湿区、温润区、暖湿区和温旱区的平均立地指数均为中等或以上(>7.5 m),宜于刺槐生长;但冷旱/润区和暖润区立地较差,整体不宜刺槐生长。对各气候分区,计算了各立地类型(地形部位与坡向的组合)的立地指数,评价了立地质量。【结论】黄土高原刺槐人工林的立地指数同时受气候和立地因子影响。综合考虑这些影响的气候分区和立地评价可以指导精细的刺槐造林立地选择和林分科学经营。

从洒金花朵反演嵌合体变化机制

嵌合体植物不稳定,洒金花朵则是其不稳定的极端表现。反演洒金花朵发育过程,推知花瓣原基为二维码式异质细胞嵌合体,经典嵌合体理论将其归结为不稳定性,而对不稳定性成因的阐述存在两大矛盾,因而无力解释洒金花朵的形成机制。利用结合了原套-原体、细胞组织分区两个学说的茎端生长锥综合结构模型,提出挤出-打印假说,阐明茎端生长锥中心区的子细胞输出过程,进而设想中心区“打印”二维码式周边区环带,从而圆满解释了洒金花朵的形成机制,揭示了嵌合体不稳定的本质。

Nutrient Content in Soils and Adaptability of Corn in Yuanzhou District,Guyuan City

[Objective] The aim was to research rational fertilization of corn in Yuanzhou District, Guyuan, Ningxia Hui Autonomous Region. [Method] Nutrient con- tents in soils in Yuanzhou District were measured with conventional analysis method and the suitable fertilization scheme of corn growth was proposed based on fertiliz- er-application rule of corn growth and nutrient balance. [Result] Soil in farmlands in Yuanzhou District was of alkalinity; organic matter, N, P and Zn were shortage; S was extremely insufficient; Fe and Mn were moderate; K was abundant; Cu would satisfy crop growth, [Conclusion] The research provides references for yield increase, reduction of chemical fertilizer and related pollution for corn growth.

Flotation bubble image segmentation based on seed region boundary growing

Segmenting blurred and conglutinated bubbles in a flotation image is done using a new segmentation method based on Seed Region and Boundary Growing（SRBG）.Bright pixels located on bubble tops were extracted as the seed regions.Seed boundaries are divided into four curves：left-top,right-top,right-bottom, and left-bottom.Bubbles are segmented from the seed boundary by moving these curves to the bubble boundaries along the corresponding directions.The SRBG method can remove noisy areas and it avoids over- and under-segmentation problems.Each bubble is segmented separately rather than segmenting the entire flotation image.The segmentation results from the SRBG method are more accurate than those from the Watershed algorithm.

Comparative Utilization of Different Fibre Feedstuffs by Weaning/Growing Pigs in the Tropics

This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel cake （PKC）, wheat offal （WO）, corn bran （CB）, rice bran （RB） and brewers＇ dried grain （BDG） were used at 25% in each of the five experimental diets that were formulated in this study. Twenty weaner pigs （12.75 ± 0.6 kg） were used for the growth study while 15 pigs （14.95 ± 0.57 kg） were used for the digestibility study. The design of the experiment was completely randomized. The results of the study showed that the performance of the experimental animals were significantly influenced （P 〈 0.05） by the dietary treatments. The apparent digestibility of the crude protein, crude fiber and ether extract showed significant differences （P 〈 0.05） while there was no significant difference （P 〉 0.05） in the apparent digestibility of their dry matter, ash and nitrogen free extract. The diet that contained WO had the best growth response and apparent nutrient digestibility. Results of economics of production also showed that diet with WO gave the best （P 〈 0.05） value in feed cost/＇kg gain and net profit/animal. It can be concluded from this study that although all the animals fed the different fibre feedstuffs performed satisfactorily on all the parameters monitored, but for optimum growth, apparent nutrients digestibility and economics of production. WO should be used as a fibre feedstuff in the diets of weaning/growing pigs in the tropics.

A MICRO-IMAGE FUSION ALGORITHM BASED ON REGION GROWING

Due to the limitation of Depth Of Field (DOF) of microscope, the regions which are not within the DOF will be blurring after imaging. Thus for micro-image fusion, the most important step is to identify the blurring regions within each micro-image, so as to remove their undesirable impacts on the fused image. In this paper, a fusion algorithm based on a novel region growing method is proposed for micro-image fusion. The local sharpness of micro-image is judged block by block, then blocks whose sharpness is lower than an adaptive threshold are used as seeds, and the sharpness of neighbors of each seed are evaluated again during the region growing until the blurring regions are identified completely. With the decreasing in block size, the obtained region segmentation becomes more and more accurate. Finally, the micro-images are fused with pixel-wise fusion rules. The experimental results show that the proposed algorithm benefits from the novel region segmentation and it is able to obtain fused micro-image with higher sharpness compared with some popular image fusion method.

Effect of Drip Irrigation Intervals and Some Antitranspirants on the Water Status, Growth and Yield of Potato （Solanum tuberosum L,）

In order to reduce the quantity of water applied by irrigation, increase the water use efficiency and determine the appropriate period for irrigation potato crop, a field experiment was implemented at vegetables field, Department of Plant Production, Agriculture Technical College, Mosul, Iraq, during spring season of 2014. This study involved four irrigation intervals （3, 4, 5 and 6 d） under drip irrigation system, with spraying by five antitranspirant substances （control, kaolin 5 g/L, MgCO3 3 g/L, liquid paraffin 2% and Nu-film 17 1%）, which subjected in a factorial experiment within split plot system in a randomized complete block design with three replications. The results showed that increasing irrigation intervals from 3 d to 6 d decreased the total water content of the leaves from 83.59% to 81.81%, the rate of relative transpiration from 0.174% to 0.162%, stomata area from 1.620 lam2/stomata to 0.921 ~m2/stomata, plant yield from 542.22 g to 425.80 g, total yield of tubers from 25.808 tons/ha to 20.253 tons/ha and marketable yield of tubers from 24.471 tons/ha to 18.822 tons/ha, whereas caused an increase in the leaf water deficit from 19.19% to 23.86% and water use efficiency from 8.63 kg/m3 to 13.32 kg/m3. Spraying potato plants with liquid paraffin 2% led to the highest total water content 83.37%, stomata area 1.466 ~tm2/stomata, the lowest relative transpiration 0.152%, the lowest leaf water deficit 20.33%, the highest plant yield 509.22 g, total yield 24.236 tons/ha, marketable yield 22.770 tons/ha and water use efficiency I 1.83 kg/m3. On the other hand, the interaction treatments between irrigation intervals and antitranspirants resulted in a significant effect in many studied parameters.

The Ecological Distributions of N, P Utilizing Bacteria and Heterotrophic Bacteria in the Moderate Hypoxia Zone of the Changjiang Estuary

The distributions of N utilizing bacteria (denitrifying bacteria and ammonifying bacteria) ,P utilizing bacteria (organic phosphobacteria and inorganic phosphobacteria) and heterotrophic bacteria in the Changjiang Estuary,and the roles of main environmental factors in distributing bacteria,are explored with observations from two cruises in June and August 2006.Comparisons between the two important periods of initial hypoxia phase (June) and developed hypoxia phase (August) show differences in both bacterial distributions and the associated main environmental factors.First,the primary group of ammonifying bacteria has larger magnitude with spatial maximum value in the hypoxic stations related to sediment in August.The phosphobacterial abundance and detection rates in August are much lower than those in June,but the denitrifying bacterial abundance becomes greater in August.However,the difference of heterotrophic bacterial abundance between June and August is not obvious.Second,main environmental factors influencing bacteria vary from initial hypoxia phase to developed hypoxia phase.Two parameters (salinity and NO3) in surface water and five environmental parameters (pH,salinity,PO43,NO3and temperature) in bottom water and surface sediment play major roles in the bacterial abundance in June,while different parameter combinations (salinity and PO43) in surface water and different parameter combinations (DO,DOC,NO3,PO43 and pH) in bottom water and surface sediment play major roles in August.Moreover,the bottom bacteria distributions in area south of 31 N are related to the position of the Taiwan Warm Current in June.The bacterial abundance and distribution may respond to the environmental change in the hypoxia processes of initial phase and developed phase.During the hypoxia processes,the whole structure of bacterial functional groups probably turns to different states,causing the recycling of nutrient regeneration and aggravating hypoxia regionally.