Effects of Long-term Fertilization on Micro-morphological Features in Purple Soil

[Objective] The study aimed to better understand the effect of different fertilizer treatments on micro-morphological characteristics of a purple soil at the 0-20 cm topsoil in a long-term fertilizer experiment. [Method] Soil micro-morphology was observed and analyzed under a single polarizing microscope. [Result] For the CK （no fertilizer） treatment, soil structure was dense with little porosity developed. Its soil microstructure was poor, sandy fabric-granular fabric. After continuously applied chemical fertilizers only for more than two decades, the soil particles did not evolve into soil structures and formed little porosity. The microstructures of soil in N, NP and NPK treatments were porphyroskelic fabric-fine sandy granular fabric, better than that of the soil in CK treatment. Adding manure obviously improved the quantity of groundmass and endowed the soil a loose structure and plenty porosity, enriched animal and plant residues, and well-formed iron-manganese nodules and humus ma- terials, all resulting in better micro-aggregates development. The type of soil microstructures in MNPK treatment was pectized-compacted takyric fabric-intertextic fabric, the best among all the treatments. [Conclusion] Combined application of both or- ganic and inorganic fertilizers can significantly improve the structure of the purple soil, enhance soil fertility and achieve soil sustainable development.

绘画写生中的感知应用探微

绘画写生是以客观对象为基础的,但是,在写生中对形、色、结构的把握,无不与感知心理发生密切的联系。本文试图结合写生教学实践,探索感知心理特征在写生中的应用,从而增强学生对物象形、色、结构的的感知力,调动学生在写生过程中的积极性、主动性,培养其美感、艺术兴趣、形象思维和创造思维的能力。

Morphological and karyotypic variation in three wild populations of Meretrix meretrix

Three wild populations of Meretrix meretrix sampled from Dongxing, Beihai, and Shankou along the coast of Guangxi, China, were investigated with morphometry and karyometry. Six morphological indices (shell length, shell height, shell width, hinge length, total wet weight and shell weight) were measured. Differences in all morphological indices except hinge length were significant among the three populations (P < 0.05). The mean values of these indices (except for the hinge length) in the Dongxing population were larger than those in the Beihai and Shankou populations, although the latter had the largest hinge length. The karyotype of the Beihai, Shankou and Dongxing samples had ten metacentric, six submetacentric, and three subtelocentric chromosome pairs. No significant difference was shown in the centromeric index values of the chromosomes in the populations (P>0.05). However, the order of metacentric, submetacentric and subtelocentric chromosome pairs was variable among the three populations. The results indicate a high level of inter-population variation in morphology and karyotype.

Analysis of phospholipids in microalga Nitzschia closterium by UPLC-Q-TOF-MS

Precise structural identification of phospholipids in the microalga Nitzschia closterium has been established using ultra performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry (UPLC-ESI-Q-TOF-MS) for direct analysis of total lipid extracts.Mass spectrometry was performed in reflective time-of-flight using electron spraying ionization in negative mode.Phospholipid molecular species identification was based on the characteristic product ions and neutral loss yielded by different phospholipids under ESI-MS/MS mode.The molecular species were confirmed by the carboxylate anions produced by phospholipids in negative mode;the regiospecificity of the two acyl chains was determined from the ratio of sn-1 to sn-2 carboxylate anion abundances.As a result,18 lipid molecular species were identified for the first time in this microalga,comprising seven phosphatidylcholines (PC),two phosphatidylethanolamines (PE),two phosphatidylinositols (PI),and seven phosphatidylglycerols (PG).Lipid standards of PC,PE,PI,and PG were added to the total lipids as internal standards for semiquantitative analysis,revealing concentrations of phospholipids in this species between 0.09 and 3.37 nmol/mg.This method can produce a full structural profile of intact phospholipid molecular species and can be used for study of the physiological and ecological functions of lipids by monitoring their individual changes over time.

Comparison of Structures and Properties between Wool and Ramie Fibers Treated by Atmospheric Pressure Ar and Ar/O_2 Plasma

The technique of atmospheric pressure plasma is of value in textile industry.In this paper,argon(Ar)and argon/oxygen(Ar/O2)atmospheric pressure plasma were used to treat wool and ramie fibers.The structures and properties of treated fibers were investigated by means of SEM,XPS,single fiber tensile tester and so on.The results proved that the effects of plasma treatments depended on structural characteristics of fibers to a great extent,besides conditions of plasma treatment.By atmospheric pressure plasma treatment,wool fiber had significant changes in morphology structure,surface chemical component,mechanic properties and dyeability,while ramie fiber just showed a little change.In additional,Ar/O2 plasma showed more effective action than argon.And at the beginning of treatment,plasma brought about remarkable effects,which did not increase with prolonging of treat time.

奇幻与优雅——陈钧德,一位海派油画的继启者

本文从海派油画艺术文脉的角度切人,通过对陈钧德艺术历程的梳理,概括并剖析了画家从新世纪以来形成的团块式构形、以意生色、线面穿插、奇幻优雅的意蕴这四个方面的风格图式,深入探讨了陈钧德油画艺术的独特风貌及形成因素。作者认为,陈钧德在当代中国意象油画探索上,以其富有独创性的以意构色的奇幻与神秘以及在这些瑰丽的色彩里所呈现出的优雅、平和与宁谧,而成为当代海派油画最鲜明的艺术符号,是继刘海粟、林风眠、关良、吴大羽之后海派油画卓有影响的继启者。

Effect of Exposing Low-Frequency Electric Fields on the Proliferative Capacity and Morphological Features of Olfactory Ensheathing Cells in vitro

Olfactory ensheathing cells(OECs) transplanted into the damaged spinal cord may be considered as a valuable remedy explorations for spinal cord repair. The proliferation of transplanted olfactory ensheathing cells depends on various environmental factors and effective cues, which may include electrical fields(EFs). In this study, we investigated the proliferative capacity, morphologic alterations of olfactory ensheathing cells derived from neonate rat that occurd when exposed to two EFs of 20 Hz, 50 mV and20 Hz, 100 mV for 6 h. For both EF treatments, the MTT results revealed that the cellular proliferation of exposed group during the last 6 h of the experiment was statistically higher than that of control group. Then, we investigated morphological structure changes in the cells stained by Coomassie brilliant blue. Compared with control group, most of cells were present at intensively proliferating appearance including the microfilaments were long and thick and the accumulated appearance of cells. It is conceivable that electrical fields as a new approach may promote the growth and proliferation of OECs and may be engineered to control the survival of transplanted OECs in injured spinal cord.Although our results have been suggesting that EFs may be non-chemical strategies for cell proliferation, the fundamental mechanisms remain to be elucidated.