Morphological and palynological assessment of taxonomically problematic genus Paspalum based on light and scanning electron microscopy

Present research work was carried out to clarify the variations among species of genus Paspalum morphologically and palynologically as this genus is taxonomically difficult due to having multiple similar morphologically overlapping characters which make it difficult to identify. Henceforth present research work was carried out to delimit taxa within the same genus by morphological and palynological tools through light microscopy (LM) and scanning electron microscopy (SEM). Both these tools are considered as the most useful taxonomic characters for taxonomically problematic genera. The results showed a lot of variations among morphological characters. In Paspalum dilatatum, the upper glume was ovate whereas in the other two species, the upper glume was elliptic. The upper glume apex found in P. dilatatum and Paspalum scrobiculatum was obtuse whereas in Paspalum distichum, upper glume apex was acute. Glume nerves showed variation in all three species. Paspalum distichum was 3 nerved, P. scrobiculatum was 5–7 nerved, and P. dilatatum was 5–9 nerved. All three species showed variation in lemma nerves. Paspalum scrobiculatum had 3 nerved lemma whereas in P. distichum 3–5 nerved and P. dilatatum 5–9 nerved lemma were present. In polar and equatorial view, pollen grains ranged from 25 (20–30) to 37.5 (30–45) μm. Paspalum distichum appeared to be the smallest in size whereas P. dilatatum was the largest. Exine thickness ranged from 0.75 (0.5–1) to 1.35 (1.2–1.5) μm. The higher value of pollen fertility was found in P. scrobiculatum as 87.69% and the lowest value was in P. distichum as 78.08%. Morphological keys were also given for correct identification.     

液压自由活塞发动机的发展历程及研究现状

介绍了液压自由活塞发动机的发展历程、工作原理、典型系统、研究现状及研发中的关键技术问题     

汽车油箱咬合成形机的设计

介绍全自动油箱咬合成形机的设计研究 ,实践证明此专机保证了产品质量 ,满足了大批量、多品种油箱生产需要     

孟子“深造自得”解析

“深造自得”一语最早出自两千多年前的思想家、教育家孟子。对此,许多学者都从不同角度进行了阐释。本文结合有关思想家、教育家的言论对其进行解读,发现“深造自得”是向内心求索的学习,是自觉与自悟的学习,是质疑问难的学习。是自我反省的学习,是虚心涵泳的学习,是自我体验的学习,是自然真乐的学习,是日新日进的学习,是居敬持志的学习。“深造自得”作为一种古代学习策略对后世学者产生了深远的影响。也得到许多后世学者直接或间接的阐释和弘扬。这一古老而富有生命力的学习策略,对于当下人们的学习仍具有启发与借鉴的价值。     

空压机润滑油系统可靠性试验研究

对空压机润滑系统进行分析,提出了一种润滑油压力调节机构,保证了空压机在高油温时油压正常,为空压机运动件提供充分润滑,从而提高空压机运行的可靠性。实验证明了该机构是可靠的,为空压机润滑系统设计提供了参考依据。     

基于用户体验的产品感官研究

随着技术的发展,用户对产品的要求不断提高.体验设计突出了顾客感性价值的重要性,它试图通过更生动更富情趣的产品,来营造更为完善的用户体验.文中在分析了用户体验理论及其与用户感官联系的基础上,针对产品设计中包括视觉、听觉、触觉在内的多种感官因素,结合案例予以分析.     

Typical flow measurement problems and their solution in the electricity supply industry

This article reviews several typical flow measurement problems encountered in the electricity supply industry and presents successful solutions to them. The results of careful performance tests on clamp-on ultrasonic flowmeters are also presented.     

Quantization of widefield fluorescence images using structured illumination and image analysis software

It is difficult to obtain precise quantitative measurements from fluorescent images captured from widefield microscopes. We wished to ascertain if reliable quantitative measurements of both biological and nonbiological specimens were possible using a widefield microscope equipped with a structured illumination system and image analysis software. In a nonbiological specimen, images were obtained from fluorescent beads of known intensity. For a biologically relevant model we used the uptake of fluorescently labeled transferrin by HeLa cells in culture. In the bead sample, the mean intensity of beads acquired with the structured illumination system showed relative intensities near to the predicted values without any further manipulation of data. In the transferrin uptake experiments, uptake and subsequent recycling of the labeled transferrin could be accurately and reproducibly measured. We conclude that using a combination of structured illumination and image processing algorithms accurate quantization of fluorescent images can be achieved in widefield microscopy.     

高速电路板设计中的特性阻抗问题研究

在高速电路板设计中，可控阻抗板和线路的特性阻抗问题困扰着许多技术人员。通过简单且直观的方法介绍了特性阻抗的基本性质、计算和测量方法。     

Automated extraction of free surface topography using SfM-MVS photogrammetry

This paper describes a spatial measurement technique to measure the free surface of natural fluid flows in laboratory applications. This effective solution is based on “Structure-from- Motion/Multi-view Stereo” (SfM-MVS) photogrammetry and is capable of reconstructing water surface morphology, both at an instant and with a high spatial resolution. The efficiency and accuracy of the method is dependent upon the acquisition of high quality imagery (i.e. sharply focussed, no motion blur) with appropriate multi-frame camera coverage and configuration, and data processing must utilise appropriate camera calibration data. The potential of the technique for developing hydraulic understanding is demonstrated using two contrasting approaches. First, the water surface behind a living vegetation element is analysed along a single transect. Second, the full three-dimensional characteristics of the captured water surfaces are examined using statistical methods which demonstrate surface dissimilarity between vegetated and non-vegetated cases. The technique is transferable to real-world field sites.     

Foliar micromorphology and its role in identification of the Apocynaceae taxa

In the present study, we evaluate the importance of foliar epidermal micromorphological characteristics of Apocyanaceae for accurate identification and classification. The species were collected from the University of Peshawar's main campus in the spring season to observe its qualitative and quantitative features. The length and width of guard cells, stomatal pore and subsidiary cells, trichomes, and crypts on both sides of the leaf were examined. Many species were observed to be hypostomatic. Plumeria rubra, Raulfia serpentine, Thevetia peruviana, Trachelospermum lucidum, Alstonia scholaris, and Catharanthus roseus demonstrated hypostomatic leaves. Nearly all the investigated species had anisocytic type of stomata only or in combination with other types of stomata on the upper and lower epidermis. Carissa carandas had anomocytic, anisocytic, and cyclocytic type of stomata on the upper epidermis, and the lower epidermis showed variations in stomatal type, such as anomocytic, stephanocytic, brachyparacytic, and hemiparacytic. Nerium oleander had no specific shape of stomata but showed stomatal crypts in which the stomata were enclosed inside many trichomes. The taxonomic key based on stomatal types, epidermal cells, stomatal index value, and statistical analysis, along with the variations in the epidermal cells, shows the link between the selected plants species, which will provide a baseline for future anatomical studies. This study highlights many undocumented micromorphological characteristics. The anatomical characteristics observed in this study will be helpful for taxonomic identification and species delimitation of the family Apocynaceae.     

CIMS环境下的工艺过程设计特点的探讨

在CIMS环境下开发的CAPP/CAM系统的基础上,探讨了CIMS对机械工艺过程设计原则、特点、基本概念及各种组成部分地位的变化。     

浅谈仪表专业控制运算在芳烃装置中的应用

对二甲苯芳烃联合装置吸附分离单元转阀自动控制系统工作情况、参数的调整,结合乌鲁木齐石化公司炼油厂年产百万吨案例进行分析,总结出此类控制运算在应用过程中出现的一些问题及相关解决方法。     

Contact force studies of a burnishing slider

In order to design the flying height of a burnishing slider accurately, the contact force between the burnishing slider and the disk needs to be well evaluated. This paper studies the contact force of a burnishing slider by both experiment and simulation. The experiment is conducted by measuring the acoustic emission signals of the contact force avalanche, and the simulation is based on the self-developed air bearing surface simulation code applying the probability model for the contact force calculation. The influence of contact force on the burnishing effect is discussed. It is observed that the simulation results are well correlated with the experimental measurements. It is believed that the simulation code is capable to design burnishing sliders with reasonable accuracy.     

集光式高精二维追日跟踪器的建模与仿真研究

太阳能可利用量巨大,具有开发的便利性和清洁型,是一种极具开发前景的可再生能源。由于阳光会随著季节和天气有规律的变化,因此需要搭建一个高精度二维追日跟踪器,提高能量利用效率。论文建立了跟踪器传动链数学模型,使用S1MULINK进行了控制系统仿真,得到不同条件下的仿真曲线,以帮助系统的设计及改进。     

Electron microscopic localization of enkephalin-like immunoreactivity in the human adrenal medulla

Enkephalin-like immunoreactivity in human adrenomedullary cells was studied at the light and electron microscopic levels. Enkephalin immunostaining was associated with chromaffin granules and, in a few cells, with the rough endoplasmic reticulum as well. The relative number of stained granules varied from cell to cell, and a correlation with a particular granular population was not noted. Both large and small granules were labelled. It is concluded that in the human the ability to store enkephalin immunoreactive peptides is a general property of chromaffin granules and, furthermore, is not correlated with specific granular subpopulations or the particular type of catecholamine stored within the cell.     

我国上市公司的会计责任现状分析及对策探讨

基于我国上市公司履行的会计社会责任,分析了上市公司的会计责任现存问题,并对各类问题提出了相应的对策和方法.     

A balanced technique for preparation of specimens from pathogenicity studies for scanning electron microscopy

This paper reports our experiences with preparing delicate biological specimens for scanning electron microscopy. Three different washing methods were evaluated: One method allowed the analysis of the location of the bacterium Mycoplasma mobile on piscine gill epithelium and the optimal evaluation of histopathologic changes caused by this microbe. These results were achieved when specimens were washed three times in a cacodylic acid buffer after completion of the in vitro infection experiment in gill explant cultures. We also found that of three different concentrations of glutaraldehyde, a fixation with a 1.5% solution was sufficient to achieve excellent structural preservation, even without using post fixation in osmium tetroxide. Furthermore, this study showed that the use of acetone-carbon dioxide in the critical point drying procedure resulted in well-preserved piscine gill epithelium and mycoplasmas. Finally, long-term storage of tissue specimens in 0.1 M cacodylic acid buffer is possible if the buffer is changed on a monthly basis to avoid growth of unwanted microorganisms, such as fungi.     

中国大学通识教育二十年的发展现状及理性省察

通识教育作为教育理念和教育实践的统一体，索，我国通识教育的理论研究与教育实践都取得了长足进步，究不足、本土化不够、制度保障不力等根本性问题。是重要的高等教育模式。经过最近20年的不懈探但由于还处于起步阶段，目前仍然存在本体论研     

Hypothalamic regulatory peptides and their receptors: Cytochemical studies of their role in regulation at the adenohypophyseal level

Hypothalamic regulatory peptides bind to specific receptors on target cells in the pituitary and control secretion. They in turn can be regulated at the pituitary level by steroid and peptide modulators. Affinity cytochemical techniques are important tools for the identification of specific target binding sites for these regulatory peptides. This presentation reviews the work in which potent, biotinylated ligands of gonadotropin releasing hormone (bio-GnRH), corticotropin releasing hormone (bio-CRH), and arginine vasopressin (bio-AVP) were applied to study the target cell responses. Bio-GnRH, bio-CRH, and bio-AVP bind to membrane receptors on specific anterior pituitary cells. Dual labeling for either gonadotropin or adrenocorticotropin (ACTH) antigens further identified the target cells. After 1–3 minutes, the label was in patches or capped on the surface. After 3 minutes, it was internalized in small vesicles and sent to receptosomes and vacuoles in the Golgi complex. Eventually the biotinylated peptides, or a metabolite, was found in the lysosomes (multivesicular bodies) and a subpopulation of secretory granules. The route and rate of uptake was similar to that described for the classical receptor-mediated endocytosis process. In contrast, intermediate lobe corticotropes internalized the bio-CRH in less than 1 minute. The route through the Golgi complex appeared to be bypassed. Instead the labeled peptide was in vesicles, on the membranes of scattered vacuoles, and in multivesicular bodies. Modulation of ligand binding by steroids showed that changes in receptor numbers correlated with changes in the number of cells that bound the ligand. In male rats, dihydrotestosterone reduced the percentage of GnRH-bound cells by 50%. Most of the reduction appeared in cells that stored luteinizing hormone (LH) antigens. In diestrous female rats, estradiol increased the percentage of bio-GnRH-bound cells. However, the steroid decreased the percentage of GnRH-bound cells in cells from proestrous rats. Glucocorticoids decreased the percentage of CRH-bound corticotropes in as little as 10 minutes. Potentiation of secretion by these ligands was correlated with increases in the percentage of ligand-bound cells. AVP pretreatment of corticotropes increased the percentage of cells that bound bio-CRH. It also increased the rate of receptor-mediated endocytosis of CRH and changed the route so that the Golgi complex was bypassed. This effect could be mimicked by activation of its second messengers (calcium and protein kinase C). Similarly, CRH pretreatment increased the percentage of corticotropes that bound AVP. Thyrotropin releasing hormone (TRH) pretreatment also increased the percentage of thyrotropes that bound AVP. Finally, calcium or sodium channel blockers altered CRH binding so that fewer cells were labeled. This binding by CRH was not dependent on extracellular calcium and tests with a calcium channel agonist showed that it was related to activation of calcium channels. To summarize, these affinity cytochemical studies have identified specific target cells in the pituitary for GnRH, CRH, and AVP. They have also identified heterogeneity in the population. They have demonstrated new information about the direct modulatory effects of steroids, ion channels, and neuropeptides on neuropeptide binding by subpopulations of these target cells.