演示"电子秤的简明原理"的教具制作

采用了学生熟悉的器材和常见的材料制作了与电子秤组成相同且原理一致的教具,该装置的力电转换部分采用了分压电路,可较好地演示电子秤的工作原理.     

拉伸法测金属丝杨氏模量实验装置的改进

对原有的杨氏模量实验仪存在的主要问题进行了分析,针对这些问题分别提出了相应的改进措施,克服了原有仪器存在的不足,在一定程度上可以提高实验精度。     

Quantification in histopathology—Can magnetic particles help?

Every year, more than 270,000 people are diagnosed with cancer in the UK alone; this means that one in three people worldwide contract cancer within their lifetime. Histopathology is the principle method for confirming cancer and directing treatment. In this paper, a novel application of magnetic particles is proposed to help address the problem of subjectivity in histopathology. Preliminary results indicate that magnetic nanoparticles cannot only be used to assist diagnosis through improving quantification but also potentially increase throughput, hence offering a way of dramatically reducing costs within the routine histopathology laboratory.     

Effects of external magnetic field on biodistribution of nanoparticles: A histological study

This study investigates the effect of external magnetic fields on the biodistribution of nanoparticles (NP). A NdFeB magnet of 2.4 kG was externally applied over the left femoral artery or right kidney. The 250 nm dextran-coated Fe₃O₄ NP was injected via tail vein in healthy rats, and organs were taken 1 or 24 h later. Prussian blue stain revealed that NP were more rapidly retained in the liver and spleen than in the lungs. NP aggregation observed in the kidney and femoral artery after application of external magnets was time dependent. Hollow organs such as the intestine, colon, and urinary bladder retained little NP.     

Homeomorphisms and the homology of non-orientable surfaces

We show that, for a closed non-orientable surfaceF, an automorphism ofH ₁(F, ℤ) is induced by a homeomorphism ofF if and only if it preserves the (mod 2) intersection pairing. We shall also prove the corresponding result for punctured surfaces.     

Slip and slide method of factoring trinomials with integer coefficients over the integers

In intermediate and college algebra courses there are a number of methods for factoring quadratic trinomials with integer coefficients over the integers. Some of these methods have been given names, such as trial and error, reversing FOIL, AC method, middle term splitting method and slip and slide method. The purpose of this article is to discuss the Slip and Slide Method and present a theoretical justification of why it works.     

Morphology and ultrastructural studies of pineal organ of the tree sparrow (Passer montanus)

We studied fine structures of the pineal organ of the tree sparrow, Passer montanus under the light, scanner electron and transmission electron microscopes. The pineal gland of the sparrow was found comprising of a pea-shaped epiphysis cerebri and a long tube-like pineal stalk that connects with the choroid plexus. Histological preparations of the pineal organ revealed that it contains follicles having pinealocytes of uniform size. The enlarged images of the gland using the SEM showed distinct granular structures or cells protruding from the surface of the epiphysis cerebri. The choroid plexus possessed varying numbers of irregular ridges and furrows. The observation under TEM revealed rounded nucleus and mitochondria in the pinealocytes. Groups of small size vesicles were also seen scattered throughout the perinuclear cytoplasm. Numbers of microtubules were found running parallel to each other. Blood capillaries that supply blood to the pineal organ were also visible in the sections. The morphology of the pineal organ of tree sparrow showed similarity with those of the other birds in possessing elongated epiphysis cerebri which remains connected to choroid plexus through a stalk. The tree sparrow resembled with some passerine birds in possessing saccular type of pineal organ having elongated tubular structure with a central lumen and a thick follicular wall. The pineal organ of the tree sparrow, thus, differed from those reported in non-passerine birds with tubulo-follicular or solid type of pineal organ. The presence of saccular pineal organ in the subtropical tree sparrow, as reported in other passerine birds elsewhere indicates the conservation of the structural organization of the pineal organ in passerine birds.     

干式生化膜片的制备及其应用

建立了一种快速检测血液中二氧化碳结合力(CO₂-CP)、葡萄糖(GLU)、尿酸(UA)含量的干式生化分析方法。筛选出合适的膜材料作为干片载体, 制备干片, 用干式生化分析仪检测干片, 建立了测定血液中CO₂-CP、GLU、UA含量的标准曲线, 对所建立的方法进行加标回收实验、稳定性实验、批间、批内重复性实验、方法学比较。 此法制备的干片颜色梯度明显、显色均匀, 测定CO₂-CP、GLU、UA的线性范围较宽;批间与批内变异系数均小于5%, 重复性良好;与临床湿化学检测相比具有良好的相关性, 相关系数大于0.99, 可应用于临床检测。     

土层锚杆抗滑桩嵌固深度的试验研究

相比普通抗滑桩,桩顶锚杆的存在可以极大减小桩身内力和嵌固深度,但其计算方法目前还不是很完善,且带有一定的工程经验,因而开展这方面的试验研究就显得十分必要。本文首先介绍了土层锚杆抗滑桩系统桩侧地层抗力分布规律的室内模型试验成果,试验分三组,其中两组在坡体后缘加载,一组用千斤顶直接在桩后加载,桩身上各贴有一定数量的土压力盒,用以测定作用于桩身上的地层抗力。从试验中,得出了土层锚杆抗滑桩桩身地层抗力主要分布在桩前滑面以下部分及最大值出现的部位,并给出了桩前滑面以下部分抗力值的大致范围。然后根据试验结果,应用滑移线解法,分别计算了抗力分布为三角形与梯形时土层锚杆抗滑桩嵌固深度,最后与实际结果进行了比较。