基于动态模板匹配技术的放疗摆位误差测量

本文考虑到病人在放射治疗过程中身体发生变形而使得基于固定模板匹配方法测量重复摆位误差精度降低的问题,提出了基于动态模板匹配的放疗病人重复摆位方法。该方法是对基于CT重建数字射线图像(DRR)作为模板进行匹配的重复摆位技术的改进,将能反映病人体态变化的视频重建三维体表模型作为匹配的模板进行摆位误差的计算。理论研究和实际检验表明,采用动态视频模板匹配的摆位方法,可以在保证摆位精度的同时消除因病人身体变形带来的不利影响。

Study on Fruit Quality, Phenological Phases and Shoot Histomorphology of a New Bud Mutant Line, ‘Chuanzao Loquat’

[Objective] This study was to explore the growth characteristics and fruit quality of a new bud mutant line, ＇Chuanzao Loquat＇. [Method] Paraffin section technique combined with field investigation method were adopted to conduct com- parative analysis of shoot histomorphology and phenological phases between two Io- quat varieties, ＇Chuanzao Loquat＇ and ＇Zaozhong 6＇. [Result] ＇Chuanzao Loquat＇ branched out and unfolded leaves about half to a month earlier than ＇Zaozhong 6＇; both the flowering and fruiting phases of ＇Chuanzao Loquat＇ were three months earlier than a precocious variety, ＇Zaozhong 6＇; the proportions of epidermis, cortex parenchyma, vascular tissue and medulla were 3.7%, 14.5%, 15.9% and 65.9%, re- spectively, in spdng shoots of ＇Chuanzao Loquat＇, and 3.1%, 42.5%, 6.9% and 47.5%, respectively, in ＇Zaozhong 6＇. [Conclusion] In terms of phenological phases, ＇Chuanzao Loqua＇ is earlier than ＇Zaozhong 6＇, a currently widely planted precocious variety, and thus is an important germplasm resource of Ioquats.

An Explorative Research into the Factors Affecting Chinese Students＇ Retention and Application of English New Words

Vocabulary has a direct impact on people＇s communication competence. A good mastery of an English word covers its pronunciation, spelling, part of speech, meaning and application. This article will focus only on factors affecting the retention and application of a word from the perspective of semantic disparities, different defining angles in English and Chinese, emotional coloring and styles, morphological changes, and collocation. The author hopes that this article will be able to provide some insights into vocabulary teaching.

Morphological Analysis and Gene Mapping of a Rice Dwarf Mutant

[Objective] This study aimed to conduct morphological analysis and gene mapping of a rice dwarf mutant. [Method] A dwarf mutant （Xiaoxiang＇ai） was used as test material for morphological observation. Xiaoxiang＇ai was used as female parent and semi-dwarf material Xiangzao143 was used as male parent to construct populations for genetic analysis. Gene mapping was conducted by using micro- satellite markers. [Result] The average height of Xiaoxiang＇ai was 55 cm; genetic analysis results showed that plant height of F1 individuals was similar with the male parent, while semi-dwarf plants and dwarf plants were observed in F2 populations and the segregation ratio was nearly 3：1, indicating that plant height trait of Xiaoxi- ang＇ai is mainly controlled by one pair of recessive gene located on rice chromo- some 5 and in the upstream of RM249, with a genetic distance of 8.4 cM. [Conclu- sion] rRH is a new dwarf gene in rice.

High temperature tribological behaviors of aluminum matrix composites reinforced with solid lubricant particles

The AA6061-10 wt.%B4 C mono composite, AA6061-10 wt.%B4 C-Gr(Gr: graphite) hybrid composites containing 2.5, 5, and 7.5 wt.% Gr particles, and AA6061-10 wt.%B4 C-Mo S2 hybrid composites containing 2.5, 5, and 7.5 wt.% Mo S2 particles were fabricated through stir casting. The dry sliding tribological behaviors of the mono composite and hybrid composites were studied as a function of temperature on high temperature pin-on-disc tribotester against EN 31 counterface. The wear rate and friction coefficient of the Gr-reinforced and Mo S2-reinforced hybrid composites decreased in the temperature range of 30-100 ℃ due to the combined lubrication offered by the wear protective layer and its solid lubricant phase. Scanning electron microscopy(SEM) observation of the worn pin surface revealed severe adhesion, delamination, and abrasion wear mechanisms at temperatures of 150, 200, and 250 ℃, respectively. At 150 ℃, transmission electron microscopy(TEM) observation of the hybrid composites revealed the formation of deformation bands due to severe plastic deformation and fine crystalline structure due to dynamic recrystallization.

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.

Karyological and morphometric variation of the North African green frog Pelophylax saharicus (Anura) in northeastern Africa

Morphometric variation ofPelophylax saharicus was analysed using univariate and multivariate statistics, with both traditional and geometric morphometrics, based on 148 specimens from four different geographical localities in Tunisia and Algeria. The results show the existence of three morphotypes in Tunisia and one in Algeria, and indicate a significant degree of variation in morphometric characters between regions. Specimens from the southernmost region have the smallest body size and the greatest morphometrie divergence from other populations. This pattern of morphometric variation probably results from phenotypic plasticity in response to local environmental factors. The results of our chromosomal study （C-, Ag-NOR-, endonuclease digestion, DAPI, CMA3 and Q-banding） reveal this species to exhibit the plesiomorphic Pelophylax karyotype of 2n=26 biarmed chromosomes and NORs on the eleventh pair. Similarities and differences of the North African green frog are discussed in relation to the different forms of data collected （chromosomal, morphometric, ecological） [Current Zoology 56 （6）： 678~586, 2010].

Mechanism of stepwise tectonic control on gas occurrence: A study in North China

To gain an understanding of gas occurrence, distribution is the fundamental basis for preventing gas disasters. Presently, how tectonic structures control gas occurrence remains problematic. This study proposes the theory and elucidates the mechanism of stepwise tectonic control on gas occurrence according to the characteristics of gas occurrence and the patterns of gas distribution in coal mines in North China. On the one hand, tectonic compression and shearing lead to stress concentration and thus deform the coal and reduce the coal seam permeability, further contributing to gas preservation. On the other hand, tectonic extension and rifting lead to stress release and thus improve the coal seam permeability, further contributing to gas emission. Therefore, the distribution zones of tectonic compression, ubiquitous coal deformation, and gas accumulation have been step-wisely revealed, and the coal-gas outburst proneness zones are finally identified. The proposed theory of step-wise tectonic control on gas occurrence is of practical significance for gas prediction and control.

Morphology and survival of cryopreserved-thawed ovarian tissues after heterotopic autotransplantation

Objective： The aim of our study was to observe the survival and morphological changes of thawed ovarian tis- sues after heterotopic transplantation. Methods： Twenty SPF-SD female rats （5-6 weeks old） were equally randomized into the control group and experimental group. In control group, the freshly isolated ovaries were fixed in formalin. In experimental group, the freshly isolated ovaries were vitrified immediately and cut into thin slices. After stored in liquid nitrogen for 21 days, the tissues of experimental group were rapidly thawed and transplanted into back muscles of rats for 2 or 4 weeks, respectively. After that, all rats in experimental group were sacrificed and the ovarian tissues were collected and fixed in 4% formaldehyde solution. Then the ovarian tissues were stained with HE and observed under the light confocal microscope. Re- suits： With the naked eyes, there was no specific alteration except the size reduction with color changing. Under microscopy, we found normal cortex and medulla in the ovary, and the primordial follicles and follicles in various stages were observed in the cortex. The normal oocytes in ovarian tissues of experimental group were significant decreased than in the control group. Conclusion： The ovarian tissues survive well in experimental group and there is no significant difference in the proportion of follicles between different times （2 and 4 weeks） after grafting. Our results suggest that thawed ovarian tissues could survive after heterotopic transplantation into back muscles of rat models and maintain their morphology and function.

Variability in the Content of 25α- and 25β-Steroidal Sapogenins among Thirty Morphologically Different Sudanese Seed Accessions of Fenugreek

Seeds of Fenugreek （Trigonellafoenum-graecum L.）, an international spice commodity, are much consumed in Sudan as a food, for flavoring and as a folk-remedy for several ailments, together with local beliefs in nutraceutical benefits. The authors have noted an immense variability in colour and other morphological characters of Fenugreek seeds offered in local Sudanese markets and wondered whether this variability is extended to their chemical composition. Steroidal sapogenins are important chemical constituents of Fenugreek seeds in view of their potential as precursors for the commercial synthesis of steroid drugs and their continually revealed beneficial biological activities. In this study, thirty Sudanese Fenugreek seed accessions collected from different geographical regions in Sudan were analyzed for their 25α-, 25β- and total sapogenin content using a simple and specific infra-red spectroscopic method. The seed accessions exhibited much morphological variability particularly in outer seed coat color and size. Preparative TLC followed by gravimetric analysis showed that steroidal sapogenins, mostly diosgenin and yamogenin, represented more than 70% of the steroids of Fenugreek seeds. Infra-red spectroscopic analysis showed that total 25α-sapogenins （calculated as diosgenin） varied from 0.65% to 1.68%. Total 25β-sapogenin （calculated as yamogenin） varied from 0.38% to 2.03%. The content of total sapogenins （α ＋ β epimeric forms） varied between 1.24% and 3.0% of the oven-dry weight of seeds. β-sapogenins （mostly yamogenin） were dominant over α-sapogenins （diosgenin） in most Sudanese Fenugreek seed accessions.

Morphological variation and distribution of free neuromasts during half-smooth tongue sole Cynoglossus semilaevis ontogeny

This study was conducted to clarify the distribution and morphology of free neuromasts during the development of half-smooth tongue sole （Cynoglossus semilaevis） using scanning electron microscopy. During development, （1） the apical surface of free neuromasts changed in shape from a circle to a four-poiut star; （2） the external structure changed from being level with the epidermis to papilla-like above the level of the epidermis; （3） the neuromast cupula changed from cylindrical to blade-shaped; （4） the free neuromasts went from occurring singly to being in clusters of a few single organs; （5） the arrangement changed from a linear array to no discernable pattern; （6） there was a significant increase in the number of free neuromasts after metamorphosis. In adult C. semilaevis, free neuromasts were only observed on the abocular side of the head. Thus, there were more free neuromasts located on the abocular side of the head with a higher concentration around the anterior nostril and mouth, which may have a mechanical sensory function to help locate food as an adaptation to a benthic mode of life.

The Preparation of Ultra-fine Calcium Carbonate and Its properties Study

This article adopts the double decomposition method, select the appropriate experimental conditions and operation process, respectively add appropriate amount of sodium carboxymethyl cellulose （CMC） as crystal control agent to study the influence of crystalline of ultrafine calcium carbonate. The experimental results show that the different concentrations of CMC as crystal control agent on the morphology and crystal structure of calcium carbonate have obvious effect, which emerge morphology change from square to spherical, crystalline transition from calcite to aragonite. Thus, the results provide experimental data and theoretical basis for the use of different additives, and provide experimental basis and feasible solution for this kind of reaction.

Motion and Deformation State of the Tancheng-Lujiang Fault Zone Derived from GPS Data

Based on the rotation in the entire block and homogeneous strain model ( REHSM) ,we firstly analyze the motion and deformation features across the southern part of Tancheng- Lujiang fault zone from GPS velocity fields in period of 1999 ～ 2001,2001 ～ 2004,2004 ～ 2007 and 2007 ～ 2009. The results show a dextral strike-slip feature in the Weifang- Tancheng segment and sinistral strike-slip in the Tancheng-Lujiang segment. And the deformation perpendicular to the Tancheng-Lujiang fault zone alternates between tension and compression in different time-intervals. Then we resolve the relative rigid motion of blocks around Bohai Bay to the Circum-Bohai Sea area by deducting the entire rigid motion of the Circum-Bohai Sea area. We find that the Yanshan-Bohai seismic belt split this area into two parts,the northern part moving NW,and the other SE.

Effects of alkaline earth oxides on precipitation behavior of metallic iron under CO atmosphere

In gaseous reduction of iron ore fines, alkaline earth oxides have profound effects on the precipitation behavior of fresh metal- lic iron on the particle surface. In this work, in situ observation was performed to reveal the influence of alkaline earth oxides on the precipitation morphology and micro-structure variation of fresh metallic iron from microscopic level by simulation of the gas-solid reaction condition on the surface of ore particles. Experimental results indicate that doping MgO in the particle surface can inhibit the reduction of iron oxide and however doping CaO, SrO and BaO promote; all alkaline earth oxides tested in this study can change the precipitation morphology of fresh metallic iron; minimum doping mole fraction of one oxide to inhibit iron whiskers growth （ NAO ） is related to its cation radius （ r：＋ ） and its extranuclear electronic layers（nAD ）, which can be expressed as NAO = 1.3 × 10^-5r^2AD,√nA^2.