新型高温永磁体的研制

通过分析影响磁体高温性能的因素,设计了新磁体的成分为:Cu含量高,Fe含量低,Zr适量,Sm含量高;采用粉末冶金工艺制备了高温Sm_2(CoFeCuZr)_(17)永磁体。制得的磁体室温磁性能为:B_r1.075 T,H_(ei)2 098.2 kA/m,H_(eb) 776.1 kA/m,H_k843.8 kA/m,(BH)_(max)210.0 kj/m~3;在200℃时的磁性能为:B_r0.991 T,H_(ci)1 175.7 kA/m,H_(cb)531.7 kA/m,H_k577.9 kA/m,(BH)_(max)172.5 kJ/m~3;矫顽力温度系数β(20～200℃)为-0.24％/℃。经理论分析和实验验证,磁体的使用温度均超过400℃,为高温环境(高于400℃)提供了一种实用性永磁材料。     

熔融盐法合成高密度锂离子电池正极材料LiNi_(0.8)Co_(0.2)O_2

采用热分析法对不同组成的LiOH-LiNO3二元体系进行研究,绘制了具有最低共熔点的该二元体系的步冷曲线和t-x相图,该体系的最低共熔点为175.7℃。利用低共熔混合物LiNO3-LiOH为锂盐,与高密度前驱体Ni0.8Co0.2(OH)2混合经2个恒温阶段烧结(600℃恒温6 h、800℃恒温24 h)制备出了振实密度高达3.23 g/cm3的锂离子电池正极材料LiNi0.8Co0.2O2。X射线衍射分析表明合成的LiNi0.8Co0.2O2具有规整的层状NaFeO2结构。电性能测试表明:在0.5 mA/cm2放电电流密度和3.0—4.3 V的电压范围内,LiNi0.8Co0.2O2首次放电比容量达175(mA.h)/g,放电比容量为163(mA.h)/g,库仑效率为93%。实验结果表明采用该工艺能够制备出电化学性能良好的锂离子正极材料。     

控制棒钴吸收体的活度分布

应用单组中子微扰理论,对辐照后控制棒钴吸收体内活度分布进行理论分析,得到活度分布计算的解析表达式。对高通量工程试验堆(HFETR)首次出堆的2根控制棒钴吸收体进行数值计算。利用钴靶活度水下测量装置进行这2根钴吸收体活度分布的实验测量。计算与实验测量结果相符。通过理论计算所得到的活度分布可作为辐照后~(60)Co同位素分装依据。本文得到的控制棒相对价值曲线理论计算值与实验测量结果符合良好。     

Searching minimax game trees under memory space constraint

Games such as CHESS, GO and OTHELLO can be represented by minimax game trees. Among various search procedures to solve such game trees,- and SSS^* are perhaps most well known. Although it is proved that SSS^* explores only a subset of the nodes explored by-, - is commonly believed to be faster in real applications, since it requires very little memory space and hence its storage management cost is low. Contrary to this folklore, however, this paper reports, using the OTHELLO game as an example, that SSS^* is much faster than-. It is also demonstrated that SSS^* can be modified to make the required memory space controllable to some extent, while retaining the high efficiency of the original SSS^*.This research was partially supported by the Ministry of Education, Science and Culture of Japan, under a Scientific Grant-in-Aid.     

Study on structure and magnetic entropy changes of Ce2-xPrxFe16.5Co0.5 alloys

A series of Ce2-xPrxFe16.5Co0.5 alloys were preparedby arc melting under purified argon atmosphere. The structure and magnetic entropy changes in Ce2-xPrxFe16.5Co0.5 alloys were investigated by means of X-ray diffraction pattern and MPMS XL-7 magnetometer. The experimental results show that the crystal structure of Ce2-xPrxFe16.5Co0.5 alloys keeps in TH2Zn17-type rhombohedral, and the Curie temperature of Ce2-xPrxFe16.5Co0.5 alloys can be shifted to room temperature around by a composition adjustment. The magnetic entropy changes (-ΔSM) in Ce2-xPrxFe16.5Co0.5 alloys are relatively large, and a platform of magnetic entropy changes appearsnear the temperature TC. Ce2-xPrxFe16.5Co0.5 alloys are the potential working media for magnetic refrigeration with their stable chemical properties and especially low price.     

含钴锆基块状非晶合金的制备与力学性能

采用水淬法制备了Zr—Ti—Cu—Ni—Be—Co块状非晶合金(BMGs)。使用XRD进行相分析，采用热分析仪进行玻璃转变温度、晶化温度和热稳定性等的测定，用SEM观察试样压缩后的外表面和断口形貌。研究了Co对Zr—Ti—Cu—Ni—Be合金非晶形成能力(GFA)、热稳定性及力学性能的影响。结果表明：含Co的所有Zr—Ti—Cu—Ni—Be BMGs都有1个明显的玻璃转变点和宽的过冷液相区(△T）。Zr38Ti17Cu10.5Co12Be22.5合金具有和Zr41Ti14Cu12.5Ni10Be22.5合金相当的△T；Co的添加明显提高Zr—Ti—Cu—Ni—Be BMGs的力学性能，含Co量大于10at％的Zr—Ti—Cu—Ni—Be BMGs的压缩断裂强度（σf）超过2000MPa，Zr38Ti17Co22.5Be22.5合金的σf达到2230MPa，比Zr41Ti14Cu12.5Ni10Be22.5合金的σf提高23％。     

一种越野轮胎的结构设计

本文介绍了285/70R17 121Q规格越野轮胎的设计。外轮廓方面:轮胎的设计外直径834 mm,充气断面宽292 mm,轮胎的行驶面宽240 mm,设计行驶面弧高度11.8 mm,胎圈着合直径取值430 mm,轮胎的胎圈着合宽度245 mm,轮胎的断面水平轴位置取值0.842 3;轮胎的胎面花纹设计分为M型和L型,2种花纹为交替变节距呈现,花纹深度13.3 mm,花纹饱和度66.26%。轮胎的施工设计方面:胎面挤出部件位全分层设计,可更好的区分胶种,功能性更强,胎侧挤出部件为双复合设计,冠带层的1#、2#带束层材料使用3×0.30 HT钢丝帘线,胎圈部位的钢丝圈为斜六角形结构,更好的保证了成品断面钢丝圈部位,切割后的近圆形;胎胚的成型使用的设备是萨驰一次法成型机,胎胚的硫化使用的设备是韩国东和液压硫化机,硫化工艺为氮气硫化。生产的成品轮胎的外缘尺寸、强度性能和耐久性能等均满足国家标准要求。     

一种雪地轮胎的结构设计

本文介绍了265/70R17115S规格雪地轮胎的设计,外轮廓方面,轮胎的设计外直径797 mm,充气断面宽282 mm,轮胎的行驶面宽207 mm,设计行驶面弧高度8.5 mm,胎圈着合直径取值430 mm,轮胎的胎圈着合宽度237.8 mm,轮胎的断面水平轴位置取值0.96746;轮胎的胎面花纹设计分为长型花纹(M型、L型)与短型花纹(S型),3种花纹为交替变节距呈现,花纹深度10.4 mm,花纹饱和度68.16%。轮胎的施工设计方面:胎面挤出部件为全分层设计,可更好的区分胶种,功能性更强,胎侧挤出部件为双复合设计,冠带层的1#、2#带束层材料使用3×0.30HT钢丝帘线,胎圈部位的钢丝圈为斜六角形结构,更好的保证了成品断面钢丝圈部位,切割后呈近圆形;胎胚成型使用的设备是萨驰一次法成型机,胎胚硫化使用的设备是韩国东和液压硫化机,硫化工艺为氮气硫化。生产的成品轮胎的外缘尺寸、强度性能和耐久性能等均满足国家标准要求。     

mRNA and miRNA Expression Analyses of the MYC/E2F/miR-17-92 Network in the Most Common Pediatric Brain Tumors

Numerous molecular factors disrupt the correctness of the cell cycle process leading to the development of cancer due to increased cell proliferation. Among known causative factors of such process is abnormal gene expression. Nowadays in the light of current knowledge such alterations are frequently considered in the context of mRNA–miRNA correlation. One of the molecular factors with potential value in tumorigenesis is the feedback loop between MYC and E2F genes in which miR-17-5p and miR-20a from the miR-17-92 cluster are involved. The current literature shows that overexpression of the members of the OncomiR-1 are involved in the development of many solid tumors. In the present work, we investigated the expression of components of the MYC/E2F/miR-17-92 network and their closely related elements including members of MYC and E2F families and miRNAs from two paralogs of miR-17-92: miR-106b-25 and miR-106a-363, in the most common brain tumors of childhood, pilocytic astrocytoma (PA), WHO grade 1; ependymoma (EP), WHO grade 2; and medulloblastoma (MB), WHO grade 4. We showed that the highest gene expression was observed in the MYC family for MYCN and in the E2F family for E2F2. Positive correlation was observed between the gene expression and tumor grade and type, with the highest expression being noted for medulloblastomas, followed by ependymomas, and the lowest for pilocytic astrocytomas. Most members of miR-17-92, miR-106a-363 and miR-106b-25 clusters were upregulated and the highest expression was noted for miR-18a and miR-18b. The rest of the miRNAs, including miR-19a, miR-92a, miR-106a, miR-93, or miR-25 also showed high values. miR-17-5p, miR-20a obtained a high level of expression in medulloblastomas and ependymomas, while close to the control in the pilocytic astrocytoma samples. miRNA expression also depended on tumor grade and histology.     

Interplay between Humoral and CLA+ T Cell Response against Candida albicans in Psoriasis

Candida albicans (CA) infections have been associated with psoriasis onset or disease flares. However, the integrated immune response against this fungus is still poorly characterized in psoriasis. We studied specific immunoglobulins in plasma and the CA response in cocultures of circulating memory CD45RA⁻ cutaneous lymphocyte antigen (CLA)^+/− T cell with autologous epidermal cells from plaque and guttate psoriasis patients (cohort 1, n = 52), and also healthy individuals (n = 17). A complete proteomic profile was also evaluated in plaque psoriasis patients (cohort 2, n = 114) regarding their anti-CA IgA levels. Increased anti-CA IgA and IgG levels are present in the plasma from plaque but not guttate psoriasis compared to healthy controls. CA cellular response is confined to CLA⁺ T cells and is primarily Th17. The levels of anti-CA IgA are directly associated with CLA⁺ Th17 response in plaque psoriasis. Proteomic analysis revealed distinct profiles in psoriasis patients with high anti-CA IgA. C-C motif chemokine ligand 18, chitinase-3-like protein 1 and azurocidin were significantly elevated in the plasma from plaque psoriasis patients with high anti-CA levels and severe disease. Our results indicate a mechanism by which Candida albicans exposure can trigger a clinically relevant IL-17 response in psoriasis. Assessing anti-CA IgA levels may be useful in order to evaluate chronic psoriasis patients.