2000年中国机械工程学会部分学术活动预报

项目编号活动项目名称时　间地点联系人电话工　作　总　部X2 0 0 0 0 0 0 1第 6届国际机械工程学会联合会会议 11.18～ 19上海张　强 0 10 - 6 85 95 319X2 0 0 0 0 0 0 2第 1届国际机械工程学术会议 11.2 0～ 2 2上海陈宝霞 0 10 - 6 85 95 318X2 0 0 0 0 0 0 3第 2 7届计算机与工业工程国际会议 10 .11～ 13北京王瑞刚 0 11- 6 85 95 318X2 0 0 0 0 0 0 4第 7届工业工程与管理工程国际学术会议 11.2 8～ 30广州毛承洁 0 2 0 - 8776 6 0 6 9- 6 5 95X2 0 0 0 0 0 0 5第 2届亚太地区系统集成与设备维修国际会议 0 8.2 3～ 2 5南京贾民平 …     

多接收双聚焦等离子体质谱法测定高精度同位素比

采用 VG Axiom型多接收双聚焦等离子质谱仪 ( MC-ICPMS)测定 Nd、Pb、U同位素比值 ,应用指数公式对测定的结果进行质量歧视校正。结果表明 :测定参考物质 Ames Nd获得的钕同位素比值为 14 3 Nd/14 4 Nd=0 .5 1 2 1 44± 0 .0 0 0 0 1 5 (确认值为 0 .5 1 2 1 3 5 )、14 5Nd/14 4 Nd=0 .3 4841 7± 0 .0 0 0 0 1 9(确认值为 0 .3 4841 8) ;测定参考物质 NIST SRM981获得的铅同位素比值为 2 0 8Pb/2 0 4Pb=3 6.71 1 4± 0 .0 0 81、2 0 7Pb/2 0 4Pb=1 5 .4886± 0 .0 0 3 8、2 0 7Pb/2 0 6Pb=0 .91 44 5 6± 0 .0 0 0 0 3 9、2 0 6Pb/2 0 4Pb=1 6.93 82± 0 .0 0 3 1、2 0 8Pb/2 0 6Pb=2 .1 660 1± 0 .0 0 0 1 6;测定参考物质 NIST SRM 0 1 0获得的铀同位素比值为 2 3 4 U/2 3 8U =0 .0 0 0 0 5 46±0 .0 0 0 0 0 0 3 (确认值为 0 .0 0 0 0 5 46)     

车大圆弧的编程技巧

数控车床广泛用于回转曲面、圆弧面、多台阶轴等工件的加工。图 1所示是我厂生产的一种皮带轮简图 ,采用ＪＷＫ— 5ＧＰ型数控系统精车Ｒ6 80外圆。加工图 1　皮带轮简图程序如下 :Ｎ0 0 1 0Ｇ0 0Ｗ -1 2 0Ｎ0 0 2 0Ｇ0 0Ｕ -3 6Ｎ0 0 3 0Ｇ0 1Ｕ -4Ｆ60Ｎ0 0 4 0Ｇ0 1Ｗ -2Ｆ60Ｎ0 0 50Ｇ0 3Ｕ0Ｗ -80　Ｉ-1 3 57.64Ｋ -4 0Ｆ80Ｎ0 0 60Ｇ2 6Ｎ0 0 70Ｇ2 9Ｍ0 2通过程序运算 ,数控系统显示Ｅ15 - 0 0 5 0出错信息 ,信息指示为终点数据偏差过大。经过仔细检查Ｎ0 0 5 0圆弧程序 :Ｇ0 3表示顺圆插补 ,Ｕ、Ｗ为终点相对于起点的坐标 ,Ｉ、Ｋ为…     

基准环规检定和传递

内径环规基准件的检定至今仍是一个很伤脑筋的问题 ,因为希望环规的不确定度能保证在± 0 5μm范围内 ,而这样高的精度是很难达到的。表 1列出了在现有水平下测量环规直径所用的仪器及测量方法。表 1　测量环规所用仪器、方法和精度仪器名称规格型号测量方法 仪器精度μm卧式测长仪4J、JD5、JDY -1 0 0T -UIM -5 0 0、ZEISEOPTON绝对测量± (2 +L/1 0 0 )测量仪MUT -1 0 0 0、TJA相对测量± (0 6+9L/1 0 0 0 0 )象点反射比长仪 2 0 0型数字式比长仪直接测量± (0 5 +L/3 0 0 +H/1 0 0 )孔径测量仪 70 1A干涉比较测量± 0 5…     

北京翰林阳光文化发展中心书讯

书　　　　名出　版定价 (元 )2 0 0 3年中国齿轮工业年鉴 0 3 1 0 90 0 02 0 0 3年中国通用机械工业年鉴 0 4 0 71 58 0 02 0 0 4中国工程机械工业年鉴 0 4 1 0 1 38 0 02 0 0 4中国农业机械年鉴 0 4 1 2 1 50 0 02 0 0 4年中国五金年鉴 (上下卷 ) 0 4 0 7350 0 02 0 0 4年中国机床工具工业年鉴 0 4 1 2 1 38 0 02 0 0 3年中国机械工业年鉴 0 3 1 1 1 98 0 02 0 0 3年中国机械通用零部件工业年鉴 0 3 1 1 1 38 0 02 0 0 1年中国机电产品市场年鉴 0 4 0 71 2 5 0 02 0 0 4年中国工业年鉴 0 4 1 2 2 80 0 02 0 0 4年汽车工业年鉴 …     

不同温度下铜基粉末冶金摩擦材料往复滑动磨损规律

研究不同温度下高速列车用铜基粉末冶金摩擦材料磨损特征。在PlintTE77高温疲劳试验机上对该材料进行磨损性能测试 ,工况分别为室温、10 0℃、2 0 0℃、3 0 0℃、3 5 0℃、5 0 0℃ ,法向载荷为 2 0 0N、45 0N等 12种工况 ,振动频率为 4Hz ,滑动幅值为± 5mm。并对摩擦后的磨痕进行Scanelectro mirror (SEM)分析。发现①在 2 0 0N、3 0 0℃时出现碾压的多源弧形裂纹 ,这和冲击时的沿树枝晶裂纹截然不同。②在 45 0N、3 0 0℃时 ,磨痕表面出现球状的石墨颗粒层 ,这起到了极好的润滑作用 ,使得 3 0 0℃时磨损较低。③在 45 0N、3 5 0℃时 ,有沿磨痕方向的长条裂纹出现。④在不同载荷 5 0 0℃时 ,发生粘附现象 ,即摩擦材料粘附到对偶材料上。根据以上分析用最小二乘法粗略拟合了该材料的磨损规律     

火焰原子发射光谱测定牛奶中的钾、钠

讨论了火焰原子发射光谱法检测牛奶中的钾钠元素的方法。将用TCA消解后的样品喷入空气—乙炔火焰中进行发射光谱测定。钾和钠的检出限分别为0 .0 0 2 0 mg/ L和0 .0 0 2 3mg/ L。相对标准偏差的范围为0 .31 %～0 .93%和0 .89%～1 .4%。     

国家工程机械质量监督检验中心检验公告(四十七)

下列产品经国家工程机械质量监督检验中心检验 ,符合有关标准要求 ,特此公告 (排名不分先后 )。企业名称 法人代表 商　标 检验产品名称及型号检验类型 检验结论证书编号联系电话宁波如意股份有限公司 储吉旺西林DF5 40× 80 0手动液压托盘搬运车型式试验达到设计要求 ,符合相关标准国工机质检证字 ( 2 0 0 3 )第 0 84号0 5 74-65 5 82 5 0 5宁波钛龙机械有限公司 金跃进—TL -C5 5 0×1 1 0 0 ( 2 5t)、TL -C5 5 0×1 1 0 0 ( 1 5t)手动液压托盘搬运车型式试验达到设计要求 ,符合相关标准国工机质检证字 ( 2 0 0 3 )第 0 85号0 5 74-…     

太阳轮热处理工艺探讨

太阳轮（见图1）,材料为8620RH,主要化学成分为：Wc=0．18％～0．23％、WM。=0．7％～0．9％、WNi=0．4％～0．7％、Wcr=0．4％～0．6％、     

2000年机械行业标准出版信息

JB/ T50 198- 2 0 0 0冷凝式内燃机冷却风扇　产品质量分等 15.0 0JB/ T884 5- 2 0 0 0轮胎式装载机变速箱操纵阀　技术条件 12 .0 0JB/ T 510 99- 2 0 0 0工程农机产品可靠性考核评定指标　体系及故障分类通则 10 .0 0JB/ T5110 2 - 2 0 0 0拖拉机制造厂产品可靠性管理办法 15.0 0JB/ T5110 3- 2 0 0 0拖拉机可靠性设计评审办法 10 .0 0JB/ T510 82 - 2 0 0 0拖拉机产品可靠性考核 35.0 0JB/ T510 57- 2 0 0 0拖拉机液压提升器　产品质量分等 15.0 0JB/ T 830 2 - 2 0 0 0农业拖拉机和机具液压输出快换接头　技术条件 10 .0 0JB…     

Reinvestigation of the alkali-metal-induced Ge(111)3 × 1 reconstruction on the basis of boundary structure observations

We have investigated the surface atomic structure of boundary area of Li- and Na-induced Ge(1 1 1)3×1 reconstruction using scanning tunneling microscope. On Li/Ge(1 1 1)3×1, the 3×1 phase was found to be terminated with a single row in the filled-state image and with dimer-like features in the empty-state image. The images of both interior and boundary of the Li/Ge(1 1 1)3×1 surface are compatible with the honeycomb-chain-channel (HCC) model, which has substrate atoms with double bonds and is well established as the structure of AM/Si(1 1 1)3×1 surfaces. In contrast, termination with zigzag double rows at the domain boundary edges was observed in the filled-state images of the Na/Ge(1 1 1)3×1 phase, which is not reconcilable with the HCC structure. The filled-state STM feature of the boundary region of the Na/Ge(1 1 1)3×1 phase supports a structural model not having Ge=Ge double bonds, which was proposed to interpret its empty-state images. The trend of bondings between atoms in the surface layer of the AM-induced 3×1 reconstruction of Si and Ge is discussed in terms of electronegativity differences.     

HMGB1 promotes the proliferation and invasion of oral squamous cell carcinoma via activating epithelial-mesenchymal transformation

This study aimed to investigate the role of high mobility group box-1 (HMGB1) expression in oral squamous cell carcinoma; HMGB1 promoted the proliferation and invasion of oral squamous cell carcinoma via activating epithelial-mesenchymal transformation (EMT). In this study, RNA transfection was used to silence the expression of HMGB1 in oral squamous cell carcinoma cells. CCK-8, cell clone formation and trans-well assays were used to detect the proliferation and invasion of cells before and after HMGB1 silencing. qRT-PCR and Western blot were used to detect changes in EMT marker protein expression before and after transfection. HMGB1 was significantly higher in OSCC tissues than in adjacent tissues, and of the cell lines examined, HMGB1 was highest in SCC-9 cells. Additionally, HMGB1 silencing decreased SCC-9 cell proliferation and viability. Down-regulation of HMBG1 expression inhibited not only the proliferation but also the invasion of SCC-9 cells. The expression of N-cadherin, Snail, and Slug, but not E-cadherin, were promoted after silencing HMGB1. The expression of HMGB1 in OSCC tissue and cell lines was higher, and HMGB1 silencing decreased SCC-9 cell proliferation and invasion, suggesting that HMGB1 has positive effects on OSCC development. Down-regulation of HMBG1 expression regulates EMT markers, suggesting that HMBG1 promotes OSCC cell proliferation and invasion is likely to be associated with EMT activation.     

关于宽凸缘圆筒件首次拉深极限变形程度的讨论

对宽凸缘工件首次拉深最大相对高度表中(dt/d1)的排序作了修正,并对最大相对高度(h1/d1)和极限拉深系数m1这两种极限变形程度的实验数据的相容性进行了推算与验证。结果表明二者有较好的一致性。     

In situ observation of the initial growth process of carbon nanotubes by time-resolved high resolution transmission electron microscopy

We succeeded in plan-view dynamic observation of the initial formation process of carbon nanotubes from β-SiC( 1 1 1 ) surfaces by time-resolved high resolution transmission electron microscopy. At 1360 °C, the flakes of graphite layers of a fibre orientation were formed on the SiC( 1 1 1 ) surfaces. From the graphite layers, carbon nanotubes were formed perpendicular to the ( 1 1 1 ) plane of the SiC. A scanning tunnelling microscopy observation showed that the end of carbon nanotube was closed. These results indicate that the caps of the carbon nanotubes are formed by a lift of a part of the graphene along the [ 1 1 1 ] direction of the SiC through generation of pentagons and heptagons. Two types of carbon nanotube, single-wall and double-wall, were observed in plan-view images. Different image intensity between an outer ring and an inner ring in double-wall nanotubes suggests that the inner layers of multiwall nanotubes are formed after the outer ones.     

Origin of phase shift in atomic force microscopic investigation of the surface morphology of NR/NBR blend film

Atomic force microscopy (AFM) was used to study the morphology and surface properties of NR/NBR blend. Blends at 1/3, 1/1 and 3/1 weight ratios were prepared in benzene and formed film by casting. AFM phase images of these blends in tapping mode displayed islands in the sea morphology or matrix-dispersed structures. For blend 1/3, NR formed dispersed phase while in blends 1/1 and 3/1 phase inversion was observed. NR showed higher phase shift angle in AFM phase imaging for all blends. This circumstance was governed by adhesion energy hysteresis between the device tip and the rubber surface rather than surface stiffness of the materials, as proved by force distance measurements in the AFM contact mode.     

Ang-(1-7) exerts anti-inflammatory and antioxidant activities on high glucose-induced injury by prohibiting NF-κB-IL-1β and activating HO-1 pathways in HUVECs

Previous reports have suggested that Ang-(1-7) may have a protective effect in endothelial cells against high glucose (HG)-induced cell injury thanks to a modulatory mechanism in the NF-κB signaling pathway. In this study, we have examined whether NF-κB-IL-1β and Heme oxygenase-1 (HO-1) pathways contribute to the protection of Ang-(1-7) against hyperglycemia-induced inflammation and oxidative stress in human umbilical vein endothelial cells (HUVECs). Our results indicate that time-varying exposures of HUVECs, from 1 h to 24 h, to high glucose concentrations result in an increased expression of phosphorylated (p)-p65 and HO-1 in a time-dependent manner. As an inhibitor of NF-κB, pyrrolidinedithiocarbamic acid (PDTC) suppressed IL-1β production induced by HG. Of note, HUVECs previously treated with Ang-(1-7) (2 μM) for 30 min before being exposed to HG concentrations significantly ameliorated the HG-increased in p-p65 and IL-1β expression; whereas obviously up-regulated the level of HO-1, along with inhibition of oxidative stress, inflammation, and the HG-induced cytotoxicity. Importantly, when HUVECs were previously treated either with PDTC or IL-1Ra for 30 min before being exposed to HG, it significantly prevented damages caused by high glucose concentrations mentioned above, while the treatment of HO-1 inhibitor Sn-protoporphyrin (SnPP) before exposure to both HG and Ang-(1-7) significantly blocked the protective effect exerted by Ang-(1-7) on endothelial cells against injuries induced by HG mentioned above. To conclude, the data of this study showed that activation and inhibition of the NF-κB-IL-1β pathway and HO-1 pathway may constitute an important defense mechanism against endothelial cell damage caused by HG concentrations. We additionally gave new evidence showing that exogenous Ang-(1-7) exerts a protective effect on HUVECs against the HG-induced cell injury via the inhibition and the activation of the NF-κB-IL-1β pathway and the HO-1 pathway, respectively.     

Structural and morphological anomalies in magnetosomes: possible biogenic origin for magnetite in ALH84001

We report biogenic magnetite whiskers, with axial ratios of 6 : 1, elongated in the [1 1 1], [1 1 2] and [1 0 0] directions, resembling the magnetite whiskers detected in the Martian meteorite ALH84001 by Bradley et al . , and interpreted by those authors as evidence of vapour-phase (abiogenic) growth. Magnetosomal whiskers with extended defects consistent with screw dislocations and magnetosomes resembling flattened twinned platelets, as well as other twinning phenomena and other structural defects, are also reported here. Magnetosomes with teardrop-shaped, cuboidal, irregular and jagged structures similar to those detected in ALH84001 by McKay et al . , coprecipitation of magnetite possibly with amorphous calcium carbonate, coprecipitation of magnetite possibly with amorphous silica, the incorporation of titanium in volutin inclusions and disoriented arrays of magnetosomes are also described. These observations demonstrate that the structures of the magnetite particles in ALH84001, their spatial arrangement and coprecipitation with carbonates and proximity to silicates are consistent with being biogenic.
Electron-beam-induced flash-melting of magnetosomes produced numerous screw dislocations in the {1 1 1}, {1 0 0} and {1 1 0} lattice planes and induced fusion of platelets. From this, the lack of screw dislocations reported in the magnetite particles in ALH84001 ( McKay et al ., and Bradley et al . ) indicates that they have a low-temperature origin.     

Differential expression and regulation of PNA and UEA‐1 bindings in rabbit uterus during preimplantation period

Peanut agglutinin (PNA) and Ulex europaeus agglutinin‐1 (UEA‐1) were used as probes to study the distribution of β‐gal (1→3) ga1Nac and α‐l ‐Fucose in rabbit uterus during early pregnancy. PNA binding was mainly localized on the surface of uterine glandular and luminal epithelium. There were no positive signals on day 1 of pregnancy. PNA binding gradually increased from day 2 and reached its highest level on days 3 and 4. The distribution of PNA binding gradually declined from day 5 and reached a low level on day 7. However, UEA‐1 binding was only localized on the luminal epithelial during early pregnancy. A high level of UEA‐1 binding had been found on the luminal epithelium on day 1 of pregnancy and low level of positive signals had been found in the uterus on days 2 and 3. UEA‐1 binding increased gradually and reached its highest level on day 4. Then the distribution of UEA‐1 binding sharply declined and no positive signals were found on days 5–7. The distribution of PNA and UEA‐1 bindings in pseudopregnant uterus was similar to that in normal pregnant uterus. During estrus cycle, there was no detectable PNA binding signal in uterus. But, a high level of UEA‐1 binding was found in the luminal epithelium of estrus uterus. In ovariectomized rabbit uterus, progesterone significantly induced the expression of PNA binding, while estrogen stimulated UEA‐1 binding expression. These results suggested that the distribution of PNA and UEA‐1 bindings in rabbit uterus may be related to rabbit implantation. Microsc. Res. Tech. 76:398–403, 2013. © 2013 Wiley Periodicals, Inc.