继续奏响振荡向上主旋律——2002年白银市场回顾及其2003年展望

本文对2002年国际国内白银市场做了全面分析,对2003年白银市场走势进行了分析预测。白银作为一种贵金属,同时又具有工业金属的特性,世界经济形势,世界政治局势的变化,都对白银价格走势产生影响。鉴于该金属的双重特性,本文就从白银的供应、需求、消费及世界经济的发展等方面论述白银市场前进趋势。     

Facile synthesis of ordered nanocrystalline alumina thin films with tunable mesopore structures

Mesoporous alumina layers have attracted attention for their potential use in ultrafiltration of salts, as a heterogeneous catalyst support, an adsorbent in environmental cleanup, and in petroleum refinement. The ability to control the fast hydrolysis rate of the inorganic precursors using simple and inexpensive routes is important for that potential to be realized. Herein, we introduce a novel and facile route to synthesize mesoporous alumina thin films from the combination of inexpensive and commercially available copolymer with aluminum chloride or nitrate (salts) in an EtOH–surfactant–NH₃ · H₂O–salts (EsNs) system through the evaporation-induced self-assembly (EISA) method. Mesoporous alumina layers obtained utilizing the EsNs system have ordered and tunable pore structures. The ability to easily control the mesophases of the alumina layers within a short time provides distinct advantages over previously reported synthesis procedures. Most importantly, we demonstrate that the binding of surfactant and NH₃ · H₂O for the formation of hydrogen bond between them in the EsNs system controls the fast hydrolysis rate of the inorganic species. This allows for the synthesis of nanocrystalline alumina layers via the aluminum oxo-clusters’ assembly with the surfactant. Such simple route may be applied in the synthesis of other non-silica mesostructured oxides.     

激光束偏转法检测金属表面层的缺陷

本文编程计算了由激光光热应产业的金属表面的温度分布和泵浦光的调制频率、金属层厚度等的关系，预言检测浓度缺陷的能力。用激光光束偏转法检测到表面下不同深处的缺陷，并把面扫描幅值信号以三维象和灰度象显示。     

Effects of capsules on attachment of human periodontal ligament fibroblasts to root surface

The stability of cimetidine (Tagamet) was investigated in total parenteral nutrition (TPN) mixtures containing different amino acid sources. TPN mixtures were stored at 5 degrees C in ethylvinyl acetate bags for 28 days and analysed by stability-indicating high-pressure liquid chromatography. Results indicated that cimetidine was physically compatible and chemically stable (less than 5% degradation) for at least 28 days in TPN mixtures containing either Freamine III, Vamin 14 or Aminoplex 12 as the amino acid source.     

一种抑制SDH网中指针调整抖动的平滑相位泄漏技术

指针调整会在ＳＤＨ网中引入非常大的低频抖动。通常，在解同步器中需要采用指针泄漏技术来抑制这种抖动以使设备满足ＩＴＵ－Ｔ建议Ｇ．７８３的要求。本文给出了一种新颖的抑制指针调整抖动的方法，这种方法通过一个数字锁相环对指针抖动进行平滑并将平滑相位调相到一个参考信号上，从而避免了１比特或１／Ｎ比特泄中存在的较大的相位量化阶跃。这种方法对指针抖动的泄漏可以近似为一个平滑的过程。对一个ＡＵ－４／Ｅ４实验系统的     

筛前神经及下鼻甲激光切割术治疗过敏性鼻炎29例临床观察

本文介绍了用筛前神经和下鼻甲激光切割术治疗２９例过敏性鼻炎病人，有效率为９７％。随访６个月至２年，除２例于术后６个月复发外，余者均未复发。实践表明这一手术优于翼管神经手术，优点是：１、解剖标志清楚；２、手术操作简便且易于掌握；３、并发症少而不严重。本文对这一手术的方法，术后处置和疗效进行了讨论。     

Ginkgolides antagonizing some effects of platelet-activating factor in vitro

The mixture of platelet-activating factor (PAF) and platelets produced significant contraction of guinea pigs' bronchus, while the contraction induced by PAF alone was mild relatively, the IC50 were 6.14 x 10(-7) mol/L and 6.32 x 10(-4) mol/L respectively. There was significant difference between these two groups (P < 0.05). When the platelets were pre-incubated with ginkgolides for 10 minutes in Tris-Tyrode's buffered saline, effects of the PAF and platelets mixture were significantly inhibited (P < 0.01). Exposure of guinea pigs' bronchus to PAF in vitro resulted in a loss of beta-adrenergic receptors and responses to isoproterenol, and this effect of PAF was prevented by prior incubation of the guinea pigs' bronchus with ginkgolides (P < 0.05). The results showed ginkgolides were a potent PAF antagonist.     

The summary of researches on ADS in China

The conceptual study on the accelerator driven system (ADS) that lasted for about five years ended in 1999 in China. As one project of the National Basic Research Program of China (973 Program) in the energy domain, which is sponsored by the China Ministry of Science and Technology (MOST), a five-year-program of fundamental research of ADS physics and related technology was launched in 2000 and passed national review at the end of 2005. The China Institute of Atomic Energy (CIAE), the Institute of High Energy Physics (IHEP), the Institute of Heavy Ion Physics in Peking University (PKU-IHIP) and other institutions jointly carried out the research. The research activities were focused on HPPA physics and technology, reactor physics of external source driven sub-critical assembly, nuclear data base and material study. For HPPA, a high current injector consisting of an ECR ion source, LEBT and an RFQ accelerating structure of 3.5 MeV was built. In reactor physics study, a series of neutron multiplication experimental study has been carried out and still being done. The VENUS facility has been constructed as the basic experimental platform for neutronics study in ADS blanket. It’s a zero power sub-critical neutron multiplying assembly driven by external neutron produced by a pulsed neutron generator. The theoretical, experimental and simulation study on nuclear data, material properties and nuclear fuel circulation related to ADS is carrying on to provide the database for ADS system analysis. The main results on ADS related researches will be reported.     

泡沫沥青混合料动态性能研究

为更好地模拟泡沫沥青混合料在车辆动载作用下的动态性能，便于与国外相关研究进行比较，采用劈裂法对混合料动态性能进行研究。通过试验研究骨料类型、级配、水泥用量等对泡沫沥青混合料动态回弹模量的影响，总结了泡沫沥青混合料动静模量的关系。