80年代黄河中游来沙减少的原因分析

80年代黄河中游来沙量减少,主要原因是降雨量减少和降雨强度减小,流域综合治理也起到了减沙作用。据分析,降雨因素减沙约占总减沙量的70％,流域综合治理减沙约占30％。     

长脉冲激光沉积原位生成YBaCuO超导膜

用长脉冲激光(脉冲宽度150μs,波长1.06μm)辐照高温烧结的YBa_2Cu_3O_(7-x)靶,在6Pa的氧气压强下,巳在(100)YSZ单晶衬底上原位生成YBa_2Cu_(?)O_(7-x)超导膜。衬底置于750℃的加热器上,衬底与靶之间的距离5cm,用该法制得的薄膜光亮坚实,正常态呈金属性,零电阻温度为84.7K。用XRD和SEM对薄膜进行了分析研究。     

脉冲激光沉积SrBi2Ta2O9铁电薄膜电容特性研究

用ＰＬＤ方法成功地制备了ＳＢＴ铁电薄膜，并制作成Ｐｔ／ＳＢＴ／Ｐｔ薄膜电容器。ＳＢＴ薄膜的晶面取向以（００８）和（１１５）为主。在５Ｖ电压下，极化反转，并且得到较饱和的电滞回线，剩余极化强度和矫顽电场分别为８４μＣ／ｃｍ２和５７ｋｖ／ｃｍ。ＩＶ特性测试显示两个对称的双稳峰，并得到零电压下，面积为３１４×１０４μｍ２，厚度为０３５μｍ的电容器，电容约为５６０ｐＦ，介电常数约为６００。疲劳测试表明Ｐｔ／ＳＢＴ／Ｐｔ具有优良的抗疲劳特性。     

离子束增强沉积薄膜合成及其在材料表面优化中的应用

作者在多年实验工作的基础上，论述了离子束增强沉积薄膜合成及其在材料表面优化中的应用、所用设备、膜的合成、表面优化技术与机理，并展望了前景。     

平衡纵剖面数值试验及其对防洪的影响研究

本文采用一维非恒定流非均匀沙的水沙数学模型，以长江中游螺山汉口河段为背景，进行了根化数值模拟试验，分析了该概化河段平衡纵剖面的变化规律及其与上游来水来沙条件的关系，并和相应的理论公式进行了比较。在此基础上，对水沙条件发生较在变化时的平衡纵比降以及带来的对长江中下游防洪的影响进行了分析。     

Pulsed laser deposition of carbon films: Dependence of film properties on laser wavelength

We have grown thin carbon films by pulsed laser deposition and have investigated the extent to which the properties of such films, as well as the processes responsible for these properties, are laser wavelength dependent. Films were grown by ablating material from a graphite target onto room temperature Si(100) substrates with 1064 and 248 nm laser radiation. The films were analyzed byin situ electron energy loss spectroscopy and byex situ Raman spectroscopy. The results indicated that films grown with 1064 nm ablation were graphitic, while those grown with 248 nm radiation were diamond-like. We have also examined the mass and kinetic energy distributions of the particles ejected from graphite by the two laser wavelengths. The results indicated that irradiation of graphite with 1064 nm laser radiation results in the ejection of a series of carbon cluster ions C _n ⁺ (1 ≤ n ≤ 30) with mean kinetic energies less than 5 eV. Ablation of graphite with 248 nm radiation results in the ejection of primarily C ₂ ⁺ and C ₃ ⁺ with mean kinetic energies of 60 and 18 eV, respectively. These results suggest that large, low energy clusters produce graphitic films, while small, high energy clusters produce films of diamond-like carbon.     

Direct electroless Ni-P deposition on AM50 magnesium alloy from sulfate bath

A bright electroless Ni-P deposition on AM50 magnesium alloy in a sulfate plating bath was proposed by using direct plating process with non-chromate pretreatment. The electroless Ni-P plating on AM50 magnesium alloy has an admirable appearance and good adhesion. The results indicate that the electroless Ni-P deposition with non-chromate pretreatment has better adhesion than that of zinc immersion coating. Anodic polarization curves indicate that the electroless Ni-P deposition obtained from the sulfate bath has similar corrosion-resistance to that obtained from basic nickel carbonate bath. The deposition process generates less pollutant by a non-chromate plating bath and is suitable for the magnesium alloys manufacture because of its low cost. The hardness of the electroless Ni-P plated AM50 is about HV 720.6 and HV 969.7 after heat treatments at 180℃ for 2 h. The wear resistance of Ni-P plated magnesium alloy specimens is about 5 to 9 times as high as that of bare magnesium alloys.     

催化部分氧化法制氢的水碳比控制与探讨

简要介绍了国内少有的干气催化部分氧化转化制氢工艺,重点讨论了转化水碳比的控制条件,对降低水碳比操作进行了有益地探讨。     

Formation of low-resistivity poly-Si and SiNx films by Cat-CVD for ULSI application

In this paper, bulk-Si metal–oxide–semiconductor field effect transistors (MOSFETs) are fabricated using the catalytic chemical vapor deposition (Cat-CVD) method as an alternative technology to the conventional high-temperature thermal chemical vapor deposition. Particularly, formation of low-resistivity phosphorus (P)-doped poly-Si films is attempted by using Cat-CVD-deposited amorphous silicon (a-Si) films and successive rapid thermal annealing (RTA) of them. Even after RTA processes, neither peeling nor bubbling are observed, since hydrogen contents in Cat-CVD a-Si films can be as low as 1.1%. Both the crystallization and low resistivity of 0.004 Ω·cm are realized by RTA at 1000 °C for only 5 s. It is also revealed that Cat-CVD SiN_x films prepared at 250 °C show excellent oxidation resistance, when the thickness of films is larger than approximately 10 nm for wet O₂ oxidation at 1100 °C. It is found that the thickness required to stop oxygen penetration is equivalent to that for thermal CVD SiN_x prepared at 750 °C. Finally, complementary MOSFETs (CMOSs) of single-crystalline Si were fabricated by using Cat-CVD poly-Si for gate electrodes and SiN_x films for masks of local oxidation of silicon (LOCOS). At 3.3 V operation, less than 1.0 pA μm⁻¹ of OFF leakage current and ON/OFF ratio of 10⁷–10⁸ are realized, i.e. the devices can operate similarly to conventional thermal CVD process.     

Increasing the corrosion resistance of equipment due to the use of film-forming amines

Results of a study of tube specimens cut from hot-water boilers show that film-forming octadecyl amine (ODA) used in the process of preservation removes deposition from the surface of the metal. An ODA film is preserved on the surface after repeated washing of the latter with hot water. The concentration of chlorides at the surface of the metal after treatment with ODA is lower than before the treatment. __________ Translated from élektricheskie Stantsii, No. 11, November 2005, pp. 15–18.