Advances in titanium metal injection molding

The approaches to production of titanium powder injection molded parts are reviewed. Historically, oxygen levels have been too high for structural use (particularly with the Ti-6Al-4V alloy). However, recent advances in starting powders, binders and sintering facilities now allow oxygen levels in the Ti-6Al-4V alloy to be controlled to about 0.2 wt.% oxygen. This should result in significant expansion of the titanium PIM market place into aerospace, automobiles, surgical instruments, dentistry, communication devices (such as computers and cell phones), knives and guns. __________ Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 5–6 (455), pp. 118–125, 2007.     

LD泵浦的声光调Q腔内倍频激光器

研制成用ＬＤ泵浦的声光调Ｑ的Ｎｄ：ＹＶＯ４－ＫＴＰ腔内倍频激光器，得到了ＴＥＭ００模、频率高达１００ｋＨｚ的稳定的５３２ｕｍ绿激光脉冲系列输出，阈值泵浦功率为２７ｍＷ；在连续５７０ｍＷ的泵浦功率下，绿激光脉冲的峰值功率达１１００Ｗ，脉宽为４．６ｕｓ；输出功率稳定，在±５℃的工作温度变化下，输出功率变化小于±２％。此种器件可望得到广泛的应用。     

Interfacial activity and rate of palladium(II) extraction with decyl pyridine monocarboxylates

Decyl isonicotiniate and decyl nicotiniate permit a rapid extraction of palladium(II) from its hydrochloride solutions. Decyl picoliniate is not a suitable extractant. 4-Octylphenylamine can act as a phase transfer catalyst when its concentration in the organic phase is at least 2·5 × 10^?4 M . It seems that the interfacial adsorption of pyridine carboxylates and of 4-octylphenylamine is not the decisive phenomenon in palladium(II) extraction. The negligible protonation of the pyridine-type extractants and the phase transfer catalysis explains well the quick extraction of palladium(II) with the commercial and highly hydrophobic extractant ACORGA CLX-50.     

石匣小流域坡地水土流失监测系统的建立及应用

以石匣小流域为坡地水土流失监测试点,以遥感及地理信息系统技术为手段,以坡地径流小区定位观测为依据,建立石匣小流域坡地水土流失监测系统,定位、定性、定量监测各种坡地类型的水土流失量、污染物流失量,为水土流失监测预报提供数据,为全市山区水土流失监测预报工作提供经验及方法,为制定水土流失防治方针政策及水土流失生态环境建设提供依据.     

A review of the effects of water transfers in the La Grande Hydroelectric Complex (Québec,Canada)

Construction of the La Grande Complex in Eastern Canada called for complete or partial diversion of six rivers, the mean annual discharge of which varied from 60 to 1600 m³ s^?1, and the transfer of water from two adjoining watersheds (1586m³ s^?1) into La Grande Rivière. Three of these rivers with reduced flow, Eastmain (from 700 to 95m³ s^?1), Opinaca (from 260 to 35m³ s^?1), and Caniapiscau (from 1708 to 960m³ s^?1) and the waterways with increased flows, Boyd-Sakami (from 1 to 811m³ s^?1) and La Grande Rivière (from 1760 to 3400m³ s^?1) were intensively monitored from 1978 to 1988, while the others were surveyed sporadically. Very few modifications were observed, compared to previous conditions, in banks stability, water quality, and aquatic fauna of the affected rivers: those which appeared can be explained by the water level fluctuations, the water quality of the tributaries of the residual drainage basin, and/or by the direct influence of the reservoirs. In James Bay, the areal extent of the Eastmain River and La Grand Rivière plumes varied with discharge in an exponential relation, mostly under ice cover; resources from the coastal environment had not yet undergone any major changes. Because of the very small population dwelling in the area, less than 3000 inhabitants, modifications in the hydrological regime of these rivers did cause relatively few impacts, the main being greater banks instability in specific locations, reduction of the thickness and ice cover on La Grande Rivière, enhancement of navigation constraints on Eastmain River, and higher mercury levels in fish related to operation of the reservoirs.     

抽余C_4烃中异丁烯催化逆流水合制叔丁醇

采用大颗粒离子交换树脂催化剂,在φ100mm×10m的反应器中进行了异丁烯催化逆流水合制叔丁醇的中间试验。考察了反应温度、水油体积比和抽余C4烃的流速等对异丁烯转化率的影响。试验结果表明,异丁烯催化逆流水合制叔丁醇的适宜操作条件为:反应温度80~90℃,水油体积比为4~5,抽余C4烃的流速为0.45~0.55mm/s。在此条件下,异丁烯的转化率可达88.8%。工业装置运转结果表明,异丁烯转化率大于75%。     

用EGS4分析9MeV行波直线加速器屏蔽系统

采用了国际上广泛使用的ＭｏｎｔｅＣａｒｌｏ模拟计算程序ＥＧＳ４对海关集装箱检测系统用加速器屏蔽系统进行了辐射模拟分析，与实际测试数据进行分析、比较，解释了特殊剂量分布的原因，提出了系统改进的参考方案。     

SiH_4－O_2体系LPCVD SiO_2薄膜的工艺及其应用

本文研究了ＳｉＨ４—Ｏ２体系ＬＰＣＶＤＳｉＯ２的工艺及设备。为了得到厚度均匀性好的薄膜，改进了反应气体的进气方式和装片舟的结构，获得了每炉１００片、直径为１００ｍｍ的硅片的膜厚不均匀性≤士５％的结果。     

高炉炉缸内铁水环流与内衬侵蚀

从分析中心焦柱在炉缸内的受力出发，计算了１０００￣５５８０ｍ＾３高炉大喷煤前后中心焦柱在炉缸铁水内的沉入深度，分析了炉缸内铁水环流的产生与炉缸内衬侵的关系，分析表明大喷煤有得利抑制铁水环流对缸内补的冲刷，提出了降低铁水环流对炉缸内衬侵蚀的途径。