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FENG Changgen ZHUO Xiaoxi LIU Xia 《中国稀土学报(英文版)》2009,27(5):717-722
A series of photocatalysts, K11[Ln(PW11O39)2]/PVA (Ln=La, Ce, Pr, Nd, Sm) were prepared by K11[Ln(PW11O39)2] (Ln=La, Ce, Pr,Nd, Sm) containing five kinds of lanthanides and polyvinyl alcohol as the support. The catalysts obtained were characterized by Fourier trans-form infrared spectra, UV-vis spectra, powder X-ray diffraction, and scanning electron microscopy, indicating that the structure of K11[Ln(PW11O39)2] and polyvinyl alcohol remained intact, respectively. The photocatalysts exhibited efficient catalytic activity to degrade methyl orange, Congo Red, Ponceau 2R. The maximal degradation conversions of the three kinds of dyes were 99.58%, 47.61%, 72.42%, respectively. 相似文献
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在香港校园里,常常有这么一群特殊的人,她们每天早早地来到学校,为学生测量体温,观摩学校早会,协助管理图书,课余为学生讲故事,中午帮学生盛饭,甚至为学校编辑刊物,放学为低年级学生辅导作业……俨然是学校的正式教师,其实是学生家长,她们为学校,帮老师做了很多事情,都是义务的,没有任何报酬,在香港,通常把她们称之为“家长义工”。 相似文献
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业绩略低于预期第三季度公司实现营业收入1471394万元,同比上涨30.67%,净利润91950万元,同比下降26.9%,每股收益0.30元,前三季度实现营业收入4154476万元,同比上涨45.46%,净利润369876万元,同比增长13.76%,每股收益1.22元,业绩略低于市场的普遍预期。 相似文献
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提出了用火焰原子吸收光谱法测定金锭中Cu,Ag,Fe,Pb,Bi,Sb的方法。用乙酸乙脂萃取分离金,水相浓缩后测定6种待测元素,方法的检出限:Cu,Ag,Fe为0.021mg/L,Pb,Bi,Sb为0.24mg/L;回收率94%~106%;RSD小于10.6%。该方法快速、简便,样品用量少,测定结果与ICP AES法和国家标准方法一致。 相似文献
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型铁中Si,Mn,P,S四大元素的测定是型铁质量评价的主要内容。以往化学法分析Si,Mn,P,S四大元素,劳动强度大,工序繁琐,偶然误差因素多,分析周期长,准确度低。近年来,X射线荧光光谱仪在冶金、地矿、水泥等分析应用方面,得到迅速发展,它具有自动化程度高,操作简单、快速、准确、非破坏性等优点,本文应用3530荧光光谱仪,分析型铁中的Si,Mn,P,S四大元素,取得了成功,方法简单、准确、快速。1实验部分1.1仪器和试剂3530X射线荧光光谱仪(日本理学),Rh靶,端窗X射线管;PR—10气体;… 相似文献
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通过马钢电炉变电所数字化改造的实践,找到冶金系统变电所数字化改造的途径和方法,总结了冶金系统变电所数字化改造的技术特点,为冶金系统变电所数字化改造提出了可行的改造途径。 相似文献
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杜智勇 《有色金属(冶炼部分)》2003,(4):26-28
详细介绍了丹江铝业公司技术改造情况和 114 .5kA预焙槽技术特点。针对我国铝工业现状以及自焙槽的改造 ,提出了丹江铝业公司改造中运用的技术对我国自焙槽技术改造的借鉴作用 相似文献
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H Englert G Dracos H Dunckley J York G Richards R Penny P Brooks 《Canadian Metallurgical Quarterly》1998,27(2):279-284
The excursion resistance between the canine flexor digitorum profundus tendon and A2 pulley was compared after pulley reconstruction using tendon grafts of either intrasynovial or extrasynovial origin at 10 days, 3 weeks, and 6 weeks after surgery. The changes over time in the underlying flexor digitorum profundus tendon after pulley reconstruction were also evaluated. The excursion resistance for both types of pulley reconstruction was significantly greater than that of the control group at all time periods. The excursion resistance of the extrasynovial tendon graft reconstruction was greater than that of intrasynovial pulley reconstruction at all time periods. In conclusion, pulley reconstruction with intrasynovial tendon grafts may facilitate tendon gliding after surgery. 相似文献
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Nowadays, in congenital or acquired large oro-maxillofacial defects microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aim of reconstruction includes not only restoration of stable continuity and esthetic contour, but also the restoration of a functioning "chewing organ". For reconstruction in maxillary and midface defects, we prefer the scapular flap for a single-step reconstruction. Tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable soft tissue conditions at the time of microsurgical reconstruction. Following dental restoration, full oral function is given. This single-stage procedure improves the psychosocial situation of the patient considerably when compared with conventional multi-stage reconstruction. 相似文献
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Time is considered extremely urgent in China’s Wenchuan earthquake reconstruction. However, little research has been undertaken on estimating the time needed for reconstruction in China, especially for this specific reconstruction. Therefore, this paper aims to explore the time-cost relationship for the Wenchuan earthquake reconstruction. Both the Bromilow’s time-cost (BTC) model and the Elman network (EN) model have been developed to predict the time of Wenchuan earthquake reconstruction projects. Data have been obtained from 72 completed construction projects in the six cities that were seriously affected by the major Wenchuan earthquake. The result from the BTC model has been compared with that from the EN model to determine which one is more accurate. The results show that the EN model provides a more accurate time prediction for Wenchuan earthquake reconstruction than the BTC model does, though the BTC model is more suitable for application in practice. It is also shown that the proposed models are both useful for estimating the duration of reconstruction projects. 相似文献
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通过对原料厂GDS监控系统的技术改造及过程的描述,说明计算机控制系统改造的思路、方法,并较详细介绍了这类控制系统改造的要点与调试的基本方法。 相似文献
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V Michelet S Duroux C Majoufre P Caix F Siberchicot 《Canadian Metallurgical Quarterly》1996,41(6):639-643
The aim of this study was to assess the reconstruction of floor of the mouth defects after cancer surgery. The medical records of 140 patients treated between January 1st, 1987 and December 31st, 1995 were reviewed. Ninety-six patients had primary reconstruction: there were 82 cutaneous or osteomyocutaneous flaps and 14 microsurgical transfers. Among these patients 15 had titanium mandibular reconstruction plates. The reconstruction procedures and postoperative follow-up were evaluated. Healing by first intention is appropriate for superficial soft tissue defects. The nasolabial flap is used only for small mucosal defects. A forearm flap should be the first choice treatment for large soft tissue defects owing to its plasticity and reliable vessels. Segmental mandibular resections often imply mandibular reconstruction. Titanium plates may be used alone or with a cutaneous flap. Tolerance of plates after radiotherapy is very good and they are an effective method of reconstruction for fragile patients. 相似文献
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GH Olivera DM Shepard PJ Reckwerdt K Ruchala J Zachman EE Fitchard TR Mackie 《Canadian Metallurgical Quarterly》1998,43(11):3277-3294
Tomotherapy is a dose delivery technique using helical or axial intensity modulated beams. One of the strengths of the tomotherapy concept is that it can incorporate a number of processes into a single piece of equipment. These processes include treatment optimization planning, dose reconstruction and kilovoltage/megavoltage image reconstruction. A common computational technique that could be used for all of these processes would be very appealing. The maximum likelihood estimator, originally developed for emission tomography, can serve as a useful tool in imaging and radiotherapy. We believe that this approach can play an important role in the processes of optimization planning, dose reconstruction and kilovoltage and/or megavoltage image reconstruction. These processes involve computations that require comparable physical methods. They are also based on equivalent assumptions, and they have similar mathematical solutions. As a result, the maximum likelihood approach is able to provide a common framework for all three of these computational problems. We will demonstrate how maximum likelihood methods can be applied to optimization planning, dose reconstruction and megavoltage image reconstruction in tomotherapy. Results for planning optimization, dose reconstruction and megavoltage image reconstruction will be presented. Strengths and weaknesses of the methodology are analysed. Future directions for this work are also suggested. 相似文献
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For appropriate patients, who are aware of and accept the risks involved, contralateral prophylactic mastectomy and bilateral reconstruction can provide a good solution to an otherwise difficult problem. Bilateral reconstruction can produce exceptionally good aesthetic results and, because good symmetry is achieved in the initial surgery, it only costs about 5% more than unilateral reconstruction. This article discusses the techniques, advantages, and disadvantages of bilateral reconstruction. 相似文献