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131.
本文研究了从草浆黑液中提取木质素的方法,不用减压和过滤设备,于每升黑液中提取木质素84.0g,并除去约90%的COD。观察黑液所形成的凝胶,发现其具有多级三维网状结构。 相似文献
132.
Jui-Sheng Chou 《清华大学学报》2008,13(Z1):114-120
The cost-efficacy control of maintenance operations in developing countries has become critical to the infrastructure asset management after highway construction. To effectively manage numerous projects annually with limited resources, it is necessary to reasonably estimate costs during the process of making maintenance project selection decisions. This study outlines the modeling of case-based reasoning (CBR) estimation that compares and retrieves the most similar instance across the case library. Four CBR approaches were presented and assessed in terms of their mean absolute prediction error rates. The resulting model demonstrates the ability of estimating the pavement maintenance project costs with the satisfactory accuracy at the early stages. 相似文献
133.
The conventional growth rate measures (such as month‐on‐month, year‐on‐year growth rates and 6‐month smoothed annualized rate adopted by the US Bureau of Labor Statistics and Economic Cycle Research Institute) are popular and can be easily obtained by computing the growth rate for monthly data based on a fixed comparison benchmark, although they do not make good use of the information underlying the economic series. By focusing on the monthly data, this paper proposes the k‐month kernel‐weighted annualized rate (k‐MKAR), which includes most existing growth rate measures as special cases. The proposed k‐MKAR measure involves the selection of smoothing parameters that are associated with the accuracy and timeliness for detecting the change in business turning points. That is, the comparison base is flexible and is likely to vary for different series under consideration. A data‐driven procedure depending upon the stepwise multiple reality check test for choosing the smoothing parameters is also suggested in this paper. The simple numerical evaluation and Monte Carlo experiment are conducted to confirm that our measures (in particular the two‐parameter k‐MKAR) improve the timeliness subject to a certain degree of accuracy. The business cycle signals issued by the Council for Economic Planning and Development over the period from 1998 to 2009 in Taiwan are taken as an example to illustrate the empirical application of our method. The empirical results show that the k‐MKAR‐based score lights are more capable of reflecting turning points earlier than the conventional year‐on‐year measure without sacrificing accuracy. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
134.
Sung WK Zheng H Li S Chen R Liu X Li Y Lee NP Lee WH Ariyaratne PN Tennakoon C Mulawadi FH Wong KF Liu AM Poon RT Fan ST Chan KL Gong Z Hu Y Lin Z Wang G Zhang Q Barber TD Chou WC Aggarwal A Hao K Zhou W Zhang C Hardwick J Buser C Xu J Kan Z Dai H Mao M Reinhard C Wang J Luk JM 《Nature genetics》2012,44(7):765-769
To survey hepatitis B virus (HBV) integration in liver cancer genomes, we conducted massively parallel sequencing of 81 HBV-positive and 7 HBV-negative hepatocellular carcinomas (HCCs) and adjacent normal tissues. We found that HBV integration is observed more frequently in the tumors (86.4%) than in adjacent liver tissues (30.7%). Copy-number variations (CNVs) were significantly increased at HBV breakpoint locations where chromosomal instability was likely induced. Approximately 40% of HBV breakpoints within the HBV genome were located within a 1,800-bp region where the viral enhancer, X gene and core gene are located. We also identified recurrent HBV integration events (in ≥ 4 HCCs) that were validated by RNA sequencing (RNA-seq) and Sanger sequencing at the known and putative cancer-related TERT, MLL4 and CCNE1 genes, which showed upregulated gene expression in tumor versus normal tissue. We also report evidence that suggests that the number of HBV integrations is associated with patient survival. 相似文献
135.
无氰电镀铜新工艺试验研究 总被引:6,自引:0,他引:6
以环保酸性浸镀铜工艺和含有复合添加剂的碱性无氰电镀铜工艺结合的小型试验,得到了产品合格并适合工业化生产应用的工艺配方.通过六因素正交试验,以镀铜速率、外观状况、抗腐蚀性作为衡量标准,获得了比较好的试验条件,重点研究了镀液温度、电流密度对镀铜速度的影响. 相似文献
136.
一种4t阶正交拉丁方的构造方法 总被引:1,自引:0,他引:1
万禧 《黑龙江科技学院学报》2001,11(3):52-54,57
一种4t阶正交拉丁方的图表构造法被首次发现。本文的4t阶正交拉丁方构造的基本思路是:运用表将编码矩阵K重新排列成正交拉方。实践表明:用本文方法可构造t=2^m(m-任意正整数)的任意4t阶正交拉丁方。介绍了8,16阶正交拉丁方的构造过程及构造结果。 相似文献
137.
138.
Reduction of titanomagnetite (TTM) powders by H2-Ar gas mixtures was investigated under a non-isothermal condition by using a thermogravimetric analysis system. It was found that non-isothermal reduction of TTM proceeded via a dual-reaction mechanism. The first reaction was reduction of TTM to wüstite and ilmenite, whereas the second one was reduction of wüstite and ilmenite to iron and titanium dioxide. By using a new model for the dual reactions, which was in an analytical form and incorporated different variables, such as time, temperature, particle size, and hydrogen partial pressure, rate-controlling steps for the dual reactions were obtained with the apparent activation energies calculated to be 90–98 and 115–132 kJ/mol for the first and second reactions, respectively. 相似文献
139.
Structural predictions based on the compositions of cathodic materials by first-principles calculations 下载免费PDF全文
A first-principles method is applied to comparatively study the stability of lithium metal oxides with layered or spinel structures to predict the most energetically favorable structure for different compositions. The binding and reaction energies of the real or virtual layered LiMO2 and spinel LiM2O4 (M=Sc-Cu, Y-Ag, Mg-Sr, and Al-In) are calculated. The effect of element M on the structural stability, especially in the case of multiple-cation compounds, is discussed herein. The calculation results indicate that the phase stability depends on both the binding and reaction energies. The oxidation state of element M also plays a role in determining the dominant structure, i.e., layered or spinel phase. Moreover, calculation-based theoretical predictions of the phase stability of the doped materials agree with the previously reported experimental data. 相似文献
140.
Chih-Cheng Chang Shih-Ying Tsai Heng Lin Hsiao-Fen Li Yi-Hsuan Lee Ying Chou Chih-Yu Jen Shu-Hui Juan 《Cellular and molecular life sciences : CMLS》2009,66(19):3193-3205
We previously demonstrated the antiproliferative and antiangiogenic effects of 3-methylcholanthrene (3MC), an aryl-hydrocarbon
receptor (AhR) agonist, in human umbilical vascular endothelial cells (HUVECs). Herein, we unraveled its molecular mechanisms
in inhibiting HUVEC motility. 3MC down-regulated FAK, but up-regulated RhoA, which was rescued by AhR knockdown. It led us
to identify novel AhR binding sites in the FAK/RhoA promoters. Additionally, 3MC increased RhoA activity via suppression of
a negative feedback pathway of FAK/p190RhoGAP. With an increase in membrane-bound RhoA, subsequent stress fiber and focal
adhesion complex formation was observed in 3MC-treated cells, and this was reversed by a RhoA inhibitor and AhR antagonists.
Notably, these compounds significantly reversed 3MC-mediated anti-migration in a transwell assay. The in vitro findings were
further confirmed using an animal model of Matrigel formation in Balb/c mice. Collectively, AhR’s genomic regulation of FAK/RhoA,
together with RhoA activation, is ascribable to the anti-migration effect of 3MC in HUVECs. 相似文献