EBW technology applied on the ICRF antenna component

Central conductor is one of the key components of ion cyclotron ranges of heating antenna, which is usually formed by welding due to the complex structures. High level of welding seam quality and small deformation are very important to central conductor. Electron beam welding (EBW) is suggested as the central conductor welding. To meet EBW requirements and reduce the risk, complex and high level of the accuracy welding fixture have been designed for central conductor EBW. Some samples were manufactured to do test and examination for EBW qualification before central conductor welding. Based on the welding parameters, thermal analysis using finite element method for the welding seam have been carried out. One mockup of central conductor for EBW has been made for proving welding parameters. In addition, some postwelding process were employed after one central conductor EBW. Results of examination and inspection of one central conductor using EBW are presented in this paper

Inhibition of bacterial adhesion to HT-29 cells by lipoteichoic acid extracted from Clostridium butyricum

The aim of this experiment was to study the effect of the lipoteichoic acid (LTA) extracted from Clostridium butyricum on the adhesion of C. butyricum and Escherichia coli to HT-29 human intestinal cells. The method of extraction of lipoteichoic acid form C. butyricum by TX114 was evaluated. The purification of the LTA by DEAE-cellulose 52 anion exchange chromatography was also investigated. In addition, the LTA was assayed for its inhibition of the adhesion of C. butyricum and E. coli to HT-29 cells and antimicrobial activity. Our results showed that LTA could be extracted by TX114 and purified by DEAE-cellulose 52 anion exchange chromatography and could inhibit the adhesion of C. butyricum and E. coli to HT-29 cells. This result also revealed that the LTA from C. butyricum could inhibit the adhesion of C. butyricum and E. coli to intestinal cells.Key words: Lipoteichoic acid, Clostridium butyricum, HT-29 cells, adhesion, Escherichia col

Extraction of Total Alkaloids from Corydalis saxicola Bunting by the Macroporous Resin

The total alkaloids were extracted from Corydalis saxicola Bunting by macroporous resin.Six different macroporous resins were used for extraction of the total alkaloids and dehydrocavidine by using static and dynamic adsorption-desorption experiments.The specific adsorption capacity and eluting of D101 macroporous resin were comparatively high.The optimum parameters of the purification process were established as the sample concentration of 0.2 g/ml at the absorption ? ow rate of 2 BV/h and with 3 BV of 60% ethanol as the desorption solvent.The contents of total alkaloids in the purifi ed extract were over 60%. 利用大孔吸附樹脂分離巖黃連中的總生物堿,采用靜態和動態吸附-解吸附方法,以總生物堿和脫氫卡維丁含量為指標,考察了6種大孔吸附樹脂對巖黃連總生物堿的吸附能力,其中D101型大孔吸附樹脂的比吸附量和比洗脫量均較高。優化后的提取工藝為:上樣藥液原藥材濃度0.2g/ml,吸附流速為2BV/h,解吸附溶劑為60%乙醇(3BV),所得巖黃連提取物中總生物堿含量大于60%

Evaluating the performance of PC-ANN for the estimation of rice nitrogen concentration from canopy hyperspectral reflectance

In this study, a wide range of leaf nitrogen concentration levels was established in field-grown rice with the application of three fertilizer levels. Hyperspectral reflectance data of the rice canopy through rice whole growth stages were acquired over the 350 nm to 2500 nm range. Comparisons of prediction power of two statistical methods (linear regression technique (LR) and artificial neural network (ANN)), for rice N estimation (nitrogen concentration, mg nitrogen g(-1) leaf dry weight) were performed using two different input variables (nitrogen sensitive hyperspectral reflectance and principal component scores). The results indicted very good agreement between the observed and the predicted N with all model methods, which was especially true for the PC-ANN model (artificial neural network based on principal component scores), with an RMSE 0.347 and REP 13.14%. Compared to the LR algorithm, the ANN increased accuracy by lowering the RMSE by 17.6% and 25.8% for models based on spectral reflectance and PCs, respectively

Plasma hydrogenation of strained Si/SiGe/Si heterostructure for layer transfer without ion implantation

We have developed an innovative approach without the use of ion implantation to transfer a high-quality thin Si layer for the fabrication of silicon-on-insulator wafers. The technique uses a buried strained SiGe layer, a few nanometers in thickness, to provide H trapping centers. In conjunction with H plasma hydrogenation, lift-off of the top Si layer can be realized with cleavage occurring at the depth of the strained SiGe layer. This technique avoids irradiation damage within the top Si layer that typically results from ion implantation used to create H trapping regions in the conventional ion-cut method. We explain the strain-facilitated layer transfer as being due to preferential vacancy aggregation within the strained layer and subsequent trapping of hydrogen, which lead to cracking in a well controlled manner. © 2005 American Institute of Physics

H-induced platelet and crack formation in hydrogenated epitaxial Si/Si <inf>0.98</inf>B <inf>0.02</inf>/Si structures

An approach to transfer a high-quality Si layer for the fabrication of silicon-on-insulator wafers has been proposed based on the investigation of platelet and crack formation in hydrogenated epitaxial Si Si0.98 B0.02 Si structures grown by molecular-beam epitaxy. H-related defect formation during hydrogenation was found to be very sensitive to the thickness of the buried Si0.98 B0.02 layer. For hydrogenated Si containing a 130 nm thick Si0.98 B0.02 layer, no platelets or cracking were observed in the B-doped region. Upon reducing the thickness of the buried Si0.98 B0.02 layer to 3 nm, localized continuous cracking was observed along the interface between the Si and the B-doped layers. In the latter case, the strains at the interface are believed to facilitate the (100)-oriented platelet formation and (100)-oriented crack propagation. © 2006 American Institute of Physics