脉冲电子束退火装置及其对注砷硅的退火结果

目前,离子注入技术虽已相当广泛地用于半导体器件的科研和生产中,然而离子注入造成的晶格损伤的恢复和注入杂质的高效率激活方法却还留下一些有待研究的课题.其中,脉冲电子束退火就是当前颇受重视的方法之一.

论一种新型对注管的设计思路

本文提出了克服速调管中散聚效应的一种新型电子器件——对注管的结构方案。并对其中的电子工作机制、器件、工作原理、管型结构以及其主要设计参量进行了分析与探讨,最后提出了该管向毫米波、亚毫米波发展的可能性。

沿垂直壁上可压缩气体层流边界层的自然对流流场及温度场

将可压缩气体边界层偏微分方程组 ,经特殊的相似变换 ,化为包含气体温度参数n的边界层温度比Tw/T∞ 的常微分方程组。再利用龙格—库塔法 ,解出了不同气体、不同边界温度比条件下层流边界层的流场和温度场的空间分布数值解。与一般的基本常物性的结果相比 。

Seismic multiple attenuation based on improved U-Net

Eff ective attenuation of seismic multiples is a crucial step in the seismic data processing workfl ow.Despite the existence of various methods for multiple attenuation,challenges persist,such as incomplete attenuation and high computational requirements,particularly in complex geological conditions.Conventional multiple attenuation methods rely on prior geological information and involve extensive computations.Using deep neural networks for multiple attenuation can effectively reduce manual labor costs while improving the efficiency of multiple suppression.This study proposes an improved U-net-based method for multiple attenuation.The conventional U-net serves as the primary network,incorporating an attentional local contrast module to effectively process detailed information in seismic data.Emphasis is placed on distinguishing between seismic multiples and primaries.The improved network is trained using seismic data containing both multiples and primaries as input and seismic data containing only primaries as output.The eff ectiveness and stability of the proposed method in multiple attenuation are validated using two horizontal layered velocity models and the Sigsbee2B velocity model.Transfer learning is employed to endow the trained model with the capability to suppress multiples across seismic exploration areas,eff ectively improving multiple attenuation effi ciency.

Well Logging Stratigraphic Correlation Algorithm Based on Semantic Segmentation

Well logging curves serve as indicators of strata attribute changes and are frequently utilized for stratigraphic analysis and comparison.Deep learning,known for its robust feature extraction capabilities,has seen continuous adoption by scholars in the realm of well logging stratigraphic correlation tasks.Nonetheless,current deep learning algorithms often struggle to accurately capture feature changes occurring at layer boundaries within the curves.Moreover,when faced with data imbalance issues,neural networks encounter challenges in accurately modeling the one-hot encoded curve stratifi cation positions,resulting in signifi cant deviations between predicted and actual stratifi cation positions.Addressing these challenges,this study proposes a novel well logging curve stratigraphic comparison algorithm based on uniformly distributed soft labels.In the training phase,a label smoothing loss function is introduced to comprehensively account for the substantial loss stemming from data imbalance and to consider the similarity between diff erent layer data.Concurrently,spatial attention and channel attention mechanisms are incorporated into the shallow and deep encoder stages of U²-Net,respectively,to better focus on changes in stratifi cation positions.During the prediction phase,an optimized confi dence threshold algorithm is proposed to constrain stratifi cation results and solve the problem of reduced prediction accuracy because of occasional layer repetition.The proposed method is applied to real-world well logging data in oil fi elds.Quantitative evaluation results demonstrate that within error ranges of 1,2,and 3 m,the accuracy of well logging curve stratigraphic division reaches 87.27%,92.68%,and 95.08%,respectively,thus validating the eff ectiveness of the algorithm presented in this paper.

High Performance 70nm CMOS Devices

A high performance 70nm CMOS device has been demonstrated for the first time in the continent, China. Some innovations in techniques are applied to restrain the short channel effect and improve the driving ability, such as 3nm nitrided oxide, dual poly Si gate electrode, novel super steep retrograde channel doping by heavy ion implantation, ultra shallow S/D extension formed by Ge PAI(Pre Amorphism Implantation) plus LEI(Low Energy Implantation), thin and low resistance Ti SALICIDE by Ge PAI and special cleaning, etc. The shortest channel length of the CMOS device is 70nm. The threshold voltages, G m and off current are 0 28V,490mS·mm -1 and 0 08nA/μm for NMOS and -0 3V,340mS·mm -1 and 0 2nA/μm for PMOS, respectively. Delays of 23 5ps/stage at 1 5V, 17 5ps/stage at 2 0V and 12 5ps/stage at 3V are achieved in the 57 stage unloaded 100nm CMOS ring oscillator circuits.

Developmental Effects of Intraperitoneal Injection of Polychlorinated Biphenyls in Rats During Pregnancy

Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided into five groups and injected daily from gestational days 7 to 18 with either 2,2′,4,4′- tetrachlorobiphenyl (PCB 47) or 3,3′,4,4′- tetrachlorobiphenyl (PCB 77) or seseme oil (control) to evaluate the effects of these PCBs on prenatal and postnatal development.Offspring were examined for malformations of genitalia at birth and in adulthood.Body weight gains of these animals were checked every 7 days through postnatal day (PND) 119.There were no clinical signs of toxicity in the PCB-treated dams or their offspring throughout the experiment.Litter size and sex ratio of the litters were not affected.Both PCBs produced a significant increase in the females' anogenital distance,suggesting a modification of androgen responsiveness in females resulting from PCB exposure during development.Similar effects were not seen with the males.The proportion of individuals with eyes open by PND 15 was significantly reduced by both PCBs.Exposure to 1 mg/kg body weight of PCB 77 significantly reduced body weight gains in male pups from PND 35 to 119.However,no significant differences were found in body weight gains of the pups exposed to PCB 47.

Floating Body Effect in Partially Depleted SOI nMOSFET with Asymmetric Structure and Ge-Implantation

The floating body effect of an asymmetric and Ge implanted partially depleted 0 8μm SOI nMOSFET is investigated.It is found that the drain breakdown voltage can be improved by about 1V and that the anomalous subthreshold slope and kink effect are also lessened.It is believed that the shallow junction in the source and defect states introduced by Ge implantation are responsible for the reduction of the floating body effect.

Impact of changing our cannulation method on the incidenceof post-endoscopic retrograde cholangiopancreatography pancreatitis after pancreatic guidewire placement

AIM： To clarify whether the incidence of post-endoscopic retrograde cholangiopancreatography （ERCP） pancreatitis （PEP） after pancreatic guidewire placement （PGW） can be reduced by using a different cannulation method. METHODS： BebNeen April 2001 and October 2009, PGW was performed in 142 patients with native papilla to overcome difficult biliary cannulation. Our cannulation method for ERCP was changed from contrast injection （CI） using a single-lumen catheter （April 2001-May 2008） to wire-guided cannulation （WGC） using a double-lumen catheter （June 2008-October 2009）. The CI protocol was also changed during the study period： in the first period it was used for routine pancreatography for detecting small pancreatic cancer （April 2001-November 2002）, whereas in the second period it was not （December 2002-May 2008）. In PGW with CI using a single- lumen catheter, the contrast medium in the catheter lumen was injected into the pancreatic duct. The success rate of biliary cannulation, the incidence of PEP according to the cannulation method, and the impact of CI using a single-lumen catheter on PEP in comparison with WGC using a double-lumen catheter were investigated.RESULTS： CI with routine pancreatography, CI without routine pancreatography, and WGC were performed in 27 patients, 77 patients and 38 patients, respectively. Routine pancreatography did not contribute to the early diagnosis of pancreatic cancer in our study period. In CI without routine pancreatography and WGC, diagnostic pancreatography was performed in 17 patients and no patients, respectively. The success rate of biliary cannulation by PGW alone was 69%, and the final success rate was increased to 80.3% by the addition of consecutive maneuvers or a second ERCP. PEP occurred in 22 patients （15.5%）, and the severity was mild in all cases. When analyzed according to cannulation method, the incidence of PEP was 37.0% （10/27） in the patients who underwent CI with routine pancreatography, 14.3% （11/77） in those who underwent CI without routine pancreatography, and 2.6% （1/38） in those who underwent WGC. In all patients who underwent CI using a singlelumen catheter, the incidence of PEP was 20% （21/104）, which was significantly higher than that in WGC using a double-lumen catheter. In univariate and multivariate analysis, CI using a single-lumen catheter showed a high, statistically significant, odds ratio for PEP after PGW. CONCLUSION： The practice of a cannulation method involving the use of a double-lumen catheter minimizes the CI dose administered to the pancreatic duct and reduces the incidence of PEP after PGW.

Review of dynamic contrast-enhanced ultrasound guidance in ablation therapy for hepatocellular carcinoma

Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly def ined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in diffi cult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an effi cient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.

Effect of Dopamine Injection on the Hemocyte Count and Prophenoloxidase System of the White Shrimp Litopenaeus vannamei

Effects of dopamine injection on the hemocyte count, phenoloxidase activity, serine proteinase activity, proteinase in-hibitor activity and α2-macroglobulin-like activity in L. vannamei were studied. Results showed that dopamine injection resulted in a significant effect on the parameters measured (P < 0.05), while no significant difference was observed in the control group (0.85% NaCl). In the experimental groups,the hemocyte count reached the minimum in 3 h;granular and semi-granular cells became stable after 12 h and hyaline cells and the total hemocyte count became stable after 18 h. Phenoloxidase activity reached the minimum in 6 h, and then became stable after 9 h. Serine protease activity and proteinase inhibitor activity reached the minimum in 3 h, and α2-macro-globulin-like activity reached the maximum in 3 h,and all the three parameters became stable after 12 h. The results suggest that the activating mechanisms of the proPO system triggered by dopamine are different from those triggered by invasive agents or sponta-neously activated under a normal physical condition.

Application of CT perfusion imaging in detection of tumor angiogenesis in osteosarcoma

Objective： The aim of the study was to explore the application of 64-slice spiral computed tomography perfusion imaging （CTPI） in evaluating angiogenesis in human osteosarcoma. Methods： Twenty-six patients （18 males and 8 females ranging from 9 to 56 years old, with an average of 19 years） with osteosarcoma underwent 64-slice spiral CTPI. We analyzed the correlations of CTPI parameters including blood flow （BF）, blood volume （BV）, time to peak （TTP）, and permeability surface （PS） with the expression of markers of angiogenesis. Statistical analysis was performed with paired-samples t test, and Pearson correlation analysis was employed to investigate the correlations of CTPI parameters with microvessel density （MVD）. Results： Mean BF, BV, TTP, and PS values of osteosarcoma group were （46.6 ± 25.1） mL/100 g/min, （61.8 ± 29.5） mL/100 g, （122.9 ± 26.2） seconds, and （44.5 ± 14.6） mL/100 g/min, respectively. Those in the normal muscle group were （5.2 ± 6.6） mL/100 g/min, （9.6 ± 7.3） mL/100 g, （115.5 ± 33.1） seconds and （17.0 ± 29.3） mL/100 g/min, respectively. Osteosarcoma group showed higher BF, BV and PS compared with the normal muscle group （P = 0.000, P = 0.000, and P = 0.000, respectively）. However, no significant difference was found in TTP between osteosarcoma tissue and normal adjacent muscle tissue （P = 0.273）. BF, BV, and PS were positively correlated with MVD （r = 0.83, P = 0.000; r = 0.87, P = 0.000; and r = 0.63, P = 0.001, respectively）. No correlation was found between TTP and MVD （r = –0.02, P = 0.93）. Conclusion： CTPI is useful for assessing tumor vascularity of osteosarcoma and CTPI parameters are positively correlated with MVD.

Puncture injection of para-toluenesulfonamide combined with chemoembolization for advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is difficult to eradicate due to its resilient nature. Portal vein is often involved in tumors of large size, which exclude the patient from surgical resection and local ablative therapy, such as percutaneous ethanol injection (PEI) and radiofrequency ablation (RFA) because they were considered neither effective nor safe. Currently, there is almost no effective treatment for HCC of such condition. As a unique antitumor agent in form of lipophilic fluid for local injection, para-toluenesulfonamide (PTS) produces mild side effects while necrotizing the tumor tissues quickly and efficiently. Being largely different from both PEI and RFA therapies, PTS can disseminate itself in tumors more easily than other caustic agents, such as alcohol. So PTS may offer additional benefit to HCCs with vascular involvement. We herein describe a 70-year-old HCC patient who was treated with the combination of PTS injection and transcatheter arterial chemoembolization, resulting in a significantly improved clinical prognosis.

Cardiac remodeling as a consequence of atrial fibrillation： An anatomical study of perfusion-fixed human heart specimens

Background Atrial fibrillation （AF） causes a continuum of atrial anatomical remodeling. Methods Using a library of perfusion-fixed human hearts, specimens with AF were compared to controls. During this preliminary assessment study, direct measurements were taken of atrial volume, pulmonary vein （PV） circumference, and left atrial （LA） wall thicknesses. Results Hearts with AF typically had larger atrial volumes, as well as a much larger variation in volume compared to controls （range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls）. For all hearts, right PVs were larger than left PVs （mean： 171.4 ± 84.6 mm^2 for right and 1182 ± 50.1 mm^2 for left, P 〈 0.005）. LA wall thicknesses ranged from 0.7 mm to 3.1 mm for both AF and control hearts. Conclusions Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF. The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.

Double Charm Decays of B Mesons in mSUGRA Model

Based on the low energy effective Hamiltonian with naive factorization, we calculate the branching ratios （BRs） and CP asymmetries （CPAs） for the twenty three double charm decays B/B8 → D（＊）D（＊） in both the standard （s） （s） model （SM） and the minimal supergravity （mSUGRA） model. Within the considered parameter space, we find that （a） the theoretical predictions for the BRs, CPAs and the polarization fractions in the SM and the mSUGRA model are all consistent with the currently available data within ±2σ errors; （b） For all the considered decays, the supersymmetric contributions in the mSUGRA model are very small, less than 7% numerically. It may be difficult to observe so small SUSY contributions even at LHC.

Efficacy of perioperative parecoxib injection on postoperative pain relief after laparoscopic cholecystectomy:A prospective,randomized study

AIM:To determine the efficacy of perioperative parecoxib injection on postoperative pain relief after laparoscopic cholecystectomy.METHODS: A prospective, double-blind, randomized, placebo-controlled study was conducted on 70 patients who underwent elective laparoscopic cholecystectomy under general anesthesia at Siriraj Hospital, Bangkok, from January 2006 to December 2007. Patients were randomized to receive either 20 mg parecoxib infusion 30 min before induction of anesthesia and at 12 h after the first dose (treatment group), or normal saline infusion, in the same schedule, as a placebo (control group). The degree of the postoperative pain was assessed every 3 h in the first 24 h after surgery, and then every 12 h the following day, using a visual analog scale. The consumption of analgesics was also recorded.RESULTS:There were 40 patients in the treatment group, and 30 patients in the control group. The pain scores at each time point, and analgesic consumption did not differ between the two groups. However,there were fewer patients in the treatment group than placebo group who required opioid infusion within the first 24 h (60% vs 37%, P=0.053).CONCLUSION: Perioperative administration of parecoxib provided no significant effect on postoperative pain relief after laparoscopic cholecystectomy. However, preoperative infusion 20 mg parecoxib could significantly reduce the postoperative opioid consumption.

Effect of Doxorubicin on Histomorphology of Liver of Wistar Albino Rats

Doxorubicin is associated with adverse effects on organs like liver. This study was done to find the effects of doxorubicin on liver of wistar albino rats. Sixty healthy wistar albino rats were taken for the study. The rats were randomly divided in to 4 groups （2 experimental groups; group AI and A2, and 2 control groups;group Bland B2 each containing 16 rats）. The experimental groups were given a single dose of doxorubicin i.e. 10 mg/kg body weight intraperitoneally and sacrificed after 7 days and 14 days for each group. Rats under control groups were given a single intraperitoneal dose of 2.5 ml/kg body weight normal saline and sacrificed with their respective experimental groups. A significant difference （p 〈 0.001） and （p = 0.005） in final body weight was observed among group A1 experimental and BI control rats, and among group A2 experimental and B2 control rats. As compared to group B2 control, group A2 experimental rats had significantly （p = 0.043） lower liver weight. Diameter ofhepatocyte （p 〈 0.001 for both groups） and nucleus （p=0.004 for group A1 and control BI, and p 〈 0.001 for group A2 and control B2） was significantly higher in experimental rats as compared to their respective controls. Cross-sections of the liver of both control groups had normal architecture. However, there was progressive destruction of liver architecture across the experimental groups. Doxorubicin causes the disruption of normal architecture of liver in rats. Thus care needs to be taken during doxorubicin chemotherapy to minimize effects on river.

Remarks on Definitions of Perturbation in General Relativity

There are two kinds of definitions of perturbation of physical quantities in the framework of general relativity： one is direct, the other is geometrical. Correspondingly, there are two types of gauge transformation related with these two definitions. The passive approach is based on the property of general covariance, and the active one is through the action of Lie-derivative. Although under a proper coordinate choice, the two approaches seem to agree with each other, they are different in nature. The geometrical definition of relativistic perturbation and the active approach for gauge transformation are more rigorous in mathematics and less confusing in physical explanation. The direct definition, however, seems to be plagued with difficulties in physical meaning, and the passive approach is more awkward to use, especially for high-order gauge transformations.

Role of intravenously administered hyoscine butyl bromide in retrograde terminal ileoscopy: A randomized, double-blinded, placebo-controlled trial

AIM： To evaluated the role of hyoscine butyl bromide in facilitating retrograde ileoscopy. METHODS： Retrograde terminal ileoscopy was attempted in 200 consecutive patients undergoing colonoscopy. After intubation of the cecum and visualization of the ileocecal valve, butyl bromide injection or normal saline was given intravenously to the patients in a double blind random fashion. The pulse rate and oxygen saturation were measured continuously. After completion of the procedure, endoscopists were then asked to score the ease of intubation and the ease of visualization of the terminal ileum on a visual scale of 1 to 10. The patients were also asked to score the pain after receiving hyoscine butyl bromide injection on a score of 1 to 10. RESULTS： Terminal ileoscopy could be performed in 188 patients. The mean （SD） visual analogue score for the ease of intubation of the cecum was 7.4 （0.65） in the injection group and 5.9 （0.8） in the placebo group （P 〈 0.001）. The mean （SD） length of ileum visualized in the injection group was 14.4 （3.3） cm and 10.4 （2.7） cm in the placebo group （P 〈 0.001）. The mean （SD） visual analogue score for ease of visualization of the terminal ileum was 7.5 （0.69） in the injection group and 5.9 （0.7） in the placebo group （P 〈 0.001）. The pain score experienced by the patients was 6.5 （0.7） in the injection group and 6.7 （0.69） in the placebo group （P 〈 0.008）. Although the pulse rate increased significantly in patients receiving the drug, no statistically significant difference was noted in the oxygen saturation between the two groups either before or after administration of the drug. No complications were observed in either of the groups. CONCLUSION： Hyoscine butyl bromide injection is a useful adjunct in helping the intubation and visualization of terminal ileum during colonoscopy.