淋雨对棒-板长空气间隙正极性直流放电影响

棒板长间隙放电模型是最典型的模型,对绝缘设计具有重要的指导意义。将高电压试验与计算机仿真相结合的研究方式具有经济实用和方便灵活、可操作性强的优势。为研究降雨对棒板长间隙击穿电压的影响规律,本文构建了对棒-板长空气间隙正极性直流放电特性进行试验研究的方案,以便为后续的研究和分析提供基础。

教会学生“放电影” 帮助掌握古诗词

古诗词在初中语文教材中的比重虽不大，但它在中招语文科目考试的地位却举足轻重，因此，大多数语文教师在教学中非常重视对学生古诗词诵读与赏析能力的培养，特别是在应考复习中更是要对学生进行大量的训练。

大气压交流金属针-水电极放电特性研究

气液两相放电受到诸多因素的影响,在液体表面表现出较为复杂的放电特性与相互作用。该文采用大气压交流金属针-水电极放电结构,对其放电特性及规律进行研究。实验结果表明,随着电源功率的增大,大气压交流金属针-水电极的放电由两种不稳定放电模式转变为稳定放电模式。电源功率足够高时,放电在正、负半周期出现截然不同的放电模式,结合放电影像和电气特性对其放电的时空演化过程进行了分析,研究了电源功率和放电间隙对放电特性及参数的影响。研究发现,击穿电压随电源功率的增大从2.3 kV减小到2.0 kV,随放电间隙的增大从1.0 kV增加到1.9 kV;电流峰值和功率峰值只在正半周期时与放电间隙的大小呈正相关关系;传导电荷量随电源功率的增大而增多,与放电间隙没有明显的关系;单次放电能量中,正半周期放电能量始终大于负半周期的放电能量,正、负半周期放电能量与电源功率呈正相关关系,与放电间隙没有明显的相关性。

放电影

路窄而长，一盏灯忽闪忽闪的，随时有熄掉的可能。来福和桂花走在这条路上，影子被月光拉到了墙壁上。

天线放电球放电对中波发射机末级的影响分析

针对雷电容易通过天调网络和馈线造成中波发射机末级功放模块和供电模块损坏的存在问题,研究了放电球放电前后天调网络的不同表现特征和规律,阐明了放电球放电是导致发射机末级功放模块和供电模块损坏的主要原因,提出了通过降低ftx,f0前、f0后和f1等振荡频率、旁路f2输出、增加馈线终端移相网络支撑来提高中波发射机防雷可靠性的方法。实验表明,该方法能够有效提升天调网络的防雷可靠性。

忆儿时看电影

记忆深处,仍深深刻着小时候看电影的情景。那时在农村看场电影还真不是易事,不过,只要哪里有放电影的消息,不管是七村八乡的,我们自会拿着凳子,不辞辛苦赶到目的地。记得去得最多的是一个叫“十大队”的地方,那里是大队部,离我们住的地方有好几里地。

基于DBD的煤燃前脱硫机理和脱硫模型

基于介质阻挡放电(DBD)等离子进行煤燃前脱硫是一种全新的煤炭脱硫技术。利用其常温常压下产生活性基团,在无催化剂、吸收剂的条件下,将煤中硫氧化为酸雾(硫酸),实现从源头上脱硫。为了更好地掌握DBD的脱硫机理和创造这种脱硫在工业上的应用,分析了加煤对DBD的影响,通过加煤后对微放电加强的现象,确定DBD等离子脱硫的可行性。实验时比较同一条件的加煤前后放电波形,进一步验证上述理论。同时,探究DBD脱除硫的内部过程和反应机理,发现DBD产生丰富的活性粒子和自由基,能够将原煤中部分硫元素氧化成H2SO4,SO2-4等物质,从而实现煤的脱硫处理。最后,利用一维脱硫模型改进多元回归模型,从而建立外加电压、电极形式-脱硫效果的二维脱硫模型,并根据模型得到当外加电压19.173 kV、介质放在电极上时,得到最佳脱硫效果值2.406。为DBD脱硫的工业应用提供了理论依据。

论初中生的学习十步骤

长期以来,教学改革偏重于对教的研究,对学生是如何学的,学的活动是如何安排的,往往较少问津.全面实施素质教育就要求学生掌握方法,科学方法是连接知识和能力的纽带,掌握方法本身就是学习.

Enhanced Field Emission from Printed Carbon Nanotubes by Hard Hairbrush

A method, the morphology of screen printed carbon nanotube pastes is modified using a hard hairbrush, is presented. In this way, the organic matrix material is preferentially removed. Compared to those untreated films, the turn-on electric field of the treated film decreases from 2.2V/μm to 1.6V/μm, while the total emission current of the treated increases from 0.6mA/cm2 to 3mA/cm2, and uniform emission site density image has also been observed.

Shallow groundwater dynamics in North China Plain

The groundwater level of 39 observation wells including 35 unconfined wells and 4 confined wells from 2004 to 2006 in North China Plain(NCP) was monitored using automatic groundwater monitoring data loggers KADEC-MIZU II of Japan.The automatic groundwater sensors were installed for the corporation project between China and Japan.Combined with the monitoring results from 2004 to 2006 with the major factors affecting the dynamic patterns of groundwater, such as topography and landform, depth of groundwater level, exploitation or discharge extent, rivers and lakes, the dynamic regions of NCP groundwater were gotten.According to the dynamic features of groundwater in NCP, six dynamic patterns of groundwater level were identified, including discharge pattern in the piedmont plain, lateral recharge-runoff-discharge pattern in the piedmont plain, recharge-discharge pattern in the central channel zone, precipitation infiltration-evaporation pattern in the shallow groundwater region of the central plain, lateral recharge-evaporation pattern in the recharge-affected area along the Yellow River and infiltration-discharge-evaporation pattern in the littoral plain.Based on this, the groundwater fluctuation features of various dynamic patterns were interpreted and the influencing factors of different dynamic patterns were compared.

Clinical implication of FDG uptake of bone marrow on PET/CT in gastric cancer patients with surgical resection

AIM To determine the relationship between F-18 fluorodeoxyglucose(FDG) uptake of bone marrow(BM) on positron emission tomography/computed tomography(PET/CT) and clinical factors and to assess the prognostic value of FDG uptake of BM in gastric carcinoma.METHODS We retrospectively enrolled 309 gastric cancer patients who underwent staging FDG PET/CT and curative surgical resection. FDG uptake of primary tumor was visually classified as positive or negative FDG uptake. Mean FDG uptake of BM(BM SUV) and BM-to-liver uptake ratio(BLR) were measured. The relationships of BM SUV or BLR with clinical factors were evaluated. The prognostic values of BM SUV, BLR, and other clinical factors for predicting recurrence-free survival(RFS) and overall survival(OS) were assessed.RESULTS Of 309 patients, 38 patients(12.3%) experienced cancer recurrence and 18 patients(5.8%) died. Patients with advanced gastric cancer, positive FDG uptake, and recurrence had higher values of BM SUV and BLR than those with early gastric cancer, negative FDG uptake, and no recurrence(P < 0.05). BM SUV and BLR were significantly correlated with hemoglobin level, neutrophil-to-lymphocyte ratio, and platelet-tolymphocyte ratio(P < 0.05). On multivariate analysis, multiple tumors, T stage, lymph node metastasis, tumor involvement of resection margin, and BLR were significantly associated with RFS(P < 0.05). T stage, lymph node metastasis, hemoglobin level, and BLR were significantly associated with OS(P < 0.05). CONCLUSION BLR on PET/CT was an independent prognostic factor for RFS and OS in gastric cancer patients with curative surgical resection.

Performance of 18-fluoro-2-deoxyglucose positron emission tomography for esophageal cancer screening

AIM To evaluate the performance of 18-fluoro-2-deoxyglucose positron emission tomography(FDG-PET) for esophageal cancer(EC) screening.METHODS We retrospectively analyzed the data of consecutive asymptomatic individuals who underwent FDG-PET and esophagogastroduodenoscopy(EGD) simultaneously for cancer screening at our institution from February 2004 to March 2013. In total, 14790 FDG-PET and EGD procedures performed for 8468 individuals were included in this study, and the performance of FDGPET for EC screening was assessed by comparing the results of FDG-PET and EGD, considering the latter as the reference.RESULTS Thirty-two EC lesions were detected in 28 individuals(31 squamous cell carcinomas and 1 adenocarcinoma). The median tumor size was 12.5 mm, and the depths of the lesions were as follows: Tis(n = 12), T1a(n = 15), and T1b(n = 5). Among the 14790 FDG-PET procedures, 51 examinations(0.3%) showed positive findings in the esophagus; only 1 was a true-positive finding. The screen sensitivity, specificity, positive predictive value, and negative predictive value of FDGPET for ECs were 3.6%(95%CI: 0.1-18.3), 99.7%(95%CI: 99.6-99.7), 2.0%(95%CI: 0.0-10.4), and 99.8%(95%CI: 99.7-99.9), respectively. Of the 50 FDG-PET false-positive cases, 31 were observed in the lower esophagus, and gastroesophageal reflux disease was observed in 17 of these 31 cases.CONCLUSION This study is the first to clarify the FDG-PET performance for EC screening. Based on the low screen sensitivity, FDG-PET is considered to be difficult to use as a screening modality for ECs.

Film Le Dēpart by Jerzy Skolimowski： Important Unknown Piece of Art

The aim of this essay is firstly to indicate a little-known film Le Dēpart made by the famous Polish director Jerzy Skolimowski in 1967 year as an example of the Polish New Wave. Although it was made in Belgium and it stars Jean-Pierre Lēaud as a car-obsessed young man trying to get possession of a Porsche for a race. The film won the Golden Bear at the 17th Berlin International Film Festival and was also selected as the Belgian entry for the Best Foreign Language Film at the 40th Academy Awards, but was not accepted as a nominee. Secondly, I analyze the reasons of misunderstanding the idea of the director in the film when it was shown in the the public. Thirdly, ＂entering＂ this movie in context of art： poetry, painting etc. Then to answer the question （hypothesis）： ＂Is the Polish Film New Wave a phenomenon that did not exist？＂ The methodology used for the paper is analysis and interpretation of the film itself; analysis of its reception in the 60s and now： poetics of receipt, cognitivism, comparative research.

Metaphor in Cinema Revisited

The theory of rhetorical figures in cinema is highly problematic, besides it can be considered as outdated as the semiotic theory of cinema,1 yet it is convenient to reexamine the idea of＂cinematographic metaphor＂ in order to throw some light on the dominant idea of cinema as narrative medium. In this paper we will examine： （l） the supposedly existing metaphor of urban and industrial man as sheep at the beginn!ng of Chaplin＇s film Modern Times; and （2） the sequence of the awakening stone lion in Eisenstein＇s Battleship Potemkin as metaphor of the proletarian revolt against czarism. We will arrive to the notion of a purely metaphoric film, which together with Zavattini＇s ideal film showing 90 minutes in the life of a man to whom nothing happens, will helps us draw some conclusions about montage and narrativity in cinema. Especially interesting in this connection is the fact that symbolical shots as the mentioned ones are like description in literature, that is, they have nothing to do neither with the time of the story nor with the time of the discourse.

The Four Horsemen of the Apocalypse： Time and the Relationship Between Video Art, Painting, and Film

Literally and figuratively, video art is not viewed in the same way as traditional forms of art. It is often relegated off to its own room or comer of a gallery, and when we see video, we think of film and conjure the idea of passively viewing a story with a set beginning, middle, and end. This is reinforced by the fact that most video art has a playing time listed or is viewed in a darkened room in the same way as one would view a movie. Alternately, once a painting is hung, the artist is no longer in control of the way it is viewing the story. The viewer now determines the time and narrative. This paper looks at a new way of expressing video art by analyzing the installation ＂The Four Horsemen of the Apocalypse＂. The animations that are part of the installation are edited as the viewer is experiencing it in an attempt to approximate how we view a painting. Finally, the impact of the installation is compared to a short film created from the same footage; this time, it is viewed in a dark room with the artist in control of how the story unfolds.

Evolving role of FDG-PET/CT in prognostic evaluation of resectable gastric cancer

Gastric cancer (GC) remains a leading cause of cancer death worldwide. Radical gastrectomy is the only potentially curative treatment, and perioperative adjuvant therapies may improve the prognosis after curative resection. Prognosis largely depends on the tumour stage and histology, but the host systemic inflammatory response (SIR) to GC may contribute as well, as has been determined for other malignancies. In GC patients, the potential utility of positron emission tomography/computed tomography (PET/CT) with the imaging radiopharmaceutical 18F-fluorodeoxyglucose (FDG) is still debated, due to its lower sensitivity in diagnosing and staging GC compared to other imaging modalities. There is, however, growing evidence that FDG uptake in the primary tumour and regional lymph nodes may be efficient for predicting prognosis of resected patients and for monitoring tumour response to perioperative treatments, having prognostic value in that it can change therapeutic strategies. Moreover, FDG uptake in bone marrow seems to be significantly associated with SIR to GC and to represent an efficient prognostic factor after curative surgery. In conclusion, PET/CT technology is efficient in GC patients, since it is useful to integrate other imaging modalities in staging tumours and may have prognostic value that can change therapeutic strategies. With ongoing improvements, PET/CT imaging may gain further importance in the management of GC patients.

Early radiological assessment of locally advanced pancreatic cancer treated with electrochemotherapy

To report early imaging assessment of ablated area post electrochemotherapy (ECT) in patients with locally advanced pancreatic cancer (LAPC). METHODSECT was performed in 19 LAPC patients enrolled in an approved ongoing clinical phase I/II study. Before and after ECT, 18 patients underwent computed tomography (CT) scan, 11 patients underwent morphological and functional magnetic resonance (MR) scan (dynamic contrast enhanced-MRI) calculating wash-in slope (WIS) and wash-out slope (WOS); diffusion weighted imaging calculating pseudo-diffusivity (Dp), perfusion fraction (fp) and tissue diffusivity (Dt); 10 patients underwent positron emission tomography (PET). Response evaluation criteria in solid tumour (RECIST) on MR and CT were used to assess tumour therapy response. Choi on CT, PET response criteria in solid tumors (PERCIST) on PET and functional parameters on MR were used to evaluate treatment response. RESULTSFor each patient no significant reduction was measurable by CT and MR using RECIST. According Choi criteria a partial response was obtained in 18/18 (100.0%) patients. According PERCIST criteria 6/10 (60.0%) patients showed a partial response, 3/10 (30.0%) stable disease and 1/10 (10.0%) progression disease. Moreover, using functional MR parameters, a significant reduction of viable tumour after ECT can be observed. According ΔWIS and ΔWOS 9/11 (81.8%) patients exhibited a partial response and 2/11 (18.2%) stable disease; 8/11 (72.7%) patients were considered in partial response by ΔDp evaluation and 3/11 (27.3%) in stable disease; according ΔDt 7/11 (63.6%) patients showed a partial response, 1/11 (9.1%) showed progression of disease and 3/11 (27.3%) were stable. Perfusion fraction fp showed a significant reduction after ECT only in four patients. No significant difference was observed after ECT in signal intensity of T1-weighted images and T2-weighted images, and in equilibrium-phase of contrast study, according to χ2 test was observed. A good correlation was reported between ΔHounsfield unit and Δmaximum standardized uptake value and between Δfp and ΔWOS, with a significant statistically difference (P < 0.05) using Spearman correlation coefficient. CONCLUSIONPerfusion and diffusion MR derived parameters, Choi, PERCIST criteria are more performant than morphological MR and CT criteria to assess ECT treatment response.

Potential application of neogalactosylalbumin in positron emission tomography evaluation of liver function

AIM To investigate the evaluation of neogalactosylalbumin (NGA) for liver function assessment based on positron emission tomography technology. METHODS Female Kunming mice were assigned randomly to two groups: fibrosis group and normal control group. A murine hepatic fibrosis model was generated by intraperitoneal injection of 10% carbon tetrachloride (CCl4) at 0.4 ml every 48 h for 42 d. F-18-labeled NGA ([F-18] FNGA) was synthesized and administered at a dosage of 3.7 MBq/mouse to both fibrosis mice and normal control mice. Distribution of [F-18] FNGA amongst organs was examined, and dynamic scanning was performed. Parameters were set up to compare the uptake of tracers by fibrotic liver and healthy liver. Serologic tests for liver function were also performed. RESULTS The liver function of the fibrosis model mice was significantly impaired by the use of CCl4. In the fibrosis model mice, hepatic fibrosis was verified by naked eye assessment and pathological analysis. [F-18] FNGA was found to predominantly accumulate in liver and kidneys in both control group (n = 21) and fibrosis group (n = 23). The liver uptake ability (LUA), peak time (T-p), and uptake rate (LUR) of [F-18] FNGA between healthy liver (n = 8) and fibrosis liver (n = 10) were significantly different (P < 0.05, < 0.01, and < 0.05, respectively). LUA was significantly correlated with total serum protein level (TP) (P < 0.05). T-p was significantly correlated with both TP and glucose (Glu) concentration (P < 0.05 both), and LUR was significantly correlated with both total bile acid and Glu concentration (P < 0.01 and < 0.05, respectively). CONCLUSION [F-18] FNGA mainly accumulated in liver and remained for sufficient time. Functionally-impaired liver showed a significant different uptake pattern of [F-18] FNGA compared to the controls.

Metabolic imaging for guidance of curative treatment of isolated pelvic implantation metastasis after resection of spontaneously ruptured hepatocellular carcinoma: A case report

Spontaneous rupture of hepatocellular carcinoma(HCC) is a life-threatening complication and its prognosis is significantly poor because of the high recurrence rate after initial hepatectomy. Resection of isolated extrahepatic metastasis of HCC has been advocated to obtain a possibility of long-term survival. However, it is a challenge for clinicians to detect implantation metastasis of spontaneously ruptured HCC. Accurate re-staging plays the most important role in making a decision on isolated metastasis resection. 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography/computed tomography(PET/CT) is useful in detecting intraabdominal implantation metastasis from a variety of malignancies and shows superior accuracy to conventional imaging modalities in determining the location of metastasis. We present one patient with a new isolated pelvic implantation metastasis detected by 18F-FDG PET/CT and pathologically confirmed by PET/CT-guided percutaneous biopsy, who had a history of resection of spontaneously ruptured HCC two years ago. The patient's condition was stable at the 6-mo follow-up after resection of the isolated pelvic metastasis.

那些消失的露天电影

上世纪六七十年代,每月能够在沪昆铁路沿线小站看上一两场露天电影,那是生活中一件再开心不过的事.那时物质匮乏、文化生活枯燥,如果放映队到铁路沿线小站放电影,那消息可就像长了翅膀一样传得飞快,附近十里八村的厂矿、学校,男女老少,都会成群结队赶去观看.