“快照”与“慢照”

摄影术发明之初 ,照相是件又苦又累的差事 ,当年在马希纳岛旅行的一位青年人———柯达先驱伊斯曼从冒着碘蒸汽的湿版帐蓬中疲惫地爬出 ,面对着在烈日下曝晒 2个小时等着看照片的当地人 ,心中对这种湿版法是多么沮丧 :太慢了 ,太繁琐了 !9年后 ,他研制出一台手提的柯达相机 :轻便、装有 6米胶卷、f 9定焦镜头、1 2 5秒速快门 ;使摄影成了大众娱乐方式 ,有的爱好者用其拍摄街道、贫民、童工、战争 ,发展成纪实快照 ;有的则模仿美术 ,用照相机作画、营造新意境 ,称为“慢照”。两种方法发展至今 ,成为摄影的纪实、画意两大支脉。快照·纪实快…     

全站仪检测立式金属罐容量方法的探索

全站仪法测量立式金属罐有两种方法,即内测法和外测法。本文主要论述这两种方法原理与测量的基本过程,在同一立式金属罐,以两种测量法得到的半径与容量实验数据进行比对,从而来说明全站仪测量立式金属罐方法重复性较好,且实验数据结果达到了国家检定规程的要求。     

计算机射线摄影CR与图像存档通讯系统PACS

本文扼要阐述了现代医学影像技术的两种新系统,计算机射线摄影ＣＲ和图像存档通讯系统ＰＡＣＳ的开发、进展,基本原理和在临床实现应用中取得的卓越成果,总结其与传统的屏片组合Ｘ线照像相比的优点,并指出：这两种新技术可还以充分利用医疗单位原有的Ｘ线设备,庆受到广泛重视和采用。     

空气间隔装药混凝土爆破试验块度分析

阐述了摄影法在块度分布上的研究现状,介绍了基于人工圈定的借助PS和CAD的图片处理方法。对不同空气层位置和比例的空气间隔装药进行了混凝土模型爆破试验,采用图像处理法从投影面积的角度采集数据并统计了各组试验爆破块度的分布规律。从块度分布曲线、最大块度和平均块度三个指标比较分析各组试验结果,初步得出了空气间隔装药爆破中空气层位置和比例对爆破块度分布的影响规律。另外,对同一组试验采用投影面积法和网筛尺寸法两种方法进行了分析比较,发现两者在描述块度分布指标上是一致的。     

连续,以涟漪诠释时间

以连续摄影这样一种视觉表现形式来诠释一个时间段的故事，是摄影者越来越乐意采用的方式，它符台叙事发展的摄影表现方法，而这种方法在仅仅一个模特身上的运用便也会产生非常有力而延续的视觉感受，以及可能产生比以往相对运用得比较多的摄影手段更深切的感觉。     

风光摄影作品的后期表现技巧（连载之18）面画的合成

风光摄影是大众喜爱的摄影表现形式之一。在每一位从事风光摄影的摄影者心目中都存在着一个唯美的、理想化的"心目中的大自然"。在风光摄影的过程中,摄影人就是在寻找与心目中的自然相吻合的意境和画面。在上一期的文章中,我们介绍了以原有的风光摄影作品为基础,直接在画面上进行调整和改变,对作品进行再创作的方法。本文,我们介绍的是另一种方法,这种方法以拍摄的照片为素材,利用两个     

多影画面拍摄方法

这里所说的多影是指某一个或两个对象被摄在同一底片上经过两次以上的多次曝光组合而成的画面。多影拍摄法也叫一底多次曝光法。采用一底多次曝光创作出的作品十分具有趣味性、新鲜感和吸引力。下面就多影艺术所需要的设备，工作原理，拍摄方法及注意事项介绍如下。     

管内壁尺寸形貌的非接触检测法

本文以光三角法为基础阐述了两种非接触测量管内壁尺寸形貌的方法：激光单光点回转扫描法及激光环形光切图像法。并给出了此两种方法的适用范围     

测定TC4钛合金β相转变温度的金相法和差示扫描量热法的对比

以TC4钛合金为例,根据航空航天工业部发布的钛合金β相转变温度的测试标准,对比分析了金相法和差示扫描量热法测试钛合金β相转变温度结果的一致性及两种方法的优缺点。结果表明:两种方法得到的两组TC4钛合金β相转变温度的差值仅为7℃和1℃。可见两种方法测试TC4钛合金β相转变温度的结果较为一致,都可作为日常测试钛合金β相转变温度的方法。     

双曝光全息图的几种记录方法

双曝光全息干涉法是利用空间波前再现原理，达到无接触地三维观测目的，是全息干涉量度技术的重要方法之一。此技术在各种领域中的应用日益广泛，本文介绍了为应用此技术而制作双曝光全息图的几种方法。     

134例急腹症患者的影像学诊断技术比较研究

目的：合理选用不同的影像学诊断技术,探讨不同影像学检查方法在急腹症诊断中的应用价值,为临床实践中影像学检查的选择提供依据。方法：选取3年多以来因急腹症就诊于我院的80例患者的影像学资料进行回顾性分析。结果：本组80例患者中,52例患者接受X线检查,35例患者接受CT检查,48例患者接受B超检查;检查结果有肠梗阻23例、尿路结石17例、胆道感染及胆石症11例、急性阑尾炎8例、消化道穿孑L6例、急性胰腺炎5例、异位妊娠7例、脏器外伤破裂3例;仅1例患者诊断时出现误诊,其余均诊断正确。结论：x线、B超及CT检查在急腹症的治疗中均具良好的应用价值,分别是于不同类型急腹症的辅助诊断,应熟练掌握各种影像学检查方法的优缺点,以便为患者选择适合的检查方法。提高诊断正确率。     

The additional dose to radiosensitive organs caused by using under-collimated X-ray beams in neonatal intensive care radiography

Radiographic technique and exposure parameters were recorded in five Israeli Neonatal Intensive Care Units for chest, abdomen and both chest and abdomen X-ray examinations. Equivalent dose and effective dose values were calculated according to actual examination field size borders and proper technique field size recommendations using PCXMC, a PC-based Monte Carlo program. Exposure of larger than required body areas resulted in an increase of the organ doses by factors of up to 162 (testes), 162 (thyroid) and 8 (thyroid) for chest, abdomen and both chest and abdomen examinations, respectively. These exposures increased the average effective dose by factors of 2.0, 1.9 and 1.3 for the chest, abdomen and both chest and abdomen examinations, respectively. Differences in exposure parameters were found between the different neonatal intensive care units-tube voltage, current-time product and focal to skin distance differences up to 13, 44 and 22%, respectively. Reduction of at least 50% of neonate exposure is feasible and can be implemented using existing methodology without any additional costs.     

经腹部联合经阴道超声诊断妇产科急腹症的应用价值研究

目的:探究在妇产科急腹症的诊疗中联合应用经腹部超声和经阴道超声的效果与价值.方法:选择在我院妇产科进行诊疗的急腹症患者作为研究对象,研究活动开展时间为2016年1月至2020年12月,急诊收治总患者人数2116例,患者入院后均接受经腹部超声与经阴道超声检查,以病理检查结果为标准,对比不同超声检查结果与联合检查结果在妇产...     

A comparison of AIS-85 with AIS-80 for injury scaling in blunt trauma

As the effects on injury scaling of the differences between the 1980 and 1985 revisions of the AIS are unknown in blunt trauma, we compared them in all 1270 critically injured (median ISS, 26) blunt trauma patients (75% male, 74% road crash, overall mortality 17%) admitted to the Department of Critical Care Medicine at Auckland Hospital from 1983 through 1987. In 911 patients (72%) there were no differences between AIS-80 and AIS-85 in any body region or in derived ISS. Changes in AIS grades were most common in the abdomen (205 patients), thorax (100 patients), and head (61 patients) regions. Median ISS overall for the 1270 patients was unchanged at 26. One percent of patients had changes in ISS of 16-24 points. Direct comparison of groups of patients scored with these two revisions of the AIS is inappropriate, particularly in those with abdomen region injury.     

Experience with continuous venovenous hemodiafiltration in four newborns: A case series and review of the literature

When conventional methods for treating complicated problems such as acute and chronic renal failure or metabolic diseases fail, the therapy of choice is peritoneal dialysis (PD) in neonatal period. However, in cases that involve technical difficulties, such as bulky lesions in the abdomen or complications from previous abdominal surgeries, it is not always possible to place a peritoneal catheter. In such situations, continuous venovenous hemodiafiltration (CVVHDF) can be effective. This case series presents our experience in 2013 with the administration of CVVHDF to four patients in our neonatal intensive care unit who could not undergo PD for various reasons.     

Biomechanics of the human chest, abdomen, and pelvis in lateral impact

Fourteen unembalmed cadavers were subjected to 44 blunt lateral impacts at velocities of approximately 4.5, 6.7, or 9.4 m/s with a 15 cm flat circular interface on a 23.4 kg pendulum accelerated to impact speed by a pneumatic impactor. Chest and abdominal injuries consisted primarily of rib fractures, with a few cases of lung or liver laceration in the highest severity impacts. There were two cases of pubic ramus fracture in the pelvic impacts. Logist analysis of the biomechanical responses and injury indicated that the maximum Viscous response had a slightly better correlation with injury than maximum compression for chest and abdominal impacts. A tolerance level of VC = 1.47 m/s for the chest and VC = 1.98 m/s for the abdomen were determined for a 25% probability of critical injury. Maximum compression was similarly set at C = 38% for the chest and at C = 44% for the abdomen. The experiments indicate that chest and abdominal injury may occur by a viscous mechanism during the rapid phase of body compression, and that the Viscous and compression responses are effective, complementary measures of injury risk in side impact. Although serious pelvic injury was infrequent, lateral public ramus fracture correlated with compression of the pelvis, not impact force or pelvic acceleration. Pelvic tolerance was set at 27% compression.     

Maltese CT doses for commonly performed examinations demonstrate alignment with published DRLs across Europe

This work recommends dose reference levels (DRLs) for abdomen, chest and head computerised tomography (CT) examinations in Malta as the first step towards national CT dose optimisation. Third quartiles volume CT dose index values for abdomen: 12.1 mGy, chest: 13.1 mGy and head: 41 mGy and third quartile dose-length product values for abdomen: 539.4, chest: 492 and head: 736 mGy cm(-1) are recommended as Maltese DRLs derived from this first Maltese CT dose survey. These values compare well with DRLs of other European countries indicating that CT scanning in Malta is consistent with standards of good practice. Further work to minimise dose without affecting image quality and extending the establishment of DRLs for other CT examinations is recommended.     

Injury patterns in frontal crashes: The association between knee-thigh-hip (KTH) and serious intra-abdominal injury

Safety belts protect occupants in frontal impacts by reducing occupant deceleration and preventing the occupant from hitting interior vehicle components likely to cause injury. However, occupants moving forward during the impact may contact the safety belt webbing across their chest and abdomen. We hypothesized that if the occupant loaded their knee-thigh-hip (KTH) region with enough force to result in injury to this region—it might prevent compression (and injury) of their abdomen by the safety belt. Crash Injury Research and Engineering Network (CIREN) data were used to test the association between KTH and intra-abdominal injury related to safety belts. Odds ratios with 95% confidence limits (CL) and logistic regression models were used to assess statistical significance. Analyses were based on 706 CIREN adult, front seat occupants using their safety belt and injured in frontal crashes. Occupants with KTH injury were four times less likely (adjusted odds ratio = 0.25, 95% CL 0.10, 0.62) to have concomitant serious intra-abdominal injury caused by the safety belt. Although safety belts save lives and prevent serious injury, some occupants may sustain serious intra-abdominal injury when the abdomen is loaded by the safety belt during a frontal impact. These results may be useful to motor vehicle manufacturers and others who design and test motor vehicle safety systems.     

超声检查在妇产科急腹症中的诊断价值

目的:对超声检查在妇产科急腹症中的诊断价值进行探讨。方法:对我院2011年至2012年间的70例妇产科急腹症进行回顾性分析,对患者的手术情况、病理以及超声检查结果进行对比分析。结果:在诊断的过程中,异位妊娠的诊断率为97.37%,卵巢囊肿蒂扭转的诊断率为100%,黄体破裂的诊断率为92.31%,胎盘早剥的诊断率为100%,急性盆腔炎的诊断率为100%,其总诊断率为97.14%。结论:超声检查在妇产科急腹症的诊断过程中具有很高的诊断率,这对于患者的治疗提供了重要的参考,值得临床推广。     

Nature and etiology of hollow-organ abdominal injuries in frontal crashes

Injuries to the hollow organs of the lower digestive system carry substantial risk of complication due to infection and blood loss, and commonly require invasive abdominal surgery to diagnose and treat. The causes of, and risk factors for, lower abdomen injury in automobile collisions are poorly understood. The goal of this study was to investigate the risk factors and potential mechanisms of hollow-organ, lower abdomen injury in belted automobile occupants in frontal collisions.