壶瓶枣自然损伤的高光谱成像检测

采用高光谱成像技术（450-1 000 nm）对壶瓶枣的5种自然损伤（缩果病、裂纹、虫害、黑斑病、鸟啄伤）进行识别研究。利用高光谱成像系统采集了5种自然损伤及完好枣一共663个壶瓶枣样本的高光谱图像,并提取相应的感兴趣区域（ROI）,得到了样本的光谱数据。应用偏最小二乘回归（PLSR）、连续投影算法（SPA）从全波段中分别提取了9条、10条特征波长,利用Kennard-Stone算法将各类样本按照3∶1的比例随机分成训练集（500个）和测试集（163个）,并对其建立最小二乘支持向量机（LS-SVM）判别模型,结果表明使用SPA-LS-SVM建立的壶瓶枣自然损伤模型的整体判别正确识别率为93.2%。运用主成分分析（PCA）对由SPA提取出的10条特征波长（535、595、657、672、685、749、826、898、964、999 nm）所对应的单波段图像进行数据压缩,分别采用Sobel算子、区域生长算法Regiongrow并结合主成分图像识别出163个壶瓶枣样本的边缘与自然损伤特征区域,得出平均正确识别率达到90.8%。研究结果表明：采用高光谱成像技术可以对壶瓶枣的自然损伤进行光谱判别和图像识别。

高光谱成像技术对鲜枣内外部品质检测的研究

外部缺陷以及内部可溶性固形物的含量对提升鲜枣的采后附加值和鲜枣后续生产加工具有重要的意义,因此,为了实现同时对鲜枣内外部品质进行快速、准确识别,利用高光谱成像技术(450-1,000nm)对壶瓶枣的"自然损伤"和可溶性固形物含量同时进行检测研究。首先,对光谱数据进行主成分分析(PCA)得到前7个主成分光谱值,对图像数据采用灰度共生矩阵(GLCM)提取到7项图像纹理指标(对比度、相关性、能量、同质性、方差、均值、熵)。然后,分别使用光谱主成分值、图像纹理特征值、以及主成分与纹理特征融合值建立偏最小二乘支持向量机(LS-SVM)模型对壶瓶枣的外部缺陷("自然损伤")和内部品质(可溶性固形物含量)进行检测研究。结果表明:使用主成分与纹理特征融合值建立的LS-SVM模型可作为通用模型同时对壶瓶枣内外部品质进行检测研究,其"自然损伤"判别正确率为92.5%,可溶性固形物预测集的预测相关系数(Rp)和预测均方根误差(RMSEP)分别达到了0.944和0.495。表明,采用高光谱成像技术可以建立通用模型同时对壶瓶枣的内外部品质进行检测,该研究为壶瓶枣的无损检测提供了理论参考。

单面冻融下不同再生骨料取代率的混凝土性能劣化研究

为了研究再生混凝土在单面冻融环境下的抗冻性劣化,本文对不同再生骨料取代率的混凝土进行单面冻融试验,分析了不同再生骨料取代率混凝土在单面冻融环境下的相对动弹性模量与抗压强度损失。结果表明,随着单面冻融次数的增加,再生混凝土的相对动弹性模量下降,单面冻融环境下损伤程度最严重的为100%再生骨料掺量的混凝土。同时,建立不同再生骨料取代率混凝土的单面冻融损伤劣化模型。试验数据拟合表明,自然衰变损伤模型的拟合精度高,引入再生骨料掺量系数可以表征不同再生骨料取代率混凝土的损伤劣化规律。

Numerical and Experimental Research on the Influence of the Centrifugal Pumps Rotor Damage on Their Natural Frequency Response

The paper presents process of creating a centrifugal pump rotor model in CAD environment. Modeling of a virtual object was divided into two stages, modeling of the efficient pump and the simulated failure of one of the impeller＇s blades. Comparison of the results of the resonance frequency obtained from the model analysis, with those obtained from measurements on the actual object was shown. Measurements and simulations were conducted on the pump before and after the simulated damaged of the rotor. In order to verify the model the rotor of pump was weighted and compared with the masses of the respective components obtained from the virtual object. In the second stage genuine rotor was subjected to the experimental modal analysis.

Using the endocannabinoid system as a neuroprotective strategy in perinatal hypoxic-ischemic brain injury

One of the most important causes of brain injury in the neonatal period is a perinatal hypoxicischemic event.This devastating condition can lead to long-term neurological deficits or even death.After hypoxic-ischemic brain injury,a variety of specific cellular mechanisms are set in motion,triggering cell damage and finally producing cell death.Effective therapeutic treatments against this phenomenon are still unavailable because of complex molecular mechanisms underlying hypoxic-ischemic brain injury.After a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury,various neuroprotective therapies have been developed for alleviating brain injury and improving long-term outcomes.Among them,the endocannabinoid system emerges as a natural system of neuroprotection.The endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury,acting as a natural neuroprotectant.The aim of this review is to study the use of different therapies to induce long-term therapeutic effects after hypoxic-ischemic brain injury,and analyze the important role of the endocannabinoid system as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury.

Rapid natural resolution of intracranial hematoma

Objective:To investigate the clinical character istics of intracranial hematoma and the mechanism involved in its rapid natural resolution. Methods:Seventeen cases of intracranial hematoma with typical clinical and CT manifestations were retrospectively studied. Results:Intracranial hematoma was found obviously decreased in size within 72 h after its occurrence in 8 cases. The rest 9 cases presented co mplete resolution. Conclusions:Rapid natural resolution of acute epidural hematom a is mostly found in teenagers and the resolution is correlated with cranial fra cture at the hematoma site. As for acute subdural hematoma, its rapid resolution is associated with the transfer of cerebrospinal fluid toward subdural space, t he lavage effect, and the compression caused by the increased intracranial press ure or the space left resulting from redistribution of the hematoma in brain atr ophy.

The natural history of flail chest injuries

Purpose： Flail chest （FC） injuries represent a significant burden on trauma services because of its high morbidity and mortality. Current gold standard conservative management strategies for FC, are now being challenged by renewed interest in surgical rib fixation. This retrospective epidemiological study sets out to evaluate FC patients, and quantify the natural history of this injury by studying the injury patterns, epidemiology and mortality of patients sustaining FC injuries admitted to a major trauma centre （MTC）. Methods： A retrospective cohort analysis has been conducted at an MTC with full trauma service. All patients （age 〉 16 years） sustaining FC were included. Patient demographics, injury characteristics and inpatient stay information were extracted. Results： Two hundred and ninety-three patients were identified, with a mean injury severity score （ISS） of 28.9 （range 9-75）, average age of 56.1 years （range of 16-100）, and a male predominance （78%）. Road traffic accidents accounted for 45% （n = 132） of injuries, whilst 44% were fall or jump from height （n = 129）. Associated lung contusion was present in 133 patients （45%） while 76% of patients were found to have 5 or more ribs involved in the flail segment （n = 223） with 96% （n = 281 ） having a unilateral FC. Inpatient treatment was required 19.9 days （range 0-150 days） with 59% of patients （n = 173） requiring intensive care unit （ICU） level care for 8.4 days （range 1-63） with 61.8% requiring mechanical ventilation （n = 107） for 10.5 days （range 1-54）, and Z8g underwent rib fixation with rib plates （n = 23）. The mortality rate was found to be 14% （n = 42）. A non-significant trend towards improved outcomes in the conservative group was found when compared with the fixation group; ventilation days （6.94 vs 10.06, p = 0.18） intensive treatment unit （ITU） length of stay （LOS） （12.56 vs 15.53, p = 0.28） and hospital LOS （32.62 vs 35.24, p = 0.69）. Conclusion： This study has successfully described the natural history of flail chest injuries, and has found a nonsignificant trend towards better outcomes with conservative management. With the cohort and management challenges now defined, work on outcome improvement can be targeted. In addition the comnarahility of results to other studies makes collaboration with other MTCs a realistic vrovosal.

China Medical Team： Medical rescue for ＂4.25＂ Nepal earthquake

In recent years, global natural disasters have been frequent and resulted in great casualties and property loss. Since Wenchuan earthquake, the disaster emergency rescue system of China has obtained considerable development in various aspects including team construction, task scheduling, personnel training, facilities and equipments, logistics, etc. On April 25, 2015, an earthquake that measured 8.1 on the Richter scale attacked Nepal. Chinese government firstly organized a medical team, named China Medical Team, and sent it to the attacked region in Nepal to implement medical rescue. The medical team completed the rescue mission successfully and creatively based on their experiences.