H2S optimization for lignite liquefaction

Two lignite samples, Beulah No. 3 and Big Brown No. 1, were liquefied at 420 °C using H₂ and synthesis gas to determine the optimum beneficial amount of H₂S in the batch autoclave reactor. Under the conditions employed, 50–100 psi partial pressure of H₂S, nominally 4–10 wt% of daf lignite, was optimum for both samples. Synthesis gas outperformed H₂ with and without H₂S for the liquefaction of the two coals.     

链烷烃的表面张力与内压

对Ｄａｖｉｓ和Ｒｏｓｓｅｉｎｓｋｙ提出的关系检验表明，液体的表面张力σ与Ｐ１Ｖｍ１／３之比不仅取决于温度，还与液体的种类有关，据此，建立了一个能由链烷烃的分子结构准确预测其表面张力的方法。     

摩擦诱发高铬铸铁相变的透射电镜研究

利用透射电子显微镜研究了高铬铸铁在摩擦过程中的显微组织变化。结果表明：奥氏体基体在摩擦应力的作用下发生相变。摩擦表面形成α‘Ｍ。次表层形成γ与α’Ｍ共存区；γ与．ε共存区；γ位错丛聚区。     

基于SoPC的SD卡控制器IP核的设计

针对目前在嵌入式平台中使用SD卡控制器专用芯片价格昂贵、软件模拟SPI时序控制读写速度较慢的问题,提出了一种基于SoPC技术的SD卡控制器IP核设计的架构方案.采用VHDL语言设计SD卡控制器IP核,利用自定义模块技术将其添加到SoPC中,利用Nios Ⅱ IDE编写SD卡的基础读写驱动软件并移植μC/FS文件系统,实...     

利用蜜罐提高NIDS的检测性能

目前的入侵检测技术本身存在着缺陷,比如特征检测中规则库不完备,异常检测模型中模型与实际攻击不完全符合等.由这些缺陷而导致的误报和漏报是制约其发展的重要瓶颈.Honeypot/net是一种新的安全技术,通过部署蜜罐收集攻击信息,再把这些信息加以整理传送给IDS,可以弥补入侵检测技术的一些缺点,从而降低IDS的误报率和漏报率.分析了这一设想的可行性,并提出了设计方案.此方案中包括一个Honeynet Software,它联系Honeynet 控制台和NIDS控制台,完成其中提取新模式、传递攻击信息等功能.并利用DARPA(1999)数据集对系统进行了评测,结果表明其在DOS、PROBE、U2R及U2L几个类型攻击方面与其他NIDS相比有着较低的误报率;通过对几个检测实例的分析,说明了这一系统在检测新型攻击、加密后的攻击、DDoS方面比原NIDS有较大的优势.     

α粒子微束定点照射--细胞的放射生物学效应及精确性分析

进行微束试验的关键是能够精确地控制照射的粒子数和将粒子准确地射入受照射位点.该研究通过对哥伦比亚大学单粒子微束装置在精确性、准确性以及各项指标的分析发现该装置可精确地控制照射粒子数,精确率为98.4%.同时,它可将α粒子准确地射入受照射位点,束半径为34,达到设计4的标准.在对细胞特定位点如细胞质照射上,粒子击中细胞质至少一个位点的概率为90%,在这一过程中的偶然核击中率,对大多数照射剂量(8个粒子)均小于0.8%.应用该微束装置的放射生物学研究发现单个α粒子仅导致大约20%的致死率,其存活率曲线类似于用常规照射获得的平均粒子存活曲线.诱变试验首次证实单个α粒子在AL细胞的CD59基因位点可诱导出比对照高出3倍数量的诱变子,诱变率随粒子数的增加而增加.这一结果不同于常规照射中,诱变率在高剂量照射后下降的结论.     

Parameter Blind Estimation of Frequency-Hopping Signal Based on Time–Frequency Diagram Modification

To effectively estimate the parameters of the multiple frequency-hopping signals, a blind parameter estimation method based on time–frequency diagram modification is proposed. Firstly, the observed signal is transformed to the time–frequency domain, using short time Fourier transform with overlapping windows. Then an energy detection method based on adaptive threshold is used to modify the time–frequency diagram, and the parameters of the frequency-hopping signals are finally obtained from the modified spectrogram. Theoretical analysis and simulation results show that the method proposed can get a clear time–frequency diagram at low signal-to-noise ratio (SNR), and its accuracy of parameter estimated is higher than that of previous methods. When SNR is ?10 dB, estimation errors of frequency, hopping time and hop duration is 0.0002, 0.0008 and 0.0013, respectively, which are about 1–2 orders of magnitude lower over the previous method.

     

Updates on the Risk of Neuropsychiatric and Gastrointestinal Comorbidities in Rosacea and Its Possible Relationship with the Gut–Brain–Skin Axis

Rosacea is a common chronic cutaneous inflammatory disorder. Recently, patients with rosacea were identified as having a higher risk of developing various comorbidities such as cardiovascular disease, psychiatric disorders, neurologic disorders, and gastrointestinal disorders. However, the risks of some comorbidities in patients with rosacea are somewhat contradictory, depending upon the study design. Moreover, pathomechanisms associated with the comorbidities of patients with rosacea remain poorly elucidated. The purpose of this review was to provide the most up-to-date evidence on the risks of neuropsychiatric and gastrointestinal comorbidities in patients with rosacea. Moreover, the molecular pathomechanisms associated with neuropsychiatric and gastrointestinal comorbidities in patients with rosacea were evaluated based on recent studies. This review was also intended to focus more on the role of the gut–brain–skin axis in the association of neuropsychiatric and gastrointestinal comorbidities in rosacea.     

微/纳米复合多层金刚石自支撑膜的制备及应力研究

利用大功率DC Arc Plasma Jet CVD装置,采用Ar-H2-CH4混合气体为气源,通过优化工艺参数,在多晶钼衬底上制备出了多层复合金刚石自支撑膜.利用扫描电镜(SEM)、X射线衍射(XRD)、激光拉曼谱(Raman)对膜体进行表征,结果显示,多层膜体的组织结构体现了微米金刚石与纳米金刚石的典型特征;复合金刚石自支撑膜具有光滑的表面,微米层与纳米层间呈相互嵌套式的界面;此外,利用激光拉曼谱分析了多层膜中的内应力状态,研究发现,多层膜中各层膜体具有不同的内应力状态,内应力沿膜体生长方向有明显变化,呈现出从压应力到拉应力的变化过程.