碘小姐的旅行

将碘元素拟人化,让其以卤素家族"四小姐"的身份,在这美丽的世界上走一走,并拟人化讨论了碘小姐的元素分布、物理性质以及生理活性,让读者在获得知识之余还能有美的享受。     

磷小姐升职记

将磷元素拟人化,通过生动的语言,讲述了她在生命体内的作用以及在人类生活中的应用,让磷元素的生理功能以及应用更简单易懂,使读者体会到磷元素独特的美。     

Improved Synthesis and Structure of 3-Carboxy-2-pyrazinecarbohydroxamic Acid

3-Carboxy-2-pyrazinehydroxamic acid was prepared by a one pot reaction starting from pyrazine-2,3-dicarboxylic anhydride with a high yield, and characterized by IR, Mass spectrum, 1H NMR and 13C NMR spectra and single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pī with a=4.8659(10), b=7.4233(15), c=11.602(2), α=96.904(2), β=92.422(3), γ=107.454(2)°, V=395.51(14)3 , Z=2, Dc=1.689g/cm3 , F(000)=208, μ(MoKα)=0.149 mm-1 , the final R=0.0473 and wR=0.1306 for 2853 observed reflections (I>2σ (I)). A three-dimensional framework was assembled through intermolecular hydrogen bonding between water and 3-carboxy-2-pyrazine-carbohydroxamic acid molecules.     

模拟电子技术实验教学用元器件板的设计

从模拟电子技术实验教学的实际出发,分析了模拟电子技术实验教学存在的不足,提出了一种专用的模拟电子技术实验教学元器件板的设计,并详细介绍了元器件板的组成、功能和操作方法。实验教学表明,该元器件板结构简单、紧凑,元器件齐全、直观,操作简单,方便了学生对元器件的识别,提高了学生的实验效率,同时也降低了实验教师的工作量,具有一定的实用价值。     

Rejoinder for Gaining effciency via weighted estimators for multivariate failure time data

We thank all the discussants for their interesting and stimulating contributions. They have touched various aspects that have not been considered by the original articles.     

太阳影子定位

本文给出物体在太阳底下影子长度及影子方位角的动态变化规律, 据此建立确定物体所处位置和日期的非线性最小二乘模型, 讨论相应的求解方法. 在此基础上, 利用针孔成像原理, 根据视频中物体影子的变化规律来确定视频的拍摄日期和地点.     

帕立骨化醇对糖尿病肾病肾小管 上皮间充质转化的干预作用研究

目的 探讨帕立骨化醇对糖尿病肾病（DKD）肾小管上皮间充质转化（EMT）的作用及内在机制。方法 将24 只SD 大鼠按随机数字表法分为帕立骨化醇干预组（P 组）、糖尿病肾病组（D 组）和正常对照组（C 组）,每组各8 只。P 组和D 组大鼠腹腔注射链脲佐菌素65mg/kg建立糖尿病肾病模型,造模成功后第2天P 组腹腔注射帕立骨化醇（溶于丙二醇中）0.4滋g/kg,3 次/ 周,D 组予等体积丙二醇;C组仅予等体积丙二醇。4 周后测血、尿生化指标;进行肾脏病理学检查;免疫组化及Western blot 技术检测肾组织E- 钙粘蛋白（E-cadherin）、α- 平滑肌肌动蛋白（α-SMA）、纤连蛋白（FN）、转化生长因子-β1（TGF-β1）及Klotho 的表达,并进行指标间的相关性分析。结果 D组大鼠血清肌酐（Scr）、血尿素氮（BUN）及24 h尿蛋白水平均高于C 组,P 组均低于D 组（均P＜ 0.05）。C 组大鼠肾小管结构完整清晰,无明显病理改变;D 组可见肾小管间质局部炎症细胞浸润,肾小管上皮细胞脱落,小管扩张,基底膜断裂;P 组肾小管间质病理改变较D 组减轻。D 组大鼠肾组织E-cadherin 与Klotho表达低于C组,而P组高于D组（均P＜0.05）;与C 组比较,D 组大鼠肾组织α-SMA、FN 及TGF-β1 表达增加,而P 组表达均较D 组减少（均P＜0.05）。Klotho 表达与E-cadherin呈正相关（r=0.924,P＜0.05）,而与α-SMA、FN 及TGF-β1 均呈负相关（r=-0.806、-0.623、-0.856,均P＜0.05）。结论 帕立骨化醇可抑制糖尿病肾病大鼠肾小管上皮EMT,其作用可能与增加肾组织Klotho表达,同时减少TGF-β1合成相关。     

A new test on the conditional capital asset pricing model

Testing the validity of the conditional capital asset pricing model(CAPM) is a puzzle in the finance literatureLewellen and Nagel[14]find that the variation in betas and in the equity premium would have to be implausibly large to explain important asset-pricing anomaliesUnfortunately, they do not provide a rigorous test statisticBased on a simulation study, the method proposed in Lewellen and Nagel[14]tends to reject the null too frequently.We develop a new test procedure and derive its limiting distribution under the null hypothesis.Also, we provide a Bootstrap approach to the testing procedure to gain a good finite sample performanceBoth simulations and empirical studies show that our test is necessary for making correct inferences with the conditional CAPM.     

The Investigation of Interaction Competition Between ATP and DIPP-Ala,Boc-Ala,or Ala by ESI-MS/MS and Theoretical Calculation

The interactions between ATP and N-(O,O-diisopropyl) phosphoryl-L-alanine (DIPP-Ala), N-(tert-butoxycarbonyl)-L-alanine (Boc-Ala), or L-alanine (Ala) were investigated by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The non-covalent complexes between ATP and Boc-Ala or DIPP-Ala were observed, while the complex between ATP and Ala was not found in the mass spectra. The affinity of DIPP-Ala for ATP was confirmed to be stronger than that of Boc-Ala by competition experiment. Through molecular modeling calculations, it was found that the non-covalent complexes were stabilized by intermolecular hydrogen bonds, and the affinity sequence for ATP was DIPP-Ala > Boc-Ala > Ala by comparing their binding energy, ?35.407 kcal/mol, ?15.634 kcal/mol, ?6.555 kcal/mol, respectively. The results implied that a phosphoryl group was a very important functional group to provide an interaction site between amino acids and ATP, and that N-phosphoryl amino acids can be used as a good model of protein in the studies of molecular recognition of ATP.     

热分解法和碳热还原法制备掺钨VO2 /云母复合粉体的热致变色性能

用溶胶凝胶法和喷雾干燥技术在云母微粉表面包覆了不同nW/nV的掺钨V2O5溶胶,分别采用热分解和碳热还原得到了掺钨VO2/云母复合粉体。通过XRD、SEM对复合粉体进行了物相组成、微观形貌的表征。将复合粉体添加到紫外光固化树脂中形成复合薄膜,通过FTIR测试了复合薄膜相变过程中的红外透过率图谱,并通过DSC测试了复合粉体的相变温度(Tt)。结果表明两种热处理方法均得到了VO2(M),VO2晶体以蠕虫状附着在云母表面,同时钨的掺入使云母表面的VO2颗粒更加细小。不同掺杂量的复合粉体均表现出较优异的热致变色性能,相变前后在2 200 cm-1波数处的红外透过率变化量(ΔTr)均超过20%。随着nW/nV增加,复合粉体的ΔTr逐渐减小,Tt逐步降低,同时相变陡然性减缓。