麦草浆不同筛分组份特性及其对纸浆性能的影响

本试验研究了未漂化学麦草浆不同筛分组份的特性,并探讨了其细小组份(P100)对纸浆性能的影响。研究结果表明,与纤维组份相比,富含杂细胞的细小组份(P100)有较高的灰份、木素、树脂含量,也有较高的润胀程度、较低的结晶度指数和平均聚合度。各筛分组份浆料手抄片的物理强度以长纤维组份的为最高。随着浆料粒子粒度的下降,各组份物理强度降低。化学麦草浆细小组份不同于磨木浆细小组份,浆中细小组份的存在不仅降低了纸浆纤维平均强度,而且还影响纤维间的结合。筛除20％的细小组份,可以提高强度15％,若要提高20％的强度,则需筛除30％至40％的细小组份。此外,筛除细小组份可以提高成纸的表面强度,减少印刷时的掉毛掉粉,造善纸页的印刷适性。     

一种MRI图像中自动检测肿瘤大小的新方法

MRI用于诊断脑部肿瘤、制定手术计划以及评估手术疗效等时,肿瘤大小的自动检测十分重要,其中的关键技术是检测出肿瘤部位的封闭边缘。虽然现在已有许多边缘提取算法,但这些方法应用于医学图像时很少能同时满足速度快、定位准、去噪好等要求。本文提出采用数学形态学和线形广义模糊算子相结合的方法检测肿瘤边缘,再根据检测结果得到的肿瘤部位轮廓计算肿瘤大小。试验表明,该方法在MRI图像中实施,取得了满意的效果。     

A miniaturized DNA amplifier: its application in traditional Chinese medicine

A Si-based miniaturized device for the polymerase chain reaction (PCR) has been developed. The device has Pt temperature sensors and heaters integrated on top of the reaction chamber for real-time accurate temperature sensing and control. Reaction temperature of the device is digitally controlled to achieve a temperature accuracy of +/-0.025 degrees C. The effects of PCR protocol optimization on the amplification performance of the surface-passivated chip reactor have been investigated in detail and quantitatively compared with that of the conventional thermal cycler. In this study, four traditional Chinese medicine genes including Fritillaria cirrhosa, Cartharmus tinctorius, Adenophora lobophilla, and Stephania tetrandra are used as model template. With appropriate chamber surface treatment (chlorotrimethylsilane/polyadenylic acid or SiO2 coatings), the device demonstrates amplification as efficient as that in the conventional thermal cycler at optimized MgCl2 concentration. The amplified DNA has concentration higher than 27 ng/microL, which is sufficient for subsequent on-chip analyses and detection. Experimental results reveal the importance of inclusion of BSA for an efficient amplification in the SiO2-passivated device and the excellent reusability of the device with a simple cleaning step.     

掩埋隧道结在长波长VCSEL结构中的应用

采用气态源分子束外延技术在InP(100)衬底上分别生长了δ掺杂的p -AlIn-As-n -InP和p -InP-n -InP两种隧道结结构,用电化学C-V和I-V特性曲线表征了载流子浓度和电学特性,发现p -AlInAs-n -InP隧道结性能优于p -InP-n -InP隧道结.在InP(100)衬底上生长了包含p -AlInAs-n -InP掩埋隧道结和多量子阱有源层的1.3μm垂直腔面发射激光器(VCSEL)结构,测试得出其开启电压比普通的pin结VCSEL小,室温下其电致发光谱波长为1.29μm.     

α－Pb（N_3）_2热分解和热爆炸机理的实验与论证

本文利用飞行时间质谱和电子能谱检测了α－Ｐｂ（Ｎ＿３）＿２热分解和热爆炸过程的产物，提出了两种不同的反应机理；在热分解过程中，α－Ｐｂ（Ｎ＿３）＿２热分解步骤是Ｎ＿３中π电子受激发生成Ｎ＿３自由基，Ｎ＿３自由基进一步相互碰撞生成Ｎ＿２．在热爆炸过程中，系统中能量足够高，致使Ｎ＿３中的π锻和σ键同时发生断裂，生成Ｎ原子和Ｎ＿２分子。根据实测的数据，讨论了α－Ｐｂ（Ｎ＿３）＿２热分解和热爆炸化学反应机理的差别。     

Evaluation of the carcinogenic effect of ceramic fibers in experiments on rats and mice

The metabolism of toborinone, (+/-)-6-[3-(3,4-dimethoxybenzylamino)-2-hydroxypropoxy]-2(1H)-quin - olinone, a novel inotropic agent, was studied in rats and dogs after intravenous administration. Chemical structures of the 13 metabolites were characterized by direct-probe FAB/MS and field desorption/MS, LC/FAB/MS, and various NMR measurements. After intravenous dosing of 10 mg/kg [14C]toborinone, fecal and urinary recoveries of the 14C dose were approximately 70% and 26-30%, respectively, in both rats and dogs. The predominant component of radioactivity was the unchanged toborinone in every biological specimen in rats and dogs. Although unchanged toborinone was predominantly observed, toborinone underwent extensive conjugations with glucuronic acid, sulfate, and glutathione, either directly or following phase I reaction. Metabolites resulting from oxidative N-C cleavage were minor both in number and in quantity in every biological specimen in rats and dogs. In rats, toborinone underwent O-demethylation to form M-7 and successive phase it reaction to yield the glucuronide M-1 and the sulfoconjugate M-2, and deconjugation to yield M-7, which was a primary metabolite accounted for 35.67% of the radioactivity excreted in the feces by 48 hr. Conjugates M-1 and M-2 were the major metabolites in rat plasma. In dogs, toborinone was metabolized via mercapturic acid pathway to yield the primary metabolites, cysteine conjugates M-10 and M-11 that accounted for 19.10% and 6.70% of the radioactivity excreted in the feces by 48 hr and that were detected species specifically in dogs. The glutathione conjugate M-13, which was isolated from in vitro incubations using dog liver, led us to consider a possible mercapturic acid pathway from the parent compound to M-10. Metabolites in dog plasma and those in urine in both rats and dogs were minor in quantity. The metabolic pathways of toborinone in rats and dogs are proposed herein.     

坚持自主创新 推进上海RFID应用与产业的发展

紧跟国际RFID发展步伐,上海RFID的应用及其产业的发展开始全面启动,在政府的大力支持下,上海RFID产业坚持科技创新,初步形成了政府资助、企业为主体、产学研联盟的RFID科技创新机制。     

Construction Control and Pile Body Tensile Stresses Distribution Pattern during Driving

In this paper, the pile body tensile stresses distribution pattern during driving is discussed, based on dynamic piling testing results of 13 driven piles attained by the laboratory and in situ tests. These tests indicate that the maximum driving tensile stresses occur in the upper portion of the pile, especially at the initial stages of driving the pile tip seated on soft soils or if the pile foundation is built on a soft foundation. After serious study, it can be concluded that the maximum driving tensile stress often occurs at (1/4)l (l stands for the length of pile) from pile top with its value accounts for 50% of the driving compressive stresses at the same cross section. This high driving tensile stress would lead to the occurrence of transverse cracks and even the breakage of the pile, which should claim the attention of the engineer. The tests also demonstrate that high driving tensile stresses often occur due to the usage of a conventional pile cap in the driving of a prestressed concrete (tubular) pile. To the contrary, the tensile stresses tend to diminish within the control tensile stresses (5?MPa) due to the usage of a new type of disk spring pile cap during driving. Moreover, this new pile cap can prevent driving deviation from alignment, ensure an even distribution of the hammer blow on pile top, and protect the integrity of the pile body.     

日立835与8800氨基酸分析仪的应用与比较

L 8 8 0 0的Thr -Ser、Gly -Ala、Ile -Leu分离度较 835有很大的提高 ,最低检测浓度为 3pmolAsp ,而 835则为 30pmolAsp ,分析时间也较 835缩短 ,成本大大降低而效率大为提高。比较日立 835 - 5 0型与L - 880 0型氨基酸分析仪在分析中的实际应用情况 ,对这两种机型的应用做个总结 ,使二者得到更合理、充分的利用。     

对网络内部终端安全管理的思考

随着信息化水平的不断提高,网络安全问题日益突出。如何建设维护一个稳定、安全的内部网络,已成为税务信息安全的重要问题。本文从网络终端入手,分析了网络安全管理中的现状及存在的问题,进而提出了解决问题的建议和对策。