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91.
Jacek Pigowski 《大分子材料与工程》1985,136(1):129-134
The thermal dependence of the surface tension of poly(vinyl chloride) (PVC) containing typical additives was determined below the glass transition temperature. From the results, the surface tension of PVC melts was evaluated and possible differences between the real value and estimate are discussed. It is suggested that the surface tension does not affect the wall-slipping properties of PVC melts. 相似文献
92.
In this paper the embedding of gold clusters in crystallizing bisphenol-A polycarbonate is treated as diffusion with drift in inhomogeneous and changing in time medium. Initially the gold is deposited on the polymer surface, which is subsequently exposed to acetone vapour. The polymer undergoes significant crystallization, induced by diffusing agent, while gold clusters become embedded in its bulk. The paper presents a model of gold dispersion based on Smoluchowski equation. It identifies the driving force of dispersion with the gradient of stress field generated during crystallization. Numerical results of the model are found to be in good agreement with available experimental data obtained by XPS depth profiling technique. 相似文献
93.
Rubber elements, which usually form a major part of different isolators of vibrations, are generally easily swelled by oils, greases, or fuels. This leads to meaningful changes of their mechanical characteristics and shortening of durability of rubber components in service. The influence of the semisynthetic motor oil on mechanical and, particularly, dynamic properties of swelled vulcanizates of the polar diene rubber, chloroprene (CR) and acrylonitrile‐butadiene (NBR), is estimated in this article. These elastomers, as is widely known, are resistant to the mineral oils absorption. However, our investigations showed that even a small degree of swelling of the vulcanizates causes decrease of their mechanical properties and considerable changes of the dynamic characteristics of the samples. The obtained results have shown the need to take into account the environment in which isolators of vibrations and dampers have worked, while designing the suitable composition of rubber compounds. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
94.
95.
Minati Satpathy Liya Wang Rafal Zielinski Weiping Qian Malgorzata Lipowska Jacek Capala Gee Young Lee Hong Xu Y. Andrew Wang Hui Mao Lily Yang 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(3):544-555
Despite advances in cancer diagnosis and treatment, ovarian cancer remains one of the most fatal cancer types. The development of targeted nanoparticle imaging probes and therapeutics offers promising approaches for early detection and effective treatment of ovarian cancer. In this study, HER‐2 targeted magnetic iron oxide nanoparticles (IONPs) are developed by conjugating a high affinity and small size HER‐2 affibody that is labeled with a unique near infrared dye (NIR‐830) to the nanoparticles. Using a clinically relevant orthotopic human ovarian tumor xenograft model, it is shown that HER‐2 targeted IONPs are selectively delivered into both primary and disseminated ovarian tumors, enabling non‐invasive optical and MR imaging of the tumors as small as 1 mm in the peritoneal cavity. It is determined that HER‐2 targeted delivery of the IONPs is essential for specific and sensitive imaging of the HER‐2 positive tumor since we are unable to detect the imaging signal in the tumors following systemic delivery of non‐targeted IONPs into the mice bearing HER‐2 positive SKOV3 tumors. Furthermore, imaging signals and the IONPs are not detected in HER‐2 low expressing OVCAR3 tumors after systemic delivery of HER‐2 targeted‐IONPs. Since HER‐2 is expressed in a high percentage of ovarian cancers, the HER‐2 targeted dual imaging modality IONPs have potential for the development of novel targeted imaging and therapeutic nanoparticles for ovarian cancer detection, targeted drug delivery, and image‐guided therapy and surgery. 相似文献
96.
Jacek Jasielski Stanisław Kuta Witold Machowski Wojciech Kołodziejski 《Microelectronics Journal》2014
In the paper we propose a novel architecture and implementation of 11-bit Digital Pulse Width Modulator (DPWM) circuit based on previously known building blocks. Linearized Class-AD Double-sided (LADD) algorithm has been used to calculate the DPWM signals of the 11-bit resolution hybrid DPWM for a Class-AD digital audio amplifier. Noise-shaping process is used to support high fidelity with practical values of time resolution. The proposed DPWM circuit is composed of 8-bit counter and Analog Delay Locked Loop (ADLL) using 4-bit tapped delay line. A dual ADLL employing coarse and fine programmable delay element is used to adjust the delay time of delay line and lock it to required time. The coarse- as well as fine-delay lines are implemented as a cascade of variable-delay elements based on shunt capacitor delay element or single-ended Schmitt trigger. The proposed 11-bit DPWM circuit, at a switching frequency of 352.8 kHz and clock generator frequency of 90.3 MHz allows us to attain SNR of 120 dB and THD of the output signal less than 0.1% within the audio baseband and modulation index M=0.95. Basic verification of circuit manufacturability and simulation results (Monte Carlo analysis) for real CMOS process are presented. 相似文献
97.
Optoelectronics: Flash‐Assisted Processing of Highly Conductive Zinc Oxide Electrodes from Water (Adv. Funct. Mater. 47/2015)
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98.
Anna KorusZofia Lisiewska Jacek S?upskiPiotr G?bczyński 《International Journal of Refrigeration》2011,34(6):1527-1534
The investigation showed that fresh brassicas: Brussels sprouts, broccoli, green cauliflower and white cauliflower respectively contained 50 mg, 67 mg, 72 mg and 95 mg oxalates in 100 g fresh matter. Soluble oxalates constituted 70%, 40%, 40% and 54% of total oxalates respectively. The cooked product obtained from traditionally prepared frozen vegetables (blanching-freezing-refrigerated storage-cooking) contained 45-66% of soluble oxalates. The product obtained from frozen vegetables produced using the modified method (cooking-freezing-refrigerated storage-defrosting and heating in a microwave oven) contained more oxalates than that obtained using the traditional method. The oxalate: calcium ratio in fresh vegetables varied considerably: 0.63 (Brussels sprouts); 1.10 (broccoli); 1.27 (green cauliflower); and 2.42 (white cauliflower). In products prepared for consumption the ratios were lower. The proportion of calcium bound as calcium oxalate differed between the vegetables investigated, but the treatments applied did not influence this parameter. The apparent retention of oxalate overestimated the true retention. 相似文献
99.
Nitrosamines and water 总被引:1,自引:0,他引:1
This paper provides an overview of all current issues that are connected to the presence of nitrosamines in water technology. N-nitrosodimethylamine (NDMA) is the most frequently detected member of this family. Nitrosamines became the hottest topic in drinking water science when they were identified as disinfection by-products (DBPs) in chloraminated waters. The danger that they pose to consumer health seems to be much higher than that from chlorinated DBPs. This review summarizes our contemporary knowledge of these compounds in water, their occurrence, and precursors of nitrosamines in drinking and wastewaters, in addition to attempts to remove nitrosamines from water. The paper also reviews our knowledge of the mechanisms of nitrosamine formation in water technology. The current, commonly accepted mechanism of NDMA formation during chloramination of drinking waters assumes that dichloramine reacts with dimethylamine, forms unsymmetrical dimethylhydrazine and further oxidizes to NDMA. The question to answer is which precursors are responsible for delivering the DMA moiety for the reaction since the presence of DMA in water cannot explain the quantities of NDMA that are formed. There are also reports that other oxidants that are commonly used in water technology may generate NDMA. However, the mechanisms of such transformations are unknown. Methods for the removal of nitrosamines from water are described briefly. However, the research that has been undertaken on such methods seems to be at an early stage of development. It is predicted that photolytic methods may have the greatest potential for technological application. 相似文献
100.
Boron and aluminum doping by diffusion into n-type 4H-SiC Si-face substrates was carried out at the temperatures of 1800-2000 °C. Secondary ion mass spectroscopy (SIMS) was employed to obtain the impurity profiles, which showed that linearly graded boron profile and shallow aluminum profiles have been achieved, which may be a promising application in SiC device fabrication, such as p-n diode or ohmic contact. Characterization of high temperature processing influence on SiC surface morphology has been performed. Elemental boron and aluminum carbide were determined to be the best candidates as an impurity source materials for realizing p-type diffusion. 相似文献