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排序方式: 共有110条查询结果,搜索用时 46 毫秒
51.
Siddique Muhammad Rehan Muhammad Bhatti M. K. L. Ahmed Shakeel 《Nonlinear dynamics》2017,88(4):2671-2691
Nonlinear Dynamics - This paper studies the local adaptive and robust adaptive control methodologies for the synchronization of the chaotic drive and the response systems with finite time lags,... 相似文献
52.
ABSTRACTLaser-induced plasma is a good source of X-rays. It has much importance in different fields such as industry and medical field. In the current work, Nd: YAG laser was irradiated on metal targets (Al, Cu, Ni, Zn, Sb and Pb) under vacuum 10?3?torr. Plasma plume is captured by the charged couple device. The emitted X-rays from plasma plume are detected by BPX-65 PIN photodiode through a proper biasing circuit and electrical signals are stored by digital storage oscilloscope (UNI-T UT2202C, 200?MHz). Energy was calculated from these electrical signals. The parameters of X-rays are strongly dependent on the atomic number. 相似文献
53.
N. Siddique A. Majid M. M. Chaudhry M. Tufail 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(1):219-227
The elements Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined in dust samples collected from air conditioner (AC) filters from
15 commercial sites of Lahore using flame atomic absorption spectroscopy (FAAS). The elements Cr, Mn and Zn were also determined
using instrumental neutron activation analysis (INAA). The results obtained showed that higher amounts of these metals were
measured in these dust samples than normally found in soil. This was especially true for Cd, Cu, Pb and Zn. Generally the
amounts of Cd, Cr and Mn did not vary throughout the city of Lahore but the amounts of the traffic related Cu, Pb and Zn elements
had the more variable ranges of 30–140, 30–230 and 74–2810 mg/kg respectively. The concentrations obtained for Cr, Mn and
Zn by INAA were found to be higher than those obtained using FAAS. Analysis of the data obtained showed the digestion procedure
employed to be the possible cause for this occurrence. It was also found that Mn was being over-estimated by INAA due to the
interference from the Mg peak. 相似文献
54.
An effective protocol was developed for in vitro regeneration of the Cassia angustifolia via indirect organogenesis from petiole explants excised from 21-day-old axenic seedlings. Organogenic callus were induced
on Murashige and Skoog (MS) medium supplemented with 5.0 μM 2,4-dichlorophenoxy acetic acid and 2.5 μM thidiazuron (TDZ).
Adventitious shoot regeneration was achieved on MS medium supplemented with 5.0 μM TDZ as it induced 8.5 ± 0.98 shoots in
85% cultures. The number of shoots and shoot length was significantly enhanced when cultures were subcultured on auxin–cytokinin-containing
medium. The highest number of shoots (12.5 ± 1.10) and shoot length (4.3 ± 0.20 cm) was recorded on MS medium supplemented
with 5.0 μM TDZ and 1.5 μM indole-3-acetic acid. Regenerated shoots were rooted best on MS medium supplemented with 10.0 μM
indole-3-butyric acid followed by their transfer to liquid MS filter paper bridge medium. The plants were successfully hardened
off in sterile soilrite followed by their establishment in garden soil with 70% survival rate. The plants showed normal morphological
characteristics similar to the field grown plants. 相似文献
55.
Riyazuddin Samrin Bano Fohad Mabood Husain Jamal Akhter Siddique Khadijah H. Alharbi Rais Ahmad Khan Ali Alsalme 《Molecules (Basel, Switzerland)》2020,25(24)
Epoxy resins (EP) have been used as a thermos-setting material in the field of coating, casting, bonding agent, and laminating. However, a major drawback associated with its use is the lack of good flaming properties, and it is responsible for heavy smoke along with hazardous gases considerably limiting its uses in various fields. In this study, N-ethanolamine triazine-piperizine, a melamine polymer (ETPMP), was established as a new charring-foaming agent and was successfully synthesized with ethanolamine, piperizine, cyanuric chloride, and melamine as precursor molecules via the nucleophilic substitution reaction method. Elemental analysis and Fourier transform infrared (FTIR) spectroscopy analysis were applied to approve the synthesis of ETPMP and confirmation of its structure and characterization. The epoxy coating of intumescent flame retardant (IFR) was equipped by introducing ETPMP, ammonium polyphosphate (APP), and copper oxide (CuO) in multiple composition ratios. CuO was loaded at various amounts into the IFR-coating system as a synergistic agent. The synergistic action of CuO on IFR coatings was scientifically examined by using different analytical tests such as vertical burning test (UL-94V), limited oxygen index (LOI), thermal gravimetric analysis (TGA), cone calorimeter, and scanning electron microscope (SEM). The results showed that small changes in the amount of CuO expressively amplified the LOI results and enhanced the V-0 ratings in the UL-94V test. The TGA data clearly demonstrate that the inclusion of CuO can transform the thermal deprivation behavior of coatings with a growing char slag proportion with elevated temperatures. Information from cone calorimeter data affirmed that CuO can decrease the burning factors by total heat release (THR) together with peak heat release rate (PHRR). The SEM images indicated that CuO can enrich the power and compression of the intumescent char that restricts the movement of heat and oxygen. Our results demonstrate a positive influence of CuO on the epoxy-headed intumescent flame retardant coatings. 相似文献
56.
M. Siddique M. Anwar-ul-Islam N. M. Butt N. Hussain S. Rehman M. Arshed 《Journal of Radioanalytical and Nuclear Chemistry》1999,241(1):239-240
Room temperature corrosion studies have been made on the rust of commercially available mild steel in a simulated acid rain environment using the method of transmission Mössbauer spectroscopy. The main corrosion products identified are α-FeOOH, γ-FeOOH, and a product with unfamiliar parameters which seems to be amorphous in nature (being very large linewidth ?2.5 mm/s) and may be considered as an intermediate phase. A small amount of γ-Fe2O3 (6–8%) is also observed. 相似文献
57.
S. Waheed Sabiha-Javied N. Siddique R. Shakoor M. Tufail 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(2):521-528
Sensitive nondestructive instrumental neutron activation analysis (INAA) technique has been applied for the determination
of rare earth elements (REEs) (Ce, Eu, La, Lu, Sm, Tb and Yb) in phosphate rocks (PR) and granulated single super-phosphate
(GSSP) fertilizer samples from Hazara district of Pakistan. The comparison of the PR with product fertilizers shows that most
of the quantified REEs were found to be in lower contents in the fertilizers. Six fertilizer samples with different N, P and
K ratio for distinctive application to plants were also characterized. The REEs in these showed irregular patterns that can
be attributed to difference in their manufacturing and chemical processes. The REEs contents of local phosphate fertilizer
were found to be lower in comparison to the values cited in the literature; however Ce is relatively high. For quality assurance
fair agreement was found between the results obtained for reference materials IAEA SL-1 (Lake Sediment) and GSJ-JR-1 (Rhyolite). 相似文献
58.
Motivated by a recent experiment on insulin microsphere formation where polyethylene glycol (PEG) is used as the precipitating agent, we have developed a simple theoretical model that can predict the formation of a fractal network of insulin monomers and the subsequent break-up of the fractal network into microsphere aggregates. In our approach the effect of PEG on insulin is modeled via a standard depletion attraction mechanism via the Asakura-Oosawa model. We show that even in the context of this simple model, it is possible to mimic important aspects of the insulin experiment in a brownian dynamics simulation. We simulate the effect of changing temperature in our model by changing the well depth of the Asakura-Oosawa potential. A fractal network is observed in a "deep quench" of the system, followed by a "heating" that results in a break-up of the network and subsequent formation of microspheres. 相似文献
59.
Fakhar-e-Alam M. Kishwar S. Khan Y. Siddique M. Atif M. Nur O. Willander M. 《Laser Physics》2011,21(11):1978-1988
Laser Physics - The current study exhibits the cellular response of HeLa (cervical cancer) cells to metal oxides ultrafine nanomaterials e.g. manganese dioxide nanowires (MnO2 NRs), iron oxide... 相似文献
60.
Fakhar-e-Alam M. Atif M. AlSalhi M. S. Siddique M. Kishwar S. Qadir M. I. Willander M. 《Laser Physics》2011,21(5):972-980
Laser Physics - 5-aminolevulinic acid (ALA) being an amazing second generation photosensitizer was studied as photodamaging drug on hepatocellular carcinoma (HepG2) cells. The mentioned... 相似文献