Abstract: As light-emitting nanocrystals, quantum dots (QDs) have created a new realm of bioscience by combining nanomaterials with biology. They also have been a major focus of research and development during the past decade, which will profoundly influence future biological as well as biomedical research. In recent years, near-infrared (NIR) quantum dots have emerged in analytical applications, especially for in vitro and in vivo imaging. The impetus behind such endeavors can be attributed to their unique optical and chemical properties, with size-tunable light emission, high photo stability, and manifold fluorescence colors. In this review, we focus on fluorescent imaging with near-infrared (NIR) quantum dots (QDs) both in vitro and in vivo, and the advantages of QDs and potential problems to their use in practical biomedical applications. The ultimate targets aim at decreasing the cytotoxicity of QDs and the future outlook of QD applications in biomedical fields.
Abstract: Abstact:With the development of materials science and combination with medicine, more and more nano-materials are used in clinical medicine.There are much advantage in nano-material .The reason that the nano-materials are utilized widely is its quantum effect and huge superficalarea.But with further research ,more and more disadvantages are found. Many research on the environmental and human health risks of engineered nano-materials focus on their acute toxicity. However,the long-term chronic effects of nanomaterials on living systems is neglected.The potential of nanomaterials to promote the formation of reactive oxygen species is one of the primary reason in their genotoxic. DNA would be damaged by the reactive oxygen species. If the DNA cannot be renew ,it could lead to gene mutation , canceration. This review focuses on the impact of carbon-based nano-materials on DNA .
Abstract: The problems of functionally graded materials are supposed to be studied incorporating their microstructures. The microelement method proposed here is characterized by this capability. In this work, by using the Fortran source program of microelement method established on the basis of existing finite element method, 3-D dynamic analysis of functionally graded material plates with different openings is performed. It can be known from the numerical results that the shapes and number of openings have a significant influence on natural frequency and basic vibration modes of functionally graded material plates, which is different from the results of homogeneous plates. These results are significant to applications of functionally graded material plates with openings.
Abstract: A gas sensor with planar-type micro-hotplate (MHP) with Si-island was designed and fabricated in this paper. The sensor was fabricated simply by using only three masks for the lithography process. The temperature distribution across the sensitive film was simulated and analyzed using ANSYS. A uniform temperature distribution was obtained after added Si-island. The SnO2 sensitive film was deposited through sol-gel spin-coating method and showed reasonable gas-sensing properties to hydrogen at 300°C.
Abstract: Quantum dots(QDs) usually refers to nanocrystalline materials whose diameter is smaller than the exciton Bohr radius. These materials have quantum size effect,the most significant manifestation is their optical properties change with particle size.The unique optical properties make quantum dots to be Ideal markers for tumor cell tracking and targeting,such as mammary cancer, liver cancer, and melanoma.There are broad prospects in tapping the potential of this highly sensitive technology in serum and other body fluids, so as to increase the early diagnosis rate of tumors.
Abstract: The gain model of the Yb-Er codoped optical waveguide amplifier as well as the gain equation has been established based on the analysis of energy level structure of Yb-Er codoped system and the related transition utilizing the rate and transmission equations, and then simulation of the gain characteristic has been carried out. Some most important parameters influencing the gain of the optical waveguide amplifier are discussed and the correlative conditions are optimized. Through numerical simulation, the parameter optimization scheme has been proposed, with which the pump wave length, power and the gain of the amplifier are optimized synchronously, and the maximum gain under the optimum length is obtained. Experimental results show good accordance with the numerical simulation.
Abstract: This paper aims to construct analysis model of port urban logistics arrangement using Delphi and analytical hierarchy process method, furthermore, establishment of fuzzy theory and analytical hierarchy process model and factor set. And calculate every index weight with the weighting method--Gl based on differential principle and appraise comprehensive efficiency using fuzzy theory and analytical hierarchy process evaluation method. Using the average weighting method make quantitative disposal with indexes of appraisal factors and educes port urban logistics comprehensive efficiency outcome. And in so doing，validating Shanghai port urban logistics competitiveness actually which respects its efficiency status.
Abstract: This paper concerns the dynamic modeling and vibration control of a space two-link flexible manipulator. Two types of PZT actuators, PZT shear actuator and torsional actuator, are used to suppress the bending-torsional-coupled vibration of the space manipulator. Using extended Hamilton’s principle and the finite element method, equations of motion of the space flexible manipulator with PZT actuators and tip mass are obtained. Based on modal analyze theory, the state space model of the system is then used to design the control system. A linear quadratic regulator (LQR) controller is designed to achieve vibration suppression of the space manipulator system. From the numerical results, we can get that the proposed controller has a suitable and efficient performance suppressing the bending-torsional-coupled vibration of the space two-link flexible manipulator.
Abstract: Micronized Coenzyme Q10 (CoQ10) is prepared with a rapid expansion of supercritical solution (RESS) process, which does not employ toxic organic solvent. Four factors, namely extraction pressure, extraction temperature, nozzle diameter and precipitation temperature are optimized by a four-level orthogonal array design. The optimum micronization conditions are determined as follows: extraction pressure 25 Mpa, extraction temperature 40°C, nozzle diameter 200 μm, and precipitation temperature 25°C. Under the optimum conditions, micronized CoQ10 with a MPS of 147.9±27.3 nm is obtained. The micronized CoQ10 obtained was characterized by High performance liquid chromatography-mass spectrometry (LC–MS) and High performance liquid chromatography (HPLC) analyses. The results showed that RESS micronization process does not induce degradation of CoQ10 and the obtained CoQ10 particles have higher dissolution rate and solubility compared with unprocessed CoQ10 powder.