Multi-criteria decision analysis and environmental risk assessment for nanomaterials

Nanotechnology is a broad and complex discipline that holds great promise for innovations that can benefit mankind. Yet, one must not overlook the wide array of factors involved in managing nanomaterial development, ranging from the technical specifications of the material to possible adverse effects in humans. Other opportunities to evaluate benefits and risks are inherent in environmental health and safety (EHS) issues related to nanotechnology. However, there is currently no structured approach for making justifiable and transparent decisions with explicit trade-offs between the many factors that need to be taken into account. While many possible decision-making approaches exist, we believe that multi-criteria decision analysis (MCDA) is a powerful and scientifically sound decision analytical framework for nanomaterial risk assessment and management. This paper combines state-of-the-art research in MCDA methods applicable to nanotechnology with a hypothetical case study for nanomaterial management. The example shows how MCDA application can balance societal benefits against unintended side effects and risks, and how it can also bring together multiple lines of evidence to estimate the likely toxicity and risk of nanomaterials given limited information on physical and chemical properties. The essential contribution of MCDA is to link this performance information with decision criteria and weightings elicited from scientists and managers, allowing visualization and quantification of the trade-offs involved in the decision-making process.     

建立《物理自学创新实验室》培养创新能力

阐了《物理自学创新实验室》的建立及在培养学生创新意识和工程实践能力方面的重要作用。     

Identities between q-hypergeometric and hypergeometric integrals of different dimensions

Given complex numbers m₁,l₁ and nonnegative integers m₂,l₂, such that m₁+m₂=l₁+l₂, for any a,b=0,…,min(m₂,l₂) we define an l₂-dimensional Barnes type q-hypergeometric integral I_a,b(z,μ;m₁,m₂,l₁,l₂) and an l₂-dimensional hypergeometric integral J_a,b(z,μ;m₁,m₂,l₁,l₂). The integrals depend on complex parameters z and μ. We show that I_a,b(z,μ;m₁,m₂,l₁,l₂) equals J_a,b(e^μ,z;l₁,l₂,m₁,m₂) up to an explicit factor, thus establishing an equality of l₂-dimensional q-hypergeometric and m₂-dimensional hypergeometric integrals. The identity is based on the duality for the qKZ and dynamical difference equations.     

A probabilistic proof of the Andrews-Gordon identities

Recently, Fulman proved the “extreme” cases of the Andrews-Gordon identities using a Markov chain on the non-negative integers. Here we extend Fulman's methods to prove the Andrews-Gordon identities in full generality.     

Some applications of free Fisher information on frame theory

We introduce the notion of operator-valued free Fisher information with respect to a positive map of a random variable in an operator-valued noncommutative probability space and point out its close relations to the modular frames arising from conditional expectations. Then we can apply this notion on the study of frame theory, especially on the disjointness problem of modular frames arising from conditional expectations.     

Monitoring energy transfer in hyperbranched macromolecules through fluorescence depolarization

Fluorescence depolarization under dipolar quasiresonant energy transfer allows to monitor the presence of the excitation on the originally excited chromophore. Moreover, a simple model relates the arrangement of the chromophores to the depolarization decay via the eigenvalues of the corresponding connectivity matrix. Now, for important classes of polymers (such as dendrimers and fractal hyperbranched macromolecules) these eigenvalues can be obtained without the need of diagonalizing the corresponding connectivity matrices, a fact which allows to study very large systems also. We determine the fluorescence depolarization behavior of hyperbranched systems and emphasize the possibilities offered by such measurements in differentiating between the underlying geometries.     

Performance of Nd:YLF laser by using crystal electrooptic Q-switch

The polarization rotating coefficient and the laser-damage threshold of La₃Ga₅SiO₁₄ crystal at 1064 nm are measured, which are 1.1 deg/mm and , respectively. The working principle and the design method of electrooptic Q-switch based on La₃Ga₅SiO₁₄ crystal, which has the optical activity, are reported. The performance of Nd:YLF laser with the electrooptic Q-switch of La₃Ga₅SiO₁₄ crystal was studied. The output pulses with an energy of 379 mJ, a duration of 8.7 ns and repetition of 10 Hz are achieved.