漂移管工作温度对离子迁移率谱的影响

离子迁移率、反应物离子的种类和产量与漂移管工作温度有很大的关系。本研究在不同温度下进行了离子迁移率实验,结果表明,离子迁移率随温度的升高而增大,而提高工作温度可以减少水分子对产物离子的影响,有利于改善系统检测的分辨率;选择合适漂移管工作温度,能有效地增加反应物离子的产量,从而提高系统检测的灵敏度和选择性。     

Facile Synthesis and Size Control of 2D Cyclodextrin-Based Metal–Organic Frameworks Nanosheet for Topical Drug Delivery

In this work, a 2D nanosheet (NS) of γ-cyclodextrin (CD)-based metal–organic frameworks (MOFs) is synthesized through a facile green chemistry approach. NS-MOF carrier is constructed using a water system in a simple one-pot reaction involving CD and potassium carbonate. Particle size optimization is achieved by adjusting the reaction temperature and the introduction of crystal growth suppressor (appropriate proportion of acetone). The NS-MOF stability in aqueous medium is improved by polymerization reaction of crosslinked CD-MOF (CL-CD-MOF) without blocking its cavity for drug loading. The effects of particle geometry and size of nanoporous materials on their pharmacokinetics during drug delivery are compared between the sheet-like DXM@CL-NS-MOF and 3D-cubic-shaped DXM@CL-CD-MOF loaded with the same quantity of dexamethasone (DXM). The bioefficiency of these carriers in tear fluids and aqueous humors to deliver DXM is investigated in vivo. The results demonstrate that the 2D-nanosheet particles significantly improve precorneal residence time and intraocular bioavailability over the commercial Maxidex (0.1% dexamethasone) and its 3D-cubes counterpart of similar chemical composition. It suggests that the geometry of a carrier play a significant role in the biodistribution, and the carrier of CL-NS-MOF is a good candidate for ocular drug delivery.     

面向装配的可变功能产品再设计研究

可变功能产品由于多功能及功能可变的特点, 在使用过程中往往需要频繁进行功能切换和零部件的拆装. 为改善该类产品的装配性能, 有必要对其进行面向装配的再设计. 本文首先对可变功能产品的功能优先度与使用度进行分析, 然后基于优先度和使用度对产品功能结构进行调整, 并对再设计中新引入的零件进行技术经济性分析, 在此基础上提出可变功能产品面向装配的5条再设计准则以及基于这些准则的再设计步骤, 最后以实例验证所提出方法的可行性.     

Synthesis of natural product inulavosin via Ga(OTf)3-Catalyzed Hetero Diels–Alder Dimerization of salicyl alcohol derivative

Inulavosin, a natural melanogenesis inhibitor, has been synthesized smoothly from readily available and inexpensive starting materials by using a Ga(OTf)₃-catalyzed room temperature hetero Diels–Alder dimerization of salicyl alcohol derivative and a regioselective phenol monobromination as the key steps.     

Partial theta function identities from Wang and Ma's conjecture

Recently, Wang and Ma proposed a conjecture, embedding the Andrews–Warnaar partial theta function identity in an infinite family of such identities. In this paper we use q-series methods to give a proof of the Wang–Ma conjecture. We also present a result which may be regarded as the inverse of the Wang–Ma conjecture.     

Structured FISTA for image restoration

In this paper, we propose an efficient numerical scheme for solving some large‐scale ill‐posed linear inverse problems arising from image restoration. In order to accelerate the computation, two different hidden structures are exploited. First, the coefficient matrix is approximated as the sum of a small number of Kronecker products. This procedure not only introduces one more level of parallelism into the computation but also enables the usage of computationally intensive matrix–matrix multiplications in the subsequent optimization procedure. We then derive the corresponding Tikhonov regularized minimization model and extend the fast iterative shrinkage‐thresholding algorithm (FISTA) to solve the resulting optimization problem. Because the matrices appearing in the Kronecker product approximation are all structured matrices (Toeplitz, Hankel, etc.), we can further exploit their fast matrix–vector multiplication algorithms at each iteration. The proposed algorithm is thus called structured FISTA (sFISTA). In particular, we show that the approximation error introduced by sFISTA is well under control and sFISTA can reach the same image restoration accuracy level as FISTA. Finally, both the theoretical complexity analysis and some numerical results are provided to demonstrate the efficiency of sFISTA.