单环共轭多烯的结构与芳香性研究

基于先进的量化计算软件Gaussian和波函数分析软件Multiwfn,研究结构化学课程中七种单环共轭多烯和环碳18的结构,形成“有图有真相”的立体直观的分子空间结构,形象化展示了各个分子的几何结构、分子尺寸、静电势、芳香性等。将课本知识与先进的量化软件结合起来,在量子化学层次上拓展有关芳香性的认识,引导学生加深对课本知识的理解,同时开拓学生的视野和知识层次。

A class of fully third-order accurate projection methods for solving the incompressible Navier-Stokes equations

In this paper, a fully third-order accurate projection method for solving the incompressible Navier-Stokes equations is proposed. To construct the scheme, a continuous projection procedure is firstly presented. We then derive a sufficient condition for the continuous projection equations to be temporally third-order accurate approximations of the original Navier-Stokes equations by means of the localtruncation-error-analysis technique. The continuous projection equations are discretized temporally and spatially to third-order accuracy on the staggered grids, resulting in a fully third-order discrete projection scheme. The possibility to design higher-order projection methods is thus demonstrated in the present paper. A heuristic stability analysis is performed on this projection method showing the probability of its being stable. The stability of the present scheme is further verified through numerical tests. The third-order accuracy of the present projection method is validated by several numerical test cases.

彩色光刻胶用锌酞菁染料的设计、合成及其性质

彩色光刻胶是制作彩色滤光片的重要部分之一,是实现TFT-LCD色彩显示的重要材料.为了提高彩色滤光片的色纯度和色域,颜料染料化应运而生,但染料热稳定性较差,难以应用于工业生产过程中.为了研究不同取代基对染料溶解度和热稳定性的影响,本文设计、合成了一系列锌酞菁染料.实验表明,砜基修饰的含氯锌酞菁染料具有较好的颜色性质和热稳定性.这对设计高耐热的彩色光刻胶用分子水平锌酞菁染料具有重要意义.

High-order compact finite volume methods on unstructured grids with adaptive mesh refinement for solving inviscid and viscous flows

In the present paper, high-order finite volume schemes on unstructured grids developed in our previous papers are extended to solve three-dimensional inviscid and viscous flows. The highorder variational reconstruction technique in terms of compact stencil is improved to reduce local condition numbers. To further improve the efficiency of computation, the adaptive mesh refinement technique is implemented in the framework of high-order finite volume methods. Mesh refinement and coarsening criteria are chosen to be the indicators for certain flow structures. One important challenge of the adaptive mesh refinement technique on unstructured grids is the dynamic load balancing in parallel computation. To solve this problem, the open-source library p4 est based on the forest of octrees is adopted. Several two-and three-dimensional test cases are computed to verify the accuracy and robustness of the proposed numerical schemes.

Ultraviolet-to-microwave room-temperature photodetectors based on three-dimensional graphene foams

Highly sensitive broadband photodetection is of critical importance for many applications.However,it is a great challenge to realize broadband photodetection by using a single device.Here we report photodetectors(PDs)based on three-dimensional(3 D)graphene foam(GF)photodiodes with asymmetric electrodes,which show an ultra-broadband photoresponse from ultraviolet to microwave for wavelengths ranging from 10~2 to 10~6 nm.Moreover,the devices exhibit a high photoresponsivity of 10~3 A·W^-1,short response time of 43 ms,and3 d B bandwidth of 80 Hz.The high performance of the devices can be attributed to the photothermoelectric(PTE,also known as the Seebeck)effect in 3 D GF photodiodes.The excellent optical,thermal,and electrical properties of 3 D GFs offer a superior basis for the fabrication of PTE-based PDs.This work paves the way to realize ultra-broadband and high-sensitivity PDs operated at room temperature.

High order sub-cell finite volume schemes for solving hyperbolic conservation laws I: basic formulation and one-dimensional analysis

In this paper, a family of sub-cell finite volume schemes for solving the hyperbolic conservation laws is proposed and analyzed in one-dimensional cases. The basic idea of this method is to subdivide a control volume(main cell) into several sub-cells and the finite volume discretization is applied to each of the sub-cells. The averaged values on the sub-cells of current and face neighboring main cells are used to reconstruct the polynomial distributions of the dependent variables. This method can achieve arbitrarily high order of accuracy using a compact stencil. It is similar to the spectral volume method incorporating with PNPM technique but with fundamental differences. An elaborate utilization of these differences overcomes some shortcomings of the spectral volume method and results in a family of accurate and robust schemes for solving the hyperbolic conservation laws. In this paper, the basic formulation of the proposed method is presented. The Fourier analysis is performed to study the properties of the one-dimensional schemes. A WENO limiter based on the secondary reconstruction is constructed.

Switchable nanoparticles complexing cisplatin for circumventing glutathione depletion in breast cancer chemotherapy

Cisplatin is broad-spectrum chemotherapeutic agent that has been widely used for the treatment of a variety of malignant tumors including breast cancer.However,the cisplatin chemoresistance,which derives from the inactivation by glutathione(GSH)depletion,remains a scientific issue to solve.Here,we report a novel type of smart disulfide switchable nanoparticles complexing cisplatin(switch NPs-cisplatin)that is rationally designed,and engineered by synthesizing a hyaluronic acid disulfide bonded polyaspartic acid(HA-ss-Pasp)and complexing cisplatin.The results showed that the switch NPs-cisplatin had a nanoscale of particle size(150 nm),higher drug encapsulation efficiency(>90%),and suitable drug release profile.They demonstrated evident pH responsiveness and GSH responsiveness,and targeting effect in the resistant breast cancer cells.Furthermore,they were able to block the cisplatin depletion by GSH in the resistant cancer cells,thereby circumventing the chemoresistance.Consequently,switch NPs-cisplatin displayed a remarkable killing effect in the resistant breast cancer cells in vitro,and in the resistant breast cancer-bearing mice.In conclusion,switch NPs-cisplatin could be used as a smart formulation of cisplatin for overcoming the chemoresistance of breast cancer.The present study also offers a universal drug delivery carrier platform for highly efficient but low systemic toxic chemotherapy.

Gene engineered exosome reverses T cell exhaustion in cancer immunotherapy

Cancer patients by immune checkpoint therapy have achieved long-term remission,with no recurrence of clinical symptoms of cancer for many years.Nevertheless,more than half of cancer patients are not responsive to this therapy due to immune exhaustion.Here,we report a novel gene engineered exosome which is rationally designed by engineering PD1 gene and simultaneously enveloping an immune adjuvant imiquimod(PD1-Imi Exo)for boosting response of cancer immune checkpoint blockage therapy.The results showed that PD1-Imi Exo had a vesicular round shape(approximately 139 nm),revealed a significant targeting and a strong binding effect with both cancer cell and dendritic cell,and demonstrated a remarkable therapeutic efficacy in the melanoma-bearing mice and in the breast cancer-bearing mice.The mechanism was associated with two facts that PD1-Imi Exo blocked the binding of CD8^(+)T cell with cancer cell,displaying a PD1/PDL1 immune checkpoint blockage effect,and that imiquimod released from PD1-Imi Exo promoted the maturation of immature dendritic cell,exhibiting a reversing effect on the immune exhaustion through activating and restoring function of CD8^(+)T cell.In conclusion,the gene engineered exosome could be used for reversing T cell exhaustion in cancer immunotherapy.This study also offers a promising new strategy for enhancing PD1/PDL1 therapeutic efficacy,preventing tumor recurrence or metastasis after surgery by rebuilding the patients’immunity,thus consolidating the overall prognosis.