夯实化学基础,打造创新人才——“无机和分析化学实验”课程的建设与探索

“无机和分析化学实验”是面向“强基计划”和“拔尖人才计划”的化学专业一年级本科生开设的专业课程。秉承“提高学术志趣,激发探索欲望”的教学理念,率先进行摸底考试,构建三基强化训练、综合性实验、探究性实验分阶段递进式教学内容框架,将高层次人才纳入教学团队,倡导启发式探究性教学方法,实现“拔尖人才”培养“拔尖创新人才”的目标。通过“学在浙大”教学平台实现全过程管理。创建全方位、立体化、科教融合式的化学实验课程。

Fast DOA estimation algorithm for MIMO sonar based on ant colony optimization

The maximum likelihood （ML） estimator demonstrates remarkable performance in direction of arrival （DOA） estimation for the multiple input multiple output （MIMO） sonar. However, this advantage comes with prohibitive computational complexity. In order to solve this problem, an ant colony optimization （ACO） is incorporated into the MIMO ML DOA estimator. Based on the ACO, a novel MIMO ML DOA estimator named the MIMO ACO ML （ML DOA estimator based on ACO for MIMO sonar） with even lower computational complexity is proposed. By extending the pheromone remaining process to the pheromone Gaussian kernel probability distribution function in the continuous space, the pro- posed algorithm achieves the global optimum value of the MIMO ML DOA estimator. Simulations and experimental results show that the computational cost of MIMO ACO ML is only 1/6 of the MIMO ML algorithm, while maintaining similar performance with the MIMO ML method.

Plasma Enhanced Chemical Vapor Deposition Nanocrystalline Tungsten Carbide Thin Film and Its Electro-catalytic Activity

Nanocrystalline tungsten carbide thin films were fabricated on graphite substrates by plasma enhanced chemical vapor deposition （PECVD） at H2 and Ar atmosphere, using WF6 and CH4 as precursors. The crystal phase, structure and chemical components of the films were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy-dispersive spectrometer （EDS）, respectively. The results show that the film prepared at CH4/WF6 concentration ratio of 20 and at 800℃ is composed of spherical particles with a diameter of 20-35 nm. Electrochemical investigations show that the electrochemical real surface area of electrode of the film is large, and the electrode of the film exhibits higher electro-catalytic activity in the reaction of methanol oxidation. The designated constant current of the film catalyst is 123.6 mA/cm^2 in the mixture solution of H2SO4 and CH3OH at the concentration of 0.5 and 2.0 mol/L at 70℃, and the designated constant potential is only 0.306 V （vs SCE）.

Target estimation using MIMO radar with multiple subcarriers

This paper analyzes the effect of waveform parame- ters on the joint target location and velocity estimation by a non- coherent multiple input multiple output （MIMO） radar transmitting multiple subcarriers signals. How the number of subcarriers in- fluences the estimation accuracy is illustrated by considering the joint Cramer-Rao bound and the mean square error of the maxi- mum likelihood estimate. The non-coherent MIMO radar ambiguity function with multiple subcarriers is developed and investigated by changing the number of subcarriers, the pulse width and the frequency spacing between adjacent subcarriers. The numerical results show that more subcarriers mean more accurate estimates, higher localization resolution, and larger pulse width results in a worse performance of target location estimation, while the fre- quency spacing affects target location estimation little.

New method for detection fusion of MAC based on DCM and NP rule

The problem of distributed detection fusion using multiple sensors for remote underwater target detection is studied. Considering that multiple access channel （MAC） schemes are able to offer high efficiency in bandwidth usage and consume less energy than the parallel access channel （PAC）, the MAC scheme is introduced into the underwater target detection field. The model of underwater distributed detection fusion based on MAC schemes is established. A new method for detection fusion of MAC based on deflection coefficient maximization （DCM） and Neyman-Pearson （NP） rule is proposed. Under the power constraint of local sensors, this paper uses the DCM theory to derive the optimal weight coefficients and offsets. The closed-form expressions of detection probability and false alarm probability for fusion systems are obtained. The optimal detection performance of fusion systems is analyzed and deeply researched. Both the theory analysis and simulation experiments indicate that the proposed method could improve the detection performance and decrease the error probability effectively under power constraints of local sensors and low signal to noise ratio.

Multi-channel differencing adaptive noise cancellation with multi-kernel method

Although a various of existing techniques are able to improve the performance of detection of the weak interesting sig- nal, how to adaptively and efficiently attenuate the intricate noises especially in the case of no available reference noise signal is still the bottleneck to be overcome. According to the characteristics of sonar arrays, a multi-channel differencing method is presented to provide the prerequisite reference noise. However, the ingre- dient of obtained reference noise is too complicated to be used to effectively reduce the interference noise only using the clas- sical linear cancellation methods. Hence, a novel adaptive noise cancellation method based on the multi-kernel normalized least- mean-square algorithm consisting of weighted linear and Gaussian kernel functions is proposed, which allows to simultaneously con- sider the cancellation of linear and nonlinear components in the reference noise. The simulation results demonstrate that the out- put signal-to-noise ratio （SNR） of the novel multi-kernel adaptive filtering method outperforms the conventional linear normalized least-mean-square method and the mono-kernel normalized least- mean-square method using the realistic noise data measured in the lake experiment.

Serotonin in human skin

In this review the authors summarize data of a potential role for serotonin in human skin physiology and pathology. The uncovering of endogenous serotonin synthesis and its transformation to melatonin underlines a putative important role of this pathway in melanocyte physiology and pathology. Pathways of the biosynthesis and biodegradation of serotonin have been characterized in human beings and its major cellular populations. Moreover, receptors of serotonin are expressed on keratinocytes, melanocytes, and fibroblasts and these mediate phenotypic actions on cellular proliferation and differentiation. And the widespread expression of a cutaneous seorotoninergic system indicates considerable selectivity of action to facilitate intra-, auto-, or paracrine mechanisms that define and influence skin function in a highly compartmentalized manner. Melatonin, in turn, can also act as a hormone, neurotransmitter, cytokine, biological modifier and immunomodulator. Thus, Serotonin local synthesis and cellular localization could thus become of great importance in the diagnosis and management of cutaneous pathology.

Recent advancement on autoantigens, autoantibodies and inflammatory cells in subepidermal autoimmune bullous diseases

Subepidermal autoimmune bullous diseases （SABD） are some autoimmune skin diseases that can present in a variety of forms and can be a challenging disease to treat. An overview of the different forms of SABD are discussed including bullous pemphigoid （BP）, epidermolysis bullosa acquisita （EBA）, cicatricial pemphigoid （CP）, bullous systemic lupus erythematosus （BSLE）, and Anti-p200 pemphigoid. Emphasis on recent advancement is presented. In recent years, improved knowledge of the mechanisms of intercellular and cell-matrix adhesion has led to better understanding of the blistering process in some SABD. Defects of such structures cause the subepidermal bullous diseases and have also led to the discovery of new diseases （e.g. anti-p200-pemphigoid）. Recent studies have outlined the important role of autoantibodies, mast cell lymphocytes and their cytokines in pathogenesis of SABD.

Ore genesis of Badi copper deposit, northwest Yunnan Province, China： evidence from geology, fluid inclusions, and sulfur, hydrogen and oxygen isotopes

The Badi copper deposit is located in Shangjiang town, Shangri-La County, Yunnan Province. Tectonically,it belongs to the Sanjiang Block. Vapor–liquid two-phase fluid inclusions, CO_2-bearing fluid inclusions, and daughter-bearing inclusions were identified in sulfide-rich quartz veins. Microthermometric and Raman spectroscopy studies revealed their types of ore-forming fluids:(1) low-temperature, low-salinity fluid;(2) medium-temperature, low salinity CO_2-bearing; and(3) high-temperature, Fe-rich,high sulfur fugacity. The δ^(18)O values of chalcopyritebearing quartz ranged from 4.96‰ to 5.86‰, with an average of 5.40‰. The δD values of ore-forming fluid in equilibrium with the sulfide-bearing quartz were from-87‰ to-107‰, with an average of-97.86‰. These isotopic features indicate that the ore-forming fluid is a mixing fluid between magmatic fluid and meteoric water.The δ^(34)S values of chalcopyrite ranged from 13.3‰ to15.5‰, with an average of 14.3‰. Sulfur isotope values suggest that the sulfur in the deposit most likely derived from seawater. Various fluid inclusions coexisted in the samples; similar homogenization temperature to different phases suggests that the Badi fluid inclusions might have been captured under a boiling system. Fluid boiling caused by fault activity could be the main reason for the mineral precipitation in the Badi deposit.

A Two-Level Additive Schwarz Preconditioner for Local C^0 Discontinuous Galerkin Methods of Kirchhoff Plates

A two-level additive Schwarz preconditioner based on the overlapping domain decomposition approach is proposed for the local C0 discontinuous Galerkin (LCDG) method of Kirchhoff plates.Then with the help of an intergrid transfer operator and its error estimates,it is proved that the condition number is bounded by O(1 + (H4/δ4)),where H is the diameter of the subdomains and δ measures the overlap among subdomains.And for some special cases of small overlap,the estimate can be improved as O(1 + (H3/δ3)).At last,some numerical results are reported to demonstrate the high efficiency of the two-level additive Schwarz preconditioner.

Theoretical convergence analysis of complex Gaussian kernel LMS algorithm

With the vigorous expansion of nonlinear adaptive filtering with real-valued kernel functions,its counterpart complex kernel adaptive filtering algorithms were also sequentially proposed to solve the complex-valued nonlinear problems arising in almost all real-world applications.This paper firstly presents two schemes of the complex Gaussian kernel-based adaptive filtering algorithms to illustrate their respective characteristics.Then the theoretical convergence behavior of the complex Gaussian kernel least mean square（LMS） algorithm is studied by using the fixed dictionary strategy.The simulation results demonstrate that the theoretical curves predicted by the derived analytical models consistently coincide with the Monte Carlo simulation results in both transient and steady-state stages for two introduced complex Gaussian kernel LMS algonthms using non-circular complex data.The analytical models are able to be regard as a theoretical tool evaluating ability and allow to compare with mean square error（MSE） performance among of complex kernel LMS（KLMS） methods according to the specified kernel bandwidth and the length of dictionary.

A small organic molecule strategy for remedying oxygen vacancies by bismuth defects in BiOBr nanosheet with excellent photocatalytic CO_(2)reduction

Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)reduction.However,hunting for a straightforward strategy to balance the concentration of oxygen vacancy and metal cation defect in one photocatalyst is still a great challenge.Herein,a bismuth vacancies BiOBr nanosheets(BiOBr-1)on the exposed[001]facets were constructed via an acetic acid molecule modification strategy,which can repair oxygen defect by bismuth vacancy in low-temperature solid-state chemical method.Benefiting from the formed bismuth defects that can not only broaden light absorption and elevate charge separation efficiency,but also enhance adsorption and activation of CO_(2)molecules,the evolution rates of photocatalytic CO_(2)conversion into CO(71.23μmol·g^(-1)·h^(-1))and CH4(8.90μmol·g^(-1)·h^(-1))attained by BiOBr-1 are superior 7.1 and 11 times to that of plate-like BiOBr.The photocatalytic mechanisms including adsorption concentration and activation process of CO_(2)are further revealed by the in situ diffuse reflectance infrared flourier transform spectra(DRIFTS).This finding of the existence of distinct defects in ultrathin nanosheets undoubtedly leads to new possibilities for photocatalyst design using two-dimensional materials with high solar-driven photocatalytic activity.

A New Locking-Free Virtual Element Method for Linear Elasticity Problems

This paper devises a new lowest-order conforming virtual element method(VEM)for planar linear elasticity with the pure displacement/traction boundary condition.The main trick is to view a generic polygon K as a new one K with additional vertices consisting of interior points on edges of K,so that the discrete admissible space is taken as the V1 type virtual element space related to the partition{K}instead of{K}.The method is proved to converge with optimal convergence order both in H^(1)and L^(2)norms and uniformly with respect to the Lam´e constantλ.Numerical tests are presented to illustrate the good performance of the proposed VEM and confirm the theoretical results.

Microwave Through Wall Imaging via An Induced Current Learning Method

In this paper,an induced current learning method(ICLM)for microwave through wall imaging(TWI),named as TWI-ICLM,is proposed.In the inversion of induced current,the unknown object along with the enclosed walls are treated as a combination of scatterers.Firstly,a non-iterative method called distorted-Born backpropagation(DB-BP)is utilized to generate the initial result.In the training stage,several convolutional neural networks(CNNs)are cascaded to improve the estimated induced current.In addition,a hybrid loss function consisting of the induced current error and the permittivity error is used to optimize the network parameters.Finally,the relative permittivity images are conducted analytically using the predicted current based on ICLM.Both the numerical and experimental TWI tests prove that,the proposed method can achieve better imaging accuracy compared to traditional distorted-Born iterative method(DBIM).

A PRIMAL-DUAL FIXED POINT ALGORITHM FOR MULTI-BLOCK CONVEX MINIMIZATION

We have proposed a primal-dual fixed point algorithm （PDFP） for solving minimiza- tion of the sum of three convex separable functions, which involves a smooth function with Lipschitz continuous gradient, a linear composite nonsmooth function, and a nonsmooth function. Compared with similar works, the parameters in PDFP are easier to choose and are allowed in a relatively larger range. We will extend PDFP to solve two kinds of separable multi-block minimization problems, arising in signal processing and imaging science. This work shows the flexibility of applying PDFP algorithm to multi-block prob- lems and illustrates how practical and fully splitting schemes can be derived, especially for parallel implementation of large scale problems. The connections and comparisons to the alternating direction method of multiplier （ADMM） are also present. We demonstrate how different algorithms can be obtained by splitting the problems in different ways through the classic example of sparsity regularized least square model with constraint. In particular, for a class of linearly constrained problems, which are of great interest in the context of multi-block ADMM, can be also solved by PDFP with a guarantee of convergence. Finally, some experiments are provided to illustrate the performance of several schemes derived by the PDFP algorithm.

Genesis of Xinzhai Sandstone-Type Copper Deposit in Northern Laos: Geological and Geochemical Evidences

Xinzhai sandstone-type copper deposit located in northern Laos lies in the Jiangcheng-Phongsaly-Phrae Mesozoic basin(JPMB), which is regarded as southern extension of the Lanping-Simao Mesozoic basin in China. The copper deposit belt is bounded by the AilaoshanHeishui River fault and the Dian Bien Phu-Luang Prabang fault at the east and Lancang RiverBannankan faults at the west. Two types of orebodies are identified in the Xinzhai area based on geological investigation. One is lamellar copper orebody hosted by the fine lithic feldspar sandstones and feldspar lithic sandstones; another is vein-type orebody. The sulfur isotopic compositions of the chalcopyrite and tetrahedrite are from -11.6‰ to -1.8‰, indicating that sulfur is derived from bacterial sulfate reduction(BSR). δD values of fluid inclusions in ore-bearing quartz samples are from -99‰ to -78‰. The calculated δ^(18)OH_2O values of ore-forming fluid vary from -2.3‰ to 0.4‰ using the quartz-water fractionation equations and the mineralization temperature. Oxygen and hydrogen isotopic compositions show that the ore-forming fluid was derived from basin fluid. Rock-mineral identifications show that both of the mineral grain maturity and the structural maturity are high in the Jurassic Huakaizuo Formation, reflecting a far-source accumulation and lake facies sedimentatary environment. Based on tectonic determination diagram of the Al_2O_3/SiO_2-TFe+MgO, the sandstone samples collected from the Huakaizuo Formation were plotted in the passive continental margin. The collision of the Indian and Eurasian blocks during the Cenozoic formed large-scale strikeslips and thrust nappe structures in margin of the basin. With the tectonic movement, Cu-rich basin fluid from the basement of basin migrated upward along the contemporaneous fault and into the high porosity strata. At the same time, in organic matter-riched condition, bacterial sulfate reduction(BSR) has been triggered, forming a large number of S^(2-) ions, and then precipitation of sulfide started. This mechanism describes the process of copper mineral deposition in the Xinzhai deposit.

An Augmented Lagrangian Deep Learning Method for Variational Problems with Essential Boundary Conditions

This paper is concerned with a novel deep learning method for variational problems with essential boundary conditions.To this end,wefirst reformulate the original problem into a minimax problem corresponding to a feasible augmented La-grangian,which can be solved by the augmented Lagrangian method in an infinite dimensional setting.Based on this,by expressing the primal and dual variables with two individual deep neural network functions,we present an augmented Lagrangian deep learning method for which the parameters are trained by the stochastic optimiza-tion method together with a projection technique.Compared to the traditional penalty method,the new method admits two main advantages:i)the choice of the penalty parameter isflexible and robust,and ii)the numerical solution is more accurate in the same magnitude of computational cost.As typical applications,we apply the new ap-proach to solve elliptic problems and(nonlinear)eigenvalue problems with essential boundary conditions,and numerical experiments are presented to show the effective-ness of the new method.

A Posteriori Error Analysis of a P2-CDG Space-Time Finite Element Method for the Wave Equation

This paper develops a posteriori error bound for a space-time finite element method for the linear wave equation.The standard P_(l)conforming element is used for the spatial discretization and a P_(2)-CDG method is applied for the time discretization.The essential ingredients in the a posteriori error analysis are the twice time reconstruction functions and the C^(1)(J)-smooth elliptic reconstruction,which lead to reliable a posteriori error bound in view of the energy method.As an outcome,a time adaptive algorithm is proposed with the error equidistribution strategy.Numerical experiments are reported to illustrate the performance of the a posteriori error bound and the validity of the adaptive algorithm.

A POSTERIORI ERROR ESTIMATES FOR LOCAL CO DISCONTINUOUS GALERKIN METHODS FOR KIRCHHOFF PLATE BENDING PROBLEMS

We derive some residual-type a posteriori error estimates for the local CO discontinuous Galerkin （LCDG） approximations （[31]） of the Kirchhoff bending plate clamped on the boundary. The estimator is both reliable and efficient with respect to the moment-field approximation error in an energy norm. Some numerical experiments are reported to demonstrate theoretical results.