College Students' Cognition of Genetically Modified Foods

In order to have knowledge about the college students'awareness and acceptance of genetically modified foods and their attitudes toward the identification of genetically modified foods and the government's regulation,we conduct a questionnaire survey of 150 college students'cognition of genetically modified foods in North College Town of Zhengzhou City.The results show that the college students have a certain understanding of genetically modified foods,but the cognition level is low;electronic media has become the main channel for the current college students to know the information about genetically modified foods;for security reasons,the majority of college students are wary of genetically modified foods,and pay more attention to whether there is genetically modified component in the foods labeling;college students generally believe that the government should strengthen the supervision of genetically modified foods,and make the GM labeling system strict,to protect consumers'right to know and choice.

The Ultrastructure Characteristics of Secretory Cavities Associated with the Secretory Products of <i>Ginkgo biloba</i>

The origin, development and ultrastructure of secretory cavities in leaf of Ginkgo biloba and its relation to the secretory products were studied by optical and electron microscope. The results indicated that the formation pattern of the secretory cavities was schizo-lysigenous in nature. First, some original central secretory cells in the center of secretory cavities expanded, dissolved then moved aside schizogeneously forming an intercellular space. Later the central and peripheral secretory cells continued to dissolve making the intercellular space larger. This process continued until the central secretory cells degenerated, autolyzed and separated off into cavities. It has been assumed that the secretory products in the secretory cavities of Ginkgo biloba were synthesized mainly in the plastids and the endoplasmic reticulum (ER). However it was our observation that the Mitochondrion, Golgi Body and Cytoplasm were also involved in the synthesis and translocation of the secretions. After synthesized in ER and plastids, the secretory products approached the plasmalemma and fused their membranes with the latter in the form of samll vesicles, and then was eliminated to the spaces between the plasmalemma and the wall. At last the secretory products percolated through the wall that faded into an even looser mesh of fibrillar material toward the cavity.

基于万尼尔构型观测声学拓扑角模式反常

万尼尔构型旨在描述万尼尔函数在实空间上的局域位置及其携带的电荷信息,这一物理概念的提出为刻画天然及人工晶体结构中的波函数提供了全新的视角.在二维高阶拓扑绝缘体中,万尼尔构型中的分数化电荷可以作为一种内禀的拓扑不变量来表征湮灭在体连续谱中的角模式.本文报告了一项基于测量谱电荷分布观测声学体系中万尼尔构型的实验研究.作者在构建的声子晶体中测得了表现为分数化谱电荷的拓扑角模式反常,这种模式反常可以作为一种易于观测的实空间拓扑指标对湮灭在体态中的拓扑角模式进行先验判别.在此基础上,通过将不同的万尼尔构型按照多种方式进行组合,将原本湮没在体连续谱中的角模式调制至带隙中.在组合后的声子晶体中,平庸相和非平庸相结构均可以作为包覆层,从而为在带隙中构造和调控拓扑角模式提供了一种新思路.该研究有望应用于设计高品质因子声谐振腔、声通信以及传感增强等领域.

Realization of a full hierarchical topology in hexagonal bilayer acoustic crystals

Recently, there has been significant research interest in higher-order topological states within artificial lattices, primarily due to their potential for manipulating waves. In this study, we focus on a three-dimensional hexagonal bilayer acoustic crystal with rotation, layer, and translation degrees of freedom. By systematically reducing the crystal symmetries, we realize a full hierarchical structure of the higher-order topological states. This hierarchical progression begins with the valley-induced twodimensional surface state, followed by the one-dimensional hinge state that arises from the topological obstruction, and ultimately culminating in the zero-dimensional corner state resulting from the edge polarization mechanism. Through finite element simulations and numerical calculations of topological invariants, we confirm the topological origins of all these hierarchical states. Moreover, we successfully verified the full hierarchical topology by directly probing the acoustic field within a finitesized three-dimensional sample. This study offers novel perspectives on the fundamental research pertaining to wave modulation and the intelligent control of sound fields.

Urban planning historical review of master plans and the way towards a sustainable city:Dar es Salaam,Tanzania

Urban planning in Tanzania has focused mainly on economic development.The Tanzanian government prioritizes large-scale modern projects to increase national income and propel world-class urban settlements.Dar es Salaam,Tanzania's largest city and main commercial center has experienced remarkable urban development.Unfortunately,its growth has not been consistent with the master plans,which also overlook sustainable urban development aspects.The high urbanization rate has exacerbated the degradation of the city's environment,including roadside air quality,solid waste,and water quality.The city's ongoing environmental dilapidation has led to a call for a sustainable urbanization to curb past urbanization problems and implement a sustainable future.This work reviews Dar es Salaam's available planning documents and examines how master plans can stimulate sustainable urban development.Findings suggest that master plans should not be used as a mere urban growth control tool.Master plans that are designed and conceptualized as a comprehensive strategy and integrated with different aspects of urban development can play a key role in enforcing sustainable urban development for the city.

Physics-aware training for the physical machine learning model building

In recent decades,machine learning has emerged as a very powerful computational method.Because of its exceptional successes in computer science and engineering,machine learning has ignited research interest in other disciplines,including biology,chemistry,physics,and finance.Machine learning models,which are usually regarded as mathematical models,have traditionally been implemented on the basis of digital computing platform(Figure 1A).The increasing prevalence of machine learning has been accompanied by a rapid increase of computing requirements,outpacing Moore’s law.Therefore,researchers have been committed to the development of analog computing hardware platforms to overcome the inherent limitations of computing resources.