谈爱心转化初中英语关键生方法

多年来我一直从事英语教学,而英语作为一门外国语的学习,对关键生来说尤为困难。面对这些特殊的学生,我想方设法做了大量的教育转化工作,用真诚和爱心奏响了师生和谐的乐章。

浅析初中数学关键生教学

目前,在初中数学教学中出现一种令人担扰的局面,学生中普遍存在一种厌学现象,相当一部分学生数学成绩低下,人数呈逐年攀升的趋势。本文将就初中数学关键生的教学进行探索。

Investigation of bioactivity and biodegradability of Mg-bioceramic implants:An in vitro study for biomedical applications

In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.

Emergency algorithm for enhanced survivability of key service

To work out a solution for answering the question when it is suitable for emergency response strategies to be executed, an emergency algorithm for enhanced survivability of a key service is presented. First, based on the central limit theorem and the hypothesis testing theory, the confidence interval of each key service＇s history average service response time in the host server and the spare server can be figured out, respectively. This can also be updated dynamically by a proposed method using the method of time slide window. Then, according to the five kinds of distributed situations of the current service response time＇ s confidence interval in the host server and the spare server, the proposed algorithm can dynamically choose the appropriate emergency policies such as resource reconfiguration, service degradation or service drifting, etc. in fight time. Thus, the key service request can be finished within its expected deadline by users as far as possible. Furthermore, the whole process of dynamic configuration is transparent to users. Finally, simulation tests are performed to prove the feasibility.

A worldwide bibliometric analysis of Antarctic krill research during 1960 to 2015

This study conducted a bibliometric analysis of 1251 articles related to Antarctic krill from 1960 to 2015, based on the Core Collection in Thomson Reuters＇ Web of Science. We analyzed the results from four aspects： annual distribution, Web of Science categories and the major journals, inter- national collaboration and author keywords. The Antarctic krill research has developed rapidly since 1978, with an increasing article output. The studies mostly focused on the fields of marine and freshwater biology, oceanography, and ecology. Polar Biology, Marine Ecology-Progress Series and Deep-Sea Research Part II-Topical Studies in Oceanography, were the top three journals to publish the Antarctic krill-related papers. Although Russia is the earliest state to report Antarctic krill, U.S.A. and England were leaders with the largest output quantity and the highest cooperation frequencies. The researches in PR China have taken a blooming since 2009 and will play a more and more important role in the world. The frequencies of author keywords were counted. The high-frequency keywords were further divided into four groups with cohesive subgroup analysis, which suggested the major themes. This paper depicts the existing publica- tions on Antarctic krill. Our goal is to serve a point of reference and provide the direction for the future work.

Implementation of Food Safety Legislation in Catering Establishments in Latvia

The aim of the research was to evaluate overall quality of introduction of hazard analysis and critical control points （HACCP） prerequisites and HACCP procedures in catering sector in Latvia to reveal common problems that can provoke food-borne infection outbreaks. Certain quantitative indicators were defined and analyzed to conclude about characteristic trends related to implementation of food safety legislation. The state＇s monitoring data on surveillance of catering establishments were used. Fulfillment of legislative requirements in about 6,000 catering establishments was evaluated during time period of 2004-2009. The results of investigation were obtained with help of statistical analyses using MS Excel computer program. The results of the research suggest that most of catering establishments （e.g., 83.6% during 2009） meet the hygiene requirements only partly. Non-conformities regarding HACCP-based self-control procedures were fixed during 49.2% of inspections. The research reveals characteristic shortcomings that are established from year to year, e.g., improper hygiene of premises （established during 30%-40% of inspections, depending on the year）, poor hygiene of technological equipment （established during 27%-37% of inspections）, poor personnel hygiene （established during 11%-22% of inspections）, inadequate competence of food service personnel （established during 10%-35% of inspections）, as well as non-observance of cleaning-disinfection procedures and technological parameters for food processing （established during 11%-25% of inspections, depending on the year）. Actual shortcomings can lead to both the direct and the indirect cross-contamination of food. On the base of the research, it was concluded that further detailed assessment of potential food safety risks is relevant to establish risk-based monitoring activities in catering sector.

Changes in the Ecological Characteristics of Key Biodiversity Areas in the BRI Region

Key Biodiversity Areas(KBAs)are ecological conservation priorities proposed by IUCN and widely recognized by most countries.Evaluating the changes in the ecological characteristics in KBAs is important for biodiversity conservation and the construction of Protected Areas(PAs).There are various ecosystem types in the Belt and Road Initiative(BRI)region,which has an extremely high value of biodiversity conservation,and the KBAs should be the prime targets of ecological protection efforts.Using the data of land cover,NDVI and Nighttime Light(NTL),we analyzed the ecological conditions of the KBAs in the BRI region,and their temporal and spatial variations,from the perspectives of vegetation coverage and human activities.The conclusions are:(1)There is generally no significant difference in the land cover of the KBAs,among which forest,wilderness and grassland are the main types;(2)The NDVI of the KBAs showed an increase,indicating that the vegetation was gradually improving,while a few KBAs presenting vegetation degradation were mainly distributed in the Indochina Peninsula,Qinghai-Tibet Plateau and Central and Western Asia;and(3)The NTL in the KBAs was very low,indicating that the human pressure on the natural ecosystems was limited,and only a few KBAs distributed in Central and Eastern Europe,India,and the Indochina Peninsula have high human activity intensity which also showed an increase.This study emphasizes that we should make full use of the biome succession law,and limit the interference of human activities on natural ecosystems for ecological protection of the KBAs,so as to continuously make new breakthroughs in the construction of Protected Areas(PA)in the BRI region.

The Concept, Connotation and Significance of Cultural Keystone Species in Agricultural Heritage Systems

As a new type of heritage, Agricultural Heritage Systems(AHS), represented by Globally Important Agricultural Heritage Systems(GIAHS) designated by Food and Agriculture Organization of the United Nations(FAO)and Nationally Important Agricultural Heritage Systems(NIAHS) designated by some countries’ Ministry of Agriculture, are typical Social-Ecological Systems(SES), which usually are rich in biodiversity, traditional knowledge,resource utilization technology and outstanding cultural landscapes. Cultural Keystone Species(CKS) are defined as the culturally salient species that shape the cultural identity of a people in a major way. CKS can be used as a prominent tool for the synergistic conservation of SES biology and culture, and to promote the overall enhancement of system functions. This paper summarizes a review of the definition of the CKS and its application in SES conservation. According to the characteristics and protection needs of AHS, this paper defined the CKS in AHS as:“Composites of biological resources and cultural practices, which have a significant impact on the stability of local society and culture systems, contribute to the achievement of AHS’ conservation goals.” Based on this definition,we analyzed the significance of the identification of CKS in AHS. First of all, CKS help to quickly identify the key elements of AHS. Secondly, CKS can promote community participation in the conservation and development of AHS. In addition, the identification of CKS has a significant role in food and livelihood security, biodiversity conservation, traditional knowledge and technology transmission, social organization maintenance, and cultural landscape maintenance in AHS, which helps to achieve the conservation goals of GIAHS and/or NIAHS.

High-altitude tree growth responses to climate change across the Hindu Kush Himalaya

Aims Rapid warming at high altitudes may lead to a higher sensitivity in tree growth to temperature.The key factors constraining tree radial growth and to what extent regional tree growth has suffered from climatic changes are unclear.Methods Tree-ring width data were collected from 73 sites across the Hindu Kush Himalaya(HKH),including three dominant genera(Abies,Juniperus and Picea)at high altitudes over 3000 m.Dynamic time warping was introduced to develop subregional chronologies by considering the synchrony of annual tree growth among different sites.We quantified the contribution of the climate variables,and analyzed the spatiotemporal variation of the growth–climate relationship.Important Findings The site chronologies were grouped into three clusters,corresponding to the three distinct bioclimatic zones,i.e.the western HKH,central-eastern HKH and southeastern Tibetan Plateau(TP).Tree growth was positively correlated to winter and spring precipitation in the drier western HKH,and to winter temperature and spring precipitation in the humid southeastern TP.Tree growth was markedly constrained by the minimum temperature,especially in winter,with its importance increasing from the west toward the east.As shown by moving correlation analysis,the signal of winter temperature in tree growth was weakened in the western and central-eastern HKH,while it was enhanced in the southeastern TP following rapid warming since the 1980s.Our results highlight that continuous warming may cause forest recession due to warming-induced moisture deficit in the western HKH,but forest expansion in the southeastern TP.

Spatial and seasonal characterization of net primary productivity and climate variables in southeastern China using MODIS data

We developed a sophisticated method to depict the spatial and seasonal characterization of net primary productivity (NPP) and climate variables. The role of climate variability in the seasonal variation of NPP exerts delayed and continuous effects. This study expands on this by mapping the seasonal characterization of NPP and climate variables from space using geographic information system (GIS) technology at the pixel level. Our approach was developed in southeastern China using moderate-resolution imaging spectroradiometer (MODIS) data. The results showed that air temperature,precipitation and sunshine percentage contributed significantly to seasonal variation of NPP. In the northern portion of the study area,a significant positive 32-d lagged correlation was observed between seasonal variation of NPP and climate (P<0.01),and the influences of changing climate on NPP lasted for 48 d or 64 d. In central southeastern China,NPP showed 16-d,48-d,and 96-d lagged correlation with air temperature,precipitation,and sunshine percentage,respectively (P<0.01); the influences of air temperature and precipitation on NPP lasted for 48 d or 64 d,while sunshine influence on NPP only persisted for 16 d. Due to complex topography and vegetation distribution in the southern part of the study region,the spatial patterns of vegetation-climate relationship became complicated and diversiform,especially for precipitation influences on NPP. In the northern part of the study area,all vegetation NPP had an almost similar response to seasonal variation of air temperature except for broad crops. The impacts of seasonal variation of precipitation and sunshine on broad and cereal crop NPP were slightly different from other vegetation NPP.

Development of solid-state nanopore fabrication technologies

As the key components of nanopore-based nucleic acid sequencing systems, nanopores have drawn more and more scientific interests over these years. Although most of the early nanopore-based sequencers adopted biological nanopores, solid-state nanopores have been gradually growing in popularity due to their increased robustness and durability, control over pore geometry and surface properties, as well as compatibility with the existing semiconductor and microfiuidics fabrication techniques. Besides acting as a platform for biomolecular analysis, solid-state nanopores also have great potential in many other fields such as near-field optics, nanostencil lithography and ionic logic circuitry, due to the possibility of parallel massive production. Therefore, many approaches for the fabrication of solid-state nanopores have been developed. This paper reviews the typical solid-state nanopore fabrication techniques reported to date and compares their advantages and disadvantages. The specific applications of each kind of solid-state nanopores are also summarized based on the carefully analysis of their unique morphologies and properties such as the feature size, inner structure and possibility of massive production.

Molecular dynamics reveal a novel kinase-substrate interface that regulates protein translation

A key control point in gene expression is the initiation of protein translation, with a universal stress response being constituted by in- hibitory phosphoryiation of the eukaryotic initiation factor 2α （el F2oL）. In humans, four kinases sense diverse physiological stresses to regulate elF2α to control cell differentiation, adaptation, and survival. Here we develop a computational molecular model of elF2α and one of its kinases, the protein kinase R, to simulate the dynamics of their interaction. Predictions generated by coarse-grained dynamics simulations suggest a novel mode of action. Experimentation substantiates these predictions, identifying a previously unrecognized interface in the protein complex, which is constituted by dynamic residues in both elF2α and its kinases that are crucial to regulate protein translation. These findings call for a reinterpretation of the current mechanism of action of the el F2α kinases and demonstrate the value of conducting computational analysis to evaluate protein function.

Growth factors induce the improved cardiac remodeling in autologous mesenchymal stem cell-implanted failing rat hearts

Therapeutically delivered mesenchymal stem cells (MSCs) improve ventricular remodeling. However,the mechanism underlying MSC cardiac remodeling has not been clearly determined. Congestive heart failure (CHF) was induced in rats by cauterization of the left ventricular free wall. MSCs were cultured from autologous bone marrow and injected into the border zone and the remote myocardium 5 d after injury. Ten weeks later,when compared with sham operation,CHF significantly increased nucleus mitotic index,capillary density,and expression of insulin-like growth factor 1,hepatocyte growth factor and vascular endothelial growth factor in the border zone (P<0.01) and decreased each of them in the remote myocardium (P<0.05 or P<0.01). MSC implantation in CHF dramatically elevated ex-pression of these growth factors in the remote myocardium and further elevated their expression in the border zone when compared with CHF without MSC addition (P<0.05 or P<0.01). This was paralleled by a higher nucleus mitotic index and a significantly increased capillary density both in the remote myocardium and in the border zone,and by a lower percentage of area of collagen and a higher percentage of area of myocardium in the border zone (P<0.05 or P<0.01),and cardiac remodeling markedly improved. Autologous MSC implantation promoted expression of growth factors in rat failing myocardium,which might enhance cardiomyogenesis and angiogenesis,and improved cardiac remodeling.