基于BOPPPS的无机化学实验混合式教学设计与实践

基于BOPPPS的无机化学实验混合式教学设计突出“以学为中心”,以“磺基水杨酸合铁(III)配合物的组成及稳定常数的测定”教学为例,介绍混合式教学实施过程。研究表明,基于BOPPPS的混合式教学能有效推动学生自主学习,教学效率高,有效提升学生实验能力和交流沟通能力。此外,基于BOPPPS的混合式教学能找出教学中的盲点和难点,有助于教学模式的持续改进。

Analysis of the changes of volatile flavor compounds in a traditional Chinese shrimp paste during fermentation based on electronic nose,SPME-GC-MS and HS-GC-IMS

Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study is to analyze the flavor changes in the shrimp paste fermentation process and screen out the key volatile aroma components in the shrimp paste to control the flavor quality of the shrimp paste products.The overall odor profile was detected by the electronic nose.A total of 106 volatile flavor compounds in the shrimp paste samples at different fermentation stages were identified by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)and headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS).The main aroma components alcohols,aldehydes,pyrazines and other substances in the fermentation process showed an overall upward trend.A total of 17 key volatile aroma components in shrimp paste at different fermentation stages were identified by the relative aroma activity value(ROAV)method.The combination of electronic nose,SPME-GC-MS and HS-GC-IMS could comprehensively reflect the changes of volatile components in shrimp paste at different fermentation stages,which helps to further understand the mechanism of shrimp paste flavor formation and provides a basis for the regulation of the flavor quality of shrimp paste products.

Correlation between dominant bacterial community and non-volatile organic compounds during the fermentation of shrimp sauces

Shrimp sauce,one of the traditional salt-fermented food in China,has a unique flavor that is influenced by the resident microflora.The quality of salt-fermented shrimp sauce was evaluated in this work by determining the total volatile basic nitrogen(TVB-N),the amino acid nitrogen(AAN),organic acid,5’-nucleotide and free amino acids(FAA).Moreover,the dynamics of microbial diversity during processing was investigated by using high-throughput sequencing technology.The results showed that the AAN,TVB-N,organic acid,5’-nucleotide and FAA content were in range of 0.93-1.42 g/100 mL,49.91-236.27 mg/100 mL,6.65-20.68 mg/mL,3.51-6.56 mg/mL and 81.27-102.90 mg/mL.Among the microbial diversity found in the shrimp sauce,Tetragenococcus,Flavobacterium,Polaribacter,Haematospirillum and Staphylococcus were the predominant genera.Correlation analysis indicated that the bacteria Tetragenococcus and Staphylococcus were important in the formation of non-volatile compounds.Tetragenococcus positively correlated with a variety of FAAs;Staphylococcus positively correlated with 5’-nucleotides.The analysis indicated that Tetragenococcus and Staphylococcus were the core genera affecting non-volatile components.These findings indicate the dynamics of the bacterial community and non-volatile components inter-relationships during shrimp sauce fermentation and provide a theoretical basis for improving the fermentation process of shrimp sauce.

Systematic functional analysis and potential application of a serine protease from cold-adapted Planococcus bacterium

In this study, a gene encoding serine protease(PmSpr288)from cold-adapted bacterium, namely Planococcus maritimus XJ11, was cloned and overexpressed in Escherichia coli BL21(DE3). Bioinformatics analysis revealed that PmSpr288 belongs to serine protease S8 superfamily with a classical catalytic triad comprised by the Asp49, His86 and Ser251. Moreover, PmSpr288 was found to be active over broad alkaline pH and low-moderate temperature, and exhibited wide range of protein substrate specificity. In addition, PmSpr288 was able to hydrolyze the meat proteins actin and myosin, and molecular docking results suggested that the crucial interaction between PmSpr288 and actin/myosin complexes was mainly occupied by hydrogen bonds. The muscle protein hydrolysates of silver carp prepared by PmSpr288 was shown to have antioxidant activity via DPPH radical scavenging assay, which presented an IC_(50) valve of 1.309 mg/mL. In conclusion, these characteristics imply that PmSpr288 has potential biotechnological application prospect for the production of bioactive peptides.

Effects of Litter Removal and Addition on Soil Nitrogen Mineralization of Eucalyptus Plantation

[Objectives]This study was conducted to understand the process of soil nitrogen mineralization in Eucalyptus plantations,and to identify the characteristics of soil nitrogen mineralization with different litter inputs.[Methods]With the soil of the Eucalyptus plantation in Fusui County,Guangxi as the research object,the soil nitrogen mineralization of the Eucalyptus plantation under different litter treatments(removing litter,adding litter and retaining litter)was studied by PVC tube closed-top in-situ incubation.[Results]①After 1 year of litter treatment,the inorganic nitrogen(NH_(4)^(+)-N+NO_(3)^(-)-N)in the soil of different treatments ranked as adding litter(20.15 mg/kg)>retaining litter(16.02 mg/kg)>removing litter(11.60) mg/kg),and the differences reached a significant level(P<0.05).②After 30 d of in-situ incubation,there were significant differences in soil nitrate nitrogen content before and after incubation in the three treatments(removing litter,adding litter,and retaining litter)before and after incubation(P<0.05),but no significant differences were observed in soil ammonium nitrogen content(P>0.05).Soil nitrate nitrogen contents increased from 1.47,2.01 and 1.72 mg/kg before incubation to 3.66,6.73 and 5.02 mg/kg,respectively,and soil ammonium nitrogen content increased from 11.60,20.15 and 16.02 mg/kg before incubation to 13.65,21.54 and 17.18 mg/kg,respectively.The net nitrogen mineralization quantities of the three treatments were 4.24,6.11 and 4.46 mg/kg,respectively,and the net nitrogen mineralization rates from large to small were adding litter[0.180 mg/(kg·d)]>retaining litter[0.141 mg/(kg·d)]>removing litter[0.125 mg/(kg·d)].Therefore,both removal and addition of litter affected the soil nitrogen input and nitrogen mineralization rate of the Eucalyptus plantation,thereby affecting soil nitrogen availability and the ability of soil to maintain plant-available nitrogen.[Conclusions]This study provides a theoretical basis for nutrient management in Eucalyptus plantations,especially nitrogen nutrient management.

Development Status of Grape Industry in Wuhan City and Recom-mendations

Since the beginning of grape cultivation in the 1980 s in Wuhan City,the grape industry has shown a steady growth trend. Through the survey of the local grape industry,it found out the regional distribution,scale and benefits of the grape,as well as the variety structure and cultivation management mode. It analyzed main problems in the grape production,including low degree of organization,concentrated maturity,low rate of good fruit,small cultivation scale,and low labor-saving and high-efficiency cultivation technologies. On the basis of the development status,it came up with pertinent recommendations,including optimizing the variety structure,implementing standardized management,strengthening construction of sightseeing parks,promoting integration of primary and tertiary industries,and developing the gardening experience,to promote healthy and sustainable development of the grape industry.

Breeding and Cultivation Techniques of Fly Fire,an Elite Variety of Malus micromalus

Fly fire is an elite variety of North American Begonia（ Malus micromalus）,which is characterized with dark red flowers,red young leaves,red peel,red bark,large flower amount,long flowering period and long fruit bearing period. It is propagated mainly through grafting,and is suitable for popularization and application in the landscape of the Yangtze River basin and north of the Yangtze River.

An Analysis of the Listening Comprehension in CET-6——Illustrated by the CET-6 Test on June,2018

The College English Test Band Six(CET-6)is one of the most widely applied exam across China.As a national teaching test,CET-6 is sponsored by the Department of higher education of the Ministry of education of The People’s Republic of China and held twice a year.In this study,77 sophomores of different majors were tested using the listening test in June 2018.It is ensured that the test method is exactly same as that of CET-6.The purpose of this paper is to analyze the content and specification of CET-6 listening comprehension test,and to evaluate this part in detail according to the real data,including score report and item analysis,trying to provide some enlightenment for the revision of the examination.

鸭源鸡杆菌ompW、gtxA双基因缺失株的构建及其相关特性分析

鸭源鸡杆菌(Gallibacterium anatis,G.anatis)是家禽中常见的条件性致病菌,主要引起蛋鸡生殖道疾病,造成产蛋量下降。【目的】为探究RTX样毒素GtxA及外膜蛋白(OmpW)对鸭源鸡杆菌生物学特性和致病力的影响。【方法】本研究采用自然转化法对突变株RZ△ompW进一步缺失gtxA构建突变株RZ△ompW△gtxA,通过分析其生长特性、黏附能力、引起细胞凋亡程度及对小鼠致病性等,探究其与生物学特性及致病性可能的关系。【结果】结果显示,RZ△ompW△gtxA能稳定遗传gtxA的缺失;单双基因突变株溶血活性均消失、与RZ株相比菌落形态及生长速率并未出现显著改变;相比RZ、RZ△ompW和RZ△gtxA,双基因缺失株RZ△ompW△gtxA在不同时段对鸡原代输卵管上皮细胞的黏附能力显著降低(P<0.05),诱导鸡输卵管上皮原代细胞发生凋亡的能力明显减弱,对小鼠的致病力显著降低。【结论】GtxA毒素和外膜蛋白OmpW在鸭源鸡杆菌毒力、黏附宿主细胞及诱导其细胞凋亡中起重要作用,且可能存在明显的协同关系。本研究为鸭源鸡杆菌感染机制的阐明奠定基础。

Metal-free porous nitrogen-doped carbon nanotubes for enhanced oxygen reduction and evolution reactions

开发有效没有金属的双性人功能的 electrocatalysts 被要求减少费用并且改进慢氧减小反应(ORR ) 和氧进化反应(OER ) 在电气化学的系统的动力学。多孔的做 N 的碳 nanotubes (NCNT ) 被 KOH 激活和 polypyrrole nanotubes 的热分解制作。NCNT 拥有了超过 1,000 的一个大表面区域 ? m 2?g1 。NCNT electrocatalysts，特别地，那些在 900 点退火了 ? 椠 ? 捡楴楶祴猠慴敧 ? 湡 ? 祤慮業? 敭档湡獩 ??? 桴獩猠畴祤 ? 敷爠灥牯 ? 桴 ? 牁档慥? ㈨？？

The Existing Difficulties on the Excellent Program in the college

As the leading party of the engineering talents cultivation,the colleges and universities not only need to solve the problem for the benefits of teachers who provide the daily management to the students in the enterprises, but also consider the safety problems of students who participates the Excellent Program.At the same time。

Exploration of cultivating education innovative talents

In the face of higher education is full of vigor and vitality,active thinking of student groups, they have a strong thirst for knowledge, and actively explore new problems, and strongly expressed their own views of the desire. For independent design, to explore freely have strong desires and expectations.This requires that teachers could apply the proper teaching methods in class, maximum limit to encourage students’ active exploration, active thinking。

The Main Part of Colleges-Enterprise Cooperation

Colleges and enterprise should jointly appoint the talent training objectives and standards.Excellent engineers cultivated by the school-enterprise cooperation must meet the needs of business and industries,in addition,schools and enterprises can realize operation and implementation of personnel training objectives.When colleges set the goals,they should consider the teaching staffs and teaching conditions,etc.And when the companies set goals and standards,they must consider on approving the types of talents from the perspective of social demands for engineering talents.

The Detailed Countermeasures for the Excellent Program in the University-enterprise Cooperation

1. Establish a flexible entry and exit mechanism for the students and the enterprises.Implementation of Excellence program is a long term project for companies and students, which would meet a lot of variables.From the business perspective, it is the economic organization to make profits for the purpose.