西藏大学生认知与方法论课程的解构与建设

本文以西藏大学本科生为例,以方法论课程的建设为轴心,对该课程进行必要的解构,思考和探寻该课程建设的有效途径和方法,以满足西藏培养具有人文素养、科学素养的创新型人才的需要。

当代中学生需要什么、缺乏什么、又该拥有什么

作为一名教师、一个班主任,在与学生接触的有限时间内,怎样更好地了解学生,更好地引导学生,使学校的教育更有效,使学生的学习与人格得到大的提升,所有这些在教育教学中具有深远的意义。作为一名中学教师,面对的是身体和心理都处在转变期的青少年,此时了解学生就显得尤为重要,也只有了解了学生才能使我们的引导与影响产生作用,才能使我们的教育在他们身上变为现实。本文是笔者结合自身实践经验,针对中学生的身心特点,主要从以下四个方面进行了论述:一是贴近学生的心灵,了解学生需要什么;二是让学生有责任感、有爱心;三是让学生体会到互助的快乐,集体的温暖;四是让学生有快乐的生活态度。并在教育教学实践中积极验证这些方法与措施的有效性。

Slope displacement prediction based on multisource domain transfer learning for insufficient sample data

Accurate displacement prediction is critical for the early warning of landslides.The complexity of the coupling relationship between multiple influencing factors and displacement makes the accurate prediction of displacement difficult.Moreover,in engineering practice,insufficient monitoring data limit the performance of prediction models.To alleviate this problem,a displacement prediction method based on multisource domain transfer learning,which helps accurately predict data in the target domain through the knowledge of one or more source domains,is proposed.First,an optimized variational mode decomposition model based on the minimum sample entropy is used to decompose the cumulative displacement into the trend,periodic,and stochastic components.The trend component is predicted by an autoregressive model,and the periodic component is predicted by the long short-term memory.For the stochastic component,because it is affected by uncertainties,it is predicted by a combination of a Wasserstein generative adversarial network and multisource domain transfer learning for improved prediction accuracy.Considering a real mine slope as a case study,the proposed prediction method was validated.Therefore,this study provides new insights that can be applied to scenarios lacking sample data.

通过“试误”教学走向高效解题

在教学过程中，教材编写者、教师、学生根据自身已有的知识、经验和理解水平尝试解释和探索问题时，发生的偏差或失误，并通过多边互动，在集体“识错”“思错”和“纠错”过程中动态生成的课程资源，我们称之为“错误资源”．教师要善于捕捉和运用教学中的各种“错误资源”，尝试“试误”教学，让“错误”走进课堂，并认真分析错误产生的根本原因，帮助学生真正走出各种解题误区，促进学生的学习，提高肇生的解题能力．

Advancement of Structural Botany in the Past Fifty Years in China

Structural botany, being derived from plant anatomy, has been considered as an important branch of botany, both in concept and practice. In this paper, a review concerning the evolutionary trends of development from plant developmental anatomy to plant developmental biology, plant comparative anatomy to plant systematic biology and plant ecological anatomy to plant environmental biology during the past 50 years in China is addressed and their potential development and usefulness in the near future were largely discussed.

Basal birds from China:a brief review

We use the term 'basal birds' for a relatively small number of primitive fossil birds that fall outside the major clade Ornithothoraces,which includes both modern birds and enantiorni-thines. Eight genera and twelve valid species have been reported from China in the last 15 years,whereas Archaeopteryx lithographica remains the only basal bird to have been described from non-Chinese specimens(although confuciusornithid material is apparently present in North Korea).Here we briefly review the Chinese basal birds and their anatomy,phylogeny and ecology.Chinese fossils have contributed extensively to scientific understanding of early avian evolution,demon-strating collectively that basal birds were generally relatively large and morphologically and eco-logically quite diverse.Although some significant uncertainties remain,particularly with respect to the relative phylogenetic positions of Jeholornis,Sapeornis and Zhongornis,an increasingly clear picture of the first stages of avian evolution is emerging from the Chinese fossil record.

PROPERTIES OF BIODEGRADABLE THERMOPLASTIC STARCH

Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biodegradability and rheological properties were studied. Glycerol and urea, to some extent, can both decrease the tensile strength and increase percentage elongation at break, because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. Thermoplastic starch shows thermoplasticity and its melt behaves as a pseudoplastic liquid at a low shear rate. Its biodegrading extent is slightly higher than that of native starch. The molecular weight of starch displays a decreasing tendency after thermoplastic modification.

Effect of heat treatment on microstructure, mechanical properties and in vitro degradation behavior of as-extruded Mg-2.7Nd-0.2Zn-0.4Zr alloy

Mg-2.7Nd-0.2Zn-0.4Zr （mass fraction, %） alloy was designed for degradable biomedical material. The ingots of the alloy were solution treated and then hot extruded. The extruded rods were heat treated with aging treatment, solution treatment and solution＋aging treatment, respectively. Microstructures of the alloy were observed by optical microscopy （OM） and scanning electron microscopy （SEM）. Mechanical properties at room temperature were tested. In vitro degradation behavior of the alloy immersed in simulated body fluid was measured by hydrogen evolution and mass loss tests. The degradation morphologies of the alloy with and without degradation products were observed by SEM. The results show that the grains grow apparently after solution treatment. Solution treatment improves the elongation of as-extruded alloy significantly and decreases the strength, while aging treatment improves the strength and reduces the elongation of the alloy. The yield ratio is reduced by heat treatment. The in vitro degradation results of the alloy show that solution treatment on the as-extruded alloy results in a little higher degradation rate and aging treatment on the alloy can reduce degradation rate slightly.

Isolation, Identification and Biodegradation Characteristics of a Phthalate Ester Degrading Bacterium

By using plate screening techniques with five phthalate esters （DMP, DEP, DBP, DEHP and DOP） as energy and carbon sources, an active strain was isolated from the sediments of Chaohu Lake, which was identified as Burkholderia pickettil and named B. pickettii.z-1. The biodegradation of five phthalate esters by B. pick- ettii.z-1 strain was in accordance with the pseudo first-order kinetic equation： Ct = C0.e-kt. As the concentration of phthalate esters increased, the degradation rate of phthalate esters was reduced. B. pickettii.z-1 strain exhibited remarkably different degradation effects on various PAEs. Specifically, short-side-chain DMP and DEP were degraded rapidly, while long-side-chain DBP and DEHP were degraded slowly.

Learner-centeredness in the Teaching of Listening Comprehension

In the teaching of listening comprehension, teachers should be guided by a learner-centered philosophy. Decisions about what will be taught, how it will be taught, when it will be taught, and how it will be assessed will be made with reference to the learner. With the assistance and guidance of the teacher, learners will develop the ability of learning and therefore enhance their listening comprehension.

Effects of Low Temperature on Freezing Injury of Various Winter Wheat Cultivars at Different Sowing Time

Freezing injury is one of the major disasters for the production of winter wheat in the North China Plain, which leads to a significant decrease of wheat yield. This study was conducted to investigate the impact of subfreezing temperature on freezing injury of various winter wheat cultivars at different sowing time. Three wheat cultivars, including Zhengmai 9023, Wanmai 48 and Wanmai 50, were sowed on 25 September and 5 October, respectively. Plant anatomy was applied to investi- gate the impact of subfreezing temperature on cells of three wheat cultivars, results showed that severe plasmolysis occurred in wheat sowed earlier suddenly encoun- tered subfreezing temperature without cold acclimation, compared with wheat sowed at proper sowing time. The degree of plasmolysis of different cultivars and tissues of wheat had significant differences and showed positive correlation with subfreezing temperature. Wanmai 50 had the highest cold resistance compared with Zhengmai 9023 and Wanmai 48, and there was no significant difference between Zhengmai 9023 and Wanmai 48. This study concluded that wheat cold resistance may be im- proved by adopting proper cultivars and sowing dates.

新课程科学课堂教学中教师的换位思考

在新课程教学中教师要扮演“教”的角色，成为学生学习知识的引路人；还要学会换位思考，把自己置于学生的位置来认识体验、思考问题，用学生的眼光去审视教学内容，即教师还扮演“学”的角色，从而成为学生探究知识道路上的合作者。要思学生所思、解学生之惑、料学生之错。

Biological Characteristics of Biosurfactantproducing Petroleum-degrader Bacterium Bacillus BS-8

The growth characteristics of petroleum-degrader BS-8（Bacillus sp.） and the factors influencing its biosurfactant production were tested; the biosurfactant releasing mode of BS-8 was speculated by measuring OD600, surface tension and oil displacement of fermentation broth; and the effects of carbon source, nitrogen source, temperature, p H, and Na Cl concentration on biosurfactant production by BS-8 were observed in this study. The results showed that the biosurfactant releasing mode of BS-8 was growth-correlated, the surface tension of BS-8 fermentation broth declined with the total bacteria increasing, and the oil displacement was positive correlated with biosurfactant content in fermentation broth; and the optimal culture conditions for effective biosurfactant production included： glucose as carbon source,yeast extract as nitrogen source, Na Cl concentration of 2%, p H of 7.0 and temperature at 30 ℃.

Decomposition of Cellulose by Continuous Near-Critical Water Reactions

A pilot-scale apparatus for continuous supercritical and near-critical water reaction was set up. A high-pressure slurry supplying system was developed to feed the solid material-water slurries. The apparatus features temperature up to 600℃, pressure up to 40MPa, residence time from 24s to 15min, maximum amount of slurry supply of 2.4 L·h-1, maximum solid content of slurry up to 10%(by mass) for cellulose from Merck, and resistance to corrosion. Long-time runs of decomposition of cellulose were carried out and steady runs were confirmed. Kinetics of cellulose decomposition was studied. The apparent activation energy evaluated was 147kJ·mol-1. In addition, a new three-step pathway for cellulose hydrolysis was proposed. The derived kinetic equation is in good agreement with the experimental data.

Microstructure and properties of biodegradable β-TCP reinforced Mg-Zn-Zr composites

Magnesium alloys have good biocompatibility, but their mechanical properties and corrosion resistance may not be satisfied for using as degradable materials within bone due to its high corrosion rate in the physiological environment. Nano β-TCP particles were added into Mg-Zn-Zr alloy to improve its microstructure and the properties. As-extruded Mg-3Zn-0.8Zr alloy and Mg-3Zn-0.8Zr/xβ-TCP （x=0.5%, 1.0% and 1.5%） composites were respectively fabricated. The grains of Mg-Zn-Zr/β-TCP composites were significantly refined. The results of the tensile tests indicate that the ultimate tensile strength and the elongation of composites were improved with the addition of β-TCP. The electrochemical test result in simulation body fluid shows that the corrosion resistance of the composites was strongly enhanced comparing with that of the alloy. The corrosion potential of Mg-3Zn0.8-Zr/1.0β-TCP composite is 1.547 V and its corrosion current density is 1.20×10 6 A/cm 2 .

Biodegradation of microcystin-RR and -LR by an indigenous bacterial strain MC-LTH11 isolated from Lake Taihu

The indigenous bacterial strain MC-LTH11 with the capability of degrading microcystin-RR MC-RR and microcystin-LR MC-LR was successfully isolated from Lake Taihu.The bacterium was identified as Stenotrophomonas sp. which possessed a mlrA gene. The MC-LTH11 thoroughly degraded MC-RR and MC-LR with the initial concentration of 37.13 mg/L and 18.49 mg /L respectively in the medium containing crude microcystins extract within 6 d.The degradation rates were affected by temperature pH initial MCs concentration and the kinds of media. Additionally the bacterial strain MC-LTH11 also degraded thoroughly microcystins in the water body of Lake Taihu within 1 d.These results suggest that the Stenotrophomonas sp.MC-LTH11 has the capacity to bioremediate water bodies contaminated by microcystins and may contribute to the degradation of microcystins after the outbreak of harmful cyanobacterial blooms in Lake Taihu.

Functional imaging and endoscopy

The emergence of endoscopy for the diagnosis of gastrointestinal diseases and the treatment of gastrointestinal diseases has brought great changes.The mere observation of anatomy with the imaging mode using modern endoscopy has played a significant role in this regard.However,increasing numbers of endoscopies have exposed additional deficiencies and defects such as anatomically similar diseases.Endoscopy can be used to examine lesions that are difficult to identify and diagnose.Early disease detection requires that substantive changes in biological function should be observed,but in the absence of marked morphological changes,endoscopic detection and diagnosis are difficult.Disease detection requires not only anatomic but also functional imaging to achieve a comprehensive interpretation and understanding.Therefore,we must ask if endoscopic examination can be integrated with both anatomic imaging and functional imaging.In recent years,as molecular biology and medical imaging technology have further developed,more functional imaging methods have emerged.This paper is a review of the literature related to endoscopic optical imaging methods in the hopes of initiating integration of functional imaging and anatomical imaging to yield a new and more effective type of endoscopy.

Experimental study on micro-electrolysis technology for pharmaceutical wastewater treatment

Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of pharmaceutical wastewater. The results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater. Lower initial pH could be advantageous to the removal of chromaticity. A retention time of 30 minutes was recommended for the process design of micro-electrolysis.

Students＇ Perception Towards the Use of Internet as Learning Media to Promote Reading Comprehension Skill

This study analyses student＇s perception toward the use of lnternet to improve reading comprehension. This study aims： （1） to describe the students＇ perception of the use of Interact as teaching media in learning reading comprehension; （2） to depict the students＇ perception of the importance oflnternet to access information; and （3） to explain the students＇ frequency to access Internet. This study uses the descriptive method to reveal the research problems. A questionnaire is used to collect the data. It consists of 20 questions with five options to reveal the students＇ perception of the use of Internet. The questionnaire is distributed to 120 students who took reading subject at the University of Muhammadiyah Malang. The study shows that （1） The students＇ perception toward the use of Internet to improve Reading Comprehension subject is positive; （2） According to the students, the use of Internet to access reading materials is very important; and （3） The students frequently access Internet to find the reading materials.

A review on photocatalysis in antibiotic wastewater:Pollutant degradation and hydrogen production

Surveys on antibiotics have become one of the most popular topics in the recent two decades. From 1998 to 2018, more than 5,000 articles concentrated on the research of antibiotic wastewater treatment have been published. Among them, photocatalysis has received much attention due to its green and environmental-friendly properties. In this mini-review, the recent progress of photocatalysis in antibiotic wastewater was summarized, including antibiotics degradation and hydrogen energy conversion. The photocatalysts commonly used were also discussed. It can be mainly classified as TiO2-based materials, sulfides and polymeric carbon nitride-based materials and bismuth-contained materials. Four major types of antibiotics, tetracycline, sulfonamide, β-lactam and quinolone, were involved. Furthermore, perspectives concentrated on future development and challenges, especially converting antibiotics into hydrogen energy, were also proposed.