Backwash Effects of Language Testing in EFL Classrooms

The article presents some major researches concerning the concept of backwash effect of language testing; analyses both the positive and negative effects and their implications in EFL classrooms; then provides some suggested ways to be followed when creating positive backwash effects on teaching and learning.

A Study on the Backwash Effect of the Reform of TEM-8 on Advanced English Course

TEM-8,which aims at testing students’integrated abilities of English,is more and more highly valued.Advanced Eng-lish,with its core teaching aim of cultivating this ability,should have high-quality teaching and optimized test as its objectives.Thus the test and the course can bring out the best in each other.

Effect of powdered activated carbon on Chinese traditional medicine wastewater treatment in submerged membrane bioreactor with electronic control backwashing

Chinese traditional medicine wastewater, rich in macromolecule and easy to foam in aerobic biodegradation such as Glycosides, was treated by two identical bench-scale aerobic submerged membrane bioreactors （SMBRs） operated in parallel under the same feed, equipped with the same electronic control backwashing device. One was used as the control SMBR （CSMBR） while the other was dosed with powdered activated carbon （PAC） （PAC-amended SMBR, PSMBR）. The backwashing interval was 5 min. One suction period was about 90 min by adjusting preestablished backwashing vacuum and pump frequency. The average flux of CSMBR during a steady periodic state of 24 d （576 h） was 5.87 L/h with average hydraulic residence time （HRT） of 5.97 h and that of PSMBR during a steady periodic state of 30 d （720 h） was 5.85 L/h with average HRT of 5.99 h. The average total chemical oxygen demand （COD） removal efficiency of CSMBR was 89.29% with average organic loading rate （OLR） at 4.16 kg COD/（m^3.d） while that of PSMBR was 89.79% with average OLR at 5.50 kg COD/（m^3.d）. COD concentration in the effluent of both SMBRs achieved the second level of the general wastewater effluent standard GB8978-1996 for the raw medicine material industry （300 mg/L）. Hence, SMBR with electronic control backwashing was a viable process for medium-strength Chinese traditional medicine wastewater treatment. Moreover, the increasing rates of preestablished backwashing vacuum, pump frequency, and vacuum and flux loss caused by mixed liquor in PSMBR all lagged compared to those in CSMBR; thus the actual operating time of the PSMBR system without membrane cleaning was extended by up to 1.25 times in contrast with the CSMBR system, and the average total COD removal efficiency of PSMBR was enhanced with higher average OLR.

Application of a novel backwashing process in upflow biological aerated filter

To improve the efficiency of backwashing in upflow biological aerated filter （BAF）, a novel backwashing process named air-water siphon backwashing （AWSB） was proposed and applied on laboratory scale. The effects of backwashing on turbidity and suspended solid （SS） in backwashing efluent using this new backwashing process were compared with those of traditional backwashing process, namely air-water backwashing （AWB）. In AWB, the turbidity of backwashing efluent maintained 100 NUT when consumed 60 min and 10.5 L water. However, in AWSB, it declined to 44 NUT, consumed 40 min, and 7 L water. The COD removal of BAF after backwashing was also analyzed. The average removal rate of COD in the reactor backwashed by AWB and AWSB was 89.34% and 90.91%, respectively. Compared with AWB, the backwashing interval had been prolonged 35%. The volume of backwashing water in that AWSB was only 66.7% of that in AWB. The results demonstrated that AWSB required less water and took shorter backwashing timerelative to AWB to achieve the same turbidity of backwashing efluent, and AWSB was more effective in removing fouling than that of AWB. More significant advantage of AWSB was that the backwashing interval was effectively prolonged

Membrane Fouling Alleviation by Chemically Enhanced Backwashing in Treating Algae-Containing Surface Water: From Bench-Scale to Full-Scale Application

Ultrafiltration(UF)has been increasingly implemented in drinking water treatment plants;however,algae and their secretions can cause severe membrane fouling and pose great challenges to UF in practice.In this study,a simple and practical chemically enhanced backwashing(CEB)process was developed to address such issues using various cleaning reagents,including sodium hypochlorite(NaClO),sodium chloride(NaCl),sodium hydroxide(NaOH),sodium citrate,and their combinations.The results indicate that the type of chemical played a fundamental role in alleviating the hydraulically irreversible membrane fouling(HIMF),with NaClO as the best-performing reagent,followed by NaCl.Furthermore,a CEB process using a combination of NaClO with NaCl,NaOH,or sodium citrate delivered little improvement in the alleviation of membrane fouling compared with NaClO alone.The optimized dosage and dosing frequency of NaClO were 10 mg·L^(-1) two times per day.Long-term pilot-scale and full-scale experiments further verified the feasibility of the CEB process in relieving algae-derived membrane fouling.Compared with the conventional hydraulic backwashing without chemical involvement,the CEB process can effectively remove the organic foulants including biopolymers,humic substances,and proteinlike substances by means of oxidization,thereby weakening the cohesive forces between the organic foulants and the membrane surface.Therefore,the CEB process can efficiently alleviate the algae-related membrane fouling with lower chemical consumption,and is proposed as an alternative to control membrane fouling in treating the algae-containing surface water.

Promoting Positive Backwash on Practical English Test for Colleges

Practical English Test for Colleges (PRETCO) is a large-scale national standardized EFL test for the students of higher vocational colleges,postsecondary specialized colleges,and colleges for adults.This thesis is for a preliminary research of PRETCO backwash based on previous studies from home and abroad,making use of their research methods and models.It attempts to explore the aspects of practical English learning of students from higher vocational colleges (HVC) influenced by PRETCO,and the nature of the backwash.Based on the results reported in the study,the writer analyzes the factors inducing negative backwash and puts forward some suggestions for promoting positive one.

Recycling of Mud Derived from Backwash Wastewater Coagulation as Magnetic Sodalite Sphere for Zn^(2+) Adsorption

Herein,we reported a method to prepare magnetic sodalite sphere by using the mud from backwash wastewater after polyaluminum chloride(PAC)coagulation.The results showed that approximately 100%of Fe in the wastewater was precipitated as flocculent iron mud(FM)by adding PAC.FM was converted to spherical magnetic sodalite(FMP)with a diameter of 3μm via a facile alkali hydrothermal method without adding Al/Si resources or reductant.The product FMP had the saturated magnetization of 10.9 emu g^(-1) and high Zn^(2+)adsorption capacity of 50.6 mg g^(-1).Without coagulation with PAC,the removal rate of Fe from the wastewater was only 92.7%,and the precipitated mud(RM)was converted to irregular particles(RMP),which had weak magnetic response and low capacity of Zn^(2+)adsorption comparing with FMP.With the method,the Fe in backwash wastewater was effectively recycled,and the generated sludge was converted to well-formed sodalite sphere without generating any secondary waste.

Error Analysis of CET-4 Translation Produced by Vocational & Techni⁃ cal College Students and the Backwash Effect of English Teaching

CET-4 is a national standardized English proficiency test designed and developed by the National College English Ex⁃amination Committee.The purpose of the test is to accurately measure the comprehensive English application ability of college stu⁃dents in China.The more important the test,the more obvious its backwash effect.With the increase of the proportion of subjective questions in CET-4,teachers should pay more attention to the transfer of skills and correct English expression while teaching the basic knowledge of English.In particular,the students in vocational and technical colleges are weak in English abilities,and their errors in translation are even more numerous and varied.Therefore,this study will analyze the translation errors produced by 200 vocational and technical college students in CET-4 of June 2019.By interviewing and investigating the students’actual situation of English learning,tips and proposals on backwash effect on teaching can be achieved.

Biomass and microbial activity in a biofilter during backwashing

Biomass and microbial activity in backwashing processes of a biofilter for tertiary treatment were investigated. The microbial groups revealed new distribution along the biofilter depth after low flow rate backwashing for a short time. Then the start-up process was accelerated by backwashing. The biomass profile and microbial activity profile both varying with depth before and after backwashing, can be mathematically described by quadratic equations. Using the profiles, the difference of oxygen demand can be calculated to determine the airflow rate during backwashing. Combined with the difference between biofilters and rapid gravity filters, analysis of biomass and microbial activity can determine more accurately the required airflow rate during backwashing.

The Backwash Effect of CETs on Language Education in a Broader Sense

CET4 and CET6 (combined asCETsin thispaper) have played and are still playing undeniable rolesin motivating English teaching and learning as well as providing a unified standard according to which most universities and colleges can compare with each other. However, in the recent years, a voice blaring their disadvantages has become louder and louder. This paper joins in the voice and expose their negative backwash effects on not only language education in colleges and universities but also on the activities of other institutions and organizations which are directly or indirectly involved in language training. This is what it means by"Language Education in a Broader Sense"in the title of this paper. Some improvements have been suggested in the end.

The Backwash Effect:from Negative to Positive

本文探讨了英语作为第二语言教学中的回波效应。作者首先阐述了语言教学中的回波效应,随后进一步分析了在中国教育背境下测试对英语教学的影响,提出回波效应的负面影响阻碍了目标语言的习得过程。最后提出了减小该负效应的一些策略。

Impacts of backwashing on micropollutant removal and associated microbial assembly processes in sand filters

Backwashing is crucial for preventing clogging of sand filters.However,few studies have investigated the effect of backwashing on micropollutant removal and the dynamic changes in the microbial community in sand filters.Here,we used a series of manganese and quartz sand filters under empty bed contact times(EBCTs)of 2 h and 4 h to explore variations in micropollutant degradation and temporal dynamics of the microbial community after backwashing.The results showed that the removal efficiencies of caffeine,sulfamethoxazole,sulfadiazine,trimethoprim,atrazine,and active biomass recovered within 2 d after backwashing in both types of sand filters at 2-h EBCT,but the recovery of sulfadiazine and trimethoprim was not observed at 4-h EBCT.Moreover,the removal efficiency of atenolol increased after backwashing in the manganese sand filters,whereas maintained almost complete removal efficiency in the quartz sand filters at both EBCTs.Pearson correlation analysis indicated that microbial community composition gradually recovered to the pre-backwashing level(R increased from 0.53 to 0.97)at 2-h EBCT,but shifted at 4-h EBCT(R<0.25)after backwashing.Furthermore,the compositions of the recovered,depleted,and improved groups of microbes were distinguished by applying hierarchical clustering to the differentially abundant amplicon sequence variants.The cumulative relative abundance of recovered microbes at 2-h EBCT was 82.76%±0.43%and 46.82%±4.34%in the manganese and quartz sand filters,respectively.In contrast,at 4-h EBCT,the recovered microbes dropped to 15.55%–25.69%in both types of sand filters.

“一带一路”视域下语言测试对高校英语教学的反拨效用研究

“一带一路”视域下的复合型人才培养,已上升到国家战略层面。语言测试作为考查、评估和改进语言教学的重要手段,有助于学生了解学习成效;教师明确教学状态,优化教学行为,提高教学效果。基于此,分析语言测试的意义,探究国内外反拨效用研究现状,阐述语言测试对英语教学的反拨作用,提出应用反拨效用的策略。

两种方法清洗消毒达芬奇机器人手术臂的效果比较

目的探讨达芬奇机器人手术臂有效的清洗消毒方法。方法回顾性分析2022年1月至2023年4月江西省人民医院手术室使用后的达芬奇机器人手术臂200件达芬奇机器人手术臂作为研究对象,按照不同的操作流程将其分为观察组(100件)与对照组(100件)。观察组采用流动水冲洗+腹腔镜酶剂浸泡+超声波清洗机超声+蒸汽清洗机清洗手术臂操作端+高压水枪纯水漂洗+全自动清洗机清洗消毒。对照组清洗消毒流程为流动水冲洗+腹腔镜酶剂浸泡+超声波清洗机超声+刷洗手术臂操作端+高压水枪纯水漂洗+全自动清洗机清洗消毒。采用目测检查法(四倍带光源放大镜)、腺苷三磷酸(ATP)生物荧光快速检测法进行检测,计算清洗质量不合格的返洗率,比较两组的清洗消毒操作平均耗时。结果观察组的目测检查法返洗率低于对照组,观察组的ATP生物荧光检测返洗率低于对照组,差异有统计学意义(P<0.05)。观察组清洗消毒平均耗时短于对照组,差异有统计学意义(P<0.05)。结论蒸汽清洗机清洗消毒达芬奇机器人手术臂效果比手工刷洗清洗消毒效果更为理想,可节约大量清洗消毒时间,有效节约稀有医疗资源。

反冲洗对4种换炭模式下生物活性炭层生物量和水质指标的影响

以水厂砂滤池出水作为生物活性炭柱的反冲洗水,研究了4种换炭模式下反冲洗前后炭层中生物量和出水水质指标的变化情况。结果表明,旧炭(已经运行使用3年的颗粒炭)的装填比例对炭层中生物量和出水水质指标均有不同程度的影响。通常情况下,全新炭柱上的生物量略高于旧炭,但反冲洗后旧炭比例高的炭柱生物量损失率更低。气水先后反冲洗后总生物量的损失率比单独水冲后总生物量的损失大,但附着生物量的损失基本不变,说明生物活性炭池可尝试使用单独水反冲洗。除高锰酸盐指数(COD_(Mn))变化不明显外,紫外吸光度(UV_(254))、可溶性有机碳(DOC)、生物可降解溶解性有机碳(BDOC)、生物不可降解溶解性有机碳(NBDOC)和三卤甲烷生成潜能(THMFP)的去除率在反冲洗后均有不同程度的上升。因此,反冲洗有利有弊,它既能冲刷掉部分附着在活性炭上的生物膜,对生物的冲刷力较强,同时又能恢复活性炭的吸附能力,使有机物的去除效果增强。反冲洗对填装精制新炭的4#炭柱炭层的吸附容量的恢复力最强,但其生物量的损失率却最大,说明相对于填装粗制新炭的3#炭柱,4#炭柱上的生物系统抵抗水力冲刷能力相对较弱,因此,精制或粗制炭的选择应根据活性炭池是主要发挥其吸附能力还是生物降解能力的需要进行。

全国英语阅读大赛对英语教学的反拨效应研究

语言测试对语言教学和学习具有促进作用。本研究在阐释反拨效应基本原理的基础上,对全国英语阅读大赛进行分析,探讨该赛事对大学英语教学的正面反拨效应和启示,重点研究大赛对教学内容的调整、教学模式的创新以及教学评价体系的影响。旨在顺应大学英语教学改革的时代潮流,提升大学英语教学效果。

基于PLC的滤站自动控制系统设计

针对滤站的污水处理流程,设计基于可编程逻辑控制器(Programmable Logic Controller,PLC)的滤站自动控制系统,并详细阐述该系统的硬件设计、软件设计。通过应用自动控制系统,滤站能够自动完成污水处理流程,缩短人工时间,提高工作效率。