Baseflow Separation and Its Response to Meteorological Drought in a Temperate Water-limited Basin,North China

Baseflow,a component of the total streamflow,plays a key role in maintaining aquatic habitats,particularly during extreme drought events.This study investigated baseflow response to a prolonged and extreme meteorological drought event in the Baiyangdian Basin(BYD basin),a temperate water-limited basin in North China.Applying a precipitation series,piecewise regression was used to determine this extreme meteorological drought event,while the Automatic Baseflow Identification Technique(ABIT)was used to estimate a recession parameter(α),which was used to isolate baseflow from total streamflow.Results showed that:1)annual precipitation exhibited significant decreasing trends(P<0.05)with an average change of–1.81 mm/yr^(2).The precipitation deficit revealed that the start and end date of the extreme meteorological drought event was from August 1996 to May 2011,respectively,persisting for a total of 178 months(roughly 15 yr);2)hydrological drought(including streamflow and baseflow)lagged behind meteorological drought while predictably persisting longer than extreme meteorological drought(i.e.,precipitation);and 3)baseflow decreased dramatically under meteorological drought at both seasonal and annual scales,resulting in significantly decreasing trends during drought periods.Findings from this study confirmed that hydrological events caused by extreme meteorological drought can alter the magnitude and duration of baseflow and total streamflow,which will have an inevitable influence on aquatic ecosystems.

High-temperature protective coatings on superalloys

Protective coatings are essential for superalloys to serve as blades of gas turbines at high temperatures, and they primarily include aluminide coating, MCrAlY overlay coating, thermal barrier coating and microcrystalline coating. In this paper, all these high temperature coatings are reviewed as well as their preparing techniques. Based on the most application and the main failure way, the importance is then presented for further deepgoing study on the high temperature oxidation law of aluminide coatings.

Interval of effective time-step size for the numerical computation of nonlinear ordinary differential equations

The computational uncertainty principle states that the numerical computation of nonlinear ordinary differential equations（ODEs） should use appropriately sized time steps to obtain reliable solutions.However,the interval of effective step size（IES） has not been thoroughly explored theoretically.In this paper,by using a general estimation for the total error of the numerical solutions of ODEs,a method is proposed for determining an approximate IES by translating the functions for truncation and rounding errors.It also illustrates this process with an example.Moreover,the relationship between the IES and its approximation is found,and the relative error of the approximation with respect to the IES is given.In addition,variation in the IES with increasing integration time is studied,which can provide an explanation for the observed numerical results.The findings contribute to computational step-size choice for reliable numerical solutions.

Bridging science,technology and policy in emerging contaminants control

Emerging contaminants refer to newly discovered or previously overlooked contaminants that pose potential risks to the ecological environment and human health.They have not been included in environmental management practices or are inadequately addressed by existing management measures.Main focuses of emerging contaminants include persistent organic pollutants,endocrine disrupting chemicals,antibiotics and microplastics,among others.These contaminants have been widely detected in the environment and are considered urgent concerns for environmental safety and human health.However,compared to traditional pollutants,emerging contaminants are generally not well regulated by law-enforcement agencies.

Early urinary candidate biomarker discovery in a rat thioacetamide-induced liver fibrosis model

Biomarker is the change associated with the disease. Blood is relatively stable because of the homeostatic mechanisms of the body. However, urine accumulates changes of the body, which makes it a better early biomarker source. Liver fibrosis is a reversible pathological condition, whereas cirrhosis, the end-stage of liver fibrosis, is irreversible. Consequently, noninvasive early biomarkers for fibrosis are desperately needed. In this study, differential urinary proteins were identified in the thioacetamide liver fibrosis rat model using tandem mass tagging and two-dimensional liquid chromatography tandem mass spectrometry. A total of 766 urinary proteins were identified, 143 and 118 of which were significantly changed in the TAA 1-week and3-week groups, respectively. Multiple reaction monitoring(MRM)-targeted proteomics was used to further validate the abundant differentially expressed proteins. A total of 40 urinary proteins were statistically significant, 15 of which had been previously reported as biomarkers of liver fibrosis, cirrhosis or other related diseases and 10 of which had been reported to be associated with the pathology and mechanism of liver fibrosis. These differential proteins were detected in urine before the alanine aminotransferase and aspartate transaminase changes in the serum and before fibrosis was observed upon hematoxylin and eosin(HE) and Masson's staining.

A Case Study on Elementary CSL Learners' Reading Anxiety

This paper reports a case study that explores elementary learners＇ reading anxiety over Chinese as a second language （CSL）. Two elementary CSL learners were chosen as research participants. Lived experience descriptions, think-aloud, retrospective interviews, field observations, and research journal writings were used to investigate the sources of elementary CSL learners＇ reading anxiety and the ways employed to reduce their reading anxiety. The data were analyzed by Moustakas＇ （1994） data analysis procedures, Creswell＇s （2007） three steps, and Bogdon ＆ Biklen＇s （1992） data analysis methods. Results show that elementary CSL learners do have reading anxiety in their reading process and the sources of the anxiety include cross-linguistic differences between English and Chinese expressions, lack of previous knowledge, difficult and complex vocabulary, wrong guesses, and comprehension difficulties. Both participants tried to use strategies such as guessing, looking up words, understanding two character words based on the meaning of each character, skipping and keepitag reading, and using previous knowledge to predict the rest of the text to reduce their reading anxiety. The present study provides both theoretical and pedagogical implications in the field of CSL reading learning and teaching.