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Many of the most sensitive X-ray detectors are based on toxic elements such as lead, limiting their safe applications. Here, the authors report the realization of sensitive X-ray detectors based on solution-grown thick BiI/BiI3/BiI van der Waals heterostructures, showing a detection limit down to 34 nGy s−1 and high stability.

Physiology disorders of the liver, as it is an important tissue in lipid metabolism, can cause fatty liver disease. The mechanism might be regulated by 17 circadian clock genes and 18 fat metabolism genes, together with a high-fat diet (HFD). Due to their rich nutritional and medicinal value, Chinese soft-shelled turtles (Trionyx sinensis) are very popular among the Chinese people. In the study, we aimed to investigate the influence of an HFD on the daily expression of both the core clock genes and the lipid metabolism genes in the liver tissue of the turtles. The two diets were formulated with 7.98% lipid (the CON group) and 13.86% lipid (the HFD group) to feed 180 juvenile turtles, which were randomly divided into two groups with three replicates per group and 30 turtles in each replicate for six weeks, and the diet experiment was administrated with a photophase regimen of a 24 h light/dark (12L:12D) cycle. At the end of the experiment, the liver tissue samples were collected from nine turtles per group every 3 h (zeitgeber time: ZT 0, 3, 6, 9, 12, 15, 18, 21 and 24) for 24 h to investigate the daily expression and correlation analysis of these genes. The results showed that 11 core clock genes [i.e., circadian locomotor output cycles kaput (Clock), brain and muscle arnt-like protein 1 and 2 (Bmal1/2), timeless (Tim), cryptochrome 1 (Cry2), period2 (Per2), nuclear factor IL-3 gene (Nfil3), nuclear receptor subfamily 1, treatment D, member 1 and 2 (Nr1d1/2) and retinoic acid related orphan receptor α/β/γ β and γ (Rorβ/γ)] exhibited circadian oscillation, but 6 genes did not, including neuronal PAS domain protein 2 (Npas2), Per1, Cry1, basic helix-loop-helix family, member E40 (Bhlhe40), Rorα and D-binding protein (Dbp), and 16 lipid metabolism genes including fatty acid synthase (Fas), diacylglycerol acyltransferase 1 (Dgat1), 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr), Low-density lipoprotein receptor-related protein 1-like (Ldlr1), Lipin 1 (Lipin1), Carnitine palmitoyltransferase 1A (Cpt1a), Peroxisome proliferator activation receptor α, β and γ (Pparα/β/γ), Sirtuin 1 (Sirt1), Apoa (Apoa1), Apolipoprotein B (Apob), Pyruvate Dehydrogenase kinase 4 (Pdk4), Acyl-CoA synthase long-chain1 (Acsl1), Liver X receptors α (Lxrα) and Retinoid X receptor, α (Rxra) also demonstrated circadian oscillations, but 2 genes did not, Scd and Acaca, in the liver tissues of the CON group. However, in the HFD group, the circadian rhythms’ expressional patterns were disrupted for the eight core clock genes, Clock, Cry2, Per2, Nfil3, Nr1d1/2 and Rorβ/γ, and the peak expression of Bmal1/2 and Tim showed delayed or advanced phases. Furthermore, four genes (Cry1, Per1, Dbp and Rorα) displayed no diurnal rhythm in the CON group; instead, significant circadian rhythms appeared in the HFD group. Meanwhile, the HFD disrupted the circadian rhythm expressions of seven fat metabolism genes (Fas, Cpt1a, Sirt1, Apoa1, Apob, Pdk4 and Acsl1). Meanwhile, the other nine genes in the HFD group also showed advanced or delayed expression peaks compared to the CON group. Most importantly of all, there were remarkably positive or negative correlations between the core clock genes and the lipid metabolism genes, and their correlation relationships were altered by the HFD. To sum up, circadian rhythm alterations of the core clock genes and the lipid metabolism genes were induced by the high-fat diet (HFD) in the liver tissues of T. sinensis. This result provides experimental and theoretical data for the mass breeding and production of T. sinensis in our country.

Bretschneidera sinensis, the sole species of Bretschneidera, belonging to the family Akaniaceae, is a tertiary paleotropical flora. It is considered an endangered species by the International Union for Conservation of Nature (IUCN). It has an important protective and scientific value. The study of its seed dormancy and germination mechanisms contributes to better protection. In this study, the dormancy of fresh mature B. sinensis seeds released via low-temperature wet stratification was studied. In addition, the endogenous phytohormone levels, antioxidant enzyme activity, soluble sugar content, and the key metabolic enzyme activities of seeds at different stratification time nodes were determined. The goal was to analyze the mechanisms of seed dormancy release and germination comprehensively. Results show that low-temperature wet stratification under 5 °C can release seed dormancy effectively. During the seed dormancy release, the seed germination rate was positively correlated with soluble sugar, GA3, and IAA levels, as well as G-6-PDH, SOD, POD, CAT, and APX activity, but it was negatively correlated with MDH activity and ABA content. These imply that dormancy release might be attributed to the degradation of endogenous ABA and the oxidation of reactive oxygen species induced by low-temperature wet stratification. GA3, IAA, and the metabolism of energy substrates may be correlated with the induction and promotion of germination.

Dove tree (Davidia involucrata), a tertiary vestige species, is well-adapted to cool conditions. Dormancy in D. involucrata seed lasts for an extremely long period of time, typically between 3 and 4 years, and this characteristic makes the species an excellent model for studying the mechanisms of seed dormancy. The molecular mechanisms governing germination control in D. involucrata are still unknown. Seed stratification have been reported to enhance germination in recalcitrant seeds. We performed a widely targeted metabolome profiling to identify metabolites and associated pathways in D. involucrata seeds from six different moist sand stratification durations (0–30 months) using the ultra-high-performance liquid chromatography-Q Exactive Orbitrap-Mass spectrometry. There was an increasing germination rate with prolonged stratification durations (12–30 months). Furthermore, we detected 10,008 metabolites in the stratified seeds. We also detected 48 differentially accumulated metabolites (DAMs) between all stratification periods in the seeds, with 10 highly conserved metabolites. Most of the differentially accumulated metabolites between unstratified and stratified seeds were enriched in purine metabolism, pyrimidine metabolism, flavone and flavonol biosynthesis, phenylpropanoid biosynthesis, and arginine biosynthesis pathways. Key phytohormones, abscisic acid, indole-3 acetic acid, and sinapic acid were differentially accumulated in the seeds and are predicted to regulate dormancy in D. involucrata. We have provided extensive metabolic information useful for future works on dove tree germination study.

Zein, as one of the natural and GRAS proteins in plant, is renewable, nontoxic, biocompatible and biodegradable. Over the past decade, many research efforts have been devoted to zein-based biomaterials for several industrial applications. Combining with research experiences in our research group, the preparation methods, characterizations and pharmaceutical applications of zein-based nanoparticles were summarized in this review. Zein NPs with different particle nanostructures have been prepared by chemical crosslinking, desolvating, dispersing and micromixing strategies. The pharmaceutical applications of zein NPs are mainly focus on the drug delivery. Zein NPs can improve the drug stability, increase the oral bioavailability, control the drug release and enhance the drug targeting, thereby improving the pharmaceutical effect effectively. More efforts are required to analyze the relationship among preparation methods, particle nanostructures and pharmaceutical properties in virtue of quality by design approach, and further promote the scale-up production and clinical application of zein NPs.

Metasequoia glyptostroboides, Hu and W. C. Cheng, as the only surviving relict species of the Taxodiaceae Metasequoia genus, is a critically endangered and protected species in China. There is a risk of extinction due to the low vigor of M. glyptostroboides seeds, and the physiological mechanism of seed aging in M. glyptostroboides is not yet clear. In order to investigate the physiological and molecular mechanisms underlying the aging process of M. glyptostroboides seeds, we analyzed the antioxidant system and transcriptome at 0, 2, 4, 6, and 8 days after artificial accelerated aging treatment at 40 °C and 100% relative humidity. It was found that the germination percentage of fresh dried M. glyptostroboides seeds was 54 ± 5.29%, and significantly declined to 9.33 ± 1.88% after 6 days of aging, and then gradually decreased until the seed died on day 8. Superoxide dismutase (SOD) activity, ascorbic acid (AsA), glutathione (GSH) content and superoxide anion (O2·−) content and production rate significantly decreased, while malondialdehyde (MDA) and hydrogen peroxide (H2O2) content and glutathione peroxidase (GPX) and catalase (CAT) activity gradually increased during the aging process. A total of 42,189 unigenes were identified in the whole transcriptome, and 40,446 (95.86%) unigenes were annotated in at least one protein database. A total of 15,376 differentially expressed genes (DEGs) were obtained; KEGG enrichment analysis results revealed that seed aging may be mainly involved in the protein-processing pathways in endoplasmic reticulum, oxidative phosphorylation, and ascorbate and aldarate metabolism. Weighted gene co-expression network analysis (WGCNA) revealed that the dark magenta, orange, and medium purple modules were highly correlated with physiological indicators such as SOD, CAT, and GSH and further identified 40 hub genes such as Rboh, ACO, HSF, and CML as playing important roles in the antioxidant network of M. glyptostroboides seeds. These findings provide a broader perspective for studying the regulatory mechanism of seed aging and a large number of potential target genes for the breeding of other endangered gymnosperms.

Sophora tonkinensi is a shrub of the genus Sophora in the family Fabaceae with anti-inflammatory and pain-relieving effects. While the cultivation, chemical makeup, and medicinal properties of S. tonkinensis have been reported, the physiological mechanisms governing its dehydration and cryopreservation tolerance of seeds remain unclear. In this study, we investigated the morphological, physiological, biochemical, and protein expression characteristics of S. tonkinensis seeds subjected to dehydration and cryopreservation techniques via the observation of cell microstructure, determination of antioxidant enzyme activity, and iTRAQ-based proteomic analysis, respectively. The results of the study demonstrated that the seeds possessed a certain level of tolerance to dehydration. The highest germination percentage of 83.0% was observed after 2 h of dehydration (10.1% water content), which was identified as the optimal time point for cryopreservation. However, the germination percentage was reduced to only 30.5% when the water content reached 5.4%, indicating that S. tonkinensis seeds exhibit intermediate storage behavior. Further investigation revealed that during seed dehydration and cryopreservation treatment, liposomes were gradually and highly fused, whereas the activities of ROS scavenging and stress defense were significantly enhanced. During dehydration, the seed tissues formed a protective mechanism of stress resistance based on protein processing in the endoplasmic reticulum and antioxidant system, which was related to the dehydration tolerance. Moreover, only three differentially expressed LEA proteins were identified, and it is speculated that the strengthening of intracellular metabolism and the absence of specific LEA and dehydrins could be crucial factors for the reduced germination percentage after excessive dehydration and cryopreservation.

Abstract In this study, a simple one-step ionic liquid-based ultrasound-assisted dispersive liquid–liquid microextraction technique was coupled with high-performance liquid chromatography for the analysis of four pyrethroids in three kinds of traditional Chinese medicine oral liquid preparations: simotang oral liquid, kangbingdu oral liquid, and huaji oral liquid. The extraction parameters were examined to improve extraction efficiency. The optimum extraction conditions were 50 μL of 1-octyl-3-methylimidazolium hexafluorophosphate utilized as the extraction solvent and 800 μL of acetonitrile applied as the dispersive solvent. The extraction was assisted by ultrasonication for 8 min. The limits of detection for the four pyrethroids were within 0.007–0.024 mg L−1, and the limits of quantitation ranged between 0.023 and 0.080 mg L−1. The accuracy of the pyrethroid determination ranged from 80.1 to 106.4%. It was indicated that the proposed ionic liquid-based ultrasound-assisted dispersive liquid–liquid microextraction method had an easy operation and was accurate and environmentally friendly. This approach has potential for the analysis of pyrethroids in traditional Chinese medicine oral liquid preparations.

Eucommia ulmoides Oliv., the only member of the family Eucommiaceae, is endemic to China and has great development and utilization prospects. The seeds of E. ulmoides show dormancy but the underlying mechanism remains unknown. The aim of this study was to determine the cause of the seed dormancy and provide fundamental knowledge for the breeding, genetic improvement, and conservation of the germplasm resources of this species. According to the seed dormancy classification system developed by Jerry M. Baskin and Carol C. Baskin, we compared the germination percentage between intact seeds and isolated embryos, constructed water absorption curves, and evaluated the germination of seeds treated with scarification, cold/warm-moist stratification, after-ripening during dry storage, and gibberellic acid (GA3). The results showed that the intact seeds germinated only at 10 °C with a low germination percentage of 13.3% whereas the isolated embryos had a high normal germination percentage among a wider range of temperatures. According to the results from the scarified seeds, half seeds, and intact seeds, the seed coat significantly restricted the embryo water absorption. The scarification, after-ripening, cold/warm-moist stratification, and GA3 treatments promoted seed germination. Among them, cold-moist stratification was the most effective method and the temperature range of seed germination increased in both directions from 10 °C with prolonged stratification. The germination percentage increased significantly at constant temperatures with the highest germination percentage of 93.7 ± 0.3% at 10 °C and a light/dark cycle after 90 days of cold-moist stratification. Therefore, the freshly harvested E. ulmoides seeds exhibited a combinational dormancy comprising physical and Type 3 non-deep physiological dormancy, causing limited embryo water absorption by the seed coat and a low embryo growth potential. Given the unique phylogenetic characteristics and utility of E. ulmoides, our findings should promote studies of seed dormancy evolution and the development and application of E. ulmoides germplasm resources.

Solid multicomponent systems (SMS) are gaining an increasingly important role in the pharmaceutical industry, to improve the physicochemical properties of active pharmaceutical ingredients (APIs). In recent years, various processes have been employed for SMS manufacturing. Control of the particle solid-state properties, such as size, morphology, and crystal form is required to optimize the SMS formulation. By utilizing the unique and tunable properties of supercritical fluids, supercritical anti-solvent (SAS) process holds great promise for the manipulation of the solid-state properties of APIs. The SAS techniques have been developed from batch to continuous mode. Their applications in SMS preparation are summarized in this review. Many pharmaceutical co-crystals and solid dispersions have been successfully produced via the SAS process, where the solid-state properties of APIs can be well designed by controlling the operating parameters. The underlying mechanisms on the manipulation of solid-state properties are discussed, with the help of on-line monitoring and computational techniques. With continuous researching, SAS process will give a large contribution to the scalable and continuous manufacturing of desired SMS in the near future.

Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC) employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC). The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed.

In this paper, a novel method of QuEChERS-based extraction coupled with high-performance liquid chromatography has been developed for the simultaneous determination of ursolic acid (UA) and oleanolic acid (OA) in guava leaves. The QuEChERS-based extraction parameters, including the amount of added salt, vortex-assisted extraction time, and absorbent amount, and the chromatographic conditions were investigated for the analysis of UA and OA in guava leaves. Under the optimized conditions, the method showed good linearity over a range of 1–320 μg mL−1, with correlation coefficients above 0.999. The limits of detection of UA and OA were 0.18 and 0.36 μg mL−1, respectively. The intraday and interday precision were below 1.95 and 2.55%, respectively. The accuracies of the UA and OA determinations ranged from 97.4 to 111.4%. The contents of UA and OA in the guava leaf samples were 2.50 and 0.73 mg g−1, respectively. These results demonstrate that the developed method is applicable to the simultaneous determination of UA and OA in guava leaves.

Purpose: The purpose of this paper is to help business marketers with offline channels to make decisions on whether to sell through Group-buying (GB) websites and how to set online price with the coordination of maximum deal size on GB websites. Design/methodology/approach: Considering the deal structure of GB websites especially for the service fee and minimum deal size limit required by GB websites, advertising effect of selling on GB websites, and interaction between online and offline markets, an analytical model is built to derive optimal online price and maximum deal size for sellers selling through GB website. This paper aims to answer four research questions: (1) How to make a decision on maximum deal size with coordination of the deal price? (2) Will selling on GB websites always be better than staying with offline channel only? (3) What kind of products is more appropriate to sell on GB website? (4)How could GB website operator induce sellers to offer deep discount in GB deals? Findings and Originality/value: This paper obtains optimal strategies for sellers selling on GB website and finds that: Even if a seller has sufficient capacity, he/she may still set a maximum deal size on the GB deal to take advantage of Advertisement with Limited Availability (ALA) effect; Selling through GB website may not bring a higher profit than selling only through offline channel when a GB site only has a small consumer base and/or if there is a big overlap between the online and offline markets; Low margin products are more suitable for being sold online with ALA strategies (LP-ALA or HP-ALA) than high margin ones; A GB site operator could set a small minimum deal size to induce deep discounts from the sellers selling through GB deals. Research limitations/implications: The present study assumed that the demand function is determinate and linear. It will be interesting to study how stochastic demand and a more general demand function affect the optimal strategies. Practical implications: This paper provides a very useful model framework and optimal strategies for sellers’ selling on GB website. It takes advantage of the analytical model to explain much typical practical phenomenon for E-commerce like free sale with limited availability and so forth. It also helps GB website operator to induce deep discount from sellers. Originality/value: This paper is a first attempt to examine the seller's GB sale decision problem regarding to price and bounds on deal sizes. It analyses how the minimum deal size set by the GB website affect the optimal decision of sellers’. Moreover, it also discusses the impact of the interactions between online and offline markets on sellers’ decision.

Pyrethroid residues in traditional Chinese medicines have been a serious threat to the health and treatment of patients. However, because of the matrix complexity of traditional Chinese medicine, the detection of pyrethroid residues remains a challenge. Therefore, we developed a QuEChERS method coupled with high-performance liquid chromatography and ultraviolet detection (HPLC-UV) for the determination of pyrethroid pesticides in three kinds of traditional Chinese medicine oral liquid preparations, and we investigated and optimized the extraction conditions. The matrix effect was estimated in the organic solvent and the actual samples by comparing the slopes of calibration curves, and the results showed that the matrix effect is not significant when using the modified QuEChERS method. The pyrethroid pesticides could be completely separated in 30 min. The linear correlation coefficients were more than 0.999, and the recoveries of all the pyrethroid pesticides ranged from 87.2% to 104.8%. The intra-day precisions (n = 5) were 2.44–4.62%, and the inter-day precisions (n = 5) were 1.06–3.02%. Moreover, the limits of detection were in the range of 0.007–0.018 ng mL−1, while the limits of quantitation were in the range of 0.022–0.057 ng mL−1. This simple, low-cost, and highly sensitive analytical method can be a potential tool for the analysis of pyrethroid residues in traditional Chinese medicine oral liquid preparations.

Advantages of the rice–fish co‐culture system had gained increasing attention to resolve escalating global food security demand. However, many benefits in the rice–tortoise co‐culture system had rarely been investigated. In this study, we firstly proposed 'RICE' benefits, which came from the initial abbreviation of the four words including reduce, increase, co‐existence and ecology to illustrate the advantages of the rice–tortoise co‐culture system. We constructed three groups including the tortoise monoculture group (TM), the rice monoculture group (RM) and the rice–tortoise co‐culture group (RT) to investigate this system. The 84 juvenile tortoises with the weight of 36.0 ± 2.0 g were conducted for 9 blue plastic round tanks during the 74 days of the tortoises and rice co‐culture stage. The results showed that the system could remarkably save hectare farmland acreages, irrigation water resources, reduce the use of fertilizers and pesticides, and relieve eutrophication pollution from excess nitrogen and phosphorus. Compared with the rice monoculture group, the grain yields, grain rate, 1000‐grain weights and net incomes in the rice–tortoise co‐culture group were evidently increased The results of the tortoise growth performance parameters in the rice–tortoise co‐culture group were significantly greater than those in the tortoise monoculture group Particularly, the products amino acid quality of rice and tortoises were remarkably improved in the rice–tortoise co‐culture system. Importantly, the quality of water and soil environments got better and better. As a result, the role of 'win–win' between rice and tortoises indicated that they were mutually beneficial. Interestingly, leisure and sightseeing tourism for the rice–tortoise co‐culture system had been widely welcomed. This study concluded that the efforts to unlock the co‐culture system potential for both rice and tortoises would significantly increase agricultural productivity, food security and even could contribute to the potential, healthy, ecological and sustainable agriculture. [ABSTRACT FROM AUTHOR]

Two dominant strains of bacteria Lb18-01 and Lbl8-02 were isolated and purified from scabies, liver and intestine of diseased Peodiscus sinensis. By artificial infection t est, the two strains were verified as pathogenic strains with similar characters to that of natural infectious cases. The strains Lb 18 -01 and Lbl 8-02 showed strong pathogenicity to healthy P. sinensis in the artificial infection experiment, so they were the pathogenic strain of the disease. According to the morphology, physicochemical characteristics, 16 S rDNA sequence analysis and phylogenetic tree clustering, the pathogenic strains Lbl 8-01 and Lb18-02 were identified as Proteus vulgaris and Chryseobacterium meningosepticum which were tolerant to 20 drugs such as penicillin, tetracycline and ampicillin. Histopathological observation on diseased P. sinensis showed the pathological symptoms of sepsis such as hemorrhage and congestion of liver, spleen and intestine, and glomerular disintegration. [ABSTRACT FROM AUTHOR]

In order to explore the resource utilization of the harmless treatment product (pork meat and bone meal, abbreviated PM) of pigs died of non-communicable diseases, the general nutritional components and amino acid composition of PM and fish meal were determined and compared. The results showed that the contents of moisture, crude protein, crude fat and ash in PM and fish meal were 3.25% and 8. 92%, 66. 65% and 66. 67%, 13. 52% and 8. 23%, 18. 25% and 21.50%, respectively. The contents of essential amino acids (EAA) in PM and fish meal were 19.94% and 22.35%, respectively. For PM and fish meal, the first limiting amino acid was Met (methionine) + Cys (cysteine), and the second limiting amino acid was Lys (lysine); their essential amino acid indexes (EAAI) were 66.60 and 77.04, respectively; and their delicious amino acid (DAA) contents were 26. 89% and 23. 15%, respectively. In summary, the meat and bone meal of pigs died of non-communicable diseases has the characteristics of high protein and low ash contents, and has certain development and utilization potential as a recycled waste resource, especially in aquatic feed to replace fish meal. [ABSTRACT FROM AUTHOR]

Buyer finance has been practiced by manufacturers/assemblers for years; however, fewpapers have investigated the efficacy of buyer finance in an assembly system with multiple suppliers. This paper fills the literature gap by comparing buyer finance with bank finance in a supply chain with one assembler and multiple heterogeneous capitalconstrained component suppliers. We characterize the equilibrium solutions for different financing schemes (i.e., buyer finance, bank finance, and no finance).We showthat in buyer finance the assembler should charge the suppliers the lowest possible interest rate, which may be even belowits ownunit capital opportunity cost, leading to interest losses in financing suppliers. However, the assembler can benefit more from enhanced inventory backup and lower component purchasing prices resulting from the lowbuyer-finance interest rate. We further compare the two financing schemes from the perspectives of the assembler, the borrowing and nonborrowing suppliers, and the whole supply chain. Our analysis reveals that the assembler may offer buyer finance even if its own unit capital opportunity cost is higher than the bank risk-free interest rate. We also demonstrate how the suppliers' initial capitals, production costs, and their heterogeneities affect the assembler's selection of the optimal financing scheme and identify the conditions under which buyer finance is better than bank finance for different parties in this assembly supply chain. [ABSTRACT FROM AUTHOR]

In this paper, the volatile components extracted from guava leaves by steam distillation (SD) was investigated and comprehensively analyzed for the first time. To obtain more sensitive and accurate analysis, the sample preparation procedure for Gas Chromatography-Mass Spectrometry (GC-MS) analysis of the volatile compounds was investigated and then 27 compounds were identified in the samples obtained by SD method. The volatile components in guava leaf were made up largely of sesquiterpenoids, including α-cubebene, caryophyllene, aromadendrene, α-cadinene, and calamenene. The results indicated that the volatile components from the guava leaves extracted by SD technology was quite different, and the research provided comprehensive information for the volatile compounds in the guava leaves. [ABSTRACT FROM AUTHOR]

There has been an increasing concern on thermal comfort in sleeping environments and its associated energy use in the past few years. To improve the thermal environment and reduce energy use of air conditioning in bedrooms, task/ambient air conditioning (TAC) can be applied and was studied previously. Due to the variation of the envelope thermal loads in a bedroom during night, it is necessary to study the thermal environment inside the bedroom and the energy use of a TAC system for the bedroom at varying envelope thermal loads. Therefore, this paper reports on a numerical study on a TAC system applied to a bedroom with different envelope heat gains. PMV and EUC (energy utilization coefficient) values were evaluated, respectively. The study results indicated that when envelope thermal loads was higher, the advantage of the TAC system in energy saving was greater for the same thermal comfort level. However, it should be noted that a higher envelope thermal load could also resulted in the non-uniformity in air flow and air temperature distributions, leading to a possible uncomfortable micro environment. [ABSTRACT FROM AUTHOR]

For an air source heat pump (ASHP) unit with a vertically installed multi-circuit outdoor coil, a reverse cycle defrosting (RCD) operation is always terminated when the tube surface temperature at the exit of the lowest circuit reaches a pre-set value. It is obviously that when the pre-set temperature is higher, the defrosting duration would be prolonged. Not only more energy would be consumed on heating cold ambient air, but also the occupants’ thermal comfort adversely affected. However, if the pre-set temperature is lower, more residual water would be left on the downside surface of fin in an outdoor coil, which degrades the system performance during the next frosting/defrosting cycle. In order to find a suitable DTT or its range, in this paper, an experimental investigation on RCD operation for an ASHP unit with a multi-circuit outdoor coil was conducted and reported. As concluded, DTT is suitable at the range of 20-25 o C, around 22 o C. [ABSTRACT FROM AUTHOR]

It is always a challenge to develop appropriate mathematical model for a direct expansion (DX) air conditioning (A/C) system, whose operational parameters are highly coupled and behave non-linearly. Different modeling approaches have their own merits. However, none of the currently available modeling approaches can solely satisfy the requirement, in terms of accuracy and sensitivity, for simultaneous control of air temperature and humidity using a DX A/C system, without any inadequacies. On the other hand, when developing a model for the purpose of controller development rather than investigating complete system characteristics, the focus would be on several key components, and the modeling for other components that are relatively less important may be simplified. Therefore, it is possible to utilize different modeling approaches for different physical processes to develop a novel control-oriented hybrid model, named as semi-physical model (SPM). In this paper, rationales for using different modeling approaches for different physical processes of a DX A/C system are firstly discussed, followed by the development and validation of the SPM. The development of a SPM-based controller for the simultaneous control of air temperature and humidity is also briefly introduced, and its control perform acts as additional evidence for validating the SPM.Practical application: This paper presents a hybrid modeling method, which combines the complementary merits of various modeling approaches and avoid the inadequacies of them based on the analysis of the requirement of controller development. Such a new control-oriented hybrid modeling method can be applied to not only simultaneous temperature and humidity control using a variable-speed DX A/C system but also other control applications where control loops are coupled and system operational characteristics are complicated. [ABSTRACT FROM AUTHOR]

We consider a retailer selling a single product with limited on-hand inventory over a finite selling season. Customer demand arrives according to a Poisson process, the rate of which is influenced by a single action taken by the retailer (such as price adjustment, sales commission, advertisement intensity, etc.). The relationship between the action and the demand rate is not known in advance. However, the retailer is able to learn the optimal action on the fly as she maximizes her total expected revenue based on the observed demand reactions. Using the pricing problem as an example, we propose a dynamic learning-while-doing algorithm that only involves function value estimation to achieve a near-optimal performance. Our algorithm employs a series of shrinking price intervals and iteratively tests prices within that interval using a set of carefully chosen parameters. We prove that the performance of our algorithm is among the best of all possible algorithms in terms of the asymptotic regret (the relative loss compared to the full information optimal solution). Our result closes the performance gaps between parametric and nonparametric learning and between the post-price mechanism and the customer-bidding mechanism. Important managerial insight from this research is that the values of information on both the parametric form of the demand function as well as each customer's exact reservation price are less important than prior literature suggests. Our results also suggest that firms would be better off to perform dynamic learning and action concurrently rather than sequentially. [ABSTRACT FROM AUTHOR]