This work presents polymer photovoltaic devices based on poly(3-hexylthiophene) (P3HT) and TiO2 nanorod hybrid bulk heterojunctions. Interface modification of a TiO2 nanorod surface is conducted to ...yield a very promising device performance of 2.20% with a short circuit current density (J sc) of 4.33 mA/cm2, an open circuit voltage (V oc) of 0.78 V, and a fill factor (FF) of 0.65 under simulated A.M. 1.5 illumination (100 mW/cm2). The suppression of recombination at P3HT/TiO2 nanorod interfaces by the attachment of effective ligand molecules substantially improves device performance. The correlation between surface photovoltage and hybrid morphology is revealed by scanning Kelvin probe microscopy. The proposed method provides a new route for fabricating low-cost, environmentally friendly polymer/inorganic hybrid bulk heterojunction photovoltaic devices.
Intrauterine adhesion (IUA), and its severe form Asherman syndrome (Asherman’s syndrome), is a mysterious disease, often accompanied with severe clinical problems contributing to a significant ...impairment of reproductive function, such as menstrual disturbance (amenorrhea), infertility or recurrent pregnancy loss. Among these, its correlated infertility may be one of the most challenging problems. Although there are many etiologies for the development of IUA, uterine instrumentation is the main cause of IUA. Additionally, more complicated intrauterine surgeries can be performed by advanced technology, further increasing the risk of IUA. Strategies attempting to minimize the risk and reducing its severity are urgently needed. The current review will expand the level of our knowledge required to face the troublesome disease of IUA. It is separated into six sections, addressing the introduction of the normal cyclic endometrial repairing process and its abruption causing the formation of IUA; the etiology and prevalence of IUA; the diagnosis of IUA; the classification of IUA; the pathophysiology of IUA; and the primary prevention of IUA, including (1) delicate surgical techniques, such as the use of surgical instruments, energy systems, and pre-hysteroscopic management, (2) barrier methods, such as gels, intrauterine devices, intrauterine balloons, as well as membrane structures containing hyaluronate–carboxymethylcellulose or polyethylene oxide–sodium carboxymethylcellulose as anti-adhesive barrier.
Experimental and observational studies on seedling dynamics posit mechanisms that can influence forest diversity, structure and function. However, high mortality and slow growth of seedlings make it ...difficult to evaluate the importance of this life‐history filter to total tree life history. Quantifying the duration and transition of the seedling phase would help us understand this ‘black box’ in tree population biology.
We used a 16‐year dataset of comprehensive seedling‐to‐sapling demography from a subtropical rainforest to construct population models that capture temporal demographic fluctuations for eight major tree species. We used data‐driven demographic models and simulations to estimate the transition ratios from newly recruited seedlings to saplings of 2‐m height and the time taken to attain 2‐m height for a newly recruited seedling conditional on its survival.
Projections among species estimated that as few as 57 to more than 40,000 seedlings (with a median of 2,087) were required to make a single 2‐m high sapling. Furthermore, it would take 22–200 years (with a median of 47) for a newly recruited seedling to become a 2‐m high sapling. We found that temporal variation in demographic rates could greatly reduce the number of seedlings per established sapling, but not passage times (PTs). We also identified the importance of consistently fast growth rates for seedlings to escape the high mortality of early stages.
Synthesis. Our findings demonstrate that high mortality in the very early seedling stage severely limits the probability that a newly recruited seedling will transition to the sapling stage. Although the PTs vary, we found this to be true across species with a range of life‐history strategies. Only seedlings with consistently fast growth rates are expected to pass through this life‐history filter. Findings from seedling studies should consider how short‐term studies of seedling demography might capture the rare exceptional individuals and exceptional conditions that might define the dynamics of this seedling bottleneck.
摘要
許多小苗的動態監測與實驗研究均假定此階段的動態變化會影響森林的多樣性、結構與功能。然而，受限於小苗的高死亡率與低生長率，我們很難評估小苗階段的篩選對於樹木整體生活史動態的重要性。具體量化樹木個體在小苗階段的停留時間與轉換比例，可以幫助我們了解這個樹木族群動態中的「黑盒子」。
我們使用台灣福山亞熱帶雨林長達16年的小苗動態監測資料，來建構該森林中8種主要樹種的族群模式，此一模式可以忠實呈現樹木小苗生長率、死亡率隨時間變化之特性。我們透過此一族群模式進行數值模擬，估算樹木從剛萌發的新增苗成長到2 m高小樹之轉換比例，以及若小苗可以順利存活，其成長到2 m高所需的時間。
依據模式所推估的結果，有的樹種平均只需要57株新增苗就能有一株能長成2 m高的小樹，但也有樹種需要超過40,000株新增苗才能有一株小樹 (中位數為2,087株小苗)。而樹木個體在這個階段的停留時間，則介於22到200年 (中位數為47年)。當模式中納入小苗存活率與生長率之年間變化時，可以大幅地提高新增苗成長為小樹的成功率，但並不會影響在此階段的停留時間。我們也發現，樹木小苗持續性的快速生長是其能否突破小苗建立初期高死亡率的關鍵。
我們的研究顯示樹木小苗建立初期的高死亡率是新增苗能否成長為小樹的主要限制。儘管具有不同生活史策略的樹種從小苗成長為小樹時間有所差異，但其小苗同樣都受到這個限制的影響，只有能持續快速生長的小苗可以突破這層篩選。未來我們在詮釋小苗研究成果時，必須考慮小苗調查中能否涵蓋這些稀有但是能快速生長的個體，以及能讓小苗快速生長的條件，這兩者是決定樹木是否能突破「小苗瓶頸」的關鍵因子。
We used a demographic process model to quantify the seedling‐to‐sapling transition in a subtropical rainforest. Our results show that consistently fast growth is critical for tree seedlings to escape the high mortality of early stages, suggesting that the rare exceptional individuals (and exceptional conditions) might define the dynamics of this life‐history bottleneck.
Blue, green, and red electrophosphorescent polymer light‐emitting diodes have been fabricated on silver nanowire‐polymer composite electrode. The devices are 20%‐50% more efficient than control ...devices on ITO/glass and exhibit small efficiency roll‐off at high luminances. The blue PLEDs were repeatedly bent to 1.5 mm radius concave or convex with calculated strain in the emissive layer approximately 5% (tensile or compressive).
The emergence of two-dimensional electronic materials has stimulated proposals of novel electronic and photonic devices based on the heterostructures of transition metal dichalcogenides. Here we ...report the determination of band offsets in the heterostructures of transition metal dichalcogenides by using microbeam X-ray photoelectron spectroscopy and scanning tunnelling microscopy/spectroscopy. We determine a type-II alignment between MoS2 and WSe2 with a valence band offset value of 0.83 eV and a conduction band offset of 0.76 eV. First-principles calculations show that in this heterostructure with dissimilar chalcogen atoms, the electronic structures of WSe2 and MoS2 are well retained in their respective layers due to a weak interlayer coupling. Moreover, a valence band offset of 0.94 eV is obtained from density functional theory, consistent with the experimental determination.
Vision is very important to fish as it is required for foraging food, fighting competitors, fleeing from predators, and finding potential mates. Vertebrates express opsin genes in photoreceptor cells ...to receive visual signals, and the variety of light levels in aquatic habits has driven fish to evolve multiple opsin genes with expression profiles that are highly plastic. In this study, red shiners (Cyprinella lutrensis) were exposed to four water turbidity treatments and their opsin genes were cloned to elucidate how opsin gene expression could be modulated by ambient light conditions. Opsin gene cloning revealed that these fish have single RH1, SWS1, SWS2 and LWS genes and two RH2 genes. Phylogenetic analysis also indicated that these two RH2 opsin genes-RH2A and RH2B -are in-paralogous. Using quantitative PCR, we found evidence that opsin expression is plastic in adults. Elevated proportional expression of LWS in the cone under ambient light and turbid treatment indicated that the red shiner's visual spectrum displays a red shift in response to increased turbidity.
Palladium diselenide (PdSe2), a peculiar noble metal dichalcogenide, has emerged as a new two-dimensional material with high predicted carrier mobility and a widely tunable band gap for device ...applications. The inherent in-plane anisotropy endowed by the pentagonal structure further renders PdSe2 promising for novel electronic, photonic, and thermoelectric applications. However, the direct synthesis of few-layer PdSe2 is still challenging and rarely reported. Here, we demonstrate that few-layer, single-crystal PdSe2 flakes can be synthesized at a relatively low growth temperature (300 °C) on sapphire substrates using low-pressure chemical vapor deposition (CVD). The well-defined rectangular domain shape and precisely determined layer number of the CVD-grown PdSe2 enable us to investigate their layer-dependent and in-plane anisotropic properties. The experimentally determined layer-dependent band gap shrinkage combined with first-principle calculations suggest that the interlayer interaction is weaker in few-layer PdSe2 in comparison with that in bulk crystals. Field-effect transistors based on the CVD-grown PdSe2 also show performances comparable to those based on exfoliated samples. The low-temperature synthesis method reported here provides a feasible approach to fabricate high-quality few-layer PdSe2 for device applications.
In this paper, we propose a new similarity measure between Atanassov’s intuitionistic fuzzy sets (AIFSs) based on transformation techniques and apply the proposed similarity measure between AIFSs to ...deal with pattern recognition problems. First, we present a new similarity measure between Atanassov’s intuitionistic fuzzy values (AIFVs) and prove some properties of the proposed similarity measure between AIFVs. Then, based on the proposed similarity measure between AIFVs, we propose a new similarity measure between AIFSs and prove some properties of the proposed similarity measure between AIFSs. Then, we use some examples to illustrate that the proposed similarity measure between AIFSs can overcome the drawbacks of the existing similarity measures. Finally, we apply the proposed similarity measure between AIFSs to deal with pattern recognition problems. The proposed similarity measure outperforms the existing similarity measures between AIFSs for dealing with the pattern recognition problems.
In this paper, we propose a new method for fuzzy multiattribute decision making based on the proposed transformation techniques between intuitionistic fuzzy values and right-angled triangular fuzzy ...numbers and the proposed intuitionistic fuzzy geometric averaging operators of intuitionistic fuzzy values. First, we propose a new multiplication operator between intuitionistic fuzzy values and propose a new power operator of intuitionistic fuzzy values based on the proposed transformation techniques between intuitionistic fuzzy values and right-angled triangular fuzzy numbers. Then, we propose the intuitionistic fuzzy weighted geometric averaging (IFWGA) operator, the intuitionistic fuzzy ordered weighted geometric averaging (IFOWGA) operator and the intuitionistic fuzzy hybrid geometric averaging (IFHGA) operator for aggregating intuitionistic fuzzy values. Then, we propose a new method for fuzzy multiattribute decision making based on the proposed IFWGA operator, the proposed IFOWGA operator and the proposed IFHGA operator of intuitionistic fuzzy values. The experimental results show that the proposed method can overcome the drawbacks of the existing methods for multiattribute decision making in intuitionistic fuzzy environments.
The design of π‐extended conjugation ‘V‘‐shaped red shifted bioluminescent D‐luciferin analogues based on a novel benzobisthiazole core is described. The divergent synthetic route allowed access to a ...range of amine donor substituents through an SNAr reaction. In spectroscopic studies, the ‘V’‐shaped luciferins exhibited narrower optical band gaps, more red‐shifted absorption and emission spectra than D‐luciferin. Their bioluminescence characteristics were recorded against four different luciferases (PpyLuc, FlucRed, CBR2 and PLR3). With native luciferase PpyLuc, the ‘V’‐shaped luciferins demonstrated more red‐shifted emissions than D‐luciferin (λbl=561 nm) by 60 to 80 nm. In addition, the benzobisthiazole luciferins showed a wide range of bioluminescence spectra from the visible light region (λbl=500 nm) to the nIR window (>650 nm). The computational results validate the design concept which can be used as a guide for further novel D‐luciferin analogues based upon other ‘V’‐shaped heterocyclic cores.
The synthesis of 4 new D‐luciferin analogues based upon a ‘V‘‐shaped benzobisthiazole core, with structurally and electronically different amines is described. Their bioluminescence and photophysical characteristics were determined. With a variety of luciferases, the new ‘V‘‐shaped luciferins provided longer wavelengths than D‐luciferin. The combination of luciferase PpyLuc and the pyrrolidine analogue showed the longest bioluminescence wavelength at 636 nm.
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