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Improving software development efficiency based on existing APIs is one of the hot researches in software engineering. Understanding and learning so many APIs in large software libraries is not easy and software developers prefer to provide only requirements descriptions to get the right API. In order to solve this problem, this paper proposes an API recommendation method based on WII-WMD, an improved similarity calculation algorithm. This method firstly structures the text, and then fully mines the semantic information in the text. Finally, it calculates the similarity between the user's query problem and the information described in the API document. The experiment results show that the API recommendation based on WII-WMD can improve the efficiency of the API recommendation system.

1. This unique nanostructure with 2D MoS2 nanosheets nanoconfined into amorphous carbon layers delivered the excellent electrochemical performance. 2. The composite exhibited high reversible specific capacity, good rate capability and stability.

The hybrid with super-structures is an effective strategy to improve their electrochemical performance. The Fe7S8-C/ZnS-C@MoS2/rGO sample delivered high reversible capacities in Lithium/sodium storage.

Sensory adaptation is an essential function for humans to live on the earth. Herein, a hybrid synaptic phototransistor based on the mixed-halide perovskite/organic semiconductor film is reported. This hybrid phototransistor achieves photosensitive performance including a high photoresponsivity over 4 × 103 A/W and an excellent specific detectivity of 2.8 × 1016 Jones. Due to the photoinduced halide-ion segregation of the mixed-halide perovskites and their slow recovery properties, the experience-history-dependent sensory adaptation behavior can be mimicked. Moreover, the light pulse width, intensity, light wavelength, and gate bias can be used to regulate the adaptation processes to improve its adaptability and perceptibility in different environments. The CsPbBrxI3-x/organic semiconductor hybrid films produced by spin coating are beneficial to large-scale fabrication. This study fabricates a novel solution-processable light-stimulated synapse based on inorganic perovskites for mimicking the human sensory adaptation that makes it possible to approach artificial neural sensory systems.

Amorphous multi-element oxide films were grown using a facile temperature-controlled approach. The compact IMZO film was deposited and the size of voids formed in the film reduced greatly as compared with that of the pure ZnO film. The 5 nm-thick IMZO was patterned directly with the aid of a stencil mask and applied to a thin film transistor which afforded superior performance including a field effect mobility value of 26.67 cm2 V−1 s−1 and an Ion/Ioff ratio of 7.19 × 107. Nowadays, the physics based drain current model is in great demand for better circuit design. In this work, the accurate and continuous drain current description of as fabricated multi-element oxide devices was derived using a surface potential based model with a charge sheet approach. Considering the voltage losses applied to the electrode for the existence of the interface trap, the modification factors of voltage were effectively introduced for better fitting which assisted the analysis of electrical properties of active films.

Luminescent materials such as Cd-based quantum dots, CuInS2 quantum dots, and perovskite-based materials play an important role as an exceptional class of optoelectronic materials due to their unique and novel characteristics for optoelectronic applications. However, a key challenge for luminescent materials and devices is their poor long-term stability, which is typically attributed to the irreversible changes of surface ligands or chemical structure against oxygen and moisture when exposed to ambient atmosphere. Thus, this review mainly focuses on recent important work on the stability-enhanced strategies of luminescent materials. Various strategies for their fabrication, including surface engineering and surface coating routes have been summarized, followed by their advantages and challenges. Furthermore, the corresponding optoelectronic applications of these promising stability-enhanced luminescent materials in light-emitting diodes, photodetectors, solid-state lighting chips, and solar cells were also reviewed. Afterward, the outlook and perspective are presented.

An artificial synaptic device that can provide color discrimination, image storage, and image recognition is highly required to mimic the human vision for biological robots. All-inorganic halide perovskites have attracted extensive attention for the reason of their high stability and favorable photoelectric properties. In this study, a light-stimulated synaptic phototransistor based on a CsPbBr3/organic semiconductor hybrid film is reported. The fabricated CsPbBr3 film exhibits an island structure, which reduces the hysteresis effectively and at the same time achieves a high specific detectivity of up to 2 × 1015 Jones. The decay of the photocurrent can be delayed by changing the gate bias, which is essential for achieving high-performance light-stimulated synaptic devices. Due to the outstanding detectivity of the device, the obvious synaptic functions can be observed when triggered by a light signal with a power of 1.6 nW that is much weaker than previous most perovskite-based hybrid synaptic phototransistors under a low operating voltage of -1 V. The electrical power consumption of the device could be as low as 0.076 pJ when the power of light spike was 7.36 nW. Taking into account this characterization, with changing of light intensity or wavelength, the contrast of the image was enlarged, which can further promote the image recognition accuracy. More significantly, this CsPbBr3/TIPS hybrid film can be fabricated by facile and low-cost solution processes. This study indicates the great potential of solution-processed perovskite-based light-stimulated synapses for future artificial visual systems.

Recently, perovskite quantum dots (PQDs) were employed as promising emitters in light-emitting diode devices (LEDs) mainly owing to their marvelous photoelectronics properties. However, these perovskite QLEDs suffered from the inefficient performance, especially their serious efficiency roll-off probably due to the exciton recombination dynamic in the interface of PQDs films and charge imbalance resulting from low electrical transportation. Herein, sodium dodecyl sulfate (SDS) was effectively introduced to synthesize PQDs with many excellent properties and eventually suppressed the efficiency roll-off of QLEDs. SDS-based PQDs films exhibited obviously enhanced radiative recombination, reduced trap density, and increased carrier mobility, especially the transportation of electrons. Therefore, the charge carrier was balanced at high current density together with the remarkably suppressed efficiency roll-off. QLEDs fabricated by SDS-capped PQDs exhibited significantly improved maximum brightness of 193,810 cd/m2, and achieve the external quantum efficiency of 10.13%. More importantly, the EQE roll-off of QLED optimized in the thickness of emitting layer was only 1.5% at the current density of 200 mA/cm2, representing a prominent achievement of our strategy.

Delayed hospital discharges for patients needing rehabilitation in a postacute setting can exacerbate hospital-acquired mobility loss, prolong functional recovery, and increase costs. Systematic measurement of patient mobility by nurses early during hospitalization has the potential to help identify which patients are likely to be discharged to a postacute care facility versus home. To test the predictive ability of this approach, a machine learning classification tree method was applied retrospectively to a diverse sample of hospitalized patients (N = 805) using training and validation sets. Compared with patients discharged to home, patients discharged to a postacute facility were older (median, 64 vs 56 years old) and had lower mobility scores at hospital admission (median, 32 vs 41). The final decision tree accurately classified the discharge location for 73% (95%CI:67%-78%) of patients. This study emphasizes the value of systematically measuring mobility in the hospital and provides a simple decision tree to facilitate early discharge planning.

An effective Quantum Dot Light Emitting Diodes (QLED) was developed by creatively inserting an easily controlled 2D graphene oxide (GO) film between the luminescent layer and the electron transport layer (ETL) as the electron barrier layer (EBL). As compared with the traditional PMMA and other polymer barrier layers, the GO with particular the lamellar two-dimensional structure was more conducive to the control of film thickness by spin-coating. The introduction of GO increased the conduction band edge and inhibited exciton quenching. Simultaneously, since the electron mobility of the ETL was much higher than the hole mobility of the hole transport layer (HTL), GO with high insulation could be used to inhibit the electron injection effectively and achieve the charge transport balance. The green QLEDs with high performances including a current efficiency of 22.51 cd A−1, a power efficiency of 8. 71 lm W−1 and an EQE of up to 5.98% were successively fabricated. This particular architecture of QLED with GO electron barrier layer and creative method of energy band regulation provided an efficient and feasible strategy for the next generation of QLED displays with high performance and solid-state lighting technologies.

CuInS2-based quantum-dots (QDs) have been highlighted as promising photoelectric materials for their low toxicity and color adjustable emissions as well as stability. Here, multi-shell CuInS2/ZnS/ZnS QDs with high PLQY of 76% were synthesized by employing a high temperature and long-time growth strategy while highly bright and efficient quantum-dot-light-emitting diodes (QLEDs) were fabricated by using these multi-shell QDs as an emission layer and polyethylenimine (PEI) as an insulating layer, respectively. By introducing PEI between the QDs and ZnO EML layers of the QLEDs, the balance of the carriers within the QDs layer injected from HTL and ETL was greatly improved. As a result, comparing to the QLEDs without PEI, the greatly improved efficiency (1.9 times as high as that of the QLEDs without PEI) has been achieved in the optimized QLEDs with PEI. These QLEDs exhibits an outstanding performance with the maximum EQE of 1.56% and the maximum brightness of 5825 cd/m2.

Nanomaterials, especially quantum dots, have become one of the most great potential channel transport layer materials in the field of photo detection mainly due to their particular light absorption characteristics. However, there are still many disadvantages such as low carrier transport capability possibly attributable to the discontinuity nature of materials. Therefore, particular phototransistors with pentacene/CdSe@ZnS QDs composite materials channels have been prepared by simply blending and spin-coating 6,13-Bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) and QDs solution in weight ratio of 3:1. The particular device architecture with organic/quantum dot composite materials channels effectively combined the high carrier mobility advantage of organic semiconductors with the strong absorption characteristic of quantum dots in specific optical band regions and further overcame the low conductivity shortcomings of pure quantum dot materials. The device with particular pentacene/CdSe@ZnS QDs composite channel exhibited excellent electrical and optical properties with current switch ratio Ion/off of 104, carriers mobility of ~0.161 cm2/V, photosensitivity P of 105, responsivity R of 0.33 mA/W and detectivity D of 1.48 × 1011 Jones at drain voltage of −35 V and light intensity of 1.6 mW/cm2, respectively, indicating that this composite, as one of the most promising channel transport layer material candidates for photodetector, provides one chance to improve the characteristic of photodetector transistors just by using hybrid channel technology.

Quantum dots fluorescence-enhanced films, which mainly consisted of CdSe@ZnS quantum dots and noble metal nanoparticles or nanorods, were formed by layer-by-layer self-assembly techniques. This particular architecture consisting of metal nanoparticles-poly (diallyl dimethylammonium chloride) (PDDA)-QDs was characterized by those fabrication processes mainly including surface-modifying the oleic acid-capped CdSe@ZnS QDs (high quantum yield of ~89%) with mercaptopropionic acid (MPA) to be charged negatively (–COO–) for following solution-processed assembly, adjusting the size and coating the gold nanoparticles/nanorods with silica to form suitable dielectric insulation layer and further optimize the fluorescence-enhanced performance, as well as using the cationic polyelectrolyte to control the charges between layers and form opposite charges between two adjacent layers. After optimizing the structure of the quantum dot fluorescence-enhanced films and corresponding surface plasmon enhancement effect, the enhancement factor of 10.8 in Au NPs@SiO2-PDDA-QDs complex film and that of 24.7 in Au NRs@SiO2-PDDA-QDs complex film as compared with the pure quantum dot fluorescence film were achieved, respectively. This indicated that the Au NRs@SiO2-PDDA-QDs complex film was one of the most promising potentials for further display backlight and biometric identifier application.

Semiconductor quantum dots (QDs) have attracted extensive attention because of their remarkable optical and electrical characteristics. However, the practical application of QDs and further the QD composite films have greatly been hindered mainly owing to their essential drawbacks of extreme unstability under oxygen and water environments. Herein, one simple method has been employed to enhance enormously the stability of Cd xZn1- xSe yS1- y QD composite films by a combination of Cd xZn1- xSe yS1- y QDs and poly(vinylidene) fluoride (PVDF), which is characteristic of closely arranged molecular chains and strong hydrogen bonds. There are many particular advantages in using QD/PVDF composite films such as easy processing, low cost, large-area fabrication, and especially extreme stability even in the boiling water for more than 240 min. By employing K2SiF6:Mn4+ as a red phosphor, a prototype white light-emitting diode (WLED) with color coordinates of (0.3307, 0.3387), Tc of 5568 K, and color gamut 112.1NTSC(1931)% at 20 mA has been fabricated, and there is little variation under different excitation currents, indicating that the QD/PVDF composite films fabricated by this simple blade-coating process make them ideal candidates for liquid-crystal display backlight utilization via assembling a WLED on a large scale owing to its ultrahigh stability under severe environments.