A Survey of Constrained Combinatorial Testing

Combinatorial Testing (CT) is a potentially powerful testing technique, whereas its failure revealing ability might be dramatically reduced if it fails to handle constraints in an adequate and efficient manner. To ensure the wider applicability of CT in the presence of constrained problem domains, large and diverse efforts have been invested towards the techniques and applications of constrained combinatorial testing. In this paper, we provide a comprehensive survey of representations, influences, and techniques that pertain to constraints in CT, covering 129 papers published between 1987 and 2018. This survey not only categorises the various constraint handling techniques, but also reviews comparatively less well-studied, yet potentially important, constraint identification and maintenance techniques. Since real-world programs are usually constrained, this survey can be of interest to researchers and practitioners who are looking to use and study constrained combinatorial testing techniques

Late Neo-Proterozoic Tectono-Sedimentary Evolution of the Tarim Block, NW China

The study of the late Neo-Proterozoic tectono-sedimentary evolution of the Tarim Basin is a key to unravel the tectonic setting, the intracontinental rift formation mechanism, and the sedimentary filling processes of this basin. Since in the Tarim Basin, the late Neo-Proterozoic to early Cambrian sedimentary successions were preserved, this basin represents an excellent site in order to study the Precambrian geology. Based on the outcrop data collected in the peripheral areas of the Tarim Basin, coupled with the intra-basinal drill sites and seismic data previously published, the late Neo-proterozoic tectono-sedimentary evolution of the Tarim Basin has been investigated. These data show that there were two individual blocks before the Cryogenian Period, namely, the north Tarim Block and the south Tarim Block. In the early Neo-Proterozoic (ca. 800 Ma), the amalgamation of two blocks resulted in the formation of the unified basement. During the late Neo-Proterozoic, the Tarim Block was in an extensional setting as a result of the Rodinia supercontinent breakup and then evolved into an intracontinental rift basin. The tectono-sedimentary evolution of the basin may be divided into three stages: the rifting stage (780–700 Ma), the rifting to depression transitional stage (660–600 Ma), and the post-rift depression stage (580–540 Ma). In the rifting stage, intracontinental rifts (i.e., the Awati Rift, the North Manjar Rift, and the South Manjar Rift) were formed, in which coarse-grained clastic sediments were deposited, generally accompanied by a massive volcanic activity due to an intensive stretching. In the rifting-depression transitional stage and in the post-rift depression stage, the paleogeography was characterized by uplifts to the south and depressions to the north. Three types of depositional association (i.e., clastic depositional association, clastic-carbonate mixed depositional association, and carbonate depositional association) were formed. The distribution of the lower Cambrian source rock was genetically related to the tectono-sedimentary evolution during the late Neo-Proterozoic. The lower Cambrian source rock was a stable deposit in the northern Tarim Basin, where the late Ediacaran carbonate was deposited, thinning out toward the central uplift. It was distributed throughout the entire Mangar region in the east and may be missing in the Magaiti and the southwestern Tarim Basin

Tunable polarization-drived superior energy storage performance in PbZrO3 thin films

Antiferroelectric PbZrO3 (AFE PZO) films have great potential to be used as the energy storage dielectrics due to the unique electric field (E)-induced phase transition character. However, the phase transition process always accompanies a polarization (P) hysteresis effect that induces the large energy loss (Wloss) and lowers the breakdown strength (EBDS), leading to the inferior energy storage density (Wrec) as well as low efficiency. In this work, the synergistic strategies by doping smaller ions of Li+–Al3+ to substitute Pb2+ and lowering the annealing temperature (T) from 700 to 550 ℃ are proposed to change the microstructures and tune the polarization characters of PZO films, except to dramatically improve the energy storage performances. The prepared Pb(1−x)(Li0.5Al0.5)xZrO3 (P(1−x)(L0.5A0.5)xZO) films exhibit ferroelectric (FE)-like rather than AFE character once the doping content of Li+–Al3+ ions reaches 6 mol%, accompanying a significant improvement of Wrec of 49.09 J/cm3, but the energy storage efficiency (η) is only 47.94% due to the long-correlation of FE domains. Accordingly, the low-temperature annealing is carried out to reduce the crystalline degree and the P loss. P0.94(L0.5A0.5)0.06ZO films annealed at 550 ℃ deliver a linear-like polarization behavior rather than FE-like behavior annealed at 700 ℃, and the lowered remanent polarization (Pr) as well as improved EBDS (4814 kV/cm) results in the superior Wrec of 58.7 J/cm3 and efficiency of 79.16%, simultaneously possessing excellent frequency and temperature stability and good electric fatigue tolerance

Associations and a new species of the genus Apatidelia (Trichoptera, Apataniidae) from China

Xie, Yue, Wang, Beixin, Sun, Changhai (2017): Associations and a new species of the genus Apatidelia (Trichoptera, Apataniidae) from China. European Journal of Taxonomy 333: 1-20, DOI: https://doi.org/10.5852/ejt.2017.33

Associations and a new species of the genus Apatidelia (Trichoptera, Apataniidae) from China

Nine individuals of Apatidelia from Zhejiang Province, China were examined and their barcode sequences were generated and analyzed. A new species, A. morsei Xu & Sun sp. nov., is described and illustrated. The larva, male and female of A. acuminata Leng & Yang, 1998 and the male and female of A. morsei Xu & Sun sp. nov. are associated by mtCOI gene sequences. The male of A. acuminata Leng & Yang, 1998 is re-described and re-illustrated, and the female and the larva of the same species are also described and illustrated. Females and larvae of the genus are here reported for the first time

Facilitating Water Permeation in Graphene Oxide Membranes via Incorporating Sulfonato Calix[n]arenes

Graphene oxide (GO) with its atomic thickness and abundant functional groups holds great potential in molecular-scale membrane separation. However, constructing high-speed and highly selective water transport channels within GO membranes remains a key challenge. Herein, sulfonato calix[n]arenes (SCn) molecules with a cavity structure, hydrophilic entrance, and hydrophobic wall were incorporated into GO interlayer channels through a layer-by-layer assembly approach to facilitate water permeation in a water/ethanol separation process. The hydrophilic entrance enables preferential access of water molecules to the cavity over ethanol molecules, while the high hydrophobicity of the cavity wall confers low resistance for water diffusion. After incorporating SCn molecules, the membrane shows a remarkable increase in the water/ethanol separation factor from 732 to 1260, while the permeate flux also increases by about 50%. In addition, the strong electrostatic interactions between the building blocks endow the membrane with excellent swelling resistance even under a high water content. This work provides an effective strategy of constructing high-efficiency water transport channels in membrane

One-Step Synthesis of Ultrathin Zeolitic Imidazole Framework-8 (ZIF-8) Membrane on Unmodified Porous Support via Electrophoretic Deposition

Metal–organic frameworks (MOFs) are regarded as the next-generation, disruptive membrane materials, yet the straightforward fabrication of ultrathin MOF membranes on an unmodified porous support remains a critical challenge. In this work, we proposed a facile, one-step electrophoretic deposition (EPD) method for the growth of ultrathin zeolitic imidazole framework-8 (ZIF-8) membranes on a bare porous support. The crystallinity, morphology and coverage of ZIF-8 particles on support surface can be optimized via regulating EPD parameters, yet it is still difficult to ensure the integrity of a ZIF-8 membrane with the constant voltage mode. In contrast, the constant current mode is more beneficial to the growth of a defect-free ZIF-8 membrane due to the steady migration rate of colloid particles toward the electrode. With a current of 0.65 mA/cm2 and deposition time of 60 min, a 300 nm thick ZIF-8 membrane was obtained, which exhibits a CO2 permeance of 334 GPU and a CO2/CH4 separation factor of 8.8, evidencing the defect-free structure

Improved Energy Storage Performance of All-Organic Composite Dielectric via Constructing Sandwich Structure

Improving the energy storage density of dielectrics without sacrificing charge-discharge energy storage efficiency and reliability is crucial to the performance improvement of modern electrical and electronic systems, but traditional methods of doping high-dielectric ceramics cannot achieve high energy storage densities without sacrificing reliability and storage efficiency. Here, an all-organic energy storage dielectric composed of ferroelectric and linear polymer with a sandwich structure is proposed and successfully prepared by the electrostatic spinning method. Additionally, the effect of the ferroelectric/linear volume ratio on the dielectric properties, breakdown, and energy storage is systematically studied. The results show that the structure has good energy storage characteristics with a high energy storage density (9.7 J/cm3) and a high energy storage efficiency (78%). In addition, the energy storage density of the composite dielectric under high energy storage efficiency (90%) is effectively improved (25%). This result provides theoretical analysis and experience for the preparation of multilayer energy storage dielectrics which will promote the development and application of energy storage dielectrics

Selective and Efficient SnMOF@BiVO₄ Photoanode for Two-Electron Water Oxidation to Hydrogen Peroxide Production

Photoelectrochemical water oxidation may provide one of the solutions to hydrogen peroxide production, but the selectivity and efficiency of the two-electron process still need to be improved. Precise control of the composition and structure of the photoanode materials is essential. Herein, a SnMOF@BiVO4 photoanode was fabricated for two-electron water oxidation to H2O2 production. The PEC production rate of H2O2 at 1.5 VRHE reached 0.62 μmol/min·cm2 and the Faradaic efficiency (FE) reached 82.0%. Meanwhile, the photocurrent density of SnMOF@BiVO4 was 2.5 times higher than that of pristine BiVO4, which was attributed to the enhanced two-electron oxidation selectivity and the accelerated charge transfer ability. This work provides a universal strategy for the fabrication of photoanode materials applied for PEC water oxidation to synthesize H2O2