The role of solution aggregates on the charge transport process of conjugated polymers in electronic devices has gained increasing attention; however, the correlation of the charge carrier mobilities ...between the solution aggregates and the solid‐state films remains elusive. Herein, three polymers, FBDOPV‐2T, FBDOPV‐2F2T, and FBDOPV‐4F2T, are designed and synthesized with distinct aggregation behavior in solution. By combining contact‐free ultrafast terahertz (THz) spectroscopy and field‐effect transistor measurements, we track the charge carrier mobility of the aggregates of these polymers from the solution to the thin‐film state. Remarkably, the mobility of these three polymers is found to follow nearly the same trend (FBDOPV‐2T>FBDOPV‐2F2T≫FBDOPV‐4F2T) in both solutions and thin‐film states. The quantitative mobility correlation indicates that the charge transport properties of solution aggregates play a critical role in determining the thin‐film charge transport properties and final device performance. Our results highlight the importance of investigating and controlling solution aggregation structures towards efficient organic electronic devices.
Different aggregation structures of three BDOPV‐based polymers in solution were obtained via subtle adjustment of the molecular structures. By employing contact‐free ultrafast terahertz (THz) spectroscopy, we directly reveal that the correlation of the charge carrier mobilities between the solution aggregates and the solid‐state films remains highly consistent.
The influence of changes in crystallographic texture on the Hall-Petch (H-P) relationship for an Mg alloy was investigated. First, the texture variations were facilitated by changing the uniaxial ...tensile loading orientation with respect to the normal direction of the rolled Mg plate. With a strong plane texture of the as-received material, the initial dominant deformation mechanisms were systematically varied from the basal slip and prismatic slip to extension twinning, as well as combinations thereof. Second, different grain sizes were produced for each loading orientation through isochronal annealing at various temperatures up to 773K while closely monitoring grain size and texture distributions. The experimental results are presented for the grain growth kinetics during annealing, changes in yielding behavior as a function of grain size and initial texture, and H-P relationship as a function of the texture. Moreover, the effects of changes in texture and dominant deformation mechanism on H-P parameters - namely, friction stress, sigma o , and strength coefficient, k sigma - are discussed. Finally, H-P relationships for each individual deformation mode including basal, prismatic and pyramidal slips as well as extension twin are identified.
A
bstract
Canonical threefold singularities in M-theory and Type IIB string theory give rise to superconformal field theories (SCFTs) in 5d and 4d, respectively. In this paper, we study canonical ...hypersurface singularities whose resolutions contain residual terminal singularities and/or 3-cycles. We focus on a certain class of ‘trinion’ singularities which exhibit these properties. In Type IIB, they give rise to 4d
N
= 2 SCFTs that we call
D
p
b
(
G
)-trinions, which are marginal gaugings of three SCFTs with
G
flavor symmetry. In order to understand the 5d physics of these trinion singularities in M-theory, we reduce these 4d and 5d SCFTs to 3d
N
= 4 theories, thus determining the electric and magnetic quivers (or, more generally, quiverines). In M-theory, residual terminal singularities give rise to free sectors of massless hypermultiplets, which often are discretely gauged. These free sectors appear as ‘ugly’ components of the magnetic quiver of the 5d SCFT. The 3-cycles in the crepant resolution also give rise to free hypermultiplets, but their physics is more subtle, and their presence renders the magnetic quiver ‘bad’. We propose a way to redeem the badness of these quivers using a class
S
realization. We also discover new S-dualities between different
D
p
b
(
G
)-trinions. For instance, a certain
E
8
gauging of the
E
8
Minahan-Nemeschansky theory is S-dual to an
E
8
-shaped Lagrangian quiver SCFT.
A
bstract
Using a one-way Monte Carlo algorithm from several different starting points, we get an approximation to the distribution of toric threefold bases that can be used in four-dimensional ...F-theory compactification. We separate the threefold bases into “resolvable” ones where the Weierstrass polynomials (
f, g
) can vanish to order (4
,
6) or higher on codimension-two loci and the “good” bases where these (4
,
6) loci are not allowed. A simple estimate suggests that the number of distinct resolvable base geometries exceeds 10
3000
, with over 10
250
“good” bases, though the actual numbers are likely much larger. We find that the good bases are concentrated at specific “end points” with special isolated values of
h
1,1
that are bigger than 1,000. These end point bases give Calabi-Yau fourfolds with specific Hodge numbers mirror to elliptic fibrations over simple threefolds. The non-Higgsable gauge groups on the end point bases are almost entirely made of products of
E
8
,
F
4
,
G
2
and SU(2). Nonetheless, we find a large class of good bases with a single non-Higgsable SU(3). Moreover, by randomly contracting the end point bases, we find many resolvable bases with
h
1,1
(
B
) ∼ 50-200 that cannot be contracted to another smooth threefold base.
The widespread popularity of smart meters enables an immense amount of fine-grained electricity consumption data to be collected. Meanwhile, the deregulation of the power industry, particularly on ...the delivery side, has continuously been moving forward worldwide. How to employ massive smart meter data to promote and enhance the efficiency and sustainability of the power grid is a pressing issue. To date, substantial works have been conducted on smart meter data analytics. To provide a comprehensive overview of the current research and to identify challenges for future research, this paper conducts an application-oriented review of smart meter data analytics. Following the three stages of analytics, namely, descriptive, predictive, and prescriptive analytics, we identify the key application areas as load analysis, load forecasting, and load management. We also review the techniques and methodologies adopted or developed to address each application. In addition, we also discuss some research trends, such as big data issues, novel machine learning technologies, new business models, the transition of energy systems, and data privacy and security.
A
bstract
Applying the Ashok-Denef-Douglas estimation method to elliptic Calabi-Yau fourfolds suggests that a single elliptic fourfold
ℳ
max
gives rise to
O
10
272
,
000
F-theory flux vacua, and that ...the sum total of the numbers of flux vacua from all other F-theory geometries is suppressed by a relative factor of
O
10
−
3000
. The fourfold
ℳ
max
arises from a generic elliptic fibration over a specific toric threefold base
B
max
, and gives a geometrically non-Higgsable gauge group of
E
8
9
×
F
4
8
× (
G
2
× SU(2))
16
, of which we expect some factors to be broken by G-flux to smaller groups. It is not possible to tune an SU(5) GUT group on any further divisors in
ℳ
max
, or even an SU(2) or SU(3), so the standard model gauge group appears to arise in this context only from a broken
E
8
factor. The results of this paper can either be interpreted as providing a framework for predicting how the standard model arises most naturally in F-theory and the types of dark matter to be found in a typical F-theory compactification, or as a challenge to string theorists to explain why other choices of vacua are not exponentially unlikely compared to F-theory compactifications on
ℳ
max
.
We study the general relativistic (GR) effects induced by a spinning supermassive black hole on the orbital and spin evolution of a merging black hole binary (BHB) in a hierarchical triple system. A ...sufficiently inclined outer orbit can excite Lidov-Kozai eccentricity oscillations in the BHB and induce its merger. These GR effects generate extra precessions on the BHB orbits and spins, significantly increasing the inclination window for mergers and producing a wide range of spin orientations when the BHB enters LIGO band. This "GR-enhanced" channel may play an important role in BHB mergers.
Silicon carbide (SiC), one of the third‐generation semiconductor materials with excellent electrical and optoelectronic properties, is ideal for high light‐sensing performance. Here, a self‐powered ...SiC ultraviolet (UV) photodetector (PD) is constructed with wider applicability and higher commercialization potential. The great performance of the PD is realized by a remarkable photoinduced dynamic Schottky effect derived from the symbiotic modulation of Schottky and Ohmic contact. Using the pyro‐phototronic effect that exists in the N‐doped 4H‐SiC single crystal PDs, a fast pyroelectric response time of 0.27 s is achieved, which is almost ten times shorter than that obtained from the steady‐state signal under UV illumination. The maximal transient photoresponsivity reaches 9.12 nA mW−1, which is ≈20% higher than the conventional photoelectric signal. Moreover, different regions of the 4H‐SiC centimeter‐scale chip output distinct signals under UV illumination, demonstrating efficient optical imaging and information transmission capabilities of this device. This work not only reveals the fundamental optoelectronic physics lying in this vital third‐generation semiconductor, but also sheds light on its potential photosensing applications for large‐scale commercialization.
A high‐performance self‐powered 4H‐SiC ultraviolet photodetector is realized using a strong photoinduced dynamic Schottky effect, and the pyro‐phototronic effect is first revealed in N‐doped 4H‐SiC, which is beneficial to further enhance the photodetection performance. Moreover, via delicate position designs of electrodes, the 4H‐SiC chip reveals efficient optical imaging and information transmission capabilities.
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