bluuebunny/crossref_metadata_2025 huggingface dataset:
Principe local-global pour les zéro-cycles sur les surfaces réglées
Authors: Colliot-Thélène Jean-Louis
Published: July 2002

Let

k
k

be a number field,

C

/

k

C/k

a smooth projective curve, and

X
X

a smooth projective surface which is a conic bundle over

C
C

. Let

C

H
0

(
X

/

C
)

CH_0(X/C)

be the relative Chow group, which is the kernel of the projection map

C

H
0

(
X
)
→
C

H
0

(
C
)

CH_0(X) \rightarrow CH_0(C)

on Chow groups of zero-cycles. For each place

v
v

of

k
k

, one may consider the relative Chow group
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper H 0 left-parenthesis upper X Subscript v Baseline slash upper C Subscript v Baseline right-parenthesis equals upper C upper H 0 left-parenthesis upper X times Subscript k Baseline k Subscript v Baseline slash upper C times Subscript k Baseline k Subscript v Baseline right-parenthesis">

C

H
0

(

X
v

/

C
v

)
=
C

H
0

(
X

×
k

k
v

/

C

×
k

k
v

)

CH_0(X_v/C_v)=CH_0(X\times _kk_v/C\times _kk_v)

. Under minor assumptions, we identify the diagonal image of

C

H
0

(
X

/

C
)

CH_0(X/C)

in the product of all

C

H
0

(

X
v

/

C
v

)

CH_0(X_v/C_v)

as the kernel of the natural pairing with the Brauer group of

X
X

. When

C
C

is an elliptic curve with finite Tate-Shafarevich group, under minor assumptions, we show that the Brauer-Manin obstruction to the existence of a zero-cycle of degree one on

X
X

is the only obstruction.
Declining Share of Small Firms in U.S. Output: Causes and Consequences
Authors: Dhawan Rajeev , Guo Jang‐Ting
Published: July 2002

We develop a dynamic general equilibrium model, with large and small firms, to examine possible causes and welfare implications of a declining trend in small firms' share of U.S. output since 1958. Numerical experiments indicate that recent technological advances and government tiering policies that have reduced fixed setup costs of production benefit the emergence of small firms, but lower their output share due to competition for resources among firms. However, this outcome is welfare improving. Therefore, if the policy objective is to raise small firms' output share and economic welfare simultaneously, it is desirable to concentrate on increasing antitrust and deregulatory efforts.
Towards a functional neuroanatomy of conscious perception and its modulation by volition: implications of human auditory neuroimaging studies
Authors:   The American Association for Research into Nervous and Mental Diseases, Silbersweig D. A. , Stern E.
Published: July 2002

Conscious sensory perception and its modulation by volition are integral to human mental life. Functional neuroimaging techniques provide a direct means of identifying and characterizing
in vivo
the systems-level patterns of brain activity associated with such mental functions. In a series of positron emission tomography activation experiments, we and our colleagues have examined a range of normal and abnormal auditory states that, when contrasted, provide dissociations relevant to the question of the neural substrates of sensory awareness. These dissociations include sensory awareness in the presence and absence of external sensory stimuli, the transition from sensory unawareness to awareness (or vice versa) in the presence of sensory stimuli, and sensory awareness with and without volition. The auditory states studied include hallucinations, mental imagery, cortical deafness modulated by attention, and hearing modulated by sedation. The results of these studies highlight the distributed nature of the functional neuroanatomy that is sufficient, if not necessary, for sensory awareness. The probable roles of unimodal association (as compared with primary) cortices, heteromodal cortices, limbic/paralimbic regions and subcortical structures (such as the thalamus) are discussed. In addition, interactions between pre– and post–rolandic regions are examined in the context of top–down, volitional modulation of sensory awareness.
Lipids as carriers of anthropogenic signals from prehistory
Authors: Evershed Richard P. , Dudd Stephanie N. , Charters Stephanieation , Mottram Hazel , Stott Andrew W. , Raven Anthony , van Bergen Pim F. , Bland Helen A.
Published: July 2002

Studies performed during the last two decades have shown that lipids are preserved in association with a wide range of artefacts and ecofacts recovered from archaeological sites, e.g. pottery vessels and skeletal remains. The majority of work in this area has focused on the use of molecular structures (‘biomarkers’) and distributions (‘fingerprints’) to assess the nature and origin of commodities associated with past cultural, economic and agricultural practices. However, since lipids, like all other classes of biomolecule, are affected by degradation (both pre– and post–burial), emphasis is now being placed on the complementary use of diagenetically robust, compound–specific stable isotope measurements to enhance the scope and reliability of archaeological interpretations. A feature of theδ13C values of individual lipids, rather than bulk measurements of biochemically more heterogeneous materials, lies in their capacity to reflect differences in both the isotopic composition of the carbon sources used in their biosynthesis and the routing of dietary lipids and their metabolites in consumer organisms. This isotopic information, accessible by gas chromatography–combustion–isotope ratio mass spectrometry, has opened up new avenues of investigation concerning human activity in prehistory.
Detection of infrasound and linear acceleration in fishes
Authors: Sand O. , Karlsen H.E.
Published: July 2002

Fishes have an acute sensitivity to extremely low–frequency linear acceleration, or infrasound, even down to below 1Hz. The otolith organs are the sensory system responsible for this ability. The hydrodynamic noise generated by swimming fishes is mainly in the infrasound range, and may be important in courtship and prey–predator interactions. Intense infrasound has a deterring effect on some species, and has a potential in acoustic barriers. We hypothesize that the pattern of ambient infrasound in the oceans may be used for orientation in migratory fishes, and that pelagic fishes may detect changes in the surface wave pattern associated with altered water depth and distant land formations. We suggest that the acute sensitivity to linear acceleration could be used for inertial guidance, and to detect the relative velocity of layered ocean currents. Sensitivity to infrasound may be a widespread ability among aquatic organisms, and has also been reported in cephalopods and crustaceans.
Towards NeuroML: Model Description Methods for Collaborative Modelling in Neuroscience
Authors: Goddard Nigel H. , Hucka Michael , Howell Fred , Cornelis Hugo , Shankar Kavita , Beeman David
Published: July 2002

Biological nervous systems and the mechanisms underlying their operation exhibit astonishing complexity. Computational models of these systems have been correspondingly complex. As these models become ever more sophisticated, they become increasingly difficult to define, comprehend, manage and communicate. Consequently, for scientific understanding of biological nervous systems to progress, it is crucial for modellers to have software tools that support discussion, development and exchange of computational models. We describe methodologies that focus on these tasks, improving the ability of neuroscientists to engage in the modelling process. We report our findings on the requirements for these tools and discuss the use of declarative forms of model description—equivalent to object–oriented classes and database schema—which we call templates. We introduce NeuroML, a mark–up language for the neurosciences which is defined syntactically using templates, and its specific component intended as a common format for communication between modelling–related tools. Finally, we propose a template hierarchy for this modelling component of NeuroML, sufficient for describing models ranging in structural levels from neuron cell membranes to neural networks. These templates support both a framework for user–level interaction with models, and a high–performance framework for efficient simulation of the models.
Studies on computer‐aided diagnosis systems for chest radiographs and mammograms (in Japanese)
Authors: Hara Takeshi
Published: July 2002

This thesis describes computer‐aided diagnosis (CAD) systems for chest radiographs and mammograms. Preprocessing and imaging processing methods for each CAD system include dynamic range compression and region segmentation technique. A new pattern recognition technique combines genetic algorithms with template matching methods to detect lung nodules. A genetic algorithm was employed to select the optimal shape of simulated nodular shadows to be compared with real lesions on digitized chest images. Detection performance was evaluated using 332 chest radiographs from the database of the Japanese Society of Radiological Technology. Our average true‐positive rate was 72.8% with an average of 11 false‐positive findings per image. A new detection method using high resolution digital images with 0.05 mm sampling is also proposed for the mammogram CAD system to detect very small microcalcifications. An automated classification method uses feature extraction based on fractal dimension analysis of masses. Using over 200 cases to evaluate the detection of mammographic masses and calcifications, the detection rate of masses and microcalcifications were 87% and 96% with 1.5 and 1.8 false‐positive findings, respectively. The classification performance on benign vs malignant lesions, the Az values that were defined by the areas under the ROC curves derived from classification schemes of masses and microcalcifications were 0.84 and 0.89. To demonstrate the practicality of these CAD systems in a computer‐network environment, we propose to use the mammogram CAD system via the Internet and WWW. A common gateway interface and server‐client approach for the CAD system via the Internet will permit display of the CAD results on ordinary computers.
Performance of a 41×41‐cm amorphous silicon flat panel x‐ray detector for radiographic imaging applications
Authors: Granfors Paul R. , Aufrichtig Richard
Published: July 2002

We report the performance of a amorphous silicon‐based flat panel detector designed for radiographic imaging applications. The detector consists of an array of photodiodes and thin film transistor switches on a 0.2‐mm pitch with an overlying thallium‐doped cesium iodide scintillator. The performance of the detector was evaluated through measurement of the frequency‐dependent detective quantum efficiency [DQE(f)]. Measurements of the characteristic curve and modulation transfer function (MTF) are also reported. All measurements were made in a radiographic imaging mode with a readout time of 125 ms. We evaluated a total of 15 detectors. One detector was characterized at a range of exposures and at three different electronic gain settings. Measurements of DQE(f) and MTF were also performed as a function of position on one detector. The measured DQE at an exposure of about 1 mR was 0.66 at zero spatial frequency and fell smoothly with frequency to a value of 0.24 at the Nyquist frequency, 2.5 cycles/mm. The DQE is independent of exposure for exposures in the upper 80% of each gain range, but is reduced somewhat at lower exposures because of the influence of additive system noise. The reduction can be controlled by adjusting the electronic gain. For a gain that allows a maximum exposure of 5 mR, the DQE at 0.056 mR was 0.64 at zero frequency and 0.19 at 2.5 cycles/mm. The standard deviation in DQE among measurements on different detectors was less than 0.02 at any frequency. The presampling MTF was 0.26 at 2.5 cycles/mm. The standard deviation in MTF among measurements on different detectors was less than 0.01 at any frequency. Both MTF and DQE were substantially independent of position on the detector.
Modeling the combined effects of basilar membrane nonlinearity and roughness on stimulus frequency otoacoustic emission fine structure
Authors: Talmadge Carrick L. , Tubis Arnold , Long Glenis R. , Tong Christopher
Published: July 2002

A theoretical framework for describing the effects of nonlinear reflection on otoacoustic emission fine structure is presented. The following models of cochlear reflection are analyzed: weak nonlinearity, distributed roughness, and a combination of weak nonlinearity and distributed roughness. In particular, these models are examined in the context of stimulus frequency otoacoustic emissions (SFOAEs). In agreement with previous studies, it is concluded that only linear cochlear reflection can explain the underlying properties of cochlear fine structures. However, it is shown that nonlinearity can unexpectedly, in some cases, significantly modify the level and phase behaviors of the otoacoustic emission fine structure, and actually enhance the pattern of fine structures observed. The implications of these results on the stimulus level dependence of SFOAE fine structure are also explored.
Acoustic radiation impedance of rectangular pistons on prolate spheroids
Authors: Boisvert Jeffrey E. , Van Buren A. L.
Published: July 2002

The self and mutual radiation impedances for rectangular piston(s) arbitrarily located on a rigid prolate spheroidal baffle are formulated. The pistons are assumed to vibrate with uniform normal velocity and the solution is expressed in terms of a modal series representation in spheroidal eigenfunctions. The prolate spheroidal wave functions are obtained using computer programs that have been recently developed to provide accurate values of the wave functions at high frequencies. Results for the normalized self and mutual radiation resistance and reactance are presented over a wide frequency range for different piston sizes and spheroid shapes.
Low-frequency acoustic pressure, velocity, and intensity thresholds in a bottlenose dolphin (Tursiops truncatus) and white whale (Delphinapterus leucas)
Authors: Finneran James J. , Carder Donald A. , Ridgway Sam H.
Published: July 2002

The relative contributions of acoustic pressure and particle velocity to the low-frequency, underwater hearing abilities of the bottlenose dolphin (Tursiops truncatus) and white whale (Delphinapterus leucas) were investigated by measuring (masked) hearing thresholds while manipulating the relationship between the pressure and velocity. This was accomplished by varying the distance within the near field of a single underwater sound projector (experiment I) and using two underwater sound projectors and an active sound control system (experiment II). The results of experiment I showed no significant change in pressure thresholds as the distance between the subject and the sound source was changed. In contrast, velocity thresholds tended to increase and intensity thresholds tended to decrease as the source distance decreased. These data suggest that acoustic pressure is a better indicator of threshold, compared to particle velocity or mean active intensity, in the subjects tested. Interpretation of the results of experiment II (the active sound control system) was difficult because of complex acoustic conditions and the unknown effects of the subject on the generated acoustic field; however, these data also tend to support the results of experiment I and suggest that odontocete thresholds should be reported in units of acoustic pressure, rather than intensity.
Estimation of broadband acoustic power radiated from a turbulent boundary layer-driven reinforced finite plate section due to rib and boundary forces
Authors: Rumerman M. L.
Published: July 2002

Previous papers considered an infinite fluid-loaded plate with parallel line attachments, driven by a wave-number-white pressure excitation invariant in the direction of an attachment, and established the conditions and procedure for estimating the broadband radiated power by assuming the ribs to radiate independently. This paper applies those results to a finite rectangular ribbed plate, and extends the methodology to include the contribution of the plate’s boundary support forces to the radiation and the consideration of excitation that varies in the direction parallel to the ribs. The approach is relevant to problems of sound radiation by underwater stiffened steel plates driven by turbulent boundary layer (TBL) pressures, and is also applicable to stiffened circular cylindrical shells when the response is dominated by bending. Comparisons of sample calculations with results of rigorous models validate the approximation.
Automated detection of underwater explosions by the IMS hydroacoustic network
Authors: Laney Hyrum , Dysart Paul , Freese Herbert , Brumbaugh Douglas , Le Bras Ronan , Hanson Jeffrey
Published: July 2002

An important component of the CTBT monitoring system is the 11-station hydroacoustic network designed to monitor the oceans for unannounced underwater explosions. Explosions that do not breach the sea surface consist of a series of pulses due to gas bubble oscillations. The period of oscillation is a well-known function of the yield and detonation depth for explosives up to several thousand kilograms of TNT equivalent. The presence of a bubble pulse is a strong indicator of an explosive source and, therefore, is useful in event characterization. Examples of underwater explosions, which can be used to calibrate signal processing algorithms and propagation models, are rare. A set of explosive and other impulsive events recorded on hydrophones at Wake Island and Point Sur, CA is presented. These include the French nuclear tests, volcanic events, and chemical explosions. The set also includes pressure time-series simulated using a normal-mode propagation model. The automatic signal processor has been developed to search the real cepstrum for peaks using a noise-spectral equalization algorithm similar to those used in passive sonar. Examples illustrate complications due to range, depth, ambient noise, and waveguide distortion.
Acoustic structure of chorus howling in wolves and consequences for sound propagation
Authors: Frommolt Karl-Heinz
Published: July 2002

The acoustic features of chorus howling of three captive Grey wolf packs (Canis lupus lupus) were described. Two components could be found: a part with nearly no frequency modulations (A part) and a part with deep frequency modulations (B part). Sound energy in the A part is concentrated around 400 Hz, whereas in the B part, maximum amplitudes could be measured in the region between 800 and 1200 Hz. Complex acoustic interactions of the vocalizing animals could be observed during the A part. These interactions include matching of dominant frequency and nearly synchronous onset. It is proposed that the B part would be more effective in sound propagation in respect to environment-caused excess attenuation.
General Solutions in the Hydrostatic Theory of Liquid Crystals
Authors: Ericksen J. L.
Published: July 2002

In the hydrostatic theory of liquid crystals, we characterize those orientation patterns which may occur, in the absence of externally applied body forces, no matter what the form of the stored energy function may be. It turns out that there are three types of such patterns. In one, the orientation vector is perpendicular to a family of concentric spheres. Another results from replacing these spheres by concentric circular cylinders. In the third, the orientation vector is constant in each of a family of parallel planes, the direction changing continuously with distance measured normal to these planes.
Recoverable Shear Strain and the Barus Effect in Polymer Extrusion
Authors: Bagley E. B. , Duffey H. J.
Published: July 2002

Following essentially the analysis of Nakajima and Shida but using a one-constant stored energy function a simplified relationship is given between recoverable shear strain imposed on a flowing melt during capillary flow and the magnitude of the extrudate swelling on emerging from the capillary. Where experiments on capillaries of several different (L/R) values cannot be carried out there are some advantages to studies using a zero-length (orifice) die rather than a long capillary.
Surface force apparatus and its application to nanorheological studies
Authors: Pelletier E. , Montfort J. P. , Lapique F.
Published: July 2002

A surface force apparatus has been adapted to operate as a rheometer on a molecular scale. The way it works and the new possibility given to study dynamic properties of very thin films (<1 μm) squeezed between solid surfaces are discussed. Three kinds of tests, enabling the measurement of the viscoelastic properties of confined media in addition to static interactions between the surfaces, are presented. These are: draining—the surfaces are brought together at constant speed; relaxation—the displacement is stopped and the force is decreasing toward a static force; oscillations—the surfaces are submitted to small axial sinusoidal displacements around an average position. Results obtained with dilute polymer solutions moderately confined are presented. Variations of parameters characterizing the terminal zone such as the zero shear viscosity, the average relaxation time, and a parameter connected to the dispersion of relaxation times are presented and qualitatively discussed as a function of the separation between the solid surfaces.
ETS transcription factor ELF3 (ESE‐1) is a cell cycle regulator in benign and malignant prostate
Authors: Archer Leanne K. , Frame Fiona M. , Walker Hannah F. , Droop Alastair P. , McDonald Georgina L. K. , Kucko Samuel , Berney Daniel M. , Mann Vincent M. , Simms Matthew S. , Maitland Norman J.
Published: April 2022

This study aimed to elucidate the role of ELF3, an ETS family member in normal prostate growth and prostate cancer. Silencing ELF3 in both benign prostate (BPH‐1) and prostate cancer (PC3) cell lines resulted in decreased colony‐forming ability, inhibition of cell migration and reduced cell viability due to cell cycle arrest, establishing ELF3 as a cell cycle regulator. Increased ELF3 expression in more advanced prostate tumours was shown by immunostaining of tissue microarrays and from analysis of gene expression and genetic alteration studies. This study indicates that ELF3 functions not only as a part of normal prostate epithelial growth but also as a potential oncogene in advanced prostate cancers.
Microstructure Evolution of a Nickel‐Based Powder Metallurgy Superalloy Under Different Solution Treatment Temperatures
Authors: Zhang Yuanyuan , Li Jikang , Wu You , Feng Qingshuai , Liu Jiantao , Liu Tong
Published: April 2022

The effects of solution treatment temperature from 1120 to 1220 °C on the microstructure of a new nickel‐based powder metallurgy (PM) superalloy have been systematically studied. As the solution temperature increased from 1120 to 1160 °C, the grains of γ matrix grow slowly due to the pinning of the primary γ′ phase. With the solution of γ′ phase and carbides between 1160 and 1180 °C, the γ grains enlarge quickly from 6.7 to 32.1 μm, whereas the grain growth slows down from 1180 to 1220 °C owing to the decrease of interface energy of grain boundaries. The grain growth model has been established, and the activation energy of grain growth is calculated to be 298.5 KJ mol−1. After solution treatment above 1170 °C, both the primary γ′ precipitates at the prior particle cores (PPCs) and prior particle boundaries (PPBs) dissolve completely. The size of secondary γ′ precipitates increases linearly with solution temperature, while the size of MC carbides changes slightly. The hardness variation of the samples under different solution temperatures is mainly due to the combined effects of grain size and the size of γ′ precipitates.
Multifunctionality of Nanoengineered Self‐Sensing Lattices Enabled by Additive Manufacturing
Authors: Ubaid Jabir , Schneider Johannes , Deshpande Vikram S. , Wardle Brian L. , Kumar Shanmugam
Published: April 2022

Lightweight cellular materials are engineered to enhance performance attributes such as energy absorption, specific stiffness, negative Poisson's ratio, negative thermal expansion coefficient, etc. However, self‐sensing functionality of such architected materials is seldom explored. Herein, a combined experimental and numerical study on additive manufacturing (AM)‐enabled self‐sensing cellular composites processed via fused filament fabrication, utilizing in‐house engineered multiwall carbon nanotube (MWCNT)/polypropylene random copolymer (PPR) filament feedstocks, is reported. The tunable self‐sensing and enhanced mechanical performance of PPR/MWCNT lattices are experimentally demonstrated by varying their architectural parameters in addition to the MWCNT content. The lattices reveal strain and damage sensitivity gauge factors of 12 and 1.2, respectively, comparable to bulk materials’ commercial gauge factors. Furthermore, self‐sensing lattices exhibit 200%, 155%, 153%, and 137% increase in stiffness, energy absorption capacity (as high as 4.7 MJ m−3), specific energy absorption (20.5 J g−1), and energy absorption efficiency (90%), respectively, compared with their non‐reinforced counterparts. The tunable multifunctional performance of AM‐enabled cellular composites demonstrated here provides guidelines for the design and development of composite lattices with advantaged structural and functional properties for an array of applications such as patient‐specific biomedical devices capable of measuring comfort in prosthetics.
Studying Plasmon Dispersion of MXene for Enhanced Electromagnetic Absorption
Authors: Guo Xiangdong , Li Ning , Wu Chenchen , Dai Xiaokang , Qi Ruishi , Qiao Tianyu , Su Tuoyi , Lei Dandan , Liu Nishuang , Du Jinlong , Wang Enge , Yang Xiaoxia , Gao Peng , Dai Qing
Published: April 2022

2D metal carbides and nitrides (MXene) are promising candidates for electromagnetic (EM) shielding, saturable absorption, thermal therapy, and photocatalysis owing to their excellent EM absorption. The plasmon resonances in metallic MXene micro/nanostructures may play an important role in enhancing the EM absorption; however, their contribution has not been determined due to the lack of a precise understanding of its plasmon behavior. Here, the use of high‐spatial‐resolution electron energy‐loss spectroscopy to measure the plasmon dispersion of MXene films with different thicknesses is reported, enabling accurate analysis of the EM absorption of complex MXene structures in a wide frequency range via a theoretical model. The EM absorption of MXene can be excited at the desired frequency by controlling the momentum (e.g., the sizes of the nanoflakes for EM excitation) as the strength can be enhanced by increasing the layer number and the interlayer distance in MXene. For example, a 3 nm interlayer distance can nearly double the plasmon‐enhanced EM absorption in MXene nanostructures. These findings can guide the design of advanced ultrathin EM absorption materials for a broad range of applications.
Additive Manufacturing of Columnar Thermal Barrier Coatings by Laser Cladding of Ceramic Feedstock
Authors: Vorkötter Christoph , Mack Daniel Emil , Vaßen Robert , Guillon Olivier
Published: April 2022

This study presents a new laser‐cladding‐based additive manufacturing technique named Clad2Z. Using a robot‐mounted confocal powder nozzle with axial infrared laser beam, ceramic columns with a diameter of 450 µm and an adjustable height are developed. Influence of laser parameters and robot movements on shape and microstructure is analyzed. As an example application, the common material yttria‐stabilized zirconia (YSZ) is used to deposit columnar‐structured thermal barrier coatings (TBCs). The excellent thermal cycling performance of the Clad2Z samples is demonstrated by burner rig tests and comparing lifetime and failure mechanism with conventional TBC systems.
Pressure‐Induced Superconductivity in HgTe Single‐Crystal Film
Authors: Li Qiang , Zhang Jian , Zheng Qunfei , Guo Wenyu , Cao Jiangming , Jin Meiling , Zhang Xingyu , Li Nana , Wu Yanhui , Ye Xiang , Chen Pingping , Zhu Jinlong , Wang Tao , Shi Wangzhou , Wang Feifei , Yang Wenge , Qin Xiaomei
Published: April 2022

HgTe film is widely used for quantum Hall well studies and devices, as it has unique properties, like band gap inversion, carrier‐type switch, and topological evolution depending on the film thickness modulation near the so‐called critical thickness (63.5 Å), while its counterpart bulk materials do not hold these nontrivial properties at ambient pressure. Here, much richer transport properties emerging in bulk HgTe crystal through pressure‐tuning are reported. Not only the above‐mentioned abnormal properties can be realized in a 400 nm thick bulk HgTe single crystal, but superconductivity is also discovered in a series of high‐pressure phases. Combining crystal structure, electrical transport, and Hall coefficient measurements, a p‐n carrier type switching is observed in the first high‐pressure cinnabar phase. Superconductivity emerges after the semiconductor‐to‐metal transition at 3.9 GPa and persists up to 54 GPa, crossing four high‐pressure phases with an increased upper critical field. Density functional theory calculations confirm that a surface‐dominated topologic band structure contributes these exotic properties under high pressure. This discovery presents broad and efficient tuning effects by pressure on the lattice structure and electronic modulations compared to the thickness‐dependent critical properties in 2D and 3D topologic insulators and semimetals.
Advanced Dual‐Ion Batteries with High‐Capacity Negative Electrodes Incorporating Black Phosphorus
Authors: Wrogemann Jens Matthies , Haneke Lukas , Ramireddy Thrinathreddy , Frerichs Joop Enno , Sultana Irin , Chen Ying Ian , Brink Frank , Hansen Michael Ryan , Winter Martin , Glushenkov Alexey M. , Placke Tobias
Published: April 2022

Dual‐graphite batteries (DGBs), being an all‐graphite‐electrode variation of dual‐ion batteries (DIBs), have attracted great attention in recent years as a possible low‐cost technology for stationary energy storage due to the utilization of inexpensive graphite as a positive electrode (cathode) material. However, DGBs suffer from a low specific energy limited by the capacity of both electrode materials. In this work, a composite of black phosphorus with carbon (BP‐C) is introduced as negative electrode (anode) material for DIB full‐cells for the first time. The electrochemical behavior of the graphite || BP‐C DIB cells is then discussed in the context of DGBs and DIBs using alloying anodes. Mechanistic studies confirm the staging behavior for anion storage in the graphite positive electrode and the formation of lithiated phosphorus alloys in the negative electrode. BP‐C containing full‐cells demonstrate promising electrochemical performance with specific energies of up to 319 Wh kg–1 (related to masses of both electrode active materials) or 155 Wh kg–1 (related to masses of electrode active materials and active salt), and high Coulombic efficiency. This work provides highly relevant insights for the development of advanced high‐energy and safe DIBs incorporating BP‐C and other high‐capacity alloying materials in their anodes.
Magnetoactive Acoustic Topological Transistors
Authors: Lee Kyung Hoon , Al Ba'ba'a Hasan , Yu Kunhao , Li Ketian , Zhang Yanchu , Du Haixu , Masri Sami F. , Wang Qiming
Published: April 2022

Topological field‐effect transistor is a revolutionary concept that physical fields are used to switch on and off quantum topological states of the condensed matter. Although this emerging concept has been explored in electronics, how to realize it in the acoustic realm remains elusive. In this work, a class of magnetoactive acoustic topological transistors capable of on‐demand switching on and off topological states and reconfiguring topological edges with external magnetic fields is presented. The key mechanism is to harness magnetic fields to tune air‐cavity volumes within acoustic chambers, thus breaking or preserving the inversion symmetry to manifest or conceal the quantum valley Hall effect. To switch the topological transport beyond the in‐plane routes, a magneto‐tuned non‐topological band gap to allow or forbid the wave transport out‐of‐plane is harnessed. With the reversible magnetic control, on‐demand switching of topological routes to realize topological field‐effect waveguides and wave regulators is demonstrated. Analogous to the impact of semiconductor transistors on modern electronics, this work may expand the scope of topological acoustics by achieving unprecedented functions in acoustic modulation.
Doping Free and Amorphous NiOx Film via UV Irradiation for Efficient Inverted Perovskite Solar Cells
Authors: Lian Qing , Wang Peng‐lai , Wang Guoliang , Zhang Xian , Huang Yulan , Li Dongyang , Mi Guojun , Shi Run , Amini Abbas , Zhang Liang , Cheng Chun
Published: April 2022

High crystallization and conductivity are always required for inorganic carrier transport materials for cheap and high‐performance inverted perovskite solar cells (PSCs). High temperature and external doping are inevitably introduced and thus greatly hamper the applications of inorganic materials for mass production of flexible and tandem devices. Here, an amorphous and dopant‐free inorganic material, Ni3+‐rich NiOx, is reported to be fabricated by a novel UV irradiation strategy, which is facile, easily scaled‐up, and energy‐saving because all the processing temperatures are below 82 ℃. The as‐prepared NiOx film shows highly improved conductivity and hole extraction ability. The rigid and flexible PSCs present the champion efficiencies of 22.45% and 19.7%, respectively. This work fills the gap of preparing metal oxide films at the temperature below 150 °C for inverted PSCs with the high efficiency of >22%. More importantly, this work upgrades the substantial understanding about inorganic materials to function well as efficient carrier transport layers without external doping and high crystallization.
On the sustainability of the French food system: A macroeconomic assessment
Authors: Gohin Alexandre
Published: April 2022

The French farm and food sectors face increasing societal pressures to engage in a sustainable transition. By defining ambitious environmental objectives and promising significant funds for green investment, the Green Deal roadmap of the European Union provides a unique opportunity to make this transition feasible. This paper assesses the current economic ability of the French food system to cope with the restrictions on fertilizers, pesticides, and land uses defined in this comprehensive roadmap. Integrating the most recent statistical evidence on the behaviors of French farmers and consumers into a macroeconomic simulation model, we find that these farm‐related objectives are reachable without seriously hampering the incomes of active farmers and transferring the burden onto foreign economies. These results are highly dependent on the currently unknown definition of high‐biodiversity landscape features.
Responses of seed yield, quality, and composition to the harvest‐aid paraquat in soybean grown in Mississippi
Authors: Bellaloui Nacer , Smith James R. , Ray Jeffery D. , Mengistu Alemu , Gillen Anne M. , Fisher Daniel K. , Singh Gurbir
Published: April 2022

Paraquat is used as a harvest‐aid to desiccate green tissues for increasing harvest efficiency and maintaining seed quality. However, its application can cause significant crop damage and yield loss if applied too early. Limited information is available on determining the optimum time for applying paraquat. Therefore, the objectives of this study were to investigate the effects of the timing (critical stages of seed‐fill) of paraquat application on soybean seed yield, seed quality (germination, viability, hard‐seed, and seed damage), and seed composition. Field experiments were conducted in 2019 and 2020 at Stoneville, MS. Paraquat was applied at a rate of 0.56 kg a.i. ha–1at growth stages R6 (full seed‐fill), R6.5 (pod cavities completely filled with seeds), or R7 (yellow color/beginning maturity). Cultivars P46A57BX and P48A60X were used. The results showed that the application of paraquat at R6 or R6.5 resulted in significant yield loss for both cultivars in both years, whereas application at R7 resulted in significant yield loss for P46A57BX in both years, but in only 1 yr for P48A60X. Seed germination and viability were significantly increased over the control in 2020 for both cultivars at all three application stages, but with mixed effects in 2019. No seed damage that would result in dockage was observed in any treatment, as seed damage for all treatments was below 2%. Application of paraquat at R6 resulted in significantly higher seed protein, oleic acid, raffinose, and stachyose but lower oil and sucrose. This research demonstrated that the harvest‐aid paraquat significantly reduced seed yield, increased seed protein, oleic acid, raffinose, and stachyose when applied before growth stage R7. Therefore, producers should use caution when applying paraquat for harvest efficiency before R7, as they will also likely reduce seed yield the earlier paraquat is applied.
Bone structural data for the Denver longitudinal growth study
Authors: Ruff Christopher B.
Published: April 2022

The Denver Longitudinal Growth Study is one of the most comprehensive longitudinal studies of growth carried out to date. Measurements of long bone lengths, cross‐sectional diaphyseal properties, and articular breadths were taken from archived radiographs of 20 study subjects measured at an average of 36 time points from early infancy to late adolescence. Anthropometric dimensions for these individuals were also obtained from study archives. These data are now available in an online data set: 10.5061/dryad.xsj3tx9gq.
Nickel‐Based High‐Entropy Intermetallic as a Highly Active and Selective Catalyst for Acetylene Semihydrogenation
Authors: Ma Jiamin , Xing Feilong , Nakaya Yuki , Shimizu Ken‐ichi , Furukawa Shinya
Published: April 2022

Acetylene semihydrogenation is a key technology for producing polymer‐grade ethylene from crude ethylene. Ni‐based catalysts are promising alternatives to noble‐metals for this process. However, achieving high catalytic activity and selectivity remains a big challenge. We report a novel catalyst design based on high‐entropy intermetallics (HEI), which provide thermally stable isolated Ni without excess counterpart metals and achieve exceptionally high performance. Intermetallic NiGa was multi‐metalized to a (NiFeCu)(GaGe), where the Ni and Ga sites were partially substituted with Fe/Cu and Ge, respectively, without altering the parent CsCl‐type structure. The NiFeCuGaGe/SiO2 HEI catalyst completely inhibited ethylene overhydrogenation even at complete acetylene conversion, and exhibited five‐times higher activity than other 3d‐transition‐metal‐based catalysts. The DFT study showed that the surface energy decreased by multi‐metallization, which drastically weakened ethylene adsorption.
Tetrahedral Liquid‐Crystalline Networks: An A15‐Like Frank–Kasper Phase Based on Rod‐Packing
Authors: Chen Changlong , Poppe Marco , Poppe Silvio , Wagner Matthias , Tschierske Carsten , Liu Feng
Published: April 2022

The Pm
n cubic and other low‐symmetry Frank–Kasper phases are known to be formed by soft spheres, ranging from metals to block copolymer micelles and colloidal nanoparticles. Here, we report a series of X‐shaped polyphiles composed of sticky rods and two non‐symmetric branched side‐chains, which self‐assemble into the first example of a cubic liquid‐crystalline phase representing a tetrahedral network of rods with a Pm
n lattice. It is the topological dual to the Weaire–Phelan foam, being the Voronoi tessellation of the A15 sphere packing, from which this network is obtained by Delaunay triangulation.
Stereoinvertive Nucleophilic Substitution at Quaternary Carbon Stereocenters of Cyclopropyl Ketones and Ethers
Authors: Chen Xu , Marek Ilan
Published: April 2022

A highly regio‐ and diastereoselective nucleophilic substitution at the quaternary carbon stereocenter of cyclopropyl ketones and cyclopropyl carbinol derivatives using TMSBr, DMPSCl and TMSN3 as nucleophiles has been developed. A variety of acyclic tertiary alkyl bromides, chlorides and azides were therefore prepared with excellent diastereopurity. The substitution occurs at the most substituted quaternary carbon center in a stereoinvertive manner, which may be attributed to the existence of a bicyclobutonium species.
Metal‐Free SF6Activation: A New SF5‐Based Reagent Enables Deoxyfluorination and Pentafluorosulfanylation Reactions
Authors: Taponard Alexis , Jarrosson Tristan , Khrouz Lhoussain , Médebielle Maurice , Broggi Julie , Tlili Anis
Published: April 2022

The activation of SF6, a potent greenhouse gas, under metal‐free and visible light conditions is reported. Herein, mechanistic investigations including EPR spectroscopy, NMR studies and cyclic voltammetry allowed the rational design of a new fluorinating reagent which was synthesized from the 2‐electron activation of SF6with commercially available TDAE. This new SF5‐based reagent was efficiently employed for the deoxyfluorination of CO2and the fluorinative desulfurization of CS2allowing the formation of useful fluorinated amines. Moreover, for the first time we demonstrated that our SF5‐based reagent could afford the mild generation of Cl‐SF5gas. This finding was exploited for the chloro‐pentafluorosulfanylation of alkynes and alkenes.
Solar Energy Catalysis
Authors: Sun Xiaodong , Jiang Shuaiyu , Huang Hongwei , Li Hui , Jia Baohua , Ma Tianyi
Published: April 2022

When it comes to using solar energy to promote catalytic reactions, photocatalysis technology is the first choice. However, sunlight can not only be directly converted into chemical energy through a photocatalytic process, it can also be converted through different energy‐transfer pathways. Using sunlight as the energy source, photocatalytic reactions can proceed independently, and can also be coupled with other catalytic technologies to enhance the overall catalytic efficiency. Therefore, sunlight‐driven catalytic reactions are diverse, and need to be given a specific definition. We propose a timely perspective for catalytic reactions driven by sunlight and give them a specific definition, namely “solar energy catalysis”. The concept of different types of solar energy catalysis, such as photocatalysis, photothermal catalysis, solar cell powered electrocatalysis, and pyroelectric catalysis, are highlighted. Finally, their limitations and future research directions are discussed.
Scalable Synthesis of Photoluminescent Single‐Chain Nanoparticles by Electrostatic‐Mediated Intramolecular Crosslinking
Authors: Shao Yue , Wang Yong‐Lei , Tang Zian , Wen Zhendong , Chang Chiawei , Wang Chunyu , Sun Dayin , Ye Yilan , Qiu Dong , Ke Yubin , Liu Feng , Yang Zhenzhong
Published: April 2022

We report the large‐scale synthesis of photoluminescent single‐chain nanoparticles (SCNPs) by electrostatic‐mediated intramolecular crosslinking in a concentrated solution of 40 mg mL−1 by continuous addition of the free radical initiator. Poly(vinyl benzyl chloride) was charged by quaternization with vinyl‐imidazolium for the intramolecular crosslinking by using 2,2‐dimethoxy‐2‐phenylacetophenone (DMAP) as the radical initiator. Under the electrostatic repulsion thus interchain isolation, the intrachain crosslinking experiences the transition from coil through pearl‐necklace to globular state. The SCNPs demonstrate strong photoluminescence in the visible range when the non‐emissive units are confined thereby. Composition and microstructure of the SCNPs are tunable. The photoluminescent tadpole‐like Janus SCNP can be used to selectively illuminate interfacial membranes while stabilizing the emulsions.
Thermal Alteration in Adsorption Sites over SAPO‐34 Zeolite
Authors: Li Guangchao , Yoskamtorn Tatchamapan , Chen Wei , Foo Christopher , Zheng Jianwei , Tang Chiu , Day Sarah , Zheng Anmin , Li Molly Meng‐Jung , Tsang Shik Chi Edman
Published: April 2022

Zeolites have found tremendous applications in the chemical industry. However, the dynamic nature of their active sites under the flow of adsorbate molecules for adsorption and catalysis is unclear, especially in operando conditions, which could be different from the as‐synthesized structures. In the present study, we report a structural transformation of the adsorptive active sites in SAPO‐34 zeolite by using acetone as a probe molecule under various temperatures. The combination of solid‐state nuclear magnetic resonance, in situ variable‐temperature synchrotron X‐ray diffraction, and in situ diffuse‐reflectance infrared Fourier‐transform spectroscopy allow a clear identification and quantification that the chemisorption of acetone can convert the classical Brønsted acid site adsorption mode to an induced Frustrated Lewis Pairs adsorption mode at increasing temperatures. Such facile conversion is also supported by the calculations of ab‐initio molecular‐dynamics simulations. This work sheds new light on the importance of the dynamic structural alteration of active sites in zeolites with adsorbates at elevated temperatures.
Functional analysis of nuclear receptor HR96 gene in Bombyx mori exposed to phoxim
Authors: Liu Tianrun , Xu Xinyue , An Fudong , Zhu Weihao , Luo Dongling , Liu Shuo , Wei Guoqing , Wang Lei
Published: April 2022

The nuclear receptor (NRs) gene family functions as ligand‐dependent transcription factors in a variety of animals, which participates in a variety of biological processes, such as cell differentiation, metabolic regulation, reproduction, development, insect metamorphosis. In this study, a nuclear receptor HR96 gene in silkworm Bombyx mori (BmHR96) was identified, and the responses of BmHR96 gene to 20‐hydroxyecdysone (20E), three insecticides, and two disinfectants were analyzed and its function in phoxim exposure was explored.  Quantitative real‐time polymerase chain reaction indicated that the expression of BmHR96 mRNA was the highest in ovary of 5th instar Day 3 silkworm larvae and in silk gland of the wandering stage. The expression patterns of BmHR96 gene in ovary, head, testis, and midgut of different stages were different. After injecting 20E into B. mori, the expression of BmHR96 mRNA had no significant difference compared with control. Three insecticides and two disinfectants were used to treat B. mori, respectively, and it was found that they had different influence patterns on the expression level of BmHR96. siRNA of BmHR96 was injected into silkworm larvae and the expression of BmHR96 was decreased significantly after injecting 72 h. After silencing of BmHR96, B. mori was fed with phoxim‐treated leaves. The results showed that the mortality of B. mori after silencing of BmHR96 was significantly higher than the control. Our results indicated that HR96 plays an important role in regulating the stress response of phoxim.
Robust H∞ sliding mode control for uncertain discrete singular T‐S fuzzy Markov jump systems
Authors: Wang Yongzhan , Han Yueqiao , Gao Cunchen
Published: April 2022

This paper mainly explored the problem of stability in terms of discrete singular T‐S fuzzy Markov jump systems with uncertainties and external disturbances. A new sliding mode controller is proposed for this type of system. Firstly, a common sliding surface that can be shared by all subsystems of discrete singular systems is designed, so the jumping effects could be weakened. Secondly, the proof of stochastic admissibility of the closed‐loop dynamic system is provided by deriving the linear matrix inequality (LMI) technique. Thirdly, an appropriate sliding mode control (SMC) law is designed to satisfy the discrete reaching condition. And, finally, a simulation is offered to illustrate the effectiveness of the derived results.