Realizing Persistent Zero Area Compressibility over a Wide Pressure Range in Cu GeO by Microscopic Orthogonal-Braiding Strategy.

Zero area compressibility (ZAC) is an extremely rare mechanical response that exhibits an invariant two-dimensional size under hydrostatic pressure. All known ZAC materials are constructed from units in two dimensions as a whole. Here, we propose another strategy to obtain the ZAC by microscopically orthogonal-braiding one-dimensional zero compressibility strips.

Study on Matrix Damage and Control Methods of Fracturing Fluid on Tight Sandstone Gas Reservoirs.

Hydraulic fracturing is a highly effective method for stimulating the development of gas reservoirs. However, the process of pumping fracturing fluid (FF) into the reservoir unavoidably causes damage to the surrounding matrix, leading to a decrease in the overall stimulation effect. To assess the extent of matrix permeability damage caused by the intrusion of FF, as well as its impact on the pore throat structure, and to propose appropriate measures to control this damage, we conducted a series of experimental studies on tight gas reservoirs.

Unexpected giant negative area compressibility in palladium diselenide.

Negative area compressibility (NAC) is a counterintuitive 'squeeze-expand' behavior in solids that is very rare but attractive due to possible pressure-response applications and coupling with rich physicochemical properties. Herein, NAC behavior is reported in palladium diselenide with a large magnitude and wide pressure range. We discover that, apart from the rigid flattening of layers that has been generally recognized, the unexpected giant NAC effect in PdSe largely comes from anomalous elongation of intralayer chemical bonds.

Synthesis and drag reduction properties of a hydrophobically associative polymer containing ultra-long side chains.

Different from common hydrophobic associative polymers, a new hydrophobic associative polyacrylamide (HAPAM) with ultra-long side chains was synthesized and aimed to be used as drag reducer in this work. Firstly, a water-soluble hydrophobic monomer (named AT114) was obtained by alcoholysis reaction with acryloyl chloride and triton 114, then the drag reducer was obtained by radical copolymerization of AM, AMPS and AT114. The structures of AT114 and drag reducer were characterized by IR and NMR.

(CNH)GeBr: A 2D Organic Germanium Bromide Perovskite with Strong Orange Photoluminescence Properties.

Hybrid organic-inorganic metal halide (OIMH) perovskites are regarded as potential photoluminescent (PL) materials and have attracted intensive attention. Here, we select 1-methylpiperazine as an organic component and successfully obtain a two-dimensional (2D) Ge-based OIMH perovskite, (1-mpz)GeBr. It features a 2D layered structure composed of distorted [GeBr] octahedra with organic (CHN) located between the layers.

Na Ba[Na Sn S ]: Structural Tolerance Factor-Guided NLO Performance Improvement.

The strong mutual coupling of and even the opposite change in the key parameters, such as the band gap (E ) and second-order harmonic generation (SHG), leads to the extreme scarcity in high-performance IR nonlinear optical (NLO) chalcogenides. Herein, we report 8 new sulfides, Na Ba[(Ag Na ) Sn S ] (1, x=0; 1 series, x=0.1-0.

Influencing Factors and Application of Spontaneous Imbibition of Fracturing Fluids in Tight Sandstone Gas Reservoir.

This work is based on high-precision fluid spontaneous imbibition experiments to quantitatively study the imbibition rate, imbibition capacity, and imbibition curve characteristics of fracturing fluids in tight sandstone reservoirs. The objective of the work is to explore the influence of tight sandstone physical characteristics, fracturing fluid composition, salinity, viscosity, surface tension on fracturing fluid imbibition, and further analyze its main controlling factors. To evaluate imbibition characteristics more deeply, the pore throat structure and micromorphology of tight sandstone before and after imbibition were described by mercury intrusion test and scanning electron microscope test, respectively.

sp to sp Hybridization Transformation in Ionic Crystals under Unprecedentedly Low Pressure.

Under cold pressure sp /sp -to-sp hybridization transformation has been exclusively observed in covalent or molecular crystals overwhelmingly above ≈10 GPa, and the approaches to lower the transition pressure are limited on external heat-treatment and/or catalyzers. Herein we demonstrate that, by internal-lattice stress-transfer from ionic to covalent groups, the transformation can be significantly prompted, as shown in a crystal of LiBO under 2.85 GPa for the first case in ionic crystals.

Research on collapse ultimate load of fabricated reinforced concrete column and steel beam composite frame structure.

In this work, the collapse ultimate load of a prefabricated reinforced concrete column-steel beam composite frame structure was studied. During the study, the "new RCS beam-to-column joint" was used as the beam-to-column connection in the experimental model. Further, the half-scale fabricated RCS space frame structure (2-story, 1 × 2 bay) was subjected to instantaneous failure experiments twice at the bottom of the side column under various load levels and the 2A column was quickly pulled out by the traction force of the vehicle.

Integration of negative, zero and positive linear thermal expansion makes borate optical crystals light transmission temperature-independent.

Negative and zero thermal expansion (NTE and ZTE) materials are widely adopted to eliminate the harmful effect from the "heat expansion and cool contraction" effect and frequently embrace novel fundamental physicochemical mechanisms. To date, the manipulation of NTE and ZTE materials has mainly been realized by chemical component regulation. Here, we propose another method by making use of the anisotropy of thermal expansion in noncubic single crystals, with maximal tunability from the integration of linear NTE, ZTE and positive thermal expansion (PTE).

CdSiAs, a Nonchalcopyrite Arsenide with a Strong Nonlinear-Optical Response.

A new arsenide, CdSiAs, has been successfully synthesized and characterized. It is the first arsenide that adopts a nonchalcopyrite structure and possesses a strong nonlinear-optical (NLO) response. In the structure, the CdAs trigonal planar unit, a kind of π-conjugated planar NLO-active group, was identified for the first time.

Growth, Structure, and Properties of a Multifunctional Crystal PrCaBO.

A new praseodymium-based borate crystal PrCaBO (PCB) has been grown through the high temperature solution method. PCB crystallizes in monoclinic space group 2 with unit cell parameters of = 10.9475(10) Å, = 6.

Intrinsic Isotropic Near-Zero Thermal Expansion in ZnBOX (X = O, S, Se).

Zero thermal expansion (ZTE) materials, keeping size constant as temperature varies, are valuable for resisting the deterioration of the performance from environmental temperature fluctuation, but they are rarely discovered due to the counterintuitive temperature-size effect. Herein, we demonstrate that a family of borates with sodalite cage structure, ZnBOX (X = O, S, Se), exhibits intrinsic isotropic near-ZTE behaviors from 5 to 300 K. The very low thermal expansion is mainly owing to the coupling rotation of [BO] rigid groups constrained by the bonds between Zn and cage-edged O atoms, while the central atoms in the cage have a negligible contribution.

CsZn BO X (X =F , Cl , and FCl): A Series of Beryllium-Free Deep-Ultraviolet Nonlinear-Optical Crystals with Excellent Properties.

Designing deep-ultraviolet (DUV) nonlinear-optical (NLO) crystals is one of the major current research interests, but it faces a great challenge. In order to overcome the problem of crystal growth and the toxicity of BeO raw materials in KBe BO F (KBBF), the only applicable DUV NLO crystal so far, we substitute Be cations with Zn in the KBBF structure and modify the halogen anions, by which three new Zn-containing KBBF-like compounds, CsZn BO X (X =F , Cl , and FCl), have been successfully synthesized. They all exhibit excellent NLO properties, including improved SHG responses (2.

Functional Chalcogenide NaHgSnSe and KMnGeSe Exhibiting Flexible Chain Structure and Intriguing Birefringence Tunability.

The two functional chalcogenides KMnGeSe and NaHgSnSe, featuring a straight-chain structure, have been successfully prepared and fully characterized. KMnGeSe shows paramagnetic behavior. The birefringence of NaHgSnSe is as large as 0.

A Machine Learning-Based QSAR Model for Benzimidazole Derivatives as Corrosion Inhibitors by Incorporating Comprehensive Feature Selection.

Background: Computational prediction of inhibition efficiency (IE) for inhibitor molecules is a crucial supplementary way to design novel molecules that can efficiently inhibit corrosion onto metallic surfaces.

Purpose: Here we are dedicated to developing a new machine learning-based predictor for the inhibition efficiency (IE) of benzimidazole derivatives.

Methods: First, a comprehensively numerical representation was given on inhibitor molecules from all aspects of energy, electronic, topological, physicochemical and spatial properties based on 3-D structures and 150 valid structural descriptors were obtained.

[Safety and immunological effect of domestic split influenza virus vaccine].

Objective: To evaluate the safety and immunological effect of domestic split influenza virus vaccine.

Methods: All 606 subjects were divided into three groups by under 6, 16-60 and above 60 years old. Each age group was divided as study group (n = 213), control group 1 (n = 195) and control group 2 (n= 198) by Table of Random Number, one domestic vaccine and two imported vaccines were respectively inoculated in three group people.

Towards a virtual basic laparoscopic skill trainer (VBLaST).

Surgical skill training is a long and tedious process of acquiring fine motor skills. To overcome the drawbacks of the existing toolbox trainer systems, we develop, for the first time, a virtual basic laparoscopic skill trainer (VBLaST) whereby tasks, such as the ones available in the FLS toolbox system, may be performed on the computer.

CUDA-based real time surgery simulation.

In this paper we present a general software platform that enables real time surgery simulation on the newly available compute unified device architecture (CUDA)from NVIDIA. CUDA-enabled GPUs harness the power of 128 processors which allow data parallel computations. Compared to the previous GPGPU, it is significantly more flexible with a C language interface.

Development of the VBLaST: a virtual basic laparoscopic skill trainer.

Background: The FLS training tool box has now been adopted by the Society of Gastrointestinal Endoscopic Surgeons (SAGES) as an official training tool for minimally invasive procedures.

Methods: To overcome the limitations of the physical FLS training tool box, we have developed a Virtual Basic Laparoscopic Skill Trainer (VBLaSTTM) system, which is a 3D simulator that will allow trainees to acquire basic laparoscopic skill.

Results: The outcome of this work is the development of an integrated visio-haptic workstation environment including force feedback devices and a stereo display interface whereby trainees can practice on virtual versions of the FLS.