A Bifunctional Microporous In(III)-MOF for SF Separation and Reverse Adsorption of CH/CH.

The adsorption-separation process is important to the purification of gas components due to its high efficiency and low energy consumption, but the selection of adsorbents is quite challenging. Herein, a microporous In(III)-MOF (HBU-25) was synthesized by the reaction of (: 1,1,2,2-Tetra(4-carboxylphenyl)ethylene) ligand and In(NO)·4HO. It shows a large Brunauer-Emmett-Teller (BET) specific surface area (788.

Spatially separated frequency-scanning heterodyne interferometer for absolute length measurement of opaque blocks.

A double ended frequency-scanning heterodyne interferometer was established in our previous work for absolute length measurement of opaque blocks. We found that cyclic nonlinearity errors, caused by incorrect adjustments and defects of optical components, exist in this interferometer. These errors are significant and difficult to avoid.

An Anion Pillared Metal-Organic Framework for Thermodynamic-Kinetic Synergistic Sieving of Benzene from Benzene/Cyclohexane Mixture.

Adsorption of benzene (Bz) is important to reduce environmental pollution and provide high-purity cyclohexane (Cy). However, the efficient separation of Bz and Cy still faces significant challenges because of their very similar molecular sizes and boiling points. In this work, a fluorine functionalized Metal-Organic Framework (Cu-TiF-TPA, TiF = TiF , TPA = tri(pyridin-4-yl)amine) is synthesized with a large Brunauer-Emmett-Teller (BET) surface area (1372.

A new method for the measurement of low outgassing rate of materials based on torsion balance.

Outgassing, defined as the continuous release of gas molecules from the surface of materials, is a common issue in vacuum research. Although the quantity of desorbed molecules is generally small, its impact becomes significant in high-precision scientific missions, such as the space-borne gravitational-wave (GW) detection. The detailed evaluation of this noise source relies on the outgassing rate for materials applied, while the current measurement methods all show insufficient precision, lacking practicability in measuring small-sized samples.

Boosting Acetylene Packing Density within an Isoreticular Metal-Organic Framework for Efficient CH/CO Separation.

Porous solid adsorbents for CH/CO separation are generally confronted with poor stability, high cost, or high regeneration energy, which largely inhibit their industrial implementation. A desired adsorbent material for practical implementation should exhibit a good balance between low cost, high stability, scale-up production feasibility, and good separation performance. An effective strategy is herein explored based on reticular chemistry through embedding methyl groups in a prototype microporous metal-organic framework (MOF) featuring low cost and high stability to effectively separate an CH/CO mixture.

A microporous bismuth-based MOF for efficient separation of acetylene from carbon dioxide.

The separation of acetylene from carbon dioxide is challenging due to their almost identical molecular sizes and volatilities. Metal-organic frameworks (MOFs) in general are strong candidates for the separation of gas mixtures owing to the presence of functional pore surfaces that can selectively capture specific target molecules. Herein, we report a stable and easily synthesized bismuth-based MOF, Bi-BTC, which can achieve the separation of acetylene and carbon dioxide.

Investigating temperature-induced torque noise of a torsion pendulum based on temperature modulation at different frequencies.

Torsion pendulums are widely used for the measurement of small forces. In this study, we investigated the impact of temperature fluctuations on a torsion pendulum using heating devices to modulate the environmental temperature at different specific frequencies. The response coefficient between the temperature variation and the torque of the torsion pendulum was found to vary at different frequencies, with values from 4 × 10-15 N mK-1 at 0.

Immobilization of the Polar Group into an Ultramicroporous Metal-Organic Framework Enabling Benchmark Inverse Selective CO/CH Separation with Record CH Production.

One-step harvest of high-purity light hydrocarbons without the desorption process represents an advanced and highly efficient strategy for the purification of target substances. The separation and purification of acetylene (CH) from carbon dioxide (CO) by CO-selective adsorbents are urgently demanded yet are very challenging owing to their similar physicochemical properties. Here, we employ the pore chemistry strategy to adjust the pore environment by immobilizing polar groups into an ultramicroporous metal-organic framework (MOF), achieving one-step manufacture of high-purity CH from CO/CH mixtures.

Customizing Pore System in a Microporous Metal-Organic Framework for Efficient CH Separation from CO and CH.

Selective-adsorption separation is an energy-efficient technology for the capture of acetylene (CH) from carbon dioxide (CO) and ethylene (CH). However, it remains a critical challenge to effectively recognize CH among CO and CH, owing to their analogous molecule sizes and physical properties. Herein, we report a new microporous metal-organic framework () possessing a carefully tailored pore system containing moderate pore size and nitro-functionalized channel surface for efficient separation of CH from CO and CH.

Two-Dimensional Metal-Organic Framework with Ultrahigh Water Stability for Separation of Acetylene from Carbon Dioxide and Ethylene.

Highly selective separation and purification of acetylene (CH) from ethylene (CH) and carbon dioxide (CO) are daunting challenges in light of their similar molecule sizes and physical properties. Herein, we report a two-dimensional (2D) stable metal-organic framework (MOF), ([Cu(Hmpba)]·1.5DMF) (Hmpba = 4-(3,5-dimethyl-1-pyrazol-4-yl)benzoic acid), with topology, stacked together through π-π interactions for efficient separation of CH from CH and CO.

Cu-NPs@C Nanosheets Derived from a PVP-assisted 2D Cu-MOF with Renewable Ligand for High-Efficient Selective Hydrogenation of 5-Hydroxymethylfurfural.

5-Hydroxymethylfurfural (HMF) containing C=O, C-O, and furan ring functional groups is an important platform chemical derived from C sugars. The selective hydrogenation of C=O in HMF produces 2,5-dihydroxymethylfuran (DHMF), which is a potential sustainable substitute for petroleum-based building blocks. Here, 2,5-furandicarboxylic acid (H FDC), a promising sustainable alternative to terephthalic acid, was employed as a renewable ligand to synthesize a novel Cu metal-organic framework (Cu-FDC).

Pore-Space Partition through an Embedding Metal-Carboxylate Chain-Induced Topology Upgrade Strategy for the Separation of Acetylene/Ethylene.

Ethylene (CH) is one of the most significant substances in the petrochemical industry; however, the capture of acetylene (CH) in about 1% from CH/CH mixtures is a difficult task because of the similarity of their physical properties. With the aggravation of the energy crisis, using metal-organic framework (MOF) materials to purify CH through adsorptive separation is a promising way to save energy and reduce emission. Pore-space partition (PSP) with the aim of enhancing the density of the binding sites and the strength of the host-guest interactions is an effective means to promote a solution for the challenging gas separation problems.

Propane-Trapping Ultramicroporous Metal-Organic Framework in the Low-Pressure Area toward the Purification of Propylene.

The propane (CH)-trapping adsorption behavior is considered as a potential performance to directly produce high-purity propylene (CH). Herein, we report an ultramicroporous Mn-based metal-organic framework () with a reverse CH-selective behavior in the low-pressure area. The pore structure of this material possesses more electronegative aromatic benzene rings for the stronger binding affinity to CH, and the material shows outstanding reverse ideal adsorbed solution theory (IAST) selectivity values.

Combined Test of the Gravitational Inverse-Square Law at the Centimeter Range.

Experiments measuring the Newtonian gravitational constant G can offer uniquely sensitive probes of the test of the gravitational inverse-square law. An analysis of the non-Newtonian effect in two independent experiments measuring G is presented, which permits a test of the 1/r^{2} law at the centimeter range. This work establishes the strongest bound on the magnitude α of Yukawa-type deviations from Newtonian gravity in the range of 5-500 mm and improves the previous bounds by up to a factor of 7 at the length range of 60-100 mm.

Influence of the tilt error motion of the rotation axis on the test of the equivalence principle with a rotating torsion pendulum.

Improving the precision of current tests of the equivalence principle with a rotating torsion pendulum requires a more complete analysis of systematic effects. Here, we discuss in detail one of the important systematic effects, the influence from the tilt error motion of the rotation axis of a rotary stage, namely, wandering of the instantaneous rotation axis around its average direction. Its influence on the rotating torsion pendulum is modeled phenomenologically, and the parameters in the model are calibrated.

Precision measurement of the Newtonian gravitational constant.

The Newtonian gravitational constant , which is one of the most important fundamental physical constants in nature, plays a significant role in the fields of theoretical physics, geophysics, astrophysics and astronomy. Although was the first physical constant to be introduced in the history of science, it is considered to be one of the most difficult to measure accurately so far. Over the past two decades, eleven precision measurements of the gravitational constant have been performed, and the latest recommended value for published by the Committee on Data for Science and Technology (CODATA) is (6.

Improvement for Testing the Gravitational Inverse-Square Law at the Submillimeter Range.

We improve the test of the gravitational inverse-square law at the submillimeter range by suppressing the vibration of the electrostatic shielding membrane to reduce the disturbance coupled from the residual surface potential. The result shows that, at a 95% confidence level, the gravitational inverse-square law holds (|α|≤1) down to a length scale λ=48  μm. This work establishes the strongest bound on the magnitude α of the Yukawa violation in the range of 40-350  μm, and improves the previous bounds by up to a factor of 3 at the length scale λ≈70  μm.

Microporous Metal-Organic Framework with a Completely Reversed Adsorption Relationship for C Hydrocarbons at Room Temperature.

As a new type of porous material, metal-organic frameworks (MOFs) have been widely studied in gas adsorption and separation, especially in C hydrocarbons. Considering the stronger interaction between the unsaturated molecules and the metal sites, and the smaller molecular size of unsaturated molecules, the usual relationship of affinities and adsorption capacities among C hydrocarbons in most common MOFs is CH > CH > CH. Herein, a unique microporous metal-organic framework, (activated ), with a completely reversed adsorption relationship for C hydrocarbons (CH > CH > CH) has been successfully synthesized, which breaks the traditional concept of the adsorption relationship of MOFs for C hydrocarbons.

Combined Search for a Lorentz-Violating Force in Short-Range Gravity Varying as the Inverse Sixth Power of Distance.

Precision measurements of the inverse-square law via experiments on short-range gravity provide sensitive tests of Lorentz symmetry. A combined analysis of data from experiments at the Huazhong University of Science and Technology and Indiana University sets simultaneous limits on all 22 coefficients for Lorentz violation correcting the Newton force law as the inverse sixth power of distance. Results are consistent with no effect at the level of 10^{-12}  m^{4}.

Test of the Equivalence Principle with Chiral Masses Using a Rotating Torsion Pendulum.

Here we present a new test of the equivalence principle designed to search for the possible violation of gravitational parity using test bodies with different chiralities. The test bodies are a pair of left- and right-handed quartz crystals, whose gravitational acceleration difference is measured by a rotating torsion pendulum. The result shows that the acceleration difference towards Earth Δa_{left-right}=[-1.

Measurements of the gravitational constant using two independent methods.

The Newtonian gravitational constant, G, is one of the most fundamental constants of nature, but we still do not have an accurate value for it. Despite two centuries of experimental effort, the value of G remains the least precisely known of the fundamental constants. A discrepancy of up to 0.

Magnetic effect in the test of the weak equivalence principle using a rotating torsion pendulum.

The high precision test of the weak equivalence principle (WEP) using a rotating torsion pendulum requires thorough analysis of systematic effects. Here we investigate one of the main systematic effects, the coupling of the ambient magnetic field to the pendulum. It is shown that the dominant term, the interaction between the average magnetic field and the magnetic dipole of the pendulum, is decreased by a factor of 1.

Combined Search for Lorentz Violation in Short-Range Gravity.

Short-range experiments testing the gravitational inverse-square law at the submillimeter scale offer uniquely sensitive probes of Lorentz invariance. A combined analysis of results from the short-range gravity experiments HUST-2015, HUST-2011, IU-2012, and IU-2002 permits the first independent measurements of the 14 nonrelativistic coefficients for Lorentz violation in the pure-gravity sector at the level of 10^{-9}  m^{2}, improving by an order of magnitude the sensitivity to numerous types of Lorentz violation involving quadratic curvature derivatives and curvature couplings.