Unusual Missing Linkers in an Organosulfonate-Based Primitive–Cubic (pcu)-Type Metal–Organic Framework for CO₂ Capture and Conversion under Ambient Conditions

A noninterpenetrated organosulfonate-based metal–organic framework (MOF) with a defective primitive–cubic (pcu) topology was successfully synthesized. The unusual missing linkers, along with the highest permanent porosity (∼43%) in sulfonate-MOFs, offer a versatile platform for the incorporation of alkynophilic Ag­(I) sites. The cyclic carboxylation of alkyne molecules (e.g., propargyl alcohol and propargyl amine) into α-alkylidene cyclic carbonates and oxazolidinones were successfully catalyzed by the use of Ag­(I)-embedded sulfonate-MOF under atmospheric pressure of CO₂. In all the three catalytic reactions using CO₂ as a C1 feedstock, the highly robust sulfonate-based MOF catalyst exhibit at least three-cycle reusability

Unusual Missing Linkers in an Organosulfonate-Based Primitive–Cubic (pcu)-Type Metal–Organic Framework for CO₂ Capture and Conversion under Ambient Conditions

A noninterpenetrated organosulfonate-based metal–organic framework (MOF) with a defective primitive–cubic (pcu) topology was successfully synthesized. The unusual missing linkers, along with the highest permanent porosity (∼43%) in sulfonate-MOFs, offer a versatile platform for the incorporation of alkynophilic Ag­(I) sites. The cyclic carboxylation of alkyne molecules (e.g., propargyl alcohol and propargyl amine) into α-alkylidene cyclic carbonates and oxazolidinones were successfully catalyzed by the use of Ag­(I)-embedded sulfonate-MOF under atmospheric pressure of CO₂. In all the three catalytic reactions using CO₂ as a C1 feedstock, the highly robust sulfonate-based MOF catalyst exhibit at least three-cycle reusability

Reductive Amination of Aldehydes and Amines with an Efficient Pd/NiO Catalyst

<div><p></p><p>By applying a simple Pd/NiO catalyst, the reductive amination of amines and aldehydes can progress efficiently under mild reaction conditions, and 24 substituted amines with different structures were synthesized with up to 98% isolated yields.</p> </div

Shock response to compound fault of bearing inner and outer races and rolling bodies.

(A)Time domain diagram of compound faults of inner, outer ring and rolling element. (B) Composite fault envelope spectra of inner, outer ring and rolling element. (C) Time domain diagram of complex faults of inner, outer ring and rolling element under multiple interference factors. (D) Envelope spectrum diagram of complex fault of inner and outer ring and rolling element under multiple interference factors.</p

Planetary gearbox failure characterization frequency.

Planetary gearbox failure characterization frequency.</p

Integrated fault simulation test bench of rolling bearing and planetary gearbox.

Integrated fault simulation test bench of rolling bearing and planetary gearbox.</p

Compound fault spectrum diagram of the inner race and rolling element.

(A)Time domain diagram of compound fault of inner ring and rolling element. (B) Composite fault spectrum diagram of inner ring and rolling element.</p

Shock response to compound fault of bearing inner and outer races.

(A) Time domain diagram of compound faults of inner and outer rings. (B) Envelope spectra of inner and outer ring complex faults. (C) The inner ring is compounded with the outer ring under multiple interference factors. (D) The inner ring is compounded with the outer ring under multiple interference factors.</p

Original diagnosis signal at 2000 rpm.

As a key component of rotating machinery power transmission system, rolling bearings in gas turbines are often required to serve in complex working conditions such as the high speed, the heavy load, the variable load, the variable rotational speed, and so on. The signals of bearing failures are easily drowned out by strong background noise and disturbances of related components. In the mechanical transmission system, the signals of bearing failures are easily submerged by the strong background noise and the disturbance of related components, especially for the composite bearing failures, which seriously hinders the effective identification of the vibration characteristics of the bearing operating state and increases the difficulty of fault diagnosis. In order to investigate the impact of interference on the bearing, through the establishment of rolling bearing composite fault vibration model, analyze the relationship between the vibration signals caused by different types of bearing failures and the corresponding vibration characteristics, to reveal the transmission system of the parts of the perturbation of the main multi-interference factors on the bearing fault signal influence law. The experimental verification shows that disturbance yp(t) caused by the sum of gear meshing frequency, and installation errors of the shaft, and coupling in the transmission system and background noise ni(t), which makes the fault frequency relatively weak and difficult to observe, and makes it difficult to accurately separate the fault information of the bearing. It provides a theoretical basis to solve the problem of damage identification and fault diagnosis of rolling bearings under multi-interference state.</div

Compound fault spectrum diagram of the inner race and outer race.

(A)Time domain diagram of inner and outer ring compound fault. (B) Composite fault spectrum diagram of inner and outer ring.</p