Unveiling Atom Migration Abilities Affected Anode Performance of Sodium-Ion Batteries.

In sodium-ion batteries (SIBs), the low initial coulombic efficiency (ICE) is commonly induced by irreversible phase conversion and difficult desodiation, especially on transition metal compounds (TMCs). Yet the underlying physicochemical mechanism of poor reaction reversibility is still a controversial issue. Herein, by using in situ transmission electron microscopy and in situ X-ray diffraction, we demonstrate the irreversible conversion of NiCoP@C is caused by the rapid migration of P in carbon layer and preferential formation of isolated Na3 P during discharge. By modifying the carbon coating layer, the migration of Ni/Co/P atoms is inhibited, thus the improvement of ICE and cycle stability is realized. The inhibiting of fast atom migration which induces component separation and rapid performance degradation might be applied to a wide range of electrode materials, and guides the development of advanced SIBs.

FeOOH Nanocubes Anchored on Carbon Ribbons for Use in Li/O2 Batteries.

A composite of FeOOH nanocubes anchored on carbon ribbons has been synthesized and used as a cathode material for Li/O2 batteries. Fe2+ ion-exchanged resin serves as a precursor for both FeOOH nanocubes and carbon ribbons, which are formed simultaneously. The as-prepared FeOOH cubes are proposed to have a core-shell structure, with FeOOH as the shell and Prussian blue as the core, based on information from XPS, TEM, and EDS mapping. As a cathode material for Li/O2 batteries, FeOOH delivers a specific capacity of 14816 mA h g-1 cathode with a cycling stability of 67 cycles over 400 h. The high performance is related to the low overpotential of the oxygen reduction/evolution reaction on FeOOH. The cube structure, the supporting carbon ribbons, and the -OOH moieties all contribute to the low overpotential. The discharge product Li2 O2 can be efficiently decomposed in the FeOOH cathode after a charging process, leading to higher cycling stability. Its high activity and stability make FeOOH a good candidate for use in non-aqueous Li/O2 batteries.

[Nursing of canal obturation during root canal therapy].

OBJECTIVE: To explore the nursing methods during canal obturation in order to improve efficiency and quality of root canal therapy. METHODS: 112 teeth treated by complete root canal preparation were chosen to fill the root canal, and the main points of nursing during canal obturation were summarized. RESULTS: All of 112 teeth nursed strictly during canal obturation obtained satisfactory efficiency. No one failed after root canal therapy. CONCLUSION: The main points of nursing during canal obturation are the aseptic technique, skilled coordination, instrument management, communication between nurses and patients.

[Nursing experience of acquired immune deficiency syndrome patients in oral outpatient-department].

OBJECTIVE: To explore the main point of nursing acquired immune deficiency syndrome (AIDS) patients with oral lesions. METHODS: To analyze and to summarize nursing experience through 2 patients suffering from AIDS with oral lesions. RESULTS: 2 AIDS patients changed for the better through disinfection isolation, oral nursing, psychology nursing and education propaganda. CONCLUSION: The standard nursing skills is important to AIDS patients, doctors and nurses.

[Anesthetic efficacy of 2% mepivacaine in conservative dentistry].

OBJECTIVE: To determine the efficacy of 2% mepivacaine in conservative dentistry. METHODS: The patients who needed cavity preparation or access to pulp chamber received local infiltration with 2% mepivacaine. Anesthesia time, anesthetic efficacy and cardiovascular system influences were assessed. 3% lidocaine with epinephrine served as control. RESULTS: In experiment group, the anesthesia effects were quicker and anesthesia duration was longer than that in control group. Doctors highly appreciated the anesthetic efficacy. Two groups did not show any evident change in blood pressure and heart rate. CONCLUSION: 2% mepivacaine is a safe and efficacious local anesthetic drug in conservative dentistry.