Sci-Tech

New Plant Species Discovered along China-Myanmar Border

Chinese scientists have discovered a new endangered species of flowering plant from the Annonaceae family， and the finding has been published in an international botanical journal.

Polyalthia yingjiangensis， known in Chinese as Yingjiang An Luo， was named after Yingjiang County in southwest Chinas Yunnan Province where it was discovered.“The discovery enriches the diversity of the area，” said Tan Yunhong， a botanist from Xishuangbanna Tropical Botanical Garden， Chinese Academy of Sciences （CAS）.

Tan and other scientists from Southeast Asian Biodiversity Research Center and South China Botanical Garden discovered the plant during a field survey in Hongbeng River close to the China-Myanmar border.

The plant was originally seen in 1980， but not confirmed as a new species at that time. This was the first time in 37 years it has been seen again， according to Tan.

Polyalthia yingjiangensis has been designated an endangered species， according to classification by the World Conservation Union. Currently there are only four samples available and the trees are known to grow in three localities， all in Yunnan Province.

Electronics that Degrade in Air Moisture

Chinese and U.S. researchers said on September 1 that they designed a new form of electronic devices that can degrade and physically disappear when they absorb moisture in the air.

Such devices， known as transient electronics， could have a wide range of applications， such as eco-friendly disposable electronics， according to their study published in the U.S. journal Science Advances.

“Most of the transient processes reported so far only occur in aqueous solutions or biofluids，” co-corresponding author Xu Hangxun， professor with the University of Science and Technology of China， said. “The degradation of our transient electronics is triggered by water molecules in the environment， which is more controllable.”

The trick in creating moisture-triggered transient devices was in integrating electronic components with a film made of the degradable polymer polyanhydride， Xu said.

The devices can maintain stable operation until moisture in the air initiates a process called hydrolysis， which activates corrosive organic acids digestion of all electronic elements， including metal electrodes， metal oxide dielectrics， and semiconductors.

Whats more important， the lifetime of the devices can be precisely controlled by varying humidity levels in the surrounding environment or by changing their compositions， Xu said.endprint

“The transience time scale can be tuned from a few days to several weeks， or longer， if needed，” he said.

In order to illustrate the concept and verify the feasibility of this design strategy， various transient devices， ranging from passive electronics such as antennas， resistors， and capacitors， to active electronics such as transistor， diodes， optoelectronics， and memories have been developed.

“We expect this triggered transient mode to be applicable to temporal medical implants， disposable environmental sensors， datasecure hardware systems， and moisture detection devices in the future，” Xu said.

The study was jointly led by Assistant Professor Yu Cunjiang of the University of Houston， and also included Professor Feng Xue of Tsinghua University in China.

First Flight Base for Drones Set up in Shanghai

The first test-flight base for civilian drones opened in Shanghai at the end of August， according to the East China Regional Administration of Civil Aviation Administration of China （CAAC）.

There are about 110 manufacturers of unmanned aerial vehicles （UAV） in East China， nearly 30 percent of the nations total， said Jiang Chunshui， secretary of the CPC Committee of the East China Regional Administration. East China also boasts 40，000 registered drones， more than one third of the total， Jiang added.

China has required civilian drones weighing more than 250 grams to be registered under real names from June 1 to August 31. Over 120，000 drones have so far been registered， according to Ke Yubao， executive secretary of the Aircraft Owners and Pilots Association of China.

“Drone users call for a test flight ground where they can learn the law and regulations，” said Ke.

The base is located in Qingpu District in western Shanghai. Drones are required to fly under 150 meters and all test flights are to be monitored for safety.

Homegrown C919 Highlighted at China Aviation Expo

The domestically developed jumbo jet C919， aircraft engines and other high-end aviation products were highlighted at Aviation Expo China 2017 in Beijing from September 19 to 22.

The expo was jointly organized by Commercial Aircraft Corp. of China（COMAC）， Aero Engine Corporation of China （AECC） and China Promotion Ltd.

COMAC displayed the Chinese-developed large passenger jet C919， new regional jet ARJ21， and a wide-body passenger jet that will be jointly built by China and Russia.

The C919 made a successful maiden flight on May 5 this year， and has moved to the next phase of further testing and test flight missions， according to COMAC.

The wide-body passenger jet program is currently in the preparation phase of the proposal， after the joint venture China-Russia Commercial Aircraft International Co.， Ltd. （CRAIC） was set up on May 22 this year.

The newly established AECC also displayed its achievements in aircraft engines， gas turbines， and graphene material and high precision aluminum alloy technologies.

Founded in 1984， China Aviation Expo was Chinas first professional aviation expo. This year it has attracted more than 300 exhibitors from 14 countries and regions， with eight national pavilions， including Russia， Ukraine， Italy， and Australia.endprint