科技爱好者周刊（第 388 期）：测试是新的护城河

We construct several difference families on cyclic groups of orders 47 and 97, and use them to construct skew-Hadamard matrices of orders 188 and 388. Such difference families and matrices are constructed here for the first time. The matrices are constructed by using the Goethals-Seidel array.

We have observed the canonical gigahertz-peaked spectrum source 0108+388 with the VLBA at a range of frequencies above and below the spectral peak. The activity that dominates the radio emission from 0108+388, which is also classified as a Compact Symmetric Object, is thought to be less than 1000 years old. We present strong evidence that the spectral turnover in 0108+388 results from free-free absorption by non-uniform gas, possibly in the form of a disk in the central tens of parsecs.

In this contribution to the panel discussion of the IAU Symposium 388 "Solar and Stellar Coronal Mass Ejections", I concentrate on white-light observations of solar coronal mass ejections (CMEs) from space and specifically address the following aspects: i) history of observations, ii) available catalogs of CMEs, iii) achievements of space observations of CMEs, iv) future of CME observation, and v) challenges and future directions.

环境保护工作是一项需要长期进行的工作,为了保证其能够有质量的进行,需要做好环境监测工作,对能够影响环境、污染环境的因素进行测定,提供相应的数据基础,将可以促进环境的治理。本文对新时期做好环境监测的重要性进行探讨。