重视运价改革的理论研究

铁路运价改革，应建立在认真研究和正确运用价值规律和运价理论的基础之上，同时要彻底改革“高、大、半”和“政企合一”的铁路管理体制。遵循运输业是基础结构和公共企业的特点；遵循廉价运输的原则；明确运输业的产品是“位置效用”，而不是“吨公里”和“人公里”，从而避免对运价改革产生误导。提出根据“运输价值”法则，规定运价的最高限度和最低限度，并“按运输负担能力收费”的运价制定原则制定运价。

资产阶级的铁路货物运价理论及对它的批判

一 交通运输业是一个物质生产部门，而铁路运输是各种运输中的最主要形式。它的生产物是不具物质形态的“场所变更”。这种“场所变更”，和其他一切生产物一样，作为一种商品是具有使用价值和价值两重性的。

美国铁路货物运价体系

赵传云教授撰写的《美国铁路货物运价体系》一文刊登于《成本与价格资料》杂志，这篇文章对我国铁路运价的研究有一定参考作用，现予转载。

Spin-Spin Interactions in Gauge Theory of Gravity, Violation of Weak Equivalence Principle and New Classical Test of General Relativity

For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.