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A series of imidazolium FeCl4 based magnetic monomers and polymers with different length of alkyl group have been designed and synthesized. The monomers showed paramagnetic property at 300 K when the alkyl group was “short” (n = 2, 4, 6, n represents the carbon atoms number of the alkanes). However, the monomers changed to ferromagnetic when the alkyl group was “long” (n = 12, 18) due to the ordered structure of the alkyl groups in bulk, which will enhance the ferromagnetic coupling between magnetic FeCl4 anions. And, due to the polymer main chain that restricted the freely movement of the alkyl groups, the corresponding magnetic polymers showed lower magnetic susceptibility than the small molecules. By proper design of the monomers and polymers, the magnetism could be tuned, which showed potential applications in design of new magnetic materials.

Well-defined magnetic polyelectrolytes with tetrachlorideferrate (FeCl4−) as counter ion are prepared. In this approach, norbornene-based monomer containing ammonium chloride group (TAENDI-Cl) is designed and synthesized. Well-defined magnetic polymers (Poly(TAENDI-FeCl4)) are obtained by ring-opening metathesis polymerization of TAENDI-Cl in the presence of Grubbs third generation catalyst followed by complexing with FeCl3. Magnetic block copolymers are thus prepared. Both the monomer and polymers are paramagnetic as measured by superconducting quantum interference device method. Studies show that the magnetic susceptibility increases with increasing degree of polymerization (DP) and reaches maximum at DP of 100, and then decreases with increasing DP. Block copolymer with lower FeCl4− content shows higher magnetic susceptibility. And, by introducing FeCl4−, the polymers show obviously magnetic responsive in solution, powder, and film which have potential applications in magnetic switching, transport, and separation.

Butyrylated maize starch (MSB) samples were prepared by the water-phase method using maize starch as the raw material and butyric anhydride as the esterifying agent. MSB samples with different degrees of substitution (DSs) were prepared by changing the addition amount of butyric anhydride. The crystal structures, starch-granule appearances, pasting properties, in vitro digestibilities, and fermentation characteristics of the MSBs were investigated and compared with those of native maize starch and acetylated maize starch (MSA) as controls. Fourier-transform infrared spectroscopy demonstrated that ester carbonyl groups were successfully incorporated into the starch molecules. The degree of crystallinity gradually decreased with increasing DS, with the surfaces of the MSB granules becoming more fragmented and the granules becoming more flocculated. The peak viscosity of the MSB decreased from 832 to 186 mPa s with increasing DS. Additionally, the resistant starch content increased from 18.17% to 53.80% with increasing DS. During in-vitro fermentation, the concentrations of butyric acid produced by MSB was 480.85–786.09 μmol/L. MSA produced higher concentrations of acetic acid, but the concentration of butyric acid produced by MSA was only 1.39 μmol/L. Thus, the study indicates that MSB has a better capacity for producing butyric acid upon in-vitro fermentation.

A new steeping method is put forward in this paper, in which steeping assistant is added into the solution during the vacuum permeation for the treatment of silk slices on small reels. With this new method, the traditional process of steeping raw silk and drying can be omitted. Orthogonal array L16 (43) is used to study the new method. The result shows that the optimal technological parameters are 2 h, 1.25% and five times for balance drying time, assistant concentration and vacuum number, respectively. The test indicates that the properties of silk slices show no significant difference between steeping on small reels and conventional steeping, and the new process of steeping silk slices on small reels can mostly meet the technological requirements of steeping. It is also found that the properties of knitted fabric produced by the new steeping method and conventional steeping method are quite similar to each other. However, some special properties of the former, such as abrasion resistance, bursting strength and draping, are better than the latter. Compared with the conventional steeping of raw silk, the new steeping method has lower cost and higher efficiency.

In recent years, people are dedicated to the research work of finding compact THz sources with high emission power. Smith–Purcell radiation is qualified for the possibility of coherent enhancement due to the effect of FEL mechanism. The compact experiment device is expected to produce hundreds mW level THz ray. The electron beam with good quality is provided under the optimized design of the electron gun. Besides, the grating is designed as an oscillator without any external feedbacks. While the beam passes through the grating surface, the beam bunching will be strong and the second harmonics enhancement will be evident, as is seen from the simulation results.